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41 results

sequencer.c

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  • sequencer.c 116.54 KiB
    /*
     * ***** BEGIN GPL LICENSE BLOCK *****
     *
     * This program is free software; you can redistribute it and/or
     * modify it under the terms of the GNU General Public License
     * as published by the Free Software Foundation; either version 2
     * of the License, or (at your option) any later version.
     *
     * This program is distributed in the hope that it will be useful,
     * but WITHOUT ANY WARRANTY; without even the implied warranty of
     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     * GNU General Public License for more details.
     *
     * You should have received a copy of the GNU General Public License
     * along with this program; if not, write to the Free Software Foundation,
     * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
     *
     * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
     * All rights reserved.
     *
     * Contributor(s): 
     * - Blender Foundation, 2003-2009
     * - Peter Schlaile <peter [at] schlaile [dot] de> 2005/2006
     *
     * ***** END GPL LICENSE BLOCK *****
     */
    
    /** \file blender/blenkernel/intern/sequencer.c
     *  \ingroup bke
     */
    
    #include <stddef.h>
    #include <stdlib.h>
    #include <string.h>
    #include <math.h>
    
    #include "MEM_guardedalloc.h"
    #include "MEM_CacheLimiterC-Api.h"
    
    #include "DNA_sequence_types.h"
    #include "DNA_movieclip_types.h"
    #include "DNA_mask_types.h"
    #include "DNA_scene_types.h"
    #include "DNA_anim_types.h"
    #include "DNA_object_types.h"
    #include "DNA_sound_types.h"
    
    #include "BLI_math.h"
    #include "BLI_fileops.h"
    #include "BLI_listbase.h"
    #include "BLI_path_util.h"
    #include "BLI_string.h"
    #include "BLI_string_utf8.h"
    #include "BLI_threads.h"
    #include "BLI_utildefines.h"
    
    #include "BLF_translation.h"
    
    #include "BKE_animsys.h"
    #include "BKE_depsgraph.h"
    #include "BKE_global.h"
    #include "BKE_image.h"
    #include "BKE_main.h"
    #include "BKE_sequencer.h"
    #include "BKE_movieclip.h"
    #include "BKE_fcurve.h"
    #include "BKE_scene.h"
    #include "BKE_mask.h"
    #include "BKE_library.h"
    
    #include "RNA_access.h"
    
    #include "RE_pipeline.h"
    
    #include <pthread.h>
    
    #include "IMB_imbuf.h"
    #include "IMB_imbuf_types.h"
    #include "IMB_colormanagement.h"
    
    #include "BKE_context.h"
    #include "BKE_sound.h"
    
    #ifdef WITH_AUDASPACE
    #  include "AUD_C-API.h"
    #endif
    
    static ImBuf *seq_render_strip_stack(const SeqRenderData *context, ListBase *seqbasep, float cfra, int chanshown);
    static ImBuf *seq_render_strip(const SeqRenderData *context, Sequence *seq, float cfra);
    static void seq_free_animdata(Scene *scene, Sequence *seq);
    static ImBuf *seq_render_mask(const SeqRenderData *context, Mask *mask, float nr, short make_float);
    
    /* **** XXX ******** */
    #define SELECT 1
    ListBase seqbase_clipboard;
    int seqbase_clipboard_frame;
    SequencerDrawView sequencer_view3d_cb = NULL; /* NULL in background mode */
    
    #if 0  /* unused function */
    static void printf_strip(Sequence *seq)
    {
    	fprintf(stderr, "name: '%s', len:%d, start:%d, (startofs:%d, endofs:%d), "
    	        "(startstill:%d, endstill:%d), machine:%d, (startdisp:%d, enddisp:%d)\n",
    	        seq->name, seq->len, seq->start, seq->startofs, seq->endofs, seq->startstill, seq->endstill, seq->machine,
    	        seq->startdisp, seq->enddisp);
    
    	fprintf(stderr, "\tseq_tx_set_final_left: %d %d\n\n", seq_tx_get_final_left(seq, 0),
    	        seq_tx_get_final_right(seq, 0));
    }
    #endif
    
    int BKE_sequencer_base_recursive_apply(ListBase *seqbase, int (*apply_func)(Sequence *seq, void *), void *arg)
    {
    	Sequence *iseq;
    	for (iseq = seqbase->first; iseq; iseq = iseq->next) {
    		if (BKE_sequencer_recursive_apply(iseq, apply_func, arg) == -1)
    			return -1;  /* bail out */
    	}
    	return 1;
    }
    
    int BKE_sequencer_recursive_apply(Sequence *seq, int (*apply_func)(Sequence *, void *), void *arg)
    {
    	int ret = apply_func(seq, arg);
    
    	if (ret == -1)
    		return -1;  /* bail out */
    
    	if (ret && seq->seqbase.first)
    		ret = BKE_sequencer_base_recursive_apply(&seq->seqbase, apply_func, arg);
    
    	return ret;
    }
    
    /*********************** alloc / free functions *************************/
    
    /* free */
    
    static void free_proxy_seq(Sequence *seq)
    {
    	if (seq->strip && seq->strip->proxy && seq->strip->proxy->anim) {
    		IMB_free_anim(seq->strip->proxy->anim);
    		seq->strip->proxy->anim = NULL;
    	}
    }
    
    static void seq_free_strip(Strip *strip)
    {
    	strip->us--;
    	if (strip->us > 0)
    		return;
    	if (strip->us < 0) {
    		printf("error: negative users in strip\n");
    		return;
    	}
    
    	if (strip->stripdata) {
    		MEM_freeN(strip->stripdata);
    	}
    
    	if (strip->proxy) {
    		if (strip->proxy->anim) {
    			IMB_free_anim(strip->proxy->anim);
    		}
    
    		MEM_freeN(strip->proxy);
    	}
    	if (strip->crop) {
    		MEM_freeN(strip->crop);
    	}
    	if (strip->transform) {
    		MEM_freeN(strip->transform);
    	}
    
    	MEM_freeN(strip);
    }
    
    /* only give option to skip cache locally (static func) */
    static void BKE_sequence_free_ex(Scene *scene, Sequence *seq, const bool do_cache)
    {
    	if (seq->strip)
    		seq_free_strip(seq->strip);
    
    	if (seq->anim) {
    		IMB_free_anim(seq->anim);
    		seq->anim = NULL;
    	}
    
    	if (seq->type & SEQ_TYPE_EFFECT) {
    		struct SeqEffectHandle sh = BKE_sequence_get_effect(seq);
    
    		sh.free(seq);
    	}
    
    	if (seq->sound) {
    		((ID *)seq->sound)->us--; 
    	}
    
    	/* clipboard has no scene and will never have a sound handle or be active
    	 * same goes to sequences copy for proxy rebuild job
    	 */
    	if (scene) {
    		Editing *ed = scene->ed;
    
    		if (ed->act_seq == seq)
    			ed->act_seq = NULL;
    
    		if (seq->scene_sound && ELEM(seq->type, SEQ_TYPE_SOUND_RAM, SEQ_TYPE_SCENE))
    			sound_remove_scene_sound(scene, seq->scene_sound);
    
    		seq_free_animdata(scene, seq);
    	}
    
    	/* free modifiers */
    	BKE_sequence_modifier_clear(seq);
    
    	/* free cached data used by this strip,
    	 * also invalidate cache for all dependent sequences
    	 *
    	 * be _very_ careful here, invalidating cache loops over the scene sequences and
    	 * assumes the listbase is valid for all strips, this may not be the case if lists are being freed.
    	 * this is optional BKE_sequence_invalidate_cache
    	 */
    	if (do_cache) {
    		if (scene) {
    			BKE_sequence_invalidate_cache(scene, seq);
    		}
    	}
    
    	MEM_freeN(seq);
    }
    
    void BKE_sequence_free(Scene *scene, Sequence *seq)
    {
    	BKE_sequence_free_ex(scene, seq, TRUE);
    }
    
    /* cache must be freed before calling this function
     * since it leaves the seqbase in an invalid state */
    static void seq_free_sequence_recurse(Scene *scene, Sequence *seq)
    {
    	Sequence *iseq, *iseq_next;
    
    	for (iseq = seq->seqbase.first; iseq; iseq = iseq_next) {
    		iseq_next = iseq->next;
    		seq_free_sequence_recurse(scene, iseq);
    	}
    
    	BKE_sequence_free_ex(scene, seq, FALSE);
    }
    
    
    Editing *BKE_sequencer_editing_get(Scene *scene, bool alloc)
    {
    	if (alloc) {
    		BKE_sequencer_editing_ensure(scene);
    	}
    	return scene->ed;
    }
    
    static void seq_free_clipboard_recursive(Sequence *seq_parent)
    {
    	Sequence *seq, *nseq;
    
    	for (seq = seq_parent->seqbase.first; seq; seq = nseq) {
    		nseq = seq->next;
    		seq_free_clipboard_recursive(seq);
    	}
    
    	BKE_sequence_clipboard_pointers_free(seq_parent);
    	BKE_sequence_free_ex(NULL, seq_parent, FALSE);
    }
    
    void BKE_sequencer_free_clipboard(void)
    {
    	Sequence *seq, *nseq;
    
    	for (seq = seqbase_clipboard.first; seq; seq = nseq) {
    		nseq = seq->next;
    		seq_free_clipboard_recursive(seq);
    	}
    	BLI_listbase_clear(&seqbase_clipboard);
    }
    
    /* -------------------------------------------------------------------- */
    /* Manage pointers in the clipboard.
     * note that these pointers should _never_ be access in the sequencer,
     * they are only for storage while in the clipboard
     * notice 'newid' is used for temp pointer storage here, validate on access.
     */
    #define ID_PT (*id_pt)
    static void seqclipboard_ptr_free(ID **id_pt)
    {
    	if (ID_PT) {
    		BLI_assert(ID_PT->newid != NULL);
    		MEM_freeN(ID_PT);
    		ID_PT = NULL;
    	}
    }
    static void seqclipboard_ptr_store(ID **id_pt)
    {
    	if (ID_PT) {
    		ID *id_prev = ID_PT;
    		ID_PT = MEM_dupallocN(ID_PT);
    		ID_PT->newid = id_prev;
    	}
    }
    static void seqclipboard_ptr_restore(Main *bmain, ID **id_pt)
    {
    	if (ID_PT) {
    		const ListBase *lb = which_libbase(bmain, GS(ID_PT->name));
    		void *id_restore;
    
    		BLI_assert(ID_PT->newid != NULL);
    		if (BLI_findindex(lb, (ID_PT)->newid) != -1) {
    			/* the pointer is still valid */
    			id_restore = (ID_PT)->newid;
    		}
    		else {
    			/* the pointer of the same name still exists  */
    			id_restore = BLI_findstring(lb, (ID_PT)->name + 2, offsetof(ID, name) + 2);
    		}
    
    		if (id_restore == NULL) {
    			/* check for a data with the same filename */
    			switch (GS(ID_PT->name)) {
    				case ID_SO:
    				{
    					id_restore = BLI_findstring(lb, ((bSound *)ID_PT)->name, offsetof(bSound, name));
    					if (id_restore == NULL) {
    						id_restore = sound_new_file(bmain, ((bSound *)ID_PT)->name);
    						(ID_PT)->newid = id_restore;  /* reuse next time */
    					}
    					break;
    				}
    				case ID_MC:
    				{
    					id_restore = BLI_findstring(lb, ((MovieClip *)ID_PT)->name, offsetof(MovieClip, name));
    					if (id_restore == NULL) {
    						id_restore = BKE_movieclip_file_add(bmain, ((MovieClip *)ID_PT)->name);
    						(ID_PT)->newid = id_restore;  /* reuse next time */
    					}
    					break;
    				}
    			}
    		}
    
    		ID_PT = id_restore;
    	}
    }
    #undef ID_PT
    
    void BKE_sequence_clipboard_pointers_free(Sequence *seq)
    {
    	seqclipboard_ptr_free((ID **)&seq->scene);
    	seqclipboard_ptr_free((ID **)&seq->scene_camera);
    	seqclipboard_ptr_free((ID **)&seq->clip);
    	seqclipboard_ptr_free((ID **)&seq->mask);
    	seqclipboard_ptr_free((ID **)&seq->sound);
    }
    void BKE_sequence_clipboard_pointers_store(Sequence *seq)
    {
    	seqclipboard_ptr_store((ID **)&seq->scene);
    	seqclipboard_ptr_store((ID **)&seq->scene_camera);
    	seqclipboard_ptr_store((ID **)&seq->clip);
    	seqclipboard_ptr_store((ID **)&seq->mask);
    	seqclipboard_ptr_store((ID **)&seq->sound);
    }
    void BKE_sequence_clipboard_pointers_restore(Sequence *seq, Main *bmain)
    {
    	seqclipboard_ptr_restore(bmain, (ID **)&seq->scene);
    	seqclipboard_ptr_restore(bmain, (ID **)&seq->scene_camera);
    	seqclipboard_ptr_restore(bmain, (ID **)&seq->clip);
    	seqclipboard_ptr_restore(bmain, (ID **)&seq->mask);
    	seqclipboard_ptr_restore(bmain, (ID **)&seq->sound);
    }
    /* end clipboard pointer mess */
    
    
    Editing *BKE_sequencer_editing_ensure(Scene *scene)
    {
    	if (scene->ed == NULL) {
    		Editing *ed;
    
    		ed = scene->ed = MEM_callocN(sizeof(Editing), "addseq");
    		ed->seqbasep = &ed->seqbase;
    	}
    
    	return scene->ed;
    }
    
    void BKE_sequencer_editing_free(Scene *scene)
    {
    	Editing *ed = scene->ed;
    	Sequence *seq;
    
    	if (ed == NULL)
    		return;
    
    	/* this may not be the active scene!, could be smarter about this */
    	BKE_sequencer_cache_cleanup();
    
    	SEQ_BEGIN (ed, seq)
    	{
    		/* handle cache freeing above */
    		BKE_sequence_free_ex(scene, seq, FALSE);
    	}
    	SEQ_END
    
    	BLI_freelistN(&ed->metastack);
    
    	MEM_freeN(ed);
    
    	scene->ed = NULL;
    }
    
    /*********************** Sequencer color space functions  *************************/
    
    static void sequencer_imbuf_assign_spaces(Scene *scene, ImBuf *ibuf)
    {
    	if (ibuf->rect_float) {
    		IMB_colormanagement_assign_float_colorspace(ibuf, scene->sequencer_colorspace_settings.name);
    	}
    }
    
    void BKE_sequencer_imbuf_to_sequencer_space(Scene *scene, ImBuf *ibuf, int make_float)
    {
    	const char *from_colorspace = IMB_colormanagement_role_colorspace_name_get(COLOR_ROLE_SCENE_LINEAR);
    	const char *to_colorspace = scene->sequencer_colorspace_settings.name;
    	const char *float_colorspace = IMB_colormanagement_get_float_colorspace(ibuf);
    
    	if (!ibuf->rect_float) {
    		if (ibuf->rect) {
    			const char *byte_colorspace = IMB_colormanagement_get_rect_colorspace(ibuf);
    			if (make_float || !STREQ(to_colorspace, byte_colorspace)) {
    				/* If byte space is not in sequencer's working space, we deliver float color space,
    				 * this is to to prevent data loss.
    				 */
    
    				/* when converting byte buffer to float in sequencer we need to make float
    				 * buffer be in sequencer's working space, which is currently only doable
    				 * from linear space.
    				 */
    
    				/*
    				 * OCIO_TODO: would be nice to support direct single transform from byte to sequencer's
    				 */
    
    				IMB_float_from_rect(ibuf);
    			}
    			else {
    				return;
    			}
    		}
    		else {
    			return;
    		}
    	}
    
    	if (from_colorspace && from_colorspace[0] != '\0') {
    		if (ibuf->rect)
    			imb_freerectImBuf(ibuf);
    
    		if (!STREQ(float_colorspace, to_colorspace)) {
    			IMB_colormanagement_transform_threaded(ibuf->rect_float, ibuf->x, ibuf->y, ibuf->channels,
    			                                       from_colorspace, to_colorspace, true);
    			sequencer_imbuf_assign_spaces(scene, ibuf);
    		}
    	}
    }
    
    void BKE_sequencer_imbuf_from_sequencer_space(Scene *scene, ImBuf *ibuf)
    {
    	const char *from_colorspace = scene->sequencer_colorspace_settings.name;
    	const char *to_colorspace = IMB_colormanagement_role_colorspace_name_get(COLOR_ROLE_SCENE_LINEAR);
    
    	if (!ibuf->rect_float)
    		return;
    
    	if (to_colorspace && to_colorspace[0] != '\0') {
    		IMB_colormanagement_transform_threaded(ibuf->rect_float, ibuf->x, ibuf->y, ibuf->channels,
    		                                       from_colorspace, to_colorspace, true);
    		IMB_colormanagement_assign_float_colorspace(ibuf, to_colorspace);
    	}
    }
    
    void BKE_sequencer_pixel_from_sequencer_space_v4(struct Scene *scene, float pixel[4])
    {
    	const char *from_colorspace = scene->sequencer_colorspace_settings.name;
    	const char *to_colorspace = IMB_colormanagement_role_colorspace_name_get(COLOR_ROLE_SCENE_LINEAR);
    
    	if (to_colorspace && to_colorspace[0] != '\0') {
    		IMB_colormanagement_transform_v4(pixel, from_colorspace, to_colorspace);
    	}
    	else {
    		/* if no color management enables fallback to legacy conversion */
    		srgb_to_linearrgb_v4(pixel, pixel);
    	}
    }
    
    /*********************** sequencer pipeline functions *************************/
    
    SeqRenderData BKE_sequencer_new_render_data(EvaluationContext *eval_ctx,
                                                Main *bmain, Scene *scene, int rectx, int recty,
                                                int preview_render_size)
    {
    	SeqRenderData rval;
    
    	rval.bmain = bmain;
    	rval.scene = scene;
    	rval.rectx = rectx;
    	rval.recty = recty;
    	rval.preview_render_size = preview_render_size;
    	rval.motion_blur_samples = 0;
    	rval.motion_blur_shutter = 0;
    	rval.eval_ctx = eval_ctx;
    	rval.skip_cache = false;
    
    	return rval;
    }
    
    /* ************************* iterator ************************** */
    /* *************** (replaces old WHILE_SEQ) ********************* */
    /* **************** use now SEQ_BEGIN () SEQ_END ***************** */
    
    /* sequence strip iterator:
     * - builds a full array, recursively into meta strips
     */
    
    static void seq_count(ListBase *seqbase, int *tot)
    {
    	Sequence *seq;
    
    	for (seq = seqbase->first; seq; seq = seq->next) {
    		(*tot)++;
    
    		if (seq->seqbase.first)
    			seq_count(&seq->seqbase, tot);
    	}
    }
    
    static void seq_build_array(ListBase *seqbase, Sequence ***array, int depth)
    {
    	Sequence *seq;
    
    	for (seq = seqbase->first; seq; seq = seq->next) {
    		seq->depth = depth;
    
    		if (seq->seqbase.first)
    			seq_build_array(&seq->seqbase, array, depth + 1);
    
    		**array = seq;
    		(*array)++;
    	}
    }
    
    static void seq_array(Editing *ed, Sequence ***seqarray, int *tot, int use_pointer)
    {
    	Sequence **array;
    
    	*seqarray = NULL;
    	*tot = 0;
    
    	if (ed == NULL)
    		return;
    
    	if (use_pointer)
    		seq_count(ed->seqbasep, tot);
    	else
    		seq_count(&ed->seqbase, tot);
    
    	if (*tot == 0)
    		return;
    
    	*seqarray = array = MEM_mallocN(sizeof(Sequence *) * (*tot), "SeqArray");
    	if (use_pointer)
    		seq_build_array(ed->seqbasep, &array, 0);
    	else
    		seq_build_array(&ed->seqbase, &array, 0);
    }
    
    void BKE_sequence_iterator_begin(Editing *ed, SeqIterator *iter, int use_pointer)
    {
    	memset(iter, 0, sizeof(*iter));
    	seq_array(ed, &iter->array, &iter->tot, use_pointer);
    
    	if (iter->tot) {
    		iter->cur = 0;
    		iter->seq = iter->array[iter->cur];
    		iter->valid = 1;
    	}
    }
    
    void BKE_sequence_iterator_next(SeqIterator *iter)
    {
    	if (++iter->cur < iter->tot)
    		iter->seq = iter->array[iter->cur];
    	else
    		iter->valid = 0;
    }
    
    void BKE_sequence_iterator_end(SeqIterator *iter)
    {
    	if (iter->array)
    		MEM_freeN(iter->array);
    
    	iter->valid = 0;
    }
    
    static int metaseq_start(Sequence *metaseq)
    {
    	return metaseq->start + metaseq->startofs;
    }
    
    static int metaseq_end(Sequence *metaseq)
    {
    	return metaseq->start + metaseq->len - metaseq->endofs;
    }
    
    static void seq_update_sound_bounds_recursive_rec(Scene *scene, Sequence *metaseq, int start, int end)
    {
    	Sequence *seq;
    
    	/* for sound we go over full meta tree to update bounds of the sound strips,
    	 * since sound is played outside of evaluating the imbufs, */
    	for (seq = metaseq->seqbase.first; seq; seq = seq->next) {
    		if (seq->type == SEQ_TYPE_META) {
    			seq_update_sound_bounds_recursive_rec(scene, seq, max_ii(start, metaseq_start(seq)),
    			                                      min_ii(end, metaseq_end(seq)));
    		}
    		else if (ELEM(seq->type, SEQ_TYPE_SOUND_RAM, SEQ_TYPE_SCENE)) {
    			if (seq->scene_sound) {
    				int startofs = seq->startofs;
    				int endofs = seq->endofs;
    				if (seq->startofs + seq->start < start)
    					startofs = start - seq->start;
    
    				if (seq->start + seq->len - seq->endofs > end)
    					endofs = seq->start + seq->len - end;
    
    				sound_move_scene_sound(scene, seq->scene_sound, seq->start + startofs,
    				                       seq->start + seq->len - endofs, startofs + seq->anim_startofs);
    			}
    		}
    	}
    }
    
    static void seq_update_sound_bounds_recursive(Scene *scene, Sequence *metaseq)
    {
    	seq_update_sound_bounds_recursive_rec(scene, metaseq, metaseq_start(metaseq), metaseq_end(metaseq));
    }
    
    void BKE_sequence_calc_disp(Scene *scene, Sequence *seq)
    {
    	if (seq->startofs && seq->startstill)
    		seq->startstill = 0;
    	if (seq->endofs && seq->endstill)
    		seq->endstill = 0;
    	
    	seq->startdisp = seq->start + seq->startofs - seq->startstill;
    	seq->enddisp = seq->start + seq->len - seq->endofs + seq->endstill;
    	
    	seq->handsize = 10.0;  /* 10 frames */
    	if (seq->enddisp - seq->startdisp < 10) {
    		seq->handsize = (float)(0.5 * (seq->enddisp - seq->startdisp));
    	}
    	else if (seq->enddisp - seq->startdisp > 250) {
    		seq->handsize = (float)((seq->enddisp - seq->startdisp) / 25);
    	}
    
    	if (ELEM(seq->type, SEQ_TYPE_SOUND_RAM, SEQ_TYPE_SCENE)) {
    		BKE_sequencer_update_sound_bounds(scene, seq);
    	}
    	else if (seq->type == SEQ_TYPE_META) {
    		seq_update_sound_bounds_recursive(scene, seq);
    	}
    }
    
    void BKE_sequence_calc(Scene *scene, Sequence *seq)
    {
    	Sequence *seqm;
    	int min, max;
    
    	/* check all metas recursively */
    	seqm = seq->seqbase.first;
    	while (seqm) {
    		if (seqm->seqbase.first) BKE_sequence_calc(scene, seqm);
    		seqm = seqm->next;
    	}
    
    	/* effects and meta: automatic start and end */
    
    	if (seq->type & SEQ_TYPE_EFFECT) {
    		/* pointers */
    		if (seq->seq2 == NULL)
    			seq->seq2 = seq->seq1;
    		if (seq->seq3 == NULL)
    			seq->seq3 = seq->seq1;
    
    		/* effecten go from seq1 -> seq2: test */
    
    		/* we take the largest start and smallest end */
    
    		// seq->start = seq->startdisp = MAX2(seq->seq1->startdisp, seq->seq2->startdisp);
    		// seq->enddisp = MIN2(seq->seq1->enddisp, seq->seq2->enddisp);
    
    		if (seq->seq1) {
    			/* XXX These resets should not be necessary, but users used to be able to
    			 *     edit effect's length, leading to strange results. See [#29190] */
    			seq->startofs = seq->endofs = seq->startstill = seq->endstill = 0;
    			seq->start = seq->startdisp = max_iii(seq->seq1->startdisp, seq->seq2->startdisp, seq->seq3->startdisp);
    			seq->enddisp                = min_iii(seq->seq1->enddisp,   seq->seq2->enddisp,   seq->seq3->enddisp);
    			/* we cant help if strips don't overlap, it wont give useful results.
    			 * but at least ensure 'len' is never negative which causes bad bugs elsewhere. */
    			if (seq->enddisp < seq->startdisp) {
    				/* simple start/end swap */
    				seq->start = seq->enddisp;
    				seq->enddisp = seq->startdisp;
    				seq->startdisp = seq->start;
    				seq->flag |= SEQ_INVALID_EFFECT;
    			}
    			else {
    				seq->flag &= ~SEQ_INVALID_EFFECT;
    			}
    
    			seq->len = seq->enddisp - seq->startdisp;
    		}
    		else {
    			BKE_sequence_calc_disp(scene, seq);
    		}
    	}
    	else {
    		if (seq->type == SEQ_TYPE_META) {
    			seqm = seq->seqbase.first;
    			if (seqm) {
    				min =  MAXFRAME * 2;
    				max = -MAXFRAME * 2;
    				while (seqm) {
    					if (seqm->startdisp < min) min = seqm->startdisp;
    					if (seqm->enddisp > max) max = seqm->enddisp;
    					seqm = seqm->next;
    				}
    				seq->start = min + seq->anim_startofs;
    				seq->len = max - min;
    				seq->len -= seq->anim_startofs;
    				seq->len -= seq->anim_endofs;
    			}
    			seq_update_sound_bounds_recursive(scene, seq);
    		}
    		BKE_sequence_calc_disp(scene, seq);
    	}
    }
    
    /* note: caller should run BKE_sequence_calc(scene, seq) after */
    void BKE_sequence_reload_new_file(Scene *scene, Sequence *seq, const bool lock_range)
    {
    	char str[FILE_MAX];
    	int prev_startdisp = 0, prev_enddisp = 0;
    	/* note: don't rename the strip, will break animation curves */
    
    	if (ELEM7(seq->type,
    	          SEQ_TYPE_MOVIE, SEQ_TYPE_IMAGE, SEQ_TYPE_SOUND_RAM,
    	          SEQ_TYPE_SCENE, SEQ_TYPE_META, SEQ_TYPE_MOVIECLIP, SEQ_TYPE_MASK) == 0)
    	{
    		return;
    	}
    
    	if (lock_range) {
    		/* keep so we don't have to move the actual start and end points (only the data) */
    		BKE_sequence_calc_disp(scene, seq);
    		prev_startdisp = seq->startdisp;
    		prev_enddisp = seq->enddisp;
    	}
    
    	switch (seq->type) {
    		case SEQ_TYPE_IMAGE:
    		{
    			/* Hack? */
    			size_t olen = MEM_allocN_len(seq->strip->stripdata) / sizeof(StripElem);
    
    			seq->len = olen;
    			seq->len -= seq->anim_startofs;
    			seq->len -= seq->anim_endofs;
    			if (seq->len < 0) {
    				seq->len = 0;
    			}
    			break;
    		}
    		case SEQ_TYPE_MOVIE:
    			BLI_join_dirfile(str, sizeof(str), seq->strip->dir,
    			                 seq->strip->stripdata->name);
    			BLI_path_abs(str, G.main->name);
    
    			if (seq->anim) IMB_free_anim(seq->anim);
    
    			seq->anim = openanim(str, IB_rect | ((seq->flag & SEQ_FILTERY) ? IB_animdeinterlace : 0),
    			                     seq->streamindex, seq->strip->colorspace_settings.name);
    
    			if (!seq->anim) {
    				return;
    			}
    
    			seq->len = IMB_anim_get_duration(seq->anim, seq->strip->proxy ? seq->strip->proxy->tc : IMB_TC_RECORD_RUN);
    	
    			seq->anim_preseek = IMB_anim_get_preseek(seq->anim);
    
    			seq->len -= seq->anim_startofs;
    			seq->len -= seq->anim_endofs;
    			if (seq->len < 0) {
    				seq->len = 0;
    			}
    			break;
    		case SEQ_TYPE_MOVIECLIP:
    			if (seq->clip == NULL)
    				return;
    
    			seq->len = BKE_movieclip_get_duration(seq->clip);
    
    			seq->len -= seq->anim_startofs;
    			seq->len -= seq->anim_endofs;
    			if (seq->len < 0) {
    				seq->len = 0;
    			}
    			break;
    		case SEQ_TYPE_MASK:
    			if (seq->mask == NULL)
    				return;
    			seq->len = BKE_mask_get_duration(seq->mask);
    			seq->len -= seq->anim_startofs;
    			seq->len -= seq->anim_endofs;
    			if (seq->len < 0) {
    				seq->len = 0;
    			}
    			break;
    		case SEQ_TYPE_SOUND_RAM:
    #ifdef WITH_AUDASPACE
    			if (!seq->sound)
    				return;
    			seq->len = ceil((double)AUD_getInfo(seq->sound->playback_handle).length * FPS);
    			seq->len -= seq->anim_startofs;
    			seq->len -= seq->anim_endofs;
    			if (seq->len < 0) {
    				seq->len = 0;
    			}
    #else
    			return;
    #endif
    			break;
    		case SEQ_TYPE_SCENE:
    		{
    			seq->len = (seq->scene) ? seq->scene->r.efra - seq->scene->r.sfra + 1 : 0;
    			seq->len -= seq->anim_startofs;
    			seq->len -= seq->anim_endofs;
    			if (seq->len < 0) {
    				seq->len = 0;
    			}
    			break;
    		}
    	}
    
    	free_proxy_seq(seq);
    
    	if (lock_range) {
    		BKE_sequence_tx_set_final_left(seq, prev_startdisp);
    		BKE_sequence_tx_set_final_right(seq, prev_enddisp);
    		BKE_sequence_single_fix(seq);
    	}
    	
    	BKE_sequence_calc(scene, seq);
    }
    
    void BKE_sequencer_sort(Scene *scene)
    {
    	/* all strips together per kind, and in order of y location ("machine") */
    	ListBase seqbase, effbase;
    	Editing *ed = BKE_sequencer_editing_get(scene, FALSE);
    	Sequence *seq, *seqt;
    
    	
    	if (ed == NULL)
    		return;
    
    	BLI_listbase_clear(&seqbase);
    	BLI_listbase_clear(&effbase);
    
    	while ((seq = BLI_pophead(ed->seqbasep))) {
    
    		if (seq->type & SEQ_TYPE_EFFECT) {
    			seqt = effbase.first;
    			while (seqt) {
    				if (seqt->machine >= seq->machine) {
    					BLI_insertlinkbefore(&effbase, seqt, seq);
    					break;
    				}
    				seqt = seqt->next;
    			}
    			if (seqt == NULL)
    				BLI_addtail(&effbase, seq);
    		}
    		else {
    			seqt = seqbase.first;
    			while (seqt) {
    				if (seqt->machine >= seq->machine) {
    					BLI_insertlinkbefore(&seqbase, seqt, seq);
    					break;
    				}
    				seqt = seqt->next;
    			}
    			if (seqt == NULL)
    				BLI_addtail(&seqbase, seq);
    		}
    	}
    
    	BLI_movelisttolist(&seqbase, &effbase);
    	*(ed->seqbasep) = seqbase;
    }
    
    static int clear_scene_in_allseqs_cb(Sequence *seq, void *arg_pt)
    {
    	if (seq->scene == (Scene *)arg_pt)
    		seq->scene = NULL;
    	return 1;
    }
    
    void BKE_sequencer_clear_scene_in_allseqs(Main *bmain, Scene *scene)
    {
    	Scene *scene_iter;
    
    	/* when a scene is deleted: test all seqs */
    	for (scene_iter = bmain->scene.first; scene_iter; scene_iter = scene_iter->id.next) {
    		if (scene_iter != scene && scene_iter->ed) {
    			BKE_sequencer_base_recursive_apply(&scene_iter->ed->seqbase, clear_scene_in_allseqs_cb, scene);
    		}
    	}
    }
    
    typedef struct SeqUniqueInfo {
    	Sequence *seq;
    	char name_src[SEQ_NAME_MAXSTR];
    	char name_dest[SEQ_NAME_MAXSTR];
    	int count;
    	int match;
    } SeqUniqueInfo;
    
    static void seqbase_unique_name(ListBase *seqbasep, SeqUniqueInfo *sui)
    {
    	Sequence *seq;
    	for (seq = seqbasep->first; seq; seq = seq->next) {
    		if ((sui->seq != seq) && STREQ(sui->name_dest, seq->name + 2)) {
    			/* SEQ_NAME_MAXSTR - 2 for prefix, -1 for \0, -4 for the number */
    			BLI_snprintf(sui->name_dest, sizeof(sui->name_dest), "%.59s.%03d",  sui->name_src, sui->count++);
    			sui->match = 1; /* be sure to re-scan */
    		}
    	}
    }
    
    static int seqbase_unique_name_recursive_cb(Sequence *seq, void *arg_pt)
    {
    	if (seq->seqbase.first)
    		seqbase_unique_name(&seq->seqbase, (SeqUniqueInfo *)arg_pt);
    	return 1;
    }
    
    void BKE_sequence_base_unique_name_recursive(ListBase *seqbasep, Sequence *seq)
    {
    	SeqUniqueInfo sui;
    	char *dot;
    	sui.seq = seq;
    	BLI_strncpy(sui.name_src, seq->name + 2, sizeof(sui.name_src));
    	BLI_strncpy(sui.name_dest, seq->name + 2, sizeof(sui.name_dest));
    
    	sui.count = 1;
    	sui.match = 1; /* assume the worst to start the loop */
    
    	/* Strip off the suffix */
    	if ((dot = strrchr(sui.name_src, '.'))) {
    		*dot = '\0';
    		dot++;
    
    		if (*dot)
    			sui.count = atoi(dot) + 1;
    	}
    
    	while (sui.match) {
    		sui.match = 0;
    		seqbase_unique_name(seqbasep, &sui);
    		BKE_sequencer_base_recursive_apply(seqbasep, seqbase_unique_name_recursive_cb, &sui);
    	}
    
    	BLI_strncpy(seq->name + 2, sui.name_dest, sizeof(seq->name) - 2);
    }
    
    static const char *give_seqname_by_type(int type)
    {
    	switch (type) {
    		case SEQ_TYPE_META:       return "Meta";
    		case SEQ_TYPE_IMAGE:      return "Image";
    		case SEQ_TYPE_SCENE:      return "Scene";
    		case SEQ_TYPE_MOVIE:      return "Movie";
    		case SEQ_TYPE_MOVIECLIP:  return "Clip";
    		case SEQ_TYPE_MASK:       return "Mask";
    		case SEQ_TYPE_SOUND_RAM:  return "Audio";
    		case SEQ_TYPE_CROSS:      return "Cross";
    		case SEQ_TYPE_GAMCROSS:   return "Gamma Cross";
    		case SEQ_TYPE_ADD:        return "Add";
    		case SEQ_TYPE_SUB:        return "Sub";
    		case SEQ_TYPE_MUL:        return "Mul";
    		case SEQ_TYPE_ALPHAOVER:  return "Alpha Over";
    		case SEQ_TYPE_ALPHAUNDER: return "Alpha Under";
    		case SEQ_TYPE_OVERDROP:   return "Over Drop";
    		case SEQ_TYPE_WIPE:       return "Wipe";
    		case SEQ_TYPE_GLOW:       return "Glow";
    		case SEQ_TYPE_TRANSFORM:  return "Transform";
    		case SEQ_TYPE_COLOR:      return "Color";
    		case SEQ_TYPE_MULTICAM:   return "Multicam";
    		case SEQ_TYPE_ADJUSTMENT: return "Adjustment";
    		case SEQ_TYPE_SPEED:      return "Speed";
    		default:
    			return NULL;
    	}
    }
    
    const char *BKE_sequence_give_name(Sequence *seq)
    {
    	const char *name = give_seqname_by_type(seq->type);
    
    	if (!name) {
    		if (seq->type < SEQ_TYPE_EFFECT) {
    			return seq->strip->dir;
    		}
    		else {
    			return "Effect";
    		}
    	}
    	return name;
    }
    
    /*********************** DO THE SEQUENCE *************************/
    
    static void make_black_ibuf(ImBuf *ibuf)
    {
    	unsigned int *rect;
    	float *rect_float;
    	int tot;
    
    	if (ibuf == NULL || (ibuf->rect == NULL && ibuf->rect_float == NULL)) {
    		return;
    	}
    
    	tot = ibuf->x * ibuf->y;
    
    	rect = ibuf->rect;
    	rect_float = ibuf->rect_float;
    
    	if (rect) {
    		memset(rect, 0, tot * sizeof(char) * 4);
    	}
    
    	if (rect_float) {
    		memset(rect_float, 0, tot * sizeof(float) * 4);
    	}
    }
    
    static void multibuf(ImBuf *ibuf, float fmul)
    {
    	char *rt;
    	float *rt_float;
    
    	int a, mul, icol;
    
    	mul = (int)(256.0f * fmul);
    	rt = (char *)ibuf->rect;
    	rt_float = ibuf->rect_float;
    
    	if (rt) {
    		a = ibuf->x * ibuf->y;
    		while (a--) {
    
    			icol = (mul * rt[0]) >> 8;
    			if (icol > 254) rt[0] = 255; else rt[0] = icol;
    			icol = (mul * rt[1]) >> 8;
    			if (icol > 254) rt[1] = 255; else rt[1] = icol;
    			icol = (mul * rt[2]) >> 8;
    			if (icol > 254) rt[2] = 255; else rt[2] = icol;
    			icol = (mul * rt[3]) >> 8;
    			if (icol > 254) rt[3] = 255; else rt[3] = icol;
    			
    			rt += 4;
    		}
    	}
    	if (rt_float) {
    		a = ibuf->x * ibuf->y;
    		while (a--) {
    			rt_float[0] *= fmul;
    			rt_float[1] *= fmul;
    			rt_float[2] *= fmul;
    			rt_float[3] *= fmul;
    			
    			rt_float += 4;
    		}
    	}
    }
    
    static float give_stripelem_index(Sequence *seq, float cfra)
    {
    	float nr;
    	int sta = seq->start;
    	int end = seq->start + seq->len - 1;
    
    	if (seq->type & SEQ_TYPE_EFFECT) {
    		end = seq->enddisp;
    	}
    
    	if (end < sta) {
    		return -1;
    	}
    
    	if (seq->flag & SEQ_REVERSE_FRAMES) {
    		/*reverse frame in this sequence */
    		if (cfra <= sta) nr = end - sta;
    		else if (cfra >= end) nr = 0;
    		else nr = end - cfra;
    	}
    	else {
    		if (cfra <= sta) nr = 0;
    		else if (cfra >= end) nr = end - sta;
    		else nr = cfra - sta;
    	}
    	
    	if (seq->strobe < 1.0f) seq->strobe = 1.0f;
    	
    	if (seq->strobe > 1.0f) {
    		nr -= fmodf((double)nr, (double)seq->strobe);
    	}
    
    	return nr;
    }
    
    StripElem *BKE_sequencer_give_stripelem(Sequence *seq, int cfra)
    {
    	StripElem *se = seq->strip->stripdata;
    
    	if (seq->type == SEQ_TYPE_IMAGE) {
    		/* only IMAGE strips use the whole array, MOVIE strips use only the first element,
    		 * all other strips don't use this...
    		 */
    
    		int nr = (int) give_stripelem_index(seq, cfra);
    
    		if (nr == -1 || se == NULL)
    			return NULL;
    	
    		se += nr + seq->anim_startofs;
    	}
    	return se;
    }
    
    static int evaluate_seq_frame_gen(Sequence **seq_arr, ListBase *seqbase, int cfra)
    {
    	Sequence *seq;
    	Sequence *effect_inputs[MAXSEQ + 1];
    	int i, totseq = 0, num_effect_inputs = 0;
    
    	memset(seq_arr, 0, sizeof(Sequence *) * (MAXSEQ + 1));
    
    	seq = seqbase->first;
    	while (seq) {
    		if (seq->startdisp <= cfra && seq->enddisp > cfra) {
    			if ((seq->type & SEQ_TYPE_EFFECT)) {
    				if (seq->seq1) {
    					effect_inputs[num_effect_inputs++] = seq->seq1;
    				}
    
    				if (seq->seq2) {
    					effect_inputs[num_effect_inputs++] = seq->seq2;
    				}
    
    				if (seq->seq3) {
    					effect_inputs[num_effect_inputs++] = seq->seq3;
    				}
    			}
    
    			seq_arr[seq->machine] = seq;
    			totseq++;
    		}
    		seq = seq->next;
    	}
    
    	/* Drop strips which are used for effect inputs, we don't want
    	 *them to blend into render stack in any other way than effect
    	 * string rendering.
    	 */
    	for (i = 0; i < num_effect_inputs; i++) {
    		seq = effect_inputs[i];
    		seq_arr[seq->machine] = NULL;
    	}
    
    	return totseq;
    }
    
    int BKE_sequencer_evaluate_frame(Scene *scene, int cfra)
    {
    	Editing *ed = BKE_sequencer_editing_get(scene, FALSE);
    	Sequence *seq_arr[MAXSEQ + 1];
    
    	if (ed == NULL)
    		return 0;
    
    	return evaluate_seq_frame_gen(seq_arr, ed->seqbasep, cfra);
    }
    
    static bool video_seq_is_rendered(Sequence *seq)
    {
    	return (seq && !(seq->flag & SEQ_MUTE) && seq->type != SEQ_TYPE_SOUND_RAM);
    }
    
    static int get_shown_sequences(ListBase *seqbasep, int cfra, int chanshown, Sequence **seq_arr_out)
    {
    	Sequence *seq_arr[MAXSEQ + 1];
    	int b = chanshown;
    	int cnt = 0;
    
    	if (b > MAXSEQ) {
    		return 0;
    	}
    
    	if (evaluate_seq_frame_gen(seq_arr, seqbasep, cfra)) {
    		if (b == 0) {
    			b = MAXSEQ;
    		}
    		for (; b > 0; b--) {
    			if (video_seq_is_rendered(seq_arr[b])) {
    				break;
    			}
    		}
    	}
    	
    	chanshown = b;
    
    	for (; b > 0; b--) {
    		if (video_seq_is_rendered(seq_arr[b])) {
    			if (seq_arr[b]->blend_mode == SEQ_BLEND_REPLACE) {
    				break;
    			}
    		}
    	}
    
    	for (; b <= chanshown && b >= 0; b++) {
    		if (video_seq_is_rendered(seq_arr[b])) {
    			seq_arr_out[cnt++] = seq_arr[b];
    		}
    	}
    
    	return cnt;
    }
    
    /*********************** proxy management *************************/
    
    typedef struct SeqIndexBuildContext {
    	struct IndexBuildContext *index_context;
    
    	int tc_flags;
    	int size_flags;
    	int quality;
    
    	Main *bmain;
    	Scene *scene;
    	Sequence *seq, *orig_seq;
    } SeqIndexBuildContext;
    
    #define PROXY_MAXFILE (2 * FILE_MAXDIR + FILE_MAXFILE)
    
    static IMB_Proxy_Size seq_rendersize_to_proxysize(int size)
    {
    	if (size >= 100) {
    		return IMB_PROXY_NONE;
    	}
    	if (size >= 99) {
    		return IMB_PROXY_100;
    	}
    	if (size >= 75) {
    		return IMB_PROXY_75;
    	}
    	if (size >= 50) {
    		return IMB_PROXY_50;
    	}
    	return IMB_PROXY_25;
    }
    
    static double seq_rendersize_to_scale_factor(int size)
    {
    	if (size >= 99) {
    		return 1.0;
    	}
    	if (size >= 75) {
    		return 0.75;
    	}
    	if (size >= 50) {
    		return 0.50;
    	}
    	return 0.25;
    }
    
    static void seq_open_anim_file(Sequence *seq)
    {
    	char name[FILE_MAX];
    	StripProxy *proxy;
    
    	if (seq->anim != NULL) {
    		return;
    	}
    
    	BLI_join_dirfile(name, sizeof(name),
    	                 seq->strip->dir, seq->strip->stripdata->name);
    	BLI_path_abs(name, G.main->name);
    	
    	seq->anim = openanim(name, IB_rect | ((seq->flag & SEQ_FILTERY) ? IB_animdeinterlace : 0),
    	                     seq->streamindex, seq->strip->colorspace_settings.name);
    
    	if (seq->anim == NULL) {
    		return;
    	}
    
    	proxy = seq->strip->proxy;
    
    	if (proxy == NULL) {
    		return;
    	}
    
    	if (seq->flag & SEQ_USE_PROXY_CUSTOM_DIR) {
    		char dir[FILE_MAX];
    		BLI_strncpy(dir, seq->strip->proxy->dir, sizeof(dir));
    		BLI_path_abs(dir, G.main->name);
    
    		IMB_anim_set_index_dir(seq->anim, dir);
    	}
    }
    
    
    static int seq_proxy_get_fname(Sequence *seq, int cfra, int render_size, char *name)
    {
    	int frameno;
    	char dir[PROXY_MAXFILE];
    
    	if (!seq->strip->proxy) {
    		return FALSE;
    	}
    
    	/* MOVIE tracks (only exception: custom files) are now handled 
    	 * internally by ImBuf module for various reasons: proper time code
    	 * support, quicker index build, using one file instead
    	 * of a full directory of jpeg files, etc. Trying to support old
    	 * and new method at once could lead to funny effects, if people
    	 * have both, a directory full of jpeg files and proxy avis, so
    	 * sorry folks, please rebuild your proxies... */
    
    	if (seq->flag & (SEQ_USE_PROXY_CUSTOM_DIR | SEQ_USE_PROXY_CUSTOM_FILE)) {
    		BLI_strncpy(dir, seq->strip->proxy->dir, sizeof(dir));
    	}
    	else if (seq->type == SEQ_TYPE_IMAGE) {
    		BLI_snprintf(dir, PROXY_MAXFILE, "%s/BL_proxy", seq->strip->dir);
    	}
    	else {
    		return FALSE;
    	}
    
    	if (seq->flag & SEQ_USE_PROXY_CUSTOM_FILE) {
    		BLI_join_dirfile(name, PROXY_MAXFILE,
    		                 dir, seq->strip->proxy->file);
    		BLI_path_abs(name, G.main->name);
    
    		return TRUE;
    	}
    
    	/* generate a separate proxy directory for each preview size */
    
    	if (seq->type == SEQ_TYPE_IMAGE) {
    		BLI_snprintf(name, PROXY_MAXFILE, "%s/images/%d/%s_proxy", dir, render_size,
    		             BKE_sequencer_give_stripelem(seq, cfra)->name);
    		frameno = 1;
    	}
    	else {
    		frameno = (int)give_stripelem_index(seq, cfra) + seq->anim_startofs;
    		BLI_snprintf(name, PROXY_MAXFILE, "%s/proxy_misc/%d/####", dir, render_size);
    	}
    
    	BLI_path_abs(name, G.main->name);
    	BLI_path_frame(name, frameno, 0);
    
    	strcat(name, ".jpg");
    
    	return TRUE;
    }
    
    static ImBuf *seq_proxy_fetch(const SeqRenderData *context, Sequence *seq, int cfra)
    {
    	char name[PROXY_MAXFILE];
    	IMB_Proxy_Size psize = seq_rendersize_to_proxysize(context->preview_render_size);
    	int size_flags;
    	int render_size = context->preview_render_size;
    
    	/* dirty hack to distinguish 100% render size from PROXY_100 */
    	if (render_size == 99) {
    		render_size = 100;
    	}
    
    	if (!(seq->flag & SEQ_USE_PROXY)) {
    		return NULL;
    	}
    
    	size_flags = seq->strip->proxy->build_size_flags;
    
    	/* only use proxies, if they are enabled (even if present!) */
    	if (psize == IMB_PROXY_NONE || ((size_flags & psize) != psize)) {
    		return NULL;
    	}
    
    	if (seq->flag & SEQ_USE_PROXY_CUSTOM_FILE) {
    		int frameno = (int)give_stripelem_index(seq, cfra) + seq->anim_startofs;
    		if (seq->strip->proxy->anim == NULL) {
    			if (seq_proxy_get_fname(seq, cfra, render_size, name) == 0) {
    				return NULL;
    			}
    
    			/* proxies are generated in default color space */
    			seq->strip->proxy->anim = openanim(name, IB_rect, 0, NULL);
    		}
    		if (seq->strip->proxy->anim == NULL) {
    			return NULL;
    		}
     
    		seq_open_anim_file(seq);
    
    		frameno = IMB_anim_index_get_frame_index(seq->anim, seq->strip->proxy->tc, frameno);
    
    		return IMB_anim_absolute(seq->strip->proxy->anim, frameno, IMB_TC_NONE, IMB_PROXY_NONE);
    	}
     
    	if (seq_proxy_get_fname(seq, cfra, render_size, name) == 0) {
    		return NULL;
    	}
    
    	if (BLI_exists(name)) {
    		ImBuf *ibuf = IMB_loadiffname(name, IB_rect, NULL);
    
    		if (ibuf)
    			sequencer_imbuf_assign_spaces(context->scene, ibuf);
    
    		return ibuf;
    	}
    	else {
    		return NULL;
    	}
    }
    
    static void seq_proxy_build_frame(const SeqRenderData *context, Sequence *seq, int cfra, int proxy_render_size)
    {
    	char name[PROXY_MAXFILE];
    	int quality;
    	int rectx, recty;
    	int ok;
    	ImBuf *ibuf;
    
    	if (!seq_proxy_get_fname(seq, cfra, proxy_render_size, name)) {
    		return;
    	}
    
    	ibuf = seq_render_strip(context, seq, cfra);
    
    	rectx = (proxy_render_size * ibuf->x) / 100;
    	recty = (proxy_render_size * ibuf->y) / 100;
    
    	if (ibuf->x != rectx || ibuf->y != recty) {
    		IMB_scalefastImBuf(ibuf, (short)rectx, (short)recty);
    	}
    
    	/* depth = 32 is intentionally left in, otherwise ALPHA channels
    	 * won't work... */
    	quality = seq->strip->proxy->quality;
    	ibuf->ftype = JPG | quality;
    
    	/* unsupported feature only confuses other s/w */
    	if (ibuf->planes == 32)
    		ibuf->planes = 24;
    
    	BLI_make_existing_file(name);
    
    	ok = IMB_saveiff(ibuf, name, IB_rect | IB_zbuf | IB_zbuffloat);
    	if (ok == 0) {
    		perror(name);
    	}
    
    	IMB_freeImBuf(ibuf);
    }
    
    SeqIndexBuildContext *BKE_sequencer_proxy_rebuild_context(Main *bmain, Scene *scene, Sequence *seq)
    {
    	SeqIndexBuildContext *context;
    	Sequence *nseq;
    
    	if (!seq->strip || !seq->strip->proxy) {
    		return NULL;
    	}
    
    	if (!(seq->flag & SEQ_USE_PROXY)) {
    		return NULL;
    	}
    
    	context = MEM_callocN(sizeof(SeqIndexBuildContext), "seq proxy rebuild context");
    
    	nseq = BKE_sequence_dupli_recursive(scene, scene, seq, 0);
    
    	context->tc_flags   = nseq->strip->proxy->build_tc_flags;
    	context->size_flags = nseq->strip->proxy->build_size_flags;
    	context->quality    = nseq->strip->proxy->quality;
    
    	context->bmain = bmain;
    	context->scene = scene;
    	context->orig_seq = seq;
    	context->seq = nseq;
    
    	if (nseq->type == SEQ_TYPE_MOVIE) {
    		seq_open_anim_file(nseq);
    
    		if (nseq->anim) {
    			context->index_context = IMB_anim_index_rebuild_context(nseq->anim,
    			        context->tc_flags, context->size_flags, context->quality);
    		}
    	}
    
    	return context;
    }
    
    void BKE_sequencer_proxy_rebuild(SeqIndexBuildContext *context, short *stop, short *do_update, float *progress)
    {
    	SeqRenderData render_context;
    	Sequence *seq = context->seq;
    	Scene *scene = context->scene;
    	Main *bmain = context->bmain;
    	int cfra;
    
    	if (seq->type == SEQ_TYPE_MOVIE) {
    		if (context->index_context) {
    			IMB_anim_index_rebuild(context->index_context, stop, do_update, progress);
    		}
    
    		return;
    	}
    
    	if (!(seq->flag & SEQ_USE_PROXY)) {
    		return;
    	}
    
    	/* that's why it is called custom... */
    	if (seq->flag & SEQ_USE_PROXY_CUSTOM_FILE) {
    		return;
    	}
    
    	/* fail safe code */
    
    	render_context = BKE_sequencer_new_render_data(bmain->eval_ctx, bmain, context->scene,
    	                                    (scene->r.size * (float) scene->r.xsch) / 100.0f + 0.5f,
    	                                    (scene->r.size * (float) scene->r.ysch) / 100.0f + 0.5f, 100);
    	render_context.skip_cache = true;
    	render_context.is_proxy_render = true;
    
    	for (cfra = seq->startdisp + seq->startstill;  cfra < seq->enddisp - seq->endstill; cfra++) {
    		if (context->size_flags & IMB_PROXY_25) {
    			seq_proxy_build_frame(&render_context, seq, cfra, 25);
    		}
    		if (context->size_flags & IMB_PROXY_50) {
    			seq_proxy_build_frame(&render_context, seq, cfra, 50);
    		}
    		if (context->size_flags & IMB_PROXY_75) {
    			seq_proxy_build_frame(&render_context, seq, cfra, 75);
    		}
    		if (context->size_flags & IMB_PROXY_100) {
    			seq_proxy_build_frame(&render_context, seq, cfra, 100);
    		}
    
    		*progress = (float) (cfra - seq->startdisp - seq->startstill) / (seq->enddisp - seq->endstill - seq->startdisp - seq->startstill);
    		*do_update = TRUE;
    
    		if (*stop || G.is_break)
    			break;
    	}
    }
    
    void BKE_sequencer_proxy_rebuild_finish(SeqIndexBuildContext *context, short stop)
    {
    	if (context->index_context) {
    		IMB_close_anim_proxies(context->seq->anim);
    		IMB_close_anim_proxies(context->orig_seq->anim);
    		IMB_anim_index_rebuild_finish(context->index_context, stop);
    	}
    
    	seq_free_sequence_recurse(NULL, context->seq);
    
    	MEM_freeN(context);
    }
    
    /*********************** color balance *************************/
    
    static StripColorBalance calc_cb(StripColorBalance *cb_)
    {
    	StripColorBalance cb = *cb_;
    	int c;
    
    	for (c = 0; c < 3; c++) {
    		cb.lift[c] = 2.0f - cb.lift[c];
    	}
    
    	if (cb.flag & SEQ_COLOR_BALANCE_INVERSE_LIFT) {
    		for (c = 0; c < 3; c++) {
    			/* tweak to give more subtle results
    			 * values above 1.0 are scaled */
    			if (cb.lift[c] > 1.0f)
    				cb.lift[c] = pow(cb.lift[c] - 1.0f, 2.0) + 1.0;
    
    			cb.lift[c] = 2.0f - cb.lift[c];
    		}
    	}
    
    	if (cb.flag & SEQ_COLOR_BALANCE_INVERSE_GAIN) {
    		for (c = 0; c < 3; c++) {
    			if (cb.gain[c] != 0.0f) {
    				cb.gain[c] = 1.0f / cb.gain[c];
    			}
    			else {
    				cb.gain[c] = 1000000; /* should be enough :) */
    			}
    		}
    	}
    
    	if (!(cb.flag & SEQ_COLOR_BALANCE_INVERSE_GAMMA)) {
    		for (c = 0; c < 3; c++) {
    			if (cb.gamma[c] != 0.0f) {
    				cb.gamma[c] = 1.0f / cb.gamma[c];
    			}
    			else {
    				cb.gamma[c] = 1000000; /* should be enough :) */
    			}
    		}
    	}
    
    	return cb;
    }
    
    /* note: lift is actually 2-lift */
    MINLINE float color_balance_fl(float in, const float lift, const float gain, const float gamma, const float mul)
    {
    	float x = (((in - 1.0f) * lift) + 1.0f) * gain;
    
    	/* prevent NaN */
    	if (x < 0.f)
    		x = 0.f;
    
    	return powf(x, gamma) * mul;
    }
    
    static void make_cb_table_float(float lift, float gain, float gamma,
                                    float *table, float mul)
    {
    	int y;
    
    	for (y = 0; y < 256; y++) {
    		float v = color_balance_fl((float)y * (1.0f / 255.0f), lift, gain, gamma, mul);
    
    		table[y] = v;
    	}
    }
    
    static void color_balance_byte_byte(StripColorBalance *cb_, unsigned char *rect, unsigned char *mask_rect, int width, int height, float mul)
    {
    	//unsigned char cb_tab[3][256];
    	unsigned char *cp = rect;
    	unsigned char *e = cp + width * 4 * height;
    	unsigned char *m = mask_rect;
    
    	StripColorBalance cb = calc_cb(cb_);
    
    	while (cp < e) {
    		float p[4];
    		int c;
    
    		straight_uchar_to_premul_float(p, cp);
    
    		for (c = 0; c < 3; c++) {
    			float t = color_balance_fl(p[c], cb.lift[c], cb.gain[c], cb.gamma[c], mul);
    
    			if (m) {
    				float m_normal = (float) m[c] / 255.0f;
    
    				p[c] = p[c] * (1.0f - m_normal) + t * m_normal;
    			}
    			else
    				p[c] = t;
    		}
    		
    		premul_float_to_straight_uchar(cp, p);
    
    		cp += 4;
    		if (m)
    			m += 4;
    	}
    }
    
    static void color_balance_byte_float(StripColorBalance *cb_, unsigned char *rect, float *rect_float, unsigned char *mask_rect, int width, int height, float mul)
    {
    	float cb_tab[4][256];
    	int c, i;
    	unsigned char *p = rect;
    	unsigned char *e = p + width * 4 * height;
    	unsigned char *m = mask_rect;
    	float *o;
    	StripColorBalance cb;
    
    	o = rect_float;
    
    	cb = calc_cb(cb_);
    
    	for (c = 0; c < 3; c++) {
    		make_cb_table_float(cb.lift[c], cb.gain[c], cb.gamma[c], cb_tab[c], mul);
    	}
    
    	for (i = 0; i < 256; i++) {
    		cb_tab[3][i] = ((float)i) * (1.0f / 255.0f);
    	}
    
    	while (p < e) {
    		if (m) {
    			float t[3] = {m[0] / 255.0f, m[1] / 255.0f, m[2] / 255.0f};
    
    			p[0] = p[0] * (1.0f - t[0]) + t[0] * cb_tab[0][p[0]];
    			p[1] = p[1] * (1.0f - t[1]) + t[1] * cb_tab[1][p[1]];
    			p[2] = p[2] * (1.0f - t[2]) + t[2] * cb_tab[2][p[2]];
    
    			m += 4;
    		}
    		else {
    			o[0] = cb_tab[0][p[0]];
    			o[1] = cb_tab[1][p[1]];
    			o[2] = cb_tab[2][p[2]];
    		}
    
    		o[3] = cb_tab[3][p[3]];
    
    		p += 4; o += 4;
    	}
    }
    
    static void color_balance_float_float(StripColorBalance *cb_, float *rect_float, float *mask_rect_float, int width, int height, float mul)
    {
    	float *p = rect_float;
    	float *e = rect_float + width * 4 * height;
    	float *m = mask_rect_float;
    	StripColorBalance cb = calc_cb(cb_);
    
    	while (p < e) {
    		int c;
    		for (c = 0; c < 3; c++) {
    			float t = color_balance_fl(p[c], cb.lift[c], cb.gain[c], cb.gamma[c], mul);
    
    			if (m)
    				p[c] = p[c] * (1.0f - m[c]) + t * m[c];
    			else
    				p[c] = t;
    		}
    
    		p += 4;
    		if (m)
    			m += 4;
    	}
    }
    
    typedef struct ColorBalanceInitData {
    	StripColorBalance *cb;
    	ImBuf *ibuf;
    	float mul;
    	ImBuf *mask;
    	short make_float;
    } ColorBalanceInitData;
    
    typedef struct ColorBalanceThread {
    	StripColorBalance *cb;
    	float mul;
    
    	int width, height;
    
    	unsigned char *rect, *mask_rect;
    	float *rect_float, *mask_rect_float;
    
    	short make_float;
    } ColorBalanceThread;
    
    static void color_balance_init_handle(void *handle_v, int start_line, int tot_line, void *init_data_v)
    {
    	ColorBalanceThread *handle = (ColorBalanceThread *) handle_v;
    	ColorBalanceInitData *init_data = (ColorBalanceInitData *) init_data_v;
    	ImBuf *ibuf = init_data->ibuf;
    	ImBuf *mask = init_data->mask;
    
    	int offset = 4 * start_line * ibuf->x;
    
    	memset(handle, 0, sizeof(ColorBalanceThread));
    
    	handle->cb = init_data->cb;
    	handle->mul = init_data->mul;
    	handle->width = ibuf->x;
    	handle->height = tot_line;
    	handle->make_float = init_data->make_float;
    
    	if (ibuf->rect)
    		handle->rect = (unsigned char *) ibuf->rect + offset;
    
    	if (ibuf->rect_float)
    		handle->rect_float = ibuf->rect_float + offset;
    
    	if (mask) {
    		if (mask->rect)
    			handle->mask_rect = (unsigned char *) mask->rect + offset;
    
    		if (mask->rect_float)
    			handle->mask_rect_float = mask->rect_float + offset;
    	}
    	else {
    		handle->mask_rect = NULL;
    		handle->mask_rect_float = NULL;
    	}
    }
    
    static void *color_balance_do_thread(void *thread_data_v)
    {
    	ColorBalanceThread *thread_data = (ColorBalanceThread *) thread_data_v;
    	StripColorBalance *cb = thread_data->cb;
    	int width = thread_data->width, height = thread_data->height;
    	unsigned char *rect = thread_data->rect;
    	unsigned char *mask_rect = thread_data->mask_rect;
    	float *rect_float = thread_data->rect_float;
    	float *mask_rect_float = thread_data->mask_rect_float;
    	float mul = thread_data->mul;
    
    	if (rect_float) {
    		color_balance_float_float(cb, rect_float, mask_rect_float, width, height, mul);
    	}
    	else if (thread_data->make_float) {
    		color_balance_byte_float(cb, rect, rect_float, mask_rect, width, height, mul);
    	}
    	else {
    		color_balance_byte_byte(cb, rect, mask_rect, width, height, mul);
    	}
    
    	return NULL;
    }
    
    ImBuf *BKE_sequencer_render_mask_input(const SeqRenderData *context, int mask_input_type, Sequence *mask_sequence, Mask *mask_id, int cfra, int make_float)
    {
    	ImBuf *mask_input = NULL;
    
    	if (mask_input_type == SEQUENCE_MASK_INPUT_STRIP) {
    		if (mask_sequence) {
    			mask_input = seq_render_strip(context, mask_sequence, cfra);
    
    			if (make_float) {
    				if (!mask_input->rect_float)
    					IMB_float_from_rect(mask_input);
    			}
    			else {
    				if (!mask_input->rect)
    					IMB_rect_from_float(mask_input);
    			}
    		}
    	}
    	else if (mask_input_type == SEQUENCE_MASK_INPUT_ID) {
    		mask_input = seq_render_mask(context, mask_id, cfra, make_float);
    	}
    
    	return mask_input;
    }
    
    void BKE_sequencer_color_balance_apply(StripColorBalance *cb, ImBuf *ibuf, float mul, short make_float, ImBuf *mask_input)
    {
    	ColorBalanceInitData init_data;
    
    	if (!ibuf->rect_float && make_float)
    		imb_addrectfloatImBuf(ibuf);
    
    	init_data.cb = cb;
    	init_data.ibuf = ibuf;
    	init_data.mul = mul;
    	init_data.make_float = make_float;
    	init_data.mask = mask_input;
    
    	IMB_processor_apply_threaded(ibuf->y, sizeof(ColorBalanceThread), &init_data,
    	                             color_balance_init_handle, color_balance_do_thread);
    
    	/* color balance either happens on float buffer or byte buffer, but never on both,
    	 * free byte buffer if there's float buffer since float buffer would be used for
    	 * color balance in favor of byte buffer
    	 */
    	if (ibuf->rect_float && ibuf->rect)
    		imb_freerectImBuf(ibuf);
    }
    
    /*
     *  input preprocessing for SEQ_TYPE_IMAGE, SEQ_TYPE_MOVIE, SEQ_TYPE_MOVIECLIP and SEQ_TYPE_SCENE
     *
     *  Do all the things you can't really do afterwards using sequence effects
     *  (read: before rescaling to render resolution has been done)
     *
     *  Order is important!
     *
     *  - Deinterlace
     *  - Crop and transform in image source coordinate space
     *  - Flip X + Flip Y (could be done afterwards, backward compatibility)
     *  - Promote image to float data (affects pipeline operations afterwards)
     *  - Color balance (is most efficient in the byte -> float
     *    (future: half -> float should also work fine!)
     *    case, if done on load, since we can use lookup tables)
     *  - Premultiply
     */
    
    int BKE_sequencer_input_have_to_preprocess(const SeqRenderData *context, Sequence *seq, float UNUSED(cfra))
    {
    	float mul;
    
    	if (context->is_proxy_render) {
    		return FALSE;
    	}
    
    	if (seq->flag & (SEQ_FILTERY | SEQ_USE_CROP | SEQ_USE_TRANSFORM | SEQ_FLIPX | SEQ_FLIPY | SEQ_MAKE_FLOAT)) {
    		return TRUE;
    	}
    
    	mul = seq->mul;
    
    	if (seq->blend_mode == SEQ_BLEND_REPLACE) {
    		mul *= seq->blend_opacity / 100.0f;
    	}
    
    	if (mul != 1.0f) {
    		return TRUE;
    	}
    
    	if (seq->sat != 1.0f) {
    		return TRUE;
    	}
    
    	if (seq->modifiers.first) {
    		return TRUE;
    	}
    		
    	return FALSE;
    }
    
    static ImBuf *input_preprocess(const SeqRenderData *context, Sequence *seq, float cfra, ImBuf *ibuf,
                                   const bool is_proxy_image, const bool is_preprocessed)
    {
    	Scene *scene = context->scene;
    	float mul;
    
    	ibuf = IMB_makeSingleUser(ibuf);
    
    	if ((seq->flag & SEQ_FILTERY) &&
    	    !ELEM(seq->type, SEQ_TYPE_MOVIE, SEQ_TYPE_MOVIECLIP))
    	{
    		IMB_filtery(ibuf);
    	}
    
    	if (seq->flag & (SEQ_USE_CROP | SEQ_USE_TRANSFORM)) {
    		StripCrop c = {0};
    		StripTransform t = {0};
    		int sx, sy, dx, dy;
    
    		if (is_proxy_image) {
    			double f = seq_rendersize_to_scale_factor(context->preview_render_size);
    
    			if (f != 1.0) {
    				IMB_scalefastImBuf(ibuf, ibuf->x / f, ibuf->y / f);
    			}
    		}
    
    		if (seq->flag & SEQ_USE_CROP && seq->strip->crop) {
    			c = *seq->strip->crop;
    		}
    		if (seq->flag & SEQ_USE_TRANSFORM && seq->strip->transform) {
    			t = *seq->strip->transform;
    		}
    
    		if (is_preprocessed) {
    			double xscale = scene->r.xsch ? ((double)context->rectx / (double)scene->r.xsch) : 1.0;
    			double yscale = scene->r.ysch ? ((double)context->recty / (double)scene->r.ysch) : 1.0;
    			if (seq->flag & SEQ_USE_TRANSFORM) {
    				t.xofs *= xscale;
    				t.yofs *= yscale;
    			}
    			if (seq->flag & SEQ_USE_CROP) {
    				c.left *= xscale;
    				c.right *= xscale;
    				c.top *= yscale;
    				c.bottom *= yscale;
    			}
    		}
    
    		sx = ibuf->x - c.left - c.right;
    		sy = ibuf->y - c.top - c.bottom;
    
    		if (seq->flag & SEQ_USE_TRANSFORM) {
    			if (is_preprocessed) {
    				dx = context->rectx;
    				dy = context->recty;
    			}
    			else {
    				dx = scene->r.xsch;
    				dy = scene->r.ysch;
    			}
    		}
    		else {
    			dx = sx;
    			dy = sy;
    		}
    
    		if (c.top  + c.bottom >= ibuf->y ||
    		    c.left + c.right  >= ibuf->x ||
    		    t.xofs >= dx || t.yofs >= dy)
    		{
    			make_black_ibuf(ibuf);
    		}
    		else {
    			ImBuf *i = IMB_allocImBuf(dx, dy, 32, ibuf->rect_float ? IB_rectfloat : IB_rect);
    
    			IMB_rectcpy(i, ibuf, t.xofs, t.yofs, c.left, c.bottom, sx, sy);
    			sequencer_imbuf_assign_spaces(scene, i);
    
    			IMB_freeImBuf(ibuf);
    
    			ibuf = i;
    		}
    	}
    
    	if (seq->flag & SEQ_FLIPX) {
    		IMB_flipx(ibuf);
    	}
    	
    	if (seq->flag & SEQ_FLIPY) {
    		IMB_flipy(ibuf);
    	}
    
    	if (seq->sat != 1.0f) {
    		IMB_saturation(ibuf, seq->sat);
    	}
    
    	mul = seq->mul;
    
    	if (seq->blend_mode == SEQ_BLEND_REPLACE) {
    		mul *= seq->blend_opacity / 100.0f;
    	}
    
    	if (seq->flag & SEQ_MAKE_FLOAT) {
    		if (!ibuf->rect_float) {
    			BKE_sequencer_imbuf_to_sequencer_space(scene, ibuf, TRUE);
    		}
    
    		if (ibuf->rect) {
    			imb_freerectImBuf(ibuf);
    		}
    	}
    
    	if (mul != 1.0f) {
    		multibuf(ibuf, mul);
    	}
    
    	if (ibuf->x != context->rectx || ibuf->y != context->recty) {
    		if (scene->r.mode & R_OSA) {
    			IMB_scaleImBuf(ibuf, (short)context->rectx, (short)context->recty);
    		}
    		else {
    			IMB_scalefastImBuf(ibuf, (short)context->rectx, (short)context->recty);
    		}
    	}
    
    	if (seq->modifiers.first) {
    		ImBuf *ibuf_new = BKE_sequence_modifier_apply_stack(context, seq, ibuf, cfra);
    
    		if (ibuf_new != ibuf) {
    			IMB_freeImBuf(ibuf);
    			ibuf = ibuf_new;
    		}
    	}
    
    	return ibuf;
    }
    
    static ImBuf *copy_from_ibuf_still(const SeqRenderData *context, Sequence *seq, float nr)
    {
    	ImBuf *rval = NULL;
    	ImBuf *ibuf = NULL;
    
    	if (nr == 0) {
    		ibuf = BKE_sequencer_cache_get(context, seq, seq->start, SEQ_STRIPELEM_IBUF_STARTSTILL);
    	}
    	else if (nr == seq->len - 1) {
    		ibuf = BKE_sequencer_cache_get(context, seq, seq->start, SEQ_STRIPELEM_IBUF_ENDSTILL);
    	}
    
    	if (ibuf) {
    		rval = IMB_dupImBuf(ibuf);
    		IMB_freeImBuf(ibuf);
    	}
    
    	return rval;
    }
    
    static void copy_to_ibuf_still(const SeqRenderData *context, Sequence *seq, float nr, ImBuf *ibuf)
    {
    	/* warning: ibuf may be NULL if the video fails to load */
    	if (nr == 0 || nr == seq->len - 1) {
    		/* we have to store a copy, since the passed ibuf
    		 * could be preprocessed afterwards (thereby silently
    		 * changing the cached image... */
    		ibuf = IMB_dupImBuf(ibuf);
    
    		if (ibuf) {
    			sequencer_imbuf_assign_spaces(context->scene, ibuf);
    		}
    
    		if (nr == 0) {
    			BKE_sequencer_cache_put(context, seq, seq->start, SEQ_STRIPELEM_IBUF_STARTSTILL, ibuf);
    		}
    
    		if (nr == seq->len - 1) {
    			BKE_sequencer_cache_put(context, seq, seq->start, SEQ_STRIPELEM_IBUF_ENDSTILL, ibuf);
    		}
    
    		IMB_freeImBuf(ibuf);
    	}
    }
    
    /*********************** strip rendering functions  *************************/
    
    typedef struct RenderEffectInitData {
    	struct SeqEffectHandle *sh;
    	const SeqRenderData *context;
    	Sequence *seq;
    	float cfra, facf0, facf1;
    	ImBuf *ibuf1, *ibuf2, *ibuf3;
    
    	ImBuf *out;
    } RenderEffectInitData;
    
    typedef struct RenderEffectThread {
    	struct SeqEffectHandle *sh;
    	const SeqRenderData *context;
    	Sequence *seq;
    	float cfra, facf0, facf1;
    	ImBuf *ibuf1, *ibuf2, *ibuf3;
    
    	ImBuf *out;
    	int start_line, tot_line;
    } RenderEffectThread;
    
    static void render_effect_execute_init_handle(void *handle_v, int start_line, int tot_line, void *init_data_v)
    {
    	RenderEffectThread *handle = (RenderEffectThread *) handle_v;
    	RenderEffectInitData *init_data = (RenderEffectInitData *) init_data_v;
    
    	handle->sh = init_data->sh;
    	handle->context = init_data->context;
    	handle->seq = init_data->seq;
    	handle->cfra = init_data->cfra;
    	handle->facf0 = init_data->facf0;
    	handle->facf1 = init_data->facf1;
    	handle->ibuf1 = init_data->ibuf1;
    	handle->ibuf2 = init_data->ibuf2;
    	handle->ibuf3 = init_data->ibuf3;
    	handle->out = init_data->out;
    
    	handle->start_line = start_line;
    	handle->tot_line = tot_line;
    }
    
    static void *render_effect_execute_do_thread(void *thread_data_v)
    {
    	RenderEffectThread *thread_data = (RenderEffectThread *) thread_data_v;
    
    	thread_data->sh->execute_slice(thread_data->context, thread_data->seq, thread_data->cfra,
    	                               thread_data->facf0, thread_data->facf1, thread_data->ibuf1,
    	                               thread_data->ibuf2, thread_data->ibuf3, thread_data->start_line,
    	                               thread_data->tot_line, thread_data->out);
    
    	return NULL;
    }
    
    static ImBuf *seq_render_effect_execute_threaded(struct SeqEffectHandle *sh, const SeqRenderData *context, Sequence *seq,
                                                     float cfra, float facf0, float facf1,
                                                     ImBuf *ibuf1, ImBuf *ibuf2, ImBuf *ibuf3)
    {
    	RenderEffectInitData init_data;
    	ImBuf *out = sh->init_execution(context, ibuf1, ibuf2, ibuf3);
    
    	init_data.sh = sh;
    	init_data.context = context;
    	init_data.seq = seq;
    	init_data.cfra = cfra;
    	init_data.facf0 = facf0;
    	init_data.facf1 = facf1;
    	init_data.ibuf1 = ibuf1;
    	init_data.ibuf2 = ibuf2;
    	init_data.ibuf3 = ibuf3;
    	init_data.out = out;
    
    	IMB_processor_apply_threaded(out->y, sizeof(RenderEffectThread), &init_data,
                                     render_effect_execute_init_handle, render_effect_execute_do_thread);
    
    	return out;
    }
    
    static ImBuf *seq_render_effect_strip_impl(const SeqRenderData *context, Sequence *seq, float cfra)
    {
    	Scene *scene = context->scene;
    	float fac, facf;
    	int early_out;
    	int i;
    	struct SeqEffectHandle sh = BKE_sequence_get_effect(seq);
    	FCurve *fcu = NULL;
    	ImBuf *ibuf[3];
    	Sequence *input[3];
    	ImBuf *out = NULL;
    
    	ibuf[0] = ibuf[1] = ibuf[2] = NULL;
    
    	input[0] = seq->seq1; input[1] = seq->seq2; input[2] = seq->seq3;
    
    	if (!sh.execute && !(sh.execute_slice && sh.init_execution)) {
    		/* effect not supported in this version... */
    		out = IMB_allocImBuf(context->rectx, context->recty, 32, IB_rect);
    		return out;
    	}
    
    	if (seq->flag & SEQ_USE_EFFECT_DEFAULT_FADE) {
    		sh.get_default_fac(seq, cfra, &fac, &facf);
    		
    		if ((scene->r.mode & R_FIELDS) == 0)
    			facf = fac;
    	}
    	else {
    		fcu = id_data_find_fcurve(&scene->id, seq, &RNA_Sequence, "effect_fader", 0, NULL);
    		if (fcu) {
    			fac = facf = evaluate_fcurve(fcu, cfra);
    			if (scene->r.mode & R_FIELDS) {
    				facf = evaluate_fcurve(fcu, cfra + 0.5f);
    			}
    		}
    		else {
    			fac = facf = seq->effect_fader;
    		}
    	}
    
    	early_out = sh.early_out(seq, fac, facf);
    
    	switch (early_out) {
    		case EARLY_NO_INPUT:
    			out = sh.execute(context, seq, cfra, fac, facf, NULL, NULL, NULL);
    			break;
    		case EARLY_DO_EFFECT:
    			for (i = 0; i < 3; i++) {
    				if (input[i])
    					ibuf[i] = seq_render_strip(context, input[i], cfra);
    			}
    
    			if (ibuf[0] && ibuf[1]) {
    				if (sh.multithreaded)
    					out = seq_render_effect_execute_threaded(&sh, context, seq, cfra, fac, facf, ibuf[0], ibuf[1], ibuf[2]);
    				else
    					out = sh.execute(context, seq, cfra, fac, facf, ibuf[0], ibuf[1], ibuf[2]);
    			}
    			break;
    		case EARLY_USE_INPUT_1:
    			if (input[0]) {
    				ibuf[0] = seq_render_strip(context, input[0], cfra);
    			}
    			if (ibuf[0]) {
    				if (BKE_sequencer_input_have_to_preprocess(context, seq, cfra)) {
    					out = IMB_dupImBuf(ibuf[0]);
    				}
    				else {
    					out = ibuf[0];
    					IMB_refImBuf(out);
    				}
    			}
    			break;
    		case EARLY_USE_INPUT_2:
    			if (input[1]) {
    				ibuf[1] = seq_render_strip(context, input[1], cfra);
    			}
    			if (ibuf[1]) {
    				if (BKE_sequencer_input_have_to_preprocess(context, seq, cfra)) {
    					out = IMB_dupImBuf(ibuf[1]);
    				}
    				else {
    					out = ibuf[1];
    					IMB_refImBuf(out);
    				}
    			}
    			break;
    	}
    
    	for (i = 0; i < 3; i++) {
    		IMB_freeImBuf(ibuf[i]);
    	}
    
    	if (out == NULL) {
    		out = IMB_allocImBuf(context->rectx, context->recty, 32, IB_rect);
    	}
    
    	return out;
    }
    
    static ImBuf *seq_render_movieclip_strip(const SeqRenderData *context, Sequence *seq, float nr)
    {
    	ImBuf *ibuf = NULL;
    	MovieClipUser user;
    	float tloc[2], tscale, tangle;
    
    	if (!seq->clip) {
    		return NULL;
    	}
    
    	memset(&user, 0, sizeof(MovieClipUser));
    	
    	BKE_movieclip_user_set_frame(&user, nr + seq->anim_startofs + seq->clip->start_frame);
    
    	user.render_size = MCLIP_PROXY_RENDER_SIZE_FULL;
    
    	switch (seq_rendersize_to_proxysize(context->preview_render_size)) {
    		case IMB_PROXY_NONE:
    			user.render_size = MCLIP_PROXY_RENDER_SIZE_FULL;
    			break;
    		case IMB_PROXY_100:
    			user.render_size = MCLIP_PROXY_RENDER_SIZE_100;
    			break;
    		case IMB_PROXY_75:
    			user.render_size = MCLIP_PROXY_RENDER_SIZE_75;
    			break;
    		case IMB_PROXY_50:
    			user.render_size = MCLIP_PROXY_RENDER_SIZE_50;
    			break;
    		case IMB_PROXY_25:
    			user.render_size = MCLIP_PROXY_RENDER_SIZE_25;
    			break;
    	}
    
    	if (seq->clip_flag & SEQ_MOVIECLIP_RENDER_UNDISTORTED) {
    		user.render_flag = MCLIP_PROXY_RENDER_UNDISTORT;
    	}
    
    	if (seq->clip_flag & SEQ_MOVIECLIP_RENDER_STABILIZED) {
    		ibuf = BKE_movieclip_get_stable_ibuf(seq->clip, &user, tloc, &tscale, &tangle, 0);
    	}
    	else {
    		ibuf = BKE_movieclip_get_ibuf_flag(seq->clip, &user, 0, MOVIECLIP_CACHE_SKIP);
    	}
    
    	return ibuf;
    }
    
    
    static ImBuf *seq_render_mask(const SeqRenderData *context, Mask *mask, float nr, short make_float)
    {
    	/* TODO - add option to rasterize to alpha imbuf? */
    	ImBuf *ibuf = NULL;
    	float *maskbuf;
    	int i;
    
    	if (!mask) {
    		return NULL;
    	}
    	else {
    		Mask *mask_temp;
    		MaskRasterHandle *mr_handle;
    
    		mask_temp = BKE_mask_copy_nolib(mask);
    
    		BKE_mask_evaluate(mask_temp, mask->sfra + nr, true);
    
    		maskbuf = MEM_mallocN(sizeof(float) * context->rectx * context->recty, __func__);
    
    		mr_handle = BKE_maskrasterize_handle_new();
    
    		BKE_maskrasterize_handle_init(mr_handle, mask_temp, context->rectx, context->recty, TRUE, TRUE, TRUE);
    
    		BKE_mask_free_nolib(mask_temp);
    		MEM_freeN(mask_temp);
    
    		BKE_maskrasterize_buffer(mr_handle, context->rectx, context->recty, maskbuf);
    
    		BKE_maskrasterize_handle_free(mr_handle);
    	}
    
    
    	if (make_float) {
    		/* pixels */
    		float *fp_src;
    		float *fp_dst;
    
    		ibuf = IMB_allocImBuf(context->rectx, context->recty, 32, IB_rectfloat);
    
    		fp_src = maskbuf;
    		fp_dst = ibuf->rect_float;
    		i = context->rectx * context->recty;
    		while (--i) {
    			fp_dst[0] = fp_dst[1] = fp_dst[2] = *fp_src;
    			fp_dst[3] = 1.0f;
    
    			fp_src += 1;
    			fp_dst += 4;
    		}
    	}
    	else {
    		/* pixels */
    		float *fp_src;
    		unsigned char *ub_dst;
    
    		ibuf = IMB_allocImBuf(context->rectx, context->recty, 32, IB_rect);
    
    		fp_src = maskbuf;
    		ub_dst = (unsigned char *)ibuf->rect;
    		i = context->rectx * context->recty;
    		while (--i) {
    			ub_dst[0] = ub_dst[1] = ub_dst[2] = (unsigned char)(*fp_src * 255.0f); /* already clamped */
    			ub_dst[3] = 255;
    
    			fp_src += 1;
    			ub_dst += 4;
    		}
    	}
    
    	MEM_freeN(maskbuf);
    
    	return ibuf;
    }
    
    static ImBuf *seq_render_mask_strip(const SeqRenderData *context, Sequence *seq, float nr)
    {
    	short make_float = seq->flag & SEQ_MAKE_FLOAT;
    
    	return seq_render_mask(context, seq->mask, nr, make_float);
    }
    
    static ImBuf *seq_render_scene_strip(const SeqRenderData *context, Sequence *seq, float nr)
    {
    	ImBuf *ibuf = NULL;
    	float frame;
    	float oldcfra;
    	Object *camera;
    	ListBase oldmarkers;
    	
    	/* Old info:
    	 * Hack! This function can be called from do_render_seq(), in that case
    	 * the seq->scene can already have a Render initialized with same name,
    	 * so we have to use a default name. (compositor uses scene name to
    	 * find render).
    	 * However, when called from within the UI (image preview in sequencer)
    	 * we do want to use scene Render, that way the render result is defined
    	 * for display in render/imagewindow
    	 *
    	 * Hmm, don't see, why we can't do that all the time,
    	 * and since G.is_rendering is uhm, gone... (Peter)
    	 */
    
    	/* New info:
    	 * Using the same name for the renders works just fine as the do_render_seq()
    	 * render is not used while the scene strips are rendered.
    	 *
    	 * However rendering from UI (through sequencer_preview_area_draw) can crash in
    	 * very many cases since other renders (material preview, an actual render etc.)
    	 * can be started while this sequence preview render is running. The only proper
    	 * solution is to make the sequencer preview render a proper job, which can be
    	 * stopped when needed. This would also give a nice progress bar for the preview
    	 * space so that users know there's something happening.
    	 *
    	 * As a result the active scene now only uses OpenGL rendering for the sequencer
    	 * preview. This is far from nice, but is the only way to prevent crashes at this
    	 * time.
    	 *
    	 * -jahka
    	 */
    
    	const bool is_rendering = G.is_rendering;
    	const bool  is_background = G.background;
    	const bool do_seq_gl = is_rendering ?
    	        0 /* (context->scene->r.seq_flag & R_SEQ_GL_REND) */ :
    	        (context->scene->r.seq_flag & R_SEQ_GL_PREV) != 0;
    	int do_seq;
    	// int have_seq = FALSE;  /* UNUSED */
    	int have_comp = FALSE;
    	Scene *scene;
    	int is_thread_main = BLI_thread_is_main();
    
    	/* don't refer to seq->scene above this point!, it can be NULL */
    	if (seq->scene == NULL) {
    		return NULL;
    	}
    
    	scene = seq->scene;
    	frame = scene->r.sfra + nr + seq->anim_startofs;
    
    	// have_seq = (scene->r.scemode & R_DOSEQ) && scene->ed && scene->ed->seqbase.first;  /* UNUSED */
    	have_comp = (scene->r.scemode & R_DOCOMP) && scene->use_nodes && scene->nodetree;
    
    	oldcfra = scene->r.cfra;
    	scene->r.cfra = frame;
    
    	if (seq->scene_camera) {
    		camera = seq->scene_camera;
    	}
    	else {
    		BKE_scene_camera_switch_update(scene);
    		camera = scene->camera;
    	}
    
    	if (have_comp == FALSE && camera == NULL) {
    		scene->r.cfra = oldcfra;
    		return NULL;
    	}
    
    	/* prevent eternal loop */
    	do_seq = context->scene->r.scemode & R_DOSEQ;
    	scene->r.scemode &= ~R_DOSEQ;
    	
    #ifdef DURIAN_CAMERA_SWITCH
    	/* stooping to new low's in hackyness :( */
    	oldmarkers = scene->markers;
    	BLI_listbase_clear(&scene->markers);
    #else
    	(void)oldmarkers;
    #endif
    
    	if ((sequencer_view3d_cb && do_seq_gl && camera) && is_thread_main) {
    		char err_out[256] = "unknown";
    		/* for old scened this can be uninitialized,
    		 * should probably be added to do_versions at some point if the functionality stays */
    		if (context->scene->r.seq_prev_type == 0)
    			context->scene->r.seq_prev_type = 3 /* == OB_SOLID */;
    
    		/* opengl offscreen render */
    		BKE_scene_update_for_newframe(context->eval_ctx, context->bmain, scene, scene->lay);
    		ibuf = sequencer_view3d_cb(scene, camera, context->rectx, context->recty, IB_rect,
    		                           context->scene->r.seq_prev_type, context->scene->r.seq_flag & R_SEQ_SOLID_TEX,
    		                           TRUE, scene->r.alphamode, err_out);
    		if (ibuf == NULL) {
    			fprintf(stderr, "seq_render_scene_strip failed to get opengl buffer: %s\n", err_out);
    		}
    	}
    	else {
    		Render *re = RE_GetRender(scene->id.name);
    		RenderResult rres;
    
    		/* XXX: this if can be removed when sequence preview rendering uses the job system
    		 *
    		 * disable rendered preview for sequencer while rendering -- it's very much possible
    		 * that preview render will went into conflict with final render
    		 *
    		 * When rendering from command line renderer is called from main thread, in this
    		 * case it's always safe to render scene here
    		 */
    		if (!is_thread_main || is_rendering == FALSE || is_background) {
    			if (re == NULL)
    				re = RE_NewRender(scene->id.name);
    
    			BKE_scene_update_for_newframe(context->eval_ctx, context->bmain, scene, scene->lay);
    			RE_BlenderFrame(re, context->bmain, scene, NULL, camera, scene->lay, frame, FALSE);
    
    			/* restore previous state after it was toggled on & off by RE_BlenderFrame */
    			G.is_rendering = is_rendering;
    		}
    		
    		RE_AcquireResultImage(re, &rres);
    		
    		if (rres.rectf) {
    			ibuf = IMB_allocImBuf(rres.rectx, rres.recty, 32, IB_rectfloat);
    			memcpy(ibuf->rect_float, rres.rectf, 4 * sizeof(float) * rres.rectx * rres.recty);
    			if (rres.rectz) {
    				addzbuffloatImBuf(ibuf);
    				memcpy(ibuf->zbuf_float, rres.rectz, sizeof(float) * rres.rectx * rres.recty);
    			}
    
    			/* float buffers in the sequencer are not linear */
    			BKE_sequencer_imbuf_to_sequencer_space(context->scene, ibuf, FALSE);
    		}
    		else if (rres.rect32) {
    			ibuf = IMB_allocImBuf(rres.rectx, rres.recty, 32, IB_rect);
    			memcpy(ibuf->rect, rres.rect32, 4 * rres.rectx * rres.recty);
    		}
    		
    		RE_ReleaseResultImage(re);
    		
    		// BIF_end_render_callbacks();
    	}
    	
    	/* restore */
    	scene->r.scemode |= do_seq;
    	
    	scene->r.cfra = oldcfra;
    
    	if (frame != oldcfra) {
    		BKE_scene_update_for_newframe(context->eval_ctx, context->bmain, scene, scene->lay);
    	}
    	
    #ifdef DURIAN_CAMERA_SWITCH
    	/* stooping to new low's in hackyness :( */
    	scene->markers = oldmarkers;
    #endif
    
    	return ibuf;
    }
    
    static ImBuf *do_render_strip_uncached(const SeqRenderData *context, Sequence *seq, float cfra)
    {
    	ImBuf *ibuf = NULL;
    	float nr = give_stripelem_index(seq, cfra);
    	int type = (seq->type & SEQ_TYPE_EFFECT && seq->type != SEQ_TYPE_SPEED) ? SEQ_TYPE_EFFECT : seq->type;
    	int use_preprocess = BKE_sequencer_input_have_to_preprocess(context, seq, cfra);
    	char name[FILE_MAX];
    
    	switch (type) {
    		case SEQ_TYPE_META:
    		{
    			ImBuf *meta_ibuf = NULL;
    
    			if (seq->seqbase.first)
    				meta_ibuf = seq_render_strip_stack(context, &seq->seqbase, seq->start + nr, 0);
    
    			if (meta_ibuf) {
    				ibuf = meta_ibuf;
    				if (ibuf && use_preprocess) {
    					ImBuf *i = IMB_dupImBuf(ibuf);
    
    					IMB_freeImBuf(ibuf);
    
    					ibuf = i;
    				}
    			}
    
    			break;
    		}
    
    		case SEQ_TYPE_SPEED:
    		{
    			ImBuf *child_ibuf = NULL;
    
    			float f_cfra;
    			SpeedControlVars *s = (SpeedControlVars *)seq->effectdata;
    
    			BKE_sequence_effect_speed_rebuild_map(context->scene, seq, 0);
    
    			/* weeek! */
    			f_cfra = seq->start + s->frameMap[(int)nr];
    
    			child_ibuf = seq_render_strip(context, seq->seq1, f_cfra);
    
    			if (child_ibuf) {
    				ibuf = child_ibuf;
    				if (ibuf && use_preprocess) {
    					ImBuf *i = IMB_dupImBuf(ibuf);
    
    					IMB_freeImBuf(ibuf);
    
    					ibuf = i;
    				}
    			}
    			break;
    		}
    
    		case SEQ_TYPE_EFFECT:
    		{
    			ibuf = seq_render_effect_strip_impl(context, seq, seq->start + nr);
    			break;
    		}
    
    		case SEQ_TYPE_IMAGE:
    		{
    			StripElem *s_elem = BKE_sequencer_give_stripelem(seq, cfra);
    			int flag;
    
    			if (s_elem) {
    				BLI_join_dirfile(name, sizeof(name), seq->strip->dir, s_elem->name);
    				BLI_path_abs(name, G.main->name);
    			}
    
    			flag = IB_rect;
    			if (seq->alpha_mode == SEQ_ALPHA_PREMUL)
    				flag |= IB_alphamode_premul;
    
    			if (s_elem && (ibuf = IMB_loadiffname(name, flag, seq->strip->colorspace_settings.name))) {
    				/* we don't need both (speed reasons)! */
    				if (ibuf->rect_float && ibuf->rect)
    					imb_freerectImBuf(ibuf);
    
    				/* all sequencer color is done in SRGB space, linear gives odd crossfades */
    				BKE_sequencer_imbuf_to_sequencer_space(context->scene, ibuf, FALSE);
    
    				copy_to_ibuf_still(context, seq, nr, ibuf);
    
    				s_elem->orig_width  = ibuf->x;
    				s_elem->orig_height = ibuf->y;
    			}
    			break;
    		}
    
    		case SEQ_TYPE_MOVIE:
    		{
    			seq_open_anim_file(seq);
    
    			if (seq->anim) {
    				IMB_anim_set_preseek(seq->anim, seq->anim_preseek);
    
    				ibuf = IMB_anim_absolute(seq->anim, nr + seq->anim_startofs,
    				                         seq->strip->proxy ? seq->strip->proxy->tc : IMB_TC_RECORD_RUN,
    				                         seq_rendersize_to_proxysize(context->preview_render_size));
    
    				if (ibuf) {
    					BKE_sequencer_imbuf_to_sequencer_space(context->scene, ibuf, FALSE);
    
    					/* we don't need both (speed reasons)! */
    					if (ibuf->rect_float && ibuf->rect) {
    						imb_freerectImBuf(ibuf);
    					}
    
    					seq->strip->stripdata->orig_width = ibuf->x;
    					seq->strip->stripdata->orig_height = ibuf->y;
    				}
    			}
    			copy_to_ibuf_still(context, seq, nr, ibuf);
    			break;
    		}
    
    		case SEQ_TYPE_SCENE:
    		{
    			/* scene can be NULL after deletions */
    			ibuf = seq_render_scene_strip(context, seq, nr);
    
    			/* Scene strips update all animation, so we need to restore original state.*/
    			BKE_animsys_evaluate_all_animation(context->bmain, context->scene, cfra);
    
    			copy_to_ibuf_still(context, seq, nr, ibuf);
    			break;
    		}
    
    		case SEQ_TYPE_MOVIECLIP:
    		{
    			ibuf = seq_render_movieclip_strip(context, seq, nr);
    
    			if (ibuf) {
    				/* duplicate frame so movie cache wouldn't be confused by sequencer's stuff */
    				ImBuf *i = IMB_dupImBuf(ibuf);
    				IMB_freeImBuf(ibuf);
    				ibuf = i;
    
    				if (ibuf->rect_float)
    					BKE_sequencer_imbuf_to_sequencer_space(context->scene, ibuf, FALSE);
    
    				copy_to_ibuf_still(context, seq, nr, ibuf);
    			}
    
    			break;
    		}
    
    		case SEQ_TYPE_MASK:
    		{
    			/* ibuf is alwats new */
    			ibuf = seq_render_mask_strip(context, seq, nr);
    
    			copy_to_ibuf_still(context, seq, nr, ibuf);
    			break;
    		}
    	}
    
    	if (ibuf)
    		sequencer_imbuf_assign_spaces(context->scene, ibuf);
    
    	return ibuf;
    }
    
    static ImBuf *seq_render_strip(const SeqRenderData *context, Sequence *seq, float cfra)
    {
    	ImBuf *ibuf = NULL;
    	bool use_preprocess = false;
    	bool is_proxy_image = false;
    	float nr = give_stripelem_index(seq, cfra);
    	/* all effects are handled similarly with the exception of speed effect */
    	int type = (seq->type & SEQ_TYPE_EFFECT && seq->type != SEQ_TYPE_SPEED) ? SEQ_TYPE_EFFECT : seq->type;
    	bool is_preprocessed = !ELEM3(type, SEQ_TYPE_IMAGE, SEQ_TYPE_MOVIE, SEQ_TYPE_SCENE);
    
    	ibuf = BKE_sequencer_cache_get(context, seq, cfra, SEQ_STRIPELEM_IBUF);
    
    	if (ibuf == NULL) {
    		if (ibuf == NULL)
    			ibuf = copy_from_ibuf_still(context, seq, nr);
    
    		if (ibuf == NULL) {
    			ibuf = BKE_sequencer_preprocessed_cache_get(context, seq, cfra, SEQ_STRIPELEM_IBUF);
    
    			if (ibuf == NULL) {
    				/* MOVIECLIPs have their own proxy management */
    				if (ibuf == NULL && seq->type != SEQ_TYPE_MOVIECLIP) {
    					ibuf = seq_proxy_fetch(context, seq, cfra);
    					is_proxy_image = (ibuf != NULL);
    				}
    
    				if (ibuf == NULL)
    					ibuf = do_render_strip_uncached(context, seq, cfra);
    
    				if (ibuf) {
    					if (ELEM(seq->type, SEQ_TYPE_MOVIE, SEQ_TYPE_MOVIECLIP)) {
    						is_proxy_image = (context->preview_render_size != 100);
    					}
    					BKE_sequencer_preprocessed_cache_put(context, seq, cfra, SEQ_STRIPELEM_IBUF, ibuf);
    				}
    			}
    		}
    
    		if (ibuf)
    			use_preprocess = BKE_sequencer_input_have_to_preprocess(context, seq, cfra);
    	}
    	else {
    		/* currently, we cache preprocessed images in SEQ_STRIPELEM_IBUF,
    		 * but not(!) on SEQ_STRIPELEM_IBUF_ENDSTILL and ..._STARTSTILL
    		 * so, no need in check for preprocess here
    		 */
    	}
    
    	if (ibuf == NULL) {
    		ibuf = IMB_allocImBuf(context->rectx, context->recty, 32, IB_rect);
    		sequencer_imbuf_assign_spaces(context->scene, ibuf);
    	}
    
    	if (context->is_proxy_render == false &&
    	    (ibuf->x != context->rectx || ibuf->y != context->recty))
    	{
    		use_preprocess = TRUE;
    	}
    
    	if (use_preprocess)
    		ibuf = input_preprocess(context, seq, cfra, ibuf, is_proxy_image, is_preprocessed);
    
    	BKE_sequencer_cache_put(context, seq, cfra, SEQ_STRIPELEM_IBUF, ibuf);
    
    	return ibuf;
    }
    
    /*********************** strip stack rendering functions *************************/
    
    static bool seq_must_swap_input_in_blend_mode(Sequence *seq)
    {
    	bool swap_input = FALSE;
    
    	/* bad hack, to fix crazy input ordering of 
    	 * those two effects */
    
    	if (ELEM3(seq->blend_mode, SEQ_TYPE_ALPHAOVER, SEQ_TYPE_ALPHAUNDER, SEQ_TYPE_OVERDROP)) {
    		swap_input = TRUE;
    	}
    	
    	return swap_input;
    }
    
    static int seq_get_early_out_for_blend_mode(Sequence *seq)
    {
    	struct SeqEffectHandle sh = BKE_sequence_get_blend(seq);
    	float facf = seq->blend_opacity / 100.0f;
    	int early_out = sh.early_out(seq, facf, facf);
    
    	if (ELEM(early_out, EARLY_DO_EFFECT, EARLY_NO_INPUT)) {
    		return early_out;
    	}
    
    	if (seq_must_swap_input_in_blend_mode(seq)) {
    		if (early_out == EARLY_USE_INPUT_2) {
    			return EARLY_USE_INPUT_1;
    		}
    		else if (early_out == EARLY_USE_INPUT_1) {
    			return EARLY_USE_INPUT_2;
    		}
    	}
    	return early_out;
    }
    
    static ImBuf *seq_render_strip_stack_apply_effect(const SeqRenderData *context, Sequence *seq,
                                                      float cfra, ImBuf *ibuf1, ImBuf *ibuf2)
    {
    	ImBuf *out;
    	struct SeqEffectHandle sh = BKE_sequence_get_blend(seq);
    	float facf = seq->blend_opacity / 100.0f;
    	int swap_input = seq_must_swap_input_in_blend_mode(seq);
    
    	if (swap_input) {
    		if (sh.multithreaded)
    			out = seq_render_effect_execute_threaded(&sh, context, seq, cfra, facf, facf, ibuf2, ibuf1, NULL);
    		else
    			out = sh.execute(context, seq, cfra, facf, facf, ibuf2, ibuf1, NULL);
    	}
    	else {
    		if (sh.multithreaded)
    			out = seq_render_effect_execute_threaded(&sh, context, seq, cfra, facf, facf, ibuf1, ibuf2, NULL);
    		else
    			out = sh.execute(context, seq, cfra, facf, facf, ibuf1, ibuf2, NULL);
    	}
    
    	return out;
    }
    
    static ImBuf *seq_render_strip_stack(const SeqRenderData *context, ListBase *seqbasep, float cfra, int chanshown)
    {
    	Sequence *seq_arr[MAXSEQ + 1];
    	int count;
    	int i;
    	ImBuf *out = NULL;
    
    	count = get_shown_sequences(seqbasep, cfra, chanshown, (Sequence **)&seq_arr);
    
    	if (count == 0) {
    		return NULL;
    	}
    
    #if 0 /* commentind since this breaks keyframing, since it resets the value on draw */
    	if (scene->r.cfra != cfra) {
    		/* XXX for prefetch and overlay offset!..., very bad!!! */
    		AnimData *adt = BKE_animdata_from_id(&scene->id);
    		BKE_animsys_evaluate_animdata(scene, &scene->id, adt, cfra, ADT_RECALC_ANIM);
    	}
    #endif
    
    	out = BKE_sequencer_cache_get(context, seq_arr[count - 1],  cfra, SEQ_STRIPELEM_IBUF_COMP);
    
    	if (out) {
    		return out;
    	}
    	
    	if (count == 1) {
    		Sequence *seq = seq_arr[0];
    
    		/* Some of the blend modes are unclear how to apply with only single input,
    		 * or some of them will just produce an empty result..
    		 */
    		if (ELEM3(seq->blend_mode, SEQ_BLEND_REPLACE, SEQ_TYPE_CROSS, SEQ_TYPE_ALPHAOVER)) {
    			int early_out;
    			if (seq->blend_mode == SEQ_BLEND_REPLACE) {
    				early_out = EARLY_NO_INPUT;
    			}
    			else {
    				early_out = seq_get_early_out_for_blend_mode(seq);
    			}
    
    			if (ELEM(early_out, EARLY_NO_INPUT, EARLY_USE_INPUT_2)) {
    				out = seq_render_strip(context, seq, cfra);
    			}
    			else if (early_out == EARLY_USE_INPUT_1) {
    				out = IMB_allocImBuf(context->rectx, context->recty, 32, IB_rect);
    			}
    			else {
    				out = seq_render_strip(context, seq, cfra);
    
    				if (early_out == EARLY_DO_EFFECT) {
    					ImBuf *ibuf1 = IMB_allocImBuf(context->rectx, context->recty, 32,
    					                              out->rect_float ? IB_rectfloat : IB_rect);
    					ImBuf *ibuf2 = out;
    
    					out = seq_render_strip_stack_apply_effect(context, seq, cfra, ibuf1, ibuf2);
    
    					IMB_freeImBuf(ibuf1);
    					IMB_freeImBuf(ibuf2);
    				}
    			}
    		}
    		else {
    			out = seq_render_strip(context, seq, cfra);
    		}
    
    		BKE_sequencer_cache_put(context, seq, cfra, SEQ_STRIPELEM_IBUF_COMP, out);
    
    		return out;
    	}
    
    	for (i = count - 1; i >= 0; i--) {
    		int early_out;
    		Sequence *seq = seq_arr[i];
    
    		out = BKE_sequencer_cache_get(context, seq, cfra, SEQ_STRIPELEM_IBUF_COMP);
    
    		if (out) {
    			break;
    		}
    		if (seq->blend_mode == SEQ_BLEND_REPLACE) {
    			out = seq_render_strip(context, seq, cfra);
    			break;
    		}
    
    		early_out = seq_get_early_out_for_blend_mode(seq);
    
    		switch (early_out) {
    			case EARLY_NO_INPUT:
    			case EARLY_USE_INPUT_2:
    				out = seq_render_strip(context, seq, cfra);
    				break;
    			case EARLY_USE_INPUT_1:
    				if (i == 0) {
    					out = IMB_allocImBuf(context->rectx, context->recty, 32, IB_rect);
    				}
    				break;
    			case EARLY_DO_EFFECT:
    				if (i == 0) {
    					out = seq_render_strip(context, seq, cfra);
    				}
    
    				break;
    		}
    		if (out) {
    			break;
    		}
    	}
    
    	BKE_sequencer_cache_put(context, seq_arr[i], cfra, SEQ_STRIPELEM_IBUF_COMP, out);
    
    	i++;
    
    	for (; i < count; i++) {
    		Sequence *seq = seq_arr[i];
    
    		if (seq_get_early_out_for_blend_mode(seq) == EARLY_DO_EFFECT) {
    			ImBuf *ibuf1 = out;
    			ImBuf *ibuf2 = seq_render_strip(context, seq, cfra);
    
    			out = seq_render_strip_stack_apply_effect(context, seq, cfra, ibuf1, ibuf2);
    
    			IMB_freeImBuf(ibuf1);
    			IMB_freeImBuf(ibuf2);
    		}
    
    		BKE_sequencer_cache_put(context, seq_arr[i], cfra, SEQ_STRIPELEM_IBUF_COMP, out);
    	}
    
    	return out;
    }
    
    /*
     * returned ImBuf is refed!
     * you have to free after usage!
     */
    
    ImBuf *BKE_sequencer_give_ibuf(const SeqRenderData *context, float cfra, int chanshown)
    {
    	Editing *ed = BKE_sequencer_editing_get(context->scene, FALSE);
    	int count;
    	ListBase *seqbasep;
    	
    	if (ed == NULL) return NULL;
    
    	count = BLI_countlist(&ed->metastack);
    	if ((chanshown < 0) && (count > 0)) {
    		count = max_ii(count + chanshown, 0);
    		seqbasep = ((MetaStack *)BLI_findlink(&ed->metastack, count))->oldbasep;
    	}
    	else {
    		seqbasep = ed->seqbasep;
    	}
    
    	return seq_render_strip_stack(context, seqbasep, cfra, chanshown);
    }
    
    ImBuf *BKE_sequencer_give_ibuf_seqbase(const SeqRenderData *context, float cfra, int chanshown, ListBase *seqbasep)
    {
    	return seq_render_strip_stack(context, seqbasep, cfra, chanshown);
    }
    
    
    ImBuf *BKE_sequencer_give_ibuf_direct(const SeqRenderData *context, float cfra, Sequence *seq)
    {
    	return seq_render_strip(context, seq, cfra);
    }
    
    /* *********************** threading api ******************* */
    
    static ListBase running_threads;
    static ListBase prefetch_wait;
    static ListBase prefetch_done;
    
    static pthread_mutex_t queue_lock          = PTHREAD_MUTEX_INITIALIZER;
    static pthread_mutex_t wakeup_lock         = PTHREAD_MUTEX_INITIALIZER;
    static pthread_cond_t wakeup_cond          = PTHREAD_COND_INITIALIZER;
    
    //static pthread_mutex_t prefetch_ready_lock = PTHREAD_MUTEX_INITIALIZER;
    //static pthread_cond_t  prefetch_ready_cond = PTHREAD_COND_INITIALIZER;
    
    static pthread_mutex_t frame_done_lock     = PTHREAD_MUTEX_INITIALIZER;
    static pthread_cond_t frame_done_cond      = PTHREAD_COND_INITIALIZER;
    
    static volatile int seq_thread_shutdown = TRUE; 
    static volatile int seq_last_given_monoton_cfra = 0;
    static int monoton_cfra = 0;
    
    typedef struct PrefetchThread {
    	struct PrefetchThread *next, *prev;
    	
    	Scene *scene;
    	struct PrefetchQueueElem *current;
    	pthread_t pthread;
    	int running;
    	
    } PrefetchThread;
    
    typedef struct PrefetchQueueElem {
    	struct PrefetchQueueElem *next, *prev;
    	
    	int rectx;
    	int recty;
    	float cfra;
    	int chanshown;
    	int preview_render_size;
    
    	int monoton_cfra;
    
    	ImBuf *ibuf;
    } PrefetchQueueElem;
    
    void BKE_sequencer_give_ibuf_prefetch_request(const SeqRenderData *context, float cfra, int chanshown)
    {
    	PrefetchQueueElem *e;
    	if (seq_thread_shutdown) {
    		return;
    	}
    
    	e = MEM_callocN(sizeof(PrefetchQueueElem), "prefetch_queue_elem");
    	e->rectx = context->rectx;
    	e->recty = context->recty;
    	e->cfra = cfra;
    	e->chanshown = chanshown;
    	e->preview_render_size = context->preview_render_size;
    	e->monoton_cfra = monoton_cfra++;
    
    	pthread_mutex_lock(&queue_lock);
    	BLI_addtail(&prefetch_wait, e);
    	pthread_mutex_unlock(&queue_lock);
    	
    	pthread_mutex_lock(&wakeup_lock);
    	pthread_cond_signal(&wakeup_cond);
    	pthread_mutex_unlock(&wakeup_lock);
    }
    
    ImBuf *BKE_sequencer_give_ibuf_threaded(const SeqRenderData *context, float cfra, int chanshown)
    {
    	PrefetchQueueElem *e = NULL;
    	int found_something = FALSE;
    
    	if (seq_thread_shutdown) {
    		return BKE_sequencer_give_ibuf(context, cfra, chanshown);
    	}
    
    	while (!e) {
    		int success = FALSE;
    		pthread_mutex_lock(&queue_lock);
    
    		for (e = prefetch_done.first; e; e = e->next) {
    			if (cfra == e->cfra &&
    			    chanshown == e->chanshown &&
    			    context->rectx == e->rectx &&
    			    context->recty == e->recty &&
    			    context->preview_render_size == e->preview_render_size)
    			{
    				success = TRUE;
    				found_something = TRUE;
    				break;
    			}
    		}
    
    		if (!e) {
    			for (e = prefetch_wait.first; e; e = e->next) {
    				if (cfra == e->cfra &&
    				    chanshown == e->chanshown &&
    				    context->rectx == e->rectx &&
    				    context->recty == e->recty &&
    				    context->preview_render_size == e->preview_render_size)
    				{
    					found_something = TRUE;
    					break;
    				}
    			}
    		}
    
    		if (!e) {
    			PrefetchThread *tslot;
    
    			for (tslot = running_threads.first;
    			     tslot;
    			     tslot = tslot->next)
    			{
    				if (tslot->current &&
    				    cfra == tslot->current->cfra &&
    				    chanshown == tslot->current->chanshown &&
    				    context->rectx == tslot->current->rectx &&
    				    context->recty == tslot->current->recty &&
    				    context->preview_render_size == tslot->current->preview_render_size)
    				{
    					found_something = TRUE;
    					break;
    				}
    			}
    		}
    
    		/* e->ibuf is unrefed by render thread on next round. */
    
    		if (e) {
    			seq_last_given_monoton_cfra = e->monoton_cfra;
    		}
    
    		pthread_mutex_unlock(&queue_lock);
    
    		if (!success) {
    			e = NULL;
    
    			if (!found_something) {
    				fprintf(stderr, "SEQ-THREAD: Requested frame not in queue ???\n");
    				break;
    			}
    			pthread_mutex_lock(&frame_done_lock);
    			pthread_cond_wait(&frame_done_cond, &frame_done_lock);
    			pthread_mutex_unlock(&frame_done_lock);
    		}
    	}
    	
    	return e ? e->ibuf : NULL;
    }
    
    /* Functions to free imbuf and anim data on changes */
    
    static void free_anim_seq(Sequence *seq)
    {
    	if (seq->anim) {
    		IMB_free_anim(seq->anim);
    		seq->anim = NULL;
    	}
    }
    
    /* check whether sequence cur depends on seq */
    bool BKE_sequence_check_depend(Sequence *seq, Sequence *cur)
    {
    	if (cur->seq1 == seq || cur->seq2 == seq || cur->seq3 == seq)
    		return true;
    
    	/* sequences are not intersecting in time, assume no dependency exists between them */
    	if (cur->enddisp < seq->startdisp || cur->startdisp > seq->enddisp)
    		return false;
    
    	/* checking sequence is below reference one, not dependent on it */
    	if (cur->machine < seq->machine)
    		return false;
    
    	/* sequence is not blending with lower machines, no dependency here occurs
    	 * check for non-effects only since effect could use lower machines as input
    	 */
    	if ((cur->type & SEQ_TYPE_EFFECT) == 0 &&
    	    ((cur->blend_mode == SEQ_BLEND_REPLACE) ||
    	     (cur->blend_mode == SEQ_TYPE_CROSS && cur->blend_opacity == 100.0f)))
    	{
    		return false;
    	}
    
    	return true;
    }
    
    static void sequence_do_invalidate_dependent(Sequence *seq, ListBase *seqbase)
    {
    	Sequence *cur;
    
    	for (cur = seqbase->first; cur; cur = cur->next) {
    		if (cur == seq)
    			continue;
    
    		if (BKE_sequence_check_depend(seq, cur)) {
    			BKE_sequencer_cache_cleanup_sequence(cur);
    			BKE_sequencer_preprocessed_cache_cleanup_sequence(cur);
    		}
    
    		if (cur->seqbase.first)
    			sequence_do_invalidate_dependent(seq, &cur->seqbase);
    	}
    }
    
    static void sequence_invalidate_cache(Scene *scene, Sequence *seq, int invalidate_self, int invalidate_preprocess)
    {
    	Editing *ed = scene->ed;
    
    	/* invalidate cache for current sequence */
    	if (invalidate_self) {
    		if (seq->anim) {
    			/* Animation structure holds some buffers inside,
    			 * so for proper cache invalidation we need to
    			 * re-open the animation.
    			 */
    			IMB_free_anim(seq->anim);
    			seq->anim = NULL;
    		}
    
    		BKE_sequencer_cache_cleanup_sequence(seq);
    	}
    
    	/* if invalidation is invoked from sequence free routine, effectdata would be NULL here */
    	if (seq->effectdata && seq->type == SEQ_TYPE_SPEED)
    		BKE_sequence_effect_speed_rebuild_map(scene, seq, TRUE);
    
    	if (invalidate_preprocess)
    		BKE_sequencer_preprocessed_cache_cleanup_sequence(seq);
    
    	/* invalidate cache for all dependent sequences */
    
    	/* NOTE: can not use SEQ_BEGIN/SEQ_END here because that macro will change sequence's depth,
    	 *       which makes transformation routines work incorrect
    	 */
    	sequence_do_invalidate_dependent(seq, &ed->seqbase);
    }
    
    void BKE_sequence_invalidate_cache(Scene *scene, Sequence *seq)
    {
    	sequence_invalidate_cache(scene, seq, TRUE, TRUE);
    }
    
    void BKE_sequence_invalidate_dependent(Scene *scene, Sequence *seq)
    {
    	sequence_invalidate_cache(scene, seq, FALSE, TRUE);
    }
    
    void BKE_sequence_invalidate_cache_for_modifier(Scene *scene, Sequence *seq)
    {
    	sequence_invalidate_cache(scene, seq, TRUE, FALSE);
    }
    
    void BKE_sequencer_free_imbuf(Scene *scene, ListBase *seqbase, int for_render)
    {
    	Sequence *seq;
    
    	BKE_sequencer_cache_cleanup();
    
    	for (seq = seqbase->first; seq; seq = seq->next) {
    		if (for_render && CFRA >= seq->startdisp && CFRA <= seq->enddisp) {
    			continue;
    		}
    
    		if (seq->strip) {
    			if (seq->type == SEQ_TYPE_MOVIE) {
    				free_anim_seq(seq);
    			}
    			if (seq->type == SEQ_TYPE_SPEED) {
    				BKE_sequence_effect_speed_rebuild_map(scene, seq, 1);
    			}
    		}
    		if (seq->type == SEQ_TYPE_META) {
    			BKE_sequencer_free_imbuf(scene, &seq->seqbase, for_render);
    		}
    		if (seq->type == SEQ_TYPE_SCENE) {
    			/* FIXME: recurs downwards, 
    			 * but do recurs protection somehow! */
    		}
    	}
    	
    }
    
    static int update_changed_seq_recurs(Scene *scene, Sequence *seq, Sequence *changed_seq, int len_change, int ibuf_change)
    {
    	Sequence *subseq;
    	int free_imbuf = 0;
    	
    	/* recurs downwards to see if this seq depends on the changed seq */
    	
    	if (seq == NULL)
    		return 0;
    	
    	if (seq == changed_seq)
    		free_imbuf = 1;
    	
    	for (subseq = seq->seqbase.first; subseq; subseq = subseq->next)
    		if (update_changed_seq_recurs(scene, subseq, changed_seq, len_change, ibuf_change))
    			free_imbuf = TRUE;
    	
    	if (seq->seq1)
    		if (update_changed_seq_recurs(scene, seq->seq1, changed_seq, len_change, ibuf_change))
    			free_imbuf = TRUE;
    	if (seq->seq2 && (seq->seq2 != seq->seq1))
    		if (update_changed_seq_recurs(scene, seq->seq2, changed_seq, len_change, ibuf_change))
    			free_imbuf = TRUE;
    	if (seq->seq3 && (seq->seq3 != seq->seq1) && (seq->seq3 != seq->seq2))
    		if (update_changed_seq_recurs(scene, seq->seq3, changed_seq, len_change, ibuf_change))
    			free_imbuf = TRUE;
    	
    	if (free_imbuf) {
    		if (ibuf_change) {
    			if (seq->type == SEQ_TYPE_MOVIE)
    				free_anim_seq(seq);
    			if (seq->type == SEQ_TYPE_SPEED) {
    				BKE_sequence_effect_speed_rebuild_map(scene, seq, 1);
    			}
    		}
    		
    		if (len_change)
    			BKE_sequence_calc(scene, seq);
    	}
    	
    	return free_imbuf;
    }
    
    void BKE_sequencer_update_changed_seq_and_deps(Scene *scene, Sequence *changed_seq, int len_change, int ibuf_change)
    {
    	Editing *ed = BKE_sequencer_editing_get(scene, FALSE);
    	Sequence *seq;
    	
    	if (ed == NULL) return;
    	
    	for (seq = ed->seqbase.first; seq; seq = seq->next)
    		update_changed_seq_recurs(scene, seq, changed_seq, len_change, ibuf_change);
    }
    
    /* seq funcs's for transforming internally
     * notice the difference between start/end and left/right.
     *
     * left and right are the bounds at which the sequence is rendered,
     * start and end are from the start and fixed length of the sequence.
     */
    static int seq_tx_get_start(Sequence *seq)
    {
    	return seq->start;
    }
    static int seq_tx_get_end(Sequence *seq)
    {
    	return seq->start + seq->len;
    }
    
    int BKE_sequence_tx_get_final_left(Sequence *seq, int metaclip)
    {
    	if (metaclip && seq->tmp) {
    		/* return the range clipped by the parents range */
    		return max_ii(BKE_sequence_tx_get_final_left(seq, 0), BKE_sequence_tx_get_final_left((Sequence *)seq->tmp, TRUE));
    	}
    	else {
    		return (seq->start - seq->startstill) + seq->startofs;
    	}
    
    }
    int BKE_sequence_tx_get_final_right(Sequence *seq, int metaclip)
    {
    	if (metaclip && seq->tmp) {
    		/* return the range clipped by the parents range */
    		return min_ii(BKE_sequence_tx_get_final_right(seq, 0), BKE_sequence_tx_get_final_right((Sequence *)seq->tmp, TRUE));
    	}
    	else {
    		return ((seq->start + seq->len) + seq->endstill) - seq->endofs;
    	}
    }
    
    void BKE_sequence_tx_set_final_left(Sequence *seq, int val)
    {
    	if (val < (seq)->start) {
    		seq->startstill = abs(val - (seq)->start);
    		seq->startofs = 0;
    	}
    	else {
    		seq->startofs = abs(val - (seq)->start);
    		seq->startstill = 0;
    	}
    }
    
    void BKE_sequence_tx_set_final_right(Sequence *seq, int val)
    {
    	if (val > (seq)->start + (seq)->len) {
    		seq->endstill = abs(val - (seq->start + (seq)->len));
    		seq->endofs = 0;
    	}
    	else {
    		seq->endofs = abs(val - ((seq)->start + (seq)->len));
    		seq->endstill = 0;
    	}
    }
    
    /* used so we can do a quick check for single image seq
     * since they work a bit differently to normal image seq's (during transform) */
    bool BKE_sequence_single_check(Sequence *seq)
    {
    	return ((seq->len == 1) &&
    	        (seq->type == SEQ_TYPE_IMAGE ||
    	         ((seq->type & SEQ_TYPE_EFFECT) &&
    	          BKE_sequence_effect_get_num_inputs(seq->type) == 0)));
    }
    
    /* check if the selected seq's reference unselected seq's */
    bool BKE_sequence_base_isolated_sel_check(ListBase *seqbase)
    {
    	Sequence *seq;
    	/* is there more than 1 select */
    	bool ok = false;
    
    	for (seq = seqbase->first; seq; seq = seq->next) {
    		if (seq->flag & SELECT) {
    			ok = true;
    			break;
    		}
    	}
    
    	if (ok == false)
    		return false;
    
    	/* test relationships */
    	for (seq = seqbase->first; seq; seq = seq->next) {
    		if ((seq->type & SEQ_TYPE_EFFECT) == 0)
    			continue;
    
    		if (seq->flag & SELECT) {
    			if ((seq->seq1 && (seq->seq1->flag & SELECT) == 0) ||
    			    (seq->seq2 && (seq->seq2->flag & SELECT) == 0) ||
    			    (seq->seq3 && (seq->seq3->flag & SELECT) == 0) )
    			{
    				return false;
    			}
    		}
    		else {
    			if ((seq->seq1 && (seq->seq1->flag & SELECT)) ||
    			    (seq->seq2 && (seq->seq2->flag & SELECT)) ||
    			    (seq->seq3 && (seq->seq3->flag & SELECT)) )
    			{
    				return false;
    			}
    		}
    	}
    
    	return true;
    }
    
    /* use to impose limits when dragging/extending - so impossible situations don't happen
     * Cant use the SEQ_LEFTSEL and SEQ_LEFTSEL directly because the strip may be in a metastrip */
    void BKE_sequence_tx_handle_xlimits(Sequence *seq, int leftflag, int rightflag)
    {
    	if (leftflag) {
    		if (BKE_sequence_tx_get_final_left(seq, 0) >= BKE_sequence_tx_get_final_right(seq, 0)) {
    			BKE_sequence_tx_set_final_left(seq, BKE_sequence_tx_get_final_right(seq, 0) - 1);
    		}
    
    		if (BKE_sequence_single_check(seq) == 0) {
    			if (BKE_sequence_tx_get_final_left(seq, 0) >= seq_tx_get_end(seq)) {
    				BKE_sequence_tx_set_final_left(seq, seq_tx_get_end(seq) - 1);
    			}
    
    			/* dosnt work now - TODO */
    #if 0
    			if (seq_tx_get_start(seq) >= seq_tx_get_final_right(seq, 0)) {
    				int ofs;
    				ofs = seq_tx_get_start(seq) - seq_tx_get_final_right(seq, 0);
    				seq->start -= ofs;
    				seq_tx_set_final_left(seq, seq_tx_get_final_left(seq, 0) + ofs);
    			}
    #endif
    		}
    	}
    
    	if (rightflag) {
    		if (BKE_sequence_tx_get_final_right(seq, 0) <= BKE_sequence_tx_get_final_left(seq, 0)) {
    			BKE_sequence_tx_set_final_right(seq, BKE_sequence_tx_get_final_left(seq, 0) + 1);
    		}
    
    		if (BKE_sequence_single_check(seq) == 0) {
    			if (BKE_sequence_tx_get_final_right(seq, 0) <= seq_tx_get_start(seq)) {
    				BKE_sequence_tx_set_final_right(seq, seq_tx_get_start(seq) + 1);
    			}
    		}
    	}
    
    	/* sounds cannot be extended past their endpoints */
    	if (seq->type == SEQ_TYPE_SOUND_RAM) {
    		seq->startstill = 0;
    		seq->endstill = 0;
    	}
    }
    
    void BKE_sequence_single_fix(Sequence *seq)
    {
    	int left, start, offset;
    	if (!BKE_sequence_single_check(seq))
    		return;
    
    	/* make sure the image is always at the start since there is only one,
    	 * adjusting its start should be ok */
    	left = BKE_sequence_tx_get_final_left(seq, 0);
    	start = seq->start;
    	if (start != left) {
    		offset = left - start;
    		BKE_sequence_tx_set_final_left(seq, BKE_sequence_tx_get_final_left(seq, 0) - offset);
    		BKE_sequence_tx_set_final_right(seq, BKE_sequence_tx_get_final_right(seq, 0) - offset);
    		seq->start += offset;
    	}
    }
    
    bool BKE_sequence_tx_test(Sequence *seq)
    {
    	return (seq->type < SEQ_TYPE_EFFECT) || (BKE_sequence_effect_get_num_inputs(seq->type) == 0);
    }
    
    static bool seq_overlap(Sequence *seq1, Sequence *seq2)
    {
    	return (seq1 != seq2 && seq1->machine == seq2->machine &&
    	        ((seq1->enddisp <= seq2->startdisp) || (seq1->startdisp >= seq2->enddisp)) == 0);
    }
    
    bool BKE_sequence_test_overlap(ListBase *seqbasep, Sequence *test)
    {
    	Sequence *seq;
    
    	seq = seqbasep->first;
    	while (seq) {
    		if (seq_overlap(test, seq))
    			return true;
    
    		seq = seq->next;
    	}
    	return false;
    }
    
    
    void BKE_sequence_translate(Scene *evil_scene, Sequence *seq, int delta)
    {
    	BKE_sequencer_offset_animdata(evil_scene, seq, delta);
    	seq->start += delta;
    
    	if (seq->type == SEQ_TYPE_META) {
    		Sequence *seq_child;
    		for (seq_child = seq->seqbase.first; seq_child; seq_child = seq_child->next) {
    			BKE_sequence_translate(evil_scene, seq_child, delta);
    		}
    	}
    
    	BKE_sequence_calc_disp(evil_scene, seq);
    }
    
    void BKE_sequence_sound_init(Scene *scene, Sequence *seq)
    {
    	if (seq->type == SEQ_TYPE_META) {
    		Sequence *seq_child;
    		for (seq_child = seq->seqbase.first; seq_child; seq_child = seq_child->next) {
    			BKE_sequence_sound_init(scene, seq_child);
    		}
    	}
    	else {
    		if (seq->sound) {
    			seq->scene_sound = sound_add_scene_sound_defaults(scene, seq);
    		}
    		if (seq->scene) {
    			sound_scene_add_scene_sound_defaults(scene, seq);
    		}
    	}
    }
    
    Sequence *BKE_sequencer_foreground_frame_get(Scene *scene, int frame)
    {
    	Editing *ed = BKE_sequencer_editing_get(scene, FALSE);
    	Sequence *seq, *best_seq = NULL;
    	int best_machine = -1;
    	
    	if (!ed) return NULL;
    	
    	for (seq = ed->seqbasep->first; seq; seq = seq->next) {
    		if (seq->flag & SEQ_MUTE || seq->startdisp > frame || seq->enddisp <= frame)
    			continue;
    		/* only use elements you can see - not */
    		if (ELEM5(seq->type, SEQ_TYPE_IMAGE, SEQ_TYPE_META, SEQ_TYPE_SCENE, SEQ_TYPE_MOVIE, SEQ_TYPE_COLOR)) {
    			if (seq->machine > best_machine) {
    				best_seq = seq;
    				best_machine = seq->machine;
    			}
    		}
    	}
    	return best_seq;
    }
    
    /* return 0 if there werent enough space */
    bool BKE_sequence_base_shuffle(ListBase *seqbasep, Sequence *test, Scene *evil_scene)
    {
    	int orig_machine = test->machine;
    	test->machine++;
    	BKE_sequence_calc(evil_scene, test);
    	while (BKE_sequence_test_overlap(seqbasep, test) ) {
    		if (test->machine >= MAXSEQ) {
    			break;
    		}
    		test->machine++;
    		BKE_sequence_calc(evil_scene, test); // XXX - I don't think this is needed since were only moving vertically, Campbell.
    	}
    
    	
    	if (test->machine >= MAXSEQ) {
    		/* Blender 2.4x would remove the strip.
    		 * nicer to move it to the end */
    
    		Sequence *seq;
    		int new_frame = test->enddisp;
    
    		for (seq = seqbasep->first; seq; seq = seq->next) {
    			if (seq->machine == orig_machine)
    				new_frame = max_ii(new_frame, seq->enddisp);
    		}
    
    		test->machine = orig_machine;
    		new_frame = new_frame + (test->start - test->startdisp); /* adjust by the startdisp */
    		BKE_sequence_translate(evil_scene, test, new_frame - test->start);
    
    		BKE_sequence_calc(evil_scene, test);
    		return false;
    	}
    	else {
    		return true;
    	}
    }
    
    static int shuffle_seq_time_offset_test(ListBase *seqbasep, char dir)
    {
    	int offset = 0;
    	Sequence *seq, *seq_other;
    
    	for (seq = seqbasep->first; seq; seq = seq->next) {
    		if (seq->tmp) {
    			for (seq_other = seqbasep->first; seq_other; seq_other = seq_other->next) {
    				if (!seq_other->tmp && seq_overlap(seq, seq_other)) {
    					if (dir == 'L') {
    						offset = min_ii(offset, seq_other->startdisp - seq->enddisp);
    					}
    					else {
    						offset = max_ii(offset, seq_other->enddisp - seq->startdisp);
    					}
    				}
    			}
    		}
    	}
    	return offset;
    }
    
    static int shuffle_seq_time_offset(Scene *scene, ListBase *seqbasep, char dir)
    {
    	int ofs = 0;
    	int tot_ofs = 0;
    	Sequence *seq;
    	while ( (ofs = shuffle_seq_time_offset_test(seqbasep, dir)) ) {
    		for (seq = seqbasep->first; seq; seq = seq->next) {
    			if (seq->tmp) {
    				/* seq_test_overlap only tests display values */
    				seq->startdisp +=   ofs;
    				seq->enddisp +=     ofs;
    			}
    		}
    
    		tot_ofs += ofs;
    	}
    
    	for (seq = seqbasep->first; seq; seq = seq->next) {
    		if (seq->tmp)
    			BKE_sequence_calc_disp(scene, seq);  /* corrects dummy startdisp/enddisp values */
    	}
    
    	return tot_ofs;
    }
    
    bool BKE_sequence_base_shuffle_time(ListBase *seqbasep, Scene *evil_scene)
    {
    	/* note: seq->tmp is used to tag strips to move */
    
    	Sequence *seq;
    
    	int offset_l = shuffle_seq_time_offset(evil_scene, seqbasep, 'L');
    	int offset_r = shuffle_seq_time_offset(evil_scene, seqbasep, 'R');
    	int offset = (-offset_l < offset_r) ?  offset_l : offset_r;
    
    	if (offset) {
    		for (seq = seqbasep->first; seq; seq = seq->next) {
    			if (seq->tmp) {
    				BKE_sequence_translate(evil_scene, seq, offset);
    				seq->flag &= ~SEQ_OVERLAP;
    			}
    		}
    	}
    
    	return offset ? false : true;
    }
    
    /* Unlike _update_sound_ funcs, these ones take info from audaspace to update sequence length! */
    #ifdef WITH_AUDASPACE
    static bool sequencer_refresh_sound_length_recursive(Scene *scene, ListBase *seqbase)
    {
    	Sequence *seq;
    	bool changed = false;
    
    	for (seq = seqbase->first; seq; seq = seq->next) {
    		if (seq->type == SEQ_TYPE_META) {
    			if (sequencer_refresh_sound_length_recursive(scene, &seq->seqbase)) {
    				BKE_sequence_calc(scene, seq);
    				changed = true;
    			}
    		}
    		else if (seq->type == SEQ_TYPE_SOUND_RAM) {
    			AUD_SoundInfo info = AUD_getInfo(seq->sound->playback_handle);
    			int old = seq->len;
    			float fac;
    
    			seq->len = (int)ceil((double)info.length * FPS);
    			fac = (float)seq->len / (float)old;
    			old = seq->startofs;
    			seq->startofs *= fac;
    			seq->endofs *= fac;
    			seq->start += (old - seq->startofs);  /* So that visual/"real" start frame does not change! */
    
    			BKE_sequence_calc(scene, seq);
    			changed = true;
    		}
    	}
    	return changed;
    }
    #endif
    
    void BKE_sequencer_refresh_sound_length(Scene *scene)
    {
    #ifdef WITH_AUDASPACE
    	if (scene->ed) {
    		sequencer_refresh_sound_length_recursive(scene, &scene->ed->seqbase);
    	}
    #else
    	(void)scene;
    #endif
    }
    
    void BKE_sequencer_update_sound_bounds_all(Scene *scene)
    {
    	Editing *ed = scene->ed;
    
    	if (ed) {
    		Sequence *seq;
    
    		for (seq = ed->seqbase.first; seq; seq = seq->next) {
    			if (seq->type == SEQ_TYPE_META) {
    				seq_update_sound_bounds_recursive(scene, seq);
    			}
    			else if (ELEM(seq->type, SEQ_TYPE_SOUND_RAM, SEQ_TYPE_SCENE)) {
    				BKE_sequencer_update_sound_bounds(scene, seq);
    			}
    		}
    	}
    }
    
    void BKE_sequencer_update_sound_bounds(Scene *scene, Sequence *seq)
    {
    	if (seq->type == SEQ_TYPE_SCENE) {
    		if (seq->scene_sound) {
    			/* We have to take into account start frame of the sequence's scene! */
    			int startofs = seq->startofs + seq->anim_startofs + seq->scene->r.sfra;
    
    			sound_move_scene_sound(scene, seq->scene_sound, seq->startdisp, seq->enddisp, startofs);
    		}
    	}
    	else {
    		sound_move_scene_sound_defaults(scene, seq);
    	}
    	/* mute is set in seq_update_muting_recursive */
    }
    
    static void seq_update_muting_recursive(ListBase *seqbasep, Sequence *metaseq, int mute)
    {
    	Sequence *seq;
    	int seqmute;
    
    	/* for sound we go over full meta tree to update muted state,
    	 * since sound is played outside of evaluating the imbufs, */
    	for (seq = seqbasep->first; seq; seq = seq->next) {
    		seqmute = (mute || (seq->flag & SEQ_MUTE));
    
    		if (seq->type == SEQ_TYPE_META) {
    			/* if this is the current meta sequence, unmute because
    			 * all sequences above this were set to mute */
    			if (seq == metaseq)
    				seqmute = 0;
    
    			seq_update_muting_recursive(&seq->seqbase, metaseq, seqmute);
    		}
    		else if (ELEM(seq->type, SEQ_TYPE_SOUND_RAM, SEQ_TYPE_SCENE)) {
    			if (seq->scene_sound) {
    				sound_mute_scene_sound(seq->scene_sound, seqmute);
    			}
    		}
    	}
    }
    
    void BKE_sequencer_update_muting(Editing *ed)
    {
    	if (ed) {
    		/* mute all sounds up to current metastack list */
    		MetaStack *ms = ed->metastack.last;
    
    		if (ms)
    			seq_update_muting_recursive(&ed->seqbase, ms->parseq, 1);
    		else
    			seq_update_muting_recursive(&ed->seqbase, NULL, 0);
    	}
    }
    
    static void seq_update_sound_recursive(Scene *scene, ListBase *seqbasep, bSound *sound)
    {
    	Sequence *seq;
    
    	for (seq = seqbasep->first; seq; seq = seq->next) {
    		if (seq->type == SEQ_TYPE_META) {
    			seq_update_sound_recursive(scene, &seq->seqbase, sound);
    		}
    		else if (seq->type == SEQ_TYPE_SOUND_RAM) {
    			if (seq->scene_sound && sound == seq->sound) {
    				sound_update_scene_sound(seq->scene_sound, sound);
    			}
    		}
    	}
    }
    
    void BKE_sequencer_update_sound(Scene *scene, bSound *sound)
    {
    	if (scene->ed) {
    		seq_update_sound_recursive(scene, &scene->ed->seqbase, sound);
    	}
    }
    
    /* in cases where we done know the sequence's listbase */
    ListBase *BKE_sequence_seqbase(ListBase *seqbase, Sequence *seq)
    {
    	Sequence *iseq;
    	ListBase *lb = NULL;
    
    	for (iseq = seqbase->first; iseq; iseq = iseq->next) {
    		if (seq == iseq) {
    			return seqbase;
    		}
    		else if (iseq->seqbase.first && (lb = BKE_sequence_seqbase(&iseq->seqbase, seq))) {
    			return lb;
    		}
    	}
    
    	return NULL;
    }
    
    Sequence *BKE_sequence_metastrip(ListBase *seqbase, Sequence *meta, Sequence *seq)
    {
    	Sequence *iseq;
    
    	for (iseq = seqbase->first; iseq; iseq = iseq->next) {
    		Sequence *rval;
    
    		if (seq == iseq) {
    			return meta;
    		}
    		else if (iseq->seqbase.first &&
    		         (rval = BKE_sequence_metastrip(&iseq->seqbase, iseq, seq)))
    		{
    			return rval;
    		}
    	}
    
    	return NULL;
    }
    
    int BKE_sequence_swap(Sequence *seq_a, Sequence *seq_b, const char **error_str)
    {
    	char name[sizeof(seq_a->name)];
    
    	if (seq_a->len != seq_b->len) {
    		*error_str = N_("Strips must be the same length");
    		return 0;
    	}
    
    	/* type checking, could be more advanced but disallow sound vs non-sound copy */
    	if (seq_a->type != seq_b->type) {
    		if (seq_a->type == SEQ_TYPE_SOUND_RAM || seq_b->type == SEQ_TYPE_SOUND_RAM) {
    			*error_str = N_("Strips were not compatible");
    			return 0;
    		}
    
    		/* disallow effects to swap with non-effects strips */
    		if ((seq_a->type & SEQ_TYPE_EFFECT) != (seq_b->type & SEQ_TYPE_EFFECT)) {
    			*error_str = N_("Strips were not compatible");
    			return 0;
    		}
    
    		if ((seq_a->type & SEQ_TYPE_EFFECT) && (seq_b->type & SEQ_TYPE_EFFECT)) {
    			if (BKE_sequence_effect_get_num_inputs(seq_a->type) != BKE_sequence_effect_get_num_inputs(seq_b->type)) {
    				*error_str = N_("Strips must have the same number of inputs");
    				return 0;
    			}
    		}
    	}
    
    	SWAP(Sequence, *seq_a, *seq_b);
    
    	/* swap back names so animation fcurves don't get swapped */
    	BLI_strncpy(name, seq_a->name + 2, sizeof(name));
    	BLI_strncpy(seq_a->name + 2, seq_b->name + 2, sizeof(seq_b->name) - 2);
    	BLI_strncpy(seq_b->name + 2, name, sizeof(seq_b->name) - 2);
    
    	/* swap back opacity, and overlay mode */
    	SWAP(int, seq_a->blend_mode, seq_b->blend_mode);
    	SWAP(float, seq_a->blend_opacity, seq_b->blend_opacity);
    
    
    	SWAP(Sequence *, seq_a->prev, seq_b->prev);
    	SWAP(Sequence *, seq_a->next, seq_b->next);
    	SWAP(int, seq_a->start, seq_b->start);
    	SWAP(int, seq_a->startofs, seq_b->startofs);
    	SWAP(int, seq_a->endofs, seq_b->endofs);
    	SWAP(int, seq_a->startstill, seq_b->startstill);
    	SWAP(int, seq_a->endstill, seq_b->endstill);
    	SWAP(int, seq_a->machine, seq_b->machine);
    	SWAP(int, seq_a->startdisp, seq_b->startdisp);
    	SWAP(int, seq_a->enddisp, seq_b->enddisp);
    
    	return 1;
    }
    
    /* XXX - hackish function needed for transforming strips! TODO - have some better solution */
    void BKE_sequencer_offset_animdata(Scene *scene, Sequence *seq, int ofs)
    {
    	char str[SEQ_NAME_MAXSTR + 3];
    	FCurve *fcu;
    
    	if (scene->adt == NULL || ofs == 0 || scene->adt->action == NULL)
    		return;
    
    	BLI_snprintf(str, sizeof(str), "[\"%s\"]", seq->name + 2);
    
    	for (fcu = scene->adt->action->curves.first; fcu; fcu = fcu->next) {
    		if (strstr(fcu->rna_path, "sequence_editor.sequences_all[") && strstr(fcu->rna_path, str)) {
    			unsigned int i;
    			for (i = 0; i < fcu->totvert; i++) {
    				BezTriple *bezt = &fcu->bezt[i];
    				bezt->vec[0][0] += ofs;
    				bezt->vec[1][0] += ofs;
    				bezt->vec[2][0] += ofs;
    			}
    		}
    	}
    }
    
    void BKE_sequencer_dupe_animdata(Scene *scene, const char *name_src, const char *name_dst)
    {
    	char str_from[SEQ_NAME_MAXSTR + 3];
    	FCurve *fcu;
    	FCurve *fcu_last;
    	FCurve *fcu_cpy;
    	ListBase lb = {NULL, NULL};
    
    	if (scene->adt == NULL || scene->adt->action == NULL)
    		return;
    
    	BLI_snprintf(str_from, sizeof(str_from), "[\"%s\"]", name_src);
    
    	fcu_last = scene->adt->action->curves.last;
    
    	for (fcu = scene->adt->action->curves.first; fcu && fcu->prev != fcu_last; fcu = fcu->next) {
    		if (strstr(fcu->rna_path, "sequence_editor.sequences_all[") && strstr(fcu->rna_path, str_from)) {
    			fcu_cpy = copy_fcurve(fcu);
    			BLI_addtail(&lb, fcu_cpy);
    		}
    	}
    
    	/* notice validate is 0, keep this because the seq may not be added to the scene yet */
    	BKE_animdata_fix_paths_rename(&scene->id, scene->adt, NULL, "sequence_editor.sequences_all", name_src, name_dst, 0, 0, 0);
    
    	/* add the original fcurves back */
    	BLI_movelisttolist(&scene->adt->action->curves, &lb);
    }
    
    /* XXX - hackish function needed to remove all fcurves belonging to a sequencer strip */
    static void seq_free_animdata(Scene *scene, Sequence *seq)
    {
    	char str[SEQ_NAME_MAXSTR + 3];
    	FCurve *fcu;
    
    	if (scene->adt == NULL || scene->adt->action == NULL)
    		return;
    
    	BLI_snprintf(str, sizeof(str), "[\"%s\"]", seq->name + 2);
    
    	fcu = scene->adt->action->curves.first;
    
    	while (fcu) {
    		if (strstr(fcu->rna_path, "sequence_editor.sequences_all[") && strstr(fcu->rna_path, str)) {
    			FCurve *next_fcu = fcu->next;
    			
    			BLI_remlink(&scene->adt->action->curves, fcu);
    			free_fcurve(fcu);
    
    			fcu = next_fcu;
    		}
    		else {
    			fcu = fcu->next;
    		}
    	}
    }
    
    Sequence *BKE_sequence_get_by_name(ListBase *seqbase, const char *name, int recursive)
    {
    	Sequence *iseq = NULL;
    	Sequence *rseq = NULL;
    
    	for (iseq = seqbase->first; iseq; iseq = iseq->next) {
    		if (STREQ(name, iseq->name + 2))
    			return iseq;
    		else if (recursive && (iseq->seqbase.first) && (rseq = BKE_sequence_get_by_name(&iseq->seqbase, name, 1))) {
    			return rseq;
    		}
    	}
    
    	return NULL;
    }
    
    /**
     * Only use as last resort when the StripElem is available but no the Sequence.
     * (needed for RNA)
     */
    Sequence *BKE_sequencer_from_elem(ListBase *seqbase, StripElem *se)
    {
    	Sequence *iseq;
    
    	for (iseq = seqbase->first; iseq; iseq = iseq->next) {
    		Sequence *seq_found;
    		if ((iseq->strip && iseq->strip->stripdata) &&
    		    (ARRAY_HAS_ITEM(se, iseq->strip->stripdata, iseq->len)))
    		{
    			break;
    		}
    		else if ((seq_found = BKE_sequencer_from_elem(&iseq->seqbase, se))) {
    			iseq = seq_found;
    			break;
    		}
    	}
    
    	return iseq;
    }
    
    Sequence *BKE_sequencer_active_get(Scene *scene)
    {
    	Editing *ed = BKE_sequencer_editing_get(scene, FALSE);
    
    	if (ed == NULL)
    		return NULL;
    
    	return ed->act_seq;
    }
    
    void BKE_sequencer_active_set(Scene *scene, Sequence *seq)
    {
    	Editing *ed = BKE_sequencer_editing_get(scene, FALSE);
    
    	if (ed == NULL)
    		return;
    
    	ed->act_seq = seq;
    }
    
    int BKE_sequencer_active_get_pair(Scene *scene, Sequence **seq_act, Sequence **seq_other)
    {
    	Editing *ed = BKE_sequencer_editing_get(scene, FALSE);
    
    	*seq_act = BKE_sequencer_active_get(scene);
    
    	if (*seq_act == NULL) {
    		return 0;
    	}
    	else {
    		Sequence *seq;
    
    		*seq_other = NULL;
    
    		for (seq = ed->seqbasep->first; seq; seq = seq->next) {
    			if (seq->flag & SELECT && (seq != (*seq_act))) {
    				if (*seq_other) {
    					return 0;
    				}
    				else {
    					*seq_other = seq;
    				}
    			}
    		}
    
    		return (*seq_other != NULL);
    	}
    }
    
    Mask *BKE_sequencer_mask_get(Scene *scene)
    {
    	Sequence *seq_act = BKE_sequencer_active_get(scene);
    
    	if (seq_act && seq_act->type == SEQ_TYPE_MASK) {
    		return seq_act->mask;
    	}
    	else {
    		return NULL;
    	}
    }
    
    /* api like funcs for adding */
    
    static void seq_load_apply(Scene *scene, Sequence *seq, SeqLoadInfo *seq_load)
    {
    	if (seq) {
    		BLI_strncpy_utf8(seq->name + 2, seq_load->name, sizeof(seq->name) - 2);
    		BLI_utf8_invalid_strip(seq->name + 2, strlen(seq->name + 2));
    		BKE_sequence_base_unique_name_recursive(&scene->ed->seqbase, seq);
    
    		if (seq_load->flag & SEQ_LOAD_FRAME_ADVANCE) {
    			seq_load->start_frame += (seq->enddisp - seq->startdisp);
    		}
    
    		if (seq_load->flag & SEQ_LOAD_REPLACE_SEL) {
    			seq_load->flag |= SELECT;
    			BKE_sequencer_active_set(scene, seq);
    		}
    
    		if (seq_load->flag & SEQ_LOAD_SOUND_CACHE) {
    			if (seq->sound)
    				sound_cache(seq->sound);
    		}
    
    		seq_load->tot_success++;
    	}
    	else {
    		seq_load->tot_error++;
    	}
    }
    
    Sequence *BKE_sequence_alloc(ListBase *lb, int cfra, int machine)
    {
    	Sequence *seq;
    
    	seq = MEM_callocN(sizeof(Sequence), "addseq");
    	BLI_addtail(lb, seq);
    
    	*( (short *)seq->name) = ID_SEQ;
    	seq->name[2] = 0;
    
    	seq->flag = SELECT;
    	seq->start = cfra;
    	seq->machine = machine;
    	seq->sat = 1.0;
    	seq->mul = 1.0;
    	seq->blend_opacity = 100.0;
    	seq->volume = 1.0f;
    	seq->pitch = 1.0f;
    	seq->scene_sound = NULL;
    
    	return seq;
    }
    
    void BKE_sequence_alpha_mode_from_extension(Sequence *seq)
    {
    	if (seq->strip && seq->strip->stripdata) {
    		const char *filename = seq->strip->stripdata->name;
    		seq->alpha_mode = BKE_image_alpha_mode_from_extension_ex(filename);
    	}
    }
    
    void BKE_sequence_init_colorspace(Sequence *seq)
    {
    	if (seq->strip && seq->strip->stripdata) {
    		char name[FILE_MAX];
    		ImBuf *ibuf;
    
    		BLI_join_dirfile(name, sizeof(name), seq->strip->dir, seq->strip->stripdata->name);
    		BLI_path_abs(name, G.main->name);
    
    		/* initialize input color space */
    		if (seq->type == SEQ_TYPE_IMAGE) {
    			ibuf = IMB_loadiffname(name, IB_test | IB_alphamode_detect, seq->strip->colorspace_settings.name);
    
    			/* byte images are default to straight alpha, however sequencer
    			 * works in premul space, so mark strip to be premultiplied first
    			 */
    			seq->alpha_mode = SEQ_ALPHA_STRAIGHT;
    			if (ibuf) {
    				if (ibuf->flags & IB_alphamode_premul)
    					seq->alpha_mode = IMA_ALPHA_PREMUL;
    
    				IMB_freeImBuf(ibuf);
    			}
    		}
    	}
    }
    
    /* NOTE: this function doesn't fill in image names */
    Sequence *BKE_sequencer_add_image_strip(bContext *C, ListBase *seqbasep, SeqLoadInfo *seq_load)
    {
    	Scene *scene = CTX_data_scene(C); /* only for active seq */
    	Sequence *seq;
    	Strip *strip;
    
    	seq = BKE_sequence_alloc(seqbasep, seq_load->start_frame, seq_load->channel);
    	seq->type = SEQ_TYPE_IMAGE;
    	seq->blend_mode = SEQ_TYPE_CROSS; /* so alpha adjustment fade to the strip below */
    	
    	/* basic defaults */
    	seq->strip = strip = MEM_callocN(sizeof(Strip), "strip");
    
    	seq->len = seq_load->len ? seq_load->len : 1;
    	strip->us = 1;
    	strip->stripdata = MEM_callocN(seq->len * sizeof(StripElem), "stripelem");
    	BLI_strncpy(strip->dir, seq_load->path, sizeof(strip->dir));
    
    	seq_load_apply(scene, seq, seq_load);
    
    	return seq;
    }
    
    #ifdef WITH_AUDASPACE
    Sequence *BKE_sequencer_add_sound_strip(bContext *C, ListBase *seqbasep, SeqLoadInfo *seq_load)
    {
    	Main *bmain = CTX_data_main(C);
    	Scene *scene = CTX_data_scene(C); /* only for sound */
    	Editing *ed = BKE_sequencer_editing_get(scene, TRUE);
    	bSound *sound;
    
    	Sequence *seq;  /* generic strip vars */
    	Strip *strip;
    	StripElem *se;
    
    	AUD_SoundInfo info;
    
    	sound = sound_new_file(bmain, seq_load->path); /* handles relative paths */
    
    	if (sound == NULL || sound->playback_handle == NULL) {
    #if 0
    		if (op)
    			BKE_report(op->reports, RPT_ERROR, "Unsupported audio format");
    #endif
    
    		return NULL;
    	}
    
    	info = AUD_getInfo(sound->playback_handle);
    
    	if (info.specs.channels == AUD_CHANNELS_INVALID) {
    		sound_delete(bmain, sound);
    #if 0
    		if (op)
    			BKE_report(op->reports, RPT_ERROR, "Unsupported audio format");
    #endif
    		return NULL;
    	}
    
    	seq = BKE_sequence_alloc(seqbasep, seq_load->start_frame, seq_load->channel);
    
    	seq->type = SEQ_TYPE_SOUND_RAM;
    	seq->sound = sound;
    	BLI_strncpy(seq->name + 2, "Sound", SEQ_NAME_MAXSTR - 2);
    	BKE_sequence_base_unique_name_recursive(&scene->ed->seqbase, seq);
    
    	/* basic defaults */
    	seq->strip = strip = MEM_callocN(sizeof(Strip), "strip");
    	seq->len = (int)ceil((double)info.length * FPS);
    	strip->us = 1;
    
    	/* we only need 1 element to store the filename */
    	strip->stripdata = se = MEM_callocN(sizeof(StripElem), "stripelem");
    
    	BLI_split_dirfile(seq_load->path, strip->dir, se->name, sizeof(strip->dir), sizeof(se->name));
    
    	seq->scene_sound = sound_add_scene_sound(scene, seq, seq_load->start_frame, seq_load->start_frame + seq->len, 0);
    
    	BKE_sequence_calc_disp(scene, seq);
    
    	/* last active name */
    	BLI_strncpy(ed->act_sounddir, strip->dir, FILE_MAXDIR);
    
    	seq_load_apply(scene, seq, seq_load);
    
    	return seq;
    }
    #else // WITH_AUDASPACE
    Sequence *BKE_sequencer_add_sound_strip(bContext *C, ListBase *seqbasep, SeqLoadInfo *seq_load)
    {
    	(void) C;
    	(void) seqbasep;
    	(void) seq_load;
    	return NULL;
    }
    #endif // WITH_AUDASPACE
    
    Sequence *BKE_sequencer_add_movie_strip(bContext *C, ListBase *seqbasep, SeqLoadInfo *seq_load)
    {
    	Scene *scene = CTX_data_scene(C); /* only for sound */
    	char path[sizeof(seq_load->path)];
    
    	Sequence *seq;  /* generic strip vars */
    	Strip *strip;
    	StripElem *se;
    	char colorspace[64] = "\0"; /* MAX_COLORSPACE_NAME */
    
    	struct anim *an;
    
    	BLI_strncpy(path, seq_load->path, sizeof(path));
    	BLI_path_abs(path, G.main->name);
    
    	an = openanim(path, IB_rect, 0, colorspace);
    
    	if (an == NULL)
    		return NULL;
    
    	seq = BKE_sequence_alloc(seqbasep, seq_load->start_frame, seq_load->channel);
    	seq->type = SEQ_TYPE_MOVIE;
    	seq->blend_mode = SEQ_TYPE_CROSS; /* so alpha adjustment fade to the strip below */
    
    	seq->anim = an;
    	seq->anim_preseek = IMB_anim_get_preseek(an);
    	BLI_strncpy(seq->name + 2, "Movie", SEQ_NAME_MAXSTR - 2);
    	BKE_sequence_base_unique_name_recursive(&scene->ed->seqbase, seq);
    
    	/* basic defaults */
    	seq->strip = strip = MEM_callocN(sizeof(Strip), "strip");
    	seq->len = IMB_anim_get_duration(an, IMB_TC_RECORD_RUN);
    	strip->us = 1;
    
    	BLI_strncpy(seq->strip->colorspace_settings.name, colorspace, sizeof(seq->strip->colorspace_settings.name));
    
    	/* we only need 1 element for MOVIE strips */
    	strip->stripdata = se = MEM_callocN(sizeof(StripElem), "stripelem");
    
    	BLI_split_dirfile(seq_load->path, strip->dir, se->name, sizeof(strip->dir), sizeof(se->name));
    
    	BKE_sequence_calc_disp(scene, seq);
    
    	if (seq_load->name[0] == '\0')
    		BLI_strncpy(seq_load->name, se->name, sizeof(seq_load->name));
    
    	if (seq_load->flag & SEQ_LOAD_MOVIE_SOUND) {
    		int start_frame_back = seq_load->start_frame;
    		seq_load->channel++;
    
    		BKE_sequencer_add_sound_strip(C, seqbasep, seq_load);
    
    		seq_load->start_frame = start_frame_back;
    		seq_load->channel--;
    	}
    
    	/* can be NULL */
    	seq_load_apply(scene, seq, seq_load);
    
    	return seq;
    }
    
    static Sequence *seq_dupli(Scene *scene, Scene *scene_to, Sequence *seq, int dupe_flag)
    {
    	Scene *sce_audio = scene_to ? scene_to : scene;
    	Sequence *seqn = MEM_dupallocN(seq);
    
    	seq->tmp = seqn;
    	seqn->strip = MEM_dupallocN(seq->strip);
    
    	/* XXX: add F-Curve duplication stuff? */
    
    	if (seq->strip->crop) {
    		seqn->strip->crop = MEM_dupallocN(seq->strip->crop);
    	}
    
    	if (seq->strip->transform) {
    		seqn->strip->transform = MEM_dupallocN(seq->strip->transform);
    	}
    
    	if (seq->strip->proxy) {
    		seqn->strip->proxy = MEM_dupallocN(seq->strip->proxy);
    		seqn->strip->proxy->anim = NULL;
    	}
    
    	if (seqn->modifiers.first) {
    		BLI_listbase_clear(&seqn->modifiers);
    
    		BKE_sequence_modifier_list_copy(seqn, seq);
    	}
    
    	if (seq->type == SEQ_TYPE_META) {
    		seqn->strip->stripdata = NULL;
    
    		BLI_listbase_clear(&seqn->seqbase);
    		/* WATCH OUT!!! - This metastrip is not recursively duplicated here - do this after!!! */
    		/* - seq_dupli_recursive(&seq->seqbase, &seqn->seqbase);*/
    	}
    	else if (seq->type == SEQ_TYPE_SCENE) {
    		seqn->strip->stripdata = NULL;
    		if (seq->scene_sound)
    			seqn->scene_sound = sound_scene_add_scene_sound_defaults(sce_audio, seqn);
    	}
    	else if (seq->type == SEQ_TYPE_MOVIECLIP) {
    		/* avoid assert */
    	}
    	else if (seq->type == SEQ_TYPE_MASK) {
    		/* avoid assert */
    	}
    	else if (seq->type == SEQ_TYPE_MOVIE) {
    		seqn->strip->stripdata =
    		        MEM_dupallocN(seq->strip->stripdata);
    		seqn->anim = NULL;
    	}
    	else if (seq->type == SEQ_TYPE_SOUND_RAM) {
    		seqn->strip->stripdata =
    		        MEM_dupallocN(seq->strip->stripdata);
    		if (seq->scene_sound)
    			seqn->scene_sound = sound_add_scene_sound_defaults(sce_audio, seqn);
    
    		id_us_plus((ID *)seqn->sound);
    	}
    	else if (seq->type == SEQ_TYPE_IMAGE) {
    		seqn->strip->stripdata =
    		        MEM_dupallocN(seq->strip->stripdata);
    	}
    	else if (seq->type >= SEQ_TYPE_EFFECT) {
    		if (seq->seq1 && seq->seq1->tmp) seqn->seq1 = seq->seq1->tmp;
    		if (seq->seq2 && seq->seq2->tmp) seqn->seq2 = seq->seq2->tmp;
    		if (seq->seq3 && seq->seq3->tmp) seqn->seq3 = seq->seq3->tmp;
    
    		if (seq->type & SEQ_TYPE_EFFECT) {
    			struct SeqEffectHandle sh;
    			sh = BKE_sequence_get_effect(seq);
    			if (sh.copy)
    				sh.copy(seq, seqn);
    		}
    
    		seqn->strip->stripdata = NULL;
    
    	}
    	else {
    		/* sequence type not handled in duplicate! Expect a crash now... */
    		BLI_assert(0);
    	}
    
    	if (dupe_flag & SEQ_DUPE_UNIQUE_NAME)
    		BKE_sequence_base_unique_name_recursive(&scene->ed->seqbase, seqn);
    
    	if (dupe_flag & SEQ_DUPE_ANIM)
    		BKE_sequencer_dupe_animdata(scene, seq->name + 2, seqn->name + 2);
    
    	return seqn;
    }
    
    Sequence *BKE_sequence_dupli_recursive(Scene *scene, Scene *scene_to, Sequence *seq, int dupe_flag)
    {
    	Sequence *seqn = seq_dupli(scene, scene_to, seq, dupe_flag);
    	if (seq->type == SEQ_TYPE_META) {
    		Sequence *s;
    		for (s = seq->seqbase.first; s; s = s->next) {
    			Sequence *n = BKE_sequence_dupli_recursive(scene, scene_to, s, dupe_flag);
    			if (n) {
    				BLI_addtail(&seqn->seqbase, n);
    			}
    		}
    	}
    	return seqn;
    }
    
    void BKE_sequence_base_dupli_recursive(Scene *scene, Scene *scene_to, ListBase *nseqbase, ListBase *seqbase, int dupe_flag)
    {
    	Sequence *seq;
    	Sequence *seqn = NULL;
    	Sequence *last_seq = BKE_sequencer_active_get(scene);
    
    	for (seq = seqbase->first; seq; seq = seq->next) {
    		seq->tmp = NULL;
    		if ((seq->flag & SELECT) || (dupe_flag & SEQ_DUPE_ALL)) {
    			seqn = seq_dupli(scene, scene_to, seq, dupe_flag);
    			if (seqn) { /*should never fail */
    				if (dupe_flag & SEQ_DUPE_CONTEXT) {
    					seq->flag &= ~SEQ_ALLSEL;
    					seqn->flag &= ~(SEQ_LEFTSEL + SEQ_RIGHTSEL + SEQ_LOCK);
    				}
    
    				BLI_addtail(nseqbase, seqn);
    				if (seq->type == SEQ_TYPE_META)
    					BKE_sequence_base_dupli_recursive(scene, scene_to, &seqn->seqbase, &seq->seqbase, dupe_flag);
    
    				if (dupe_flag & SEQ_DUPE_CONTEXT) {
    					if (seq == last_seq) {
    						BKE_sequencer_active_set(scene, seqn);
    					}
    				}
    			}
    		}
    	}
    }
    
    /* called on draw, needs to be fast,
     * we could cache and use a flag if we want to make checks for file paths resolving for eg. */
    bool BKE_sequence_is_valid_check(Sequence *seq)
    {
    	switch (seq->type) {
    		case SEQ_TYPE_MASK:
    			return (seq->mask != NULL);
    		case SEQ_TYPE_MOVIECLIP:
    			return (seq->clip != NULL);
    		case SEQ_TYPE_SCENE:
    			return (seq->scene != NULL);
    		case SEQ_TYPE_SOUND_RAM:
    			return (seq->sound != NULL);
    	}
    
    	return true;
    }