render.c

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/*
 * 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.
 *
 * - Blender Foundation, 2003-2009
 * - Peter Schlaile <peter [at] schlaile [dot] de> 2005/2006
 */
 
#include <time.h>
 
#include "MEM_guardedalloc.h"
 
#include "DNA_anim_types.h"
#include "DNA_mask_types.h"
#include "DNA_scene_types.h"
#include "DNA_sequence_types.h"
#include "DNA_space_types.h"
 
#include "BLI_linklist.h"
#include "BLI_listbase.h"
#include "BLI_path_util.h"
 
#include "BKE_anim_data.h"
#include "BKE_animsys.h"
#include "BKE_fcurve.h"
#include "BKE_global.h"
#include "BKE_image.h"
#include "BKE_layer.h"
#include "BKE_lib_id.h"
#include "BKE_main.h"
#include "BKE_mask.h"
#include "BKE_movieclip.h"
#include "BKE_scene.h"
#include "BKE_sequencer_offscreen.h"
 
#include "DEG_depsgraph.h"
#include "DEG_depsgraph_query.h"
 
#include "IMB_colormanagement.h"
#include "IMB_imbuf.h"
#include "IMB_imbuf_types.h"
#include "IMB_metadata.h"
 
#include "RNA_access.h"
 
#include "RE_engine.h"
#include "RE_pipeline.h"
 
#include "SEQ_effects.h"
#include "SEQ_modifier.h"
#include "SEQ_proxy.h"
#include "SEQ_render.h"
#include "SEQ_sequencer.h"
#include "SEQ_utils.h"
 
#include "effects.h"
#include "image_cache.h"
#include "multiview.h"
#include "prefetch.h"
#include "proxy.h"
#include "render.h"
#include "strip_time.h"
#include "utils.h"
 
static ImBuf *seq_render_strip_stack(const SeqRenderData *context,
                                     SeqRenderState *state,
                                     ListBase *seqbasep,
                                     float timeline_frame,
                                     int chanshown);
 
static ThreadMutex seq_render_mutex = BLI_MUTEX_INITIALIZER;
SequencerDrawView sequencer_view3d_fn = NULL; /* NULL in background mode */
 
/* -------------------------------------------------------------------- */
void seq_imbuf_assign_spaces(Scene *scene, ImBuf *ibuf)
{
#if 0
  /* Bute buffer is supposed to be in sequencer working space already. */
  if (ibuf->rect != NULL) {
    IMB_colormanagement_assign_rect_colorspace(ibuf, scene->sequencer_colorspace_settings.name);
  }
#endif
  if (ibuf->rect_float != NULL) {
    IMB_colormanagement_assign_float_colorspace(ibuf, scene->sequencer_colorspace_settings.name);
  }
}
 
void seq_imbuf_to_sequencer_space(Scene *scene, ImBuf *ibuf, bool make_float)
{
  /* Early output check: if both buffers are NULL we have nothing to convert. */
  if (ibuf->rect_float == NULL && ibuf->rect == NULL) {
    return;
  }
  /* Get common conversion settings. */
  const char *to_colorspace = scene->sequencer_colorspace_settings.name;
  /* Perform actual conversion logic. */
  if (ibuf->rect_float == NULL) {
    /* We are not requested to give float buffer and byte buffer is already
     * in thee required colorspace. Can skip doing anything here.
     */
    const char *from_colorspace = IMB_colormanagement_get_rect_colorspace(ibuf);
    if (!make_float && STREQ(from_colorspace, to_colorspace)) {
      return;
    }
    if (false) {
      /* The idea here is to provide as fast playback as possible and
       * enforcing float buffer here (a) uses more cache memory (b) might
       * make some other effects slower to apply.
       *
       * However, this might also have negative effect by adding weird
       * artifacts which will then not happen in final render.
       */
      IMB_colormanagement_transform_byte_threaded((unsigned char *)ibuf->rect,
                                                  ibuf->x,
                                                  ibuf->y,
                                                  ibuf->channels,
                                                  from_colorspace,
                                                  to_colorspace);
    }
    else {
      /* We perform conversion to a float buffer so we don't worry about
       * precision loss.
       */
      imb_addrectfloatImBuf(ibuf);
      IMB_colormanagement_transform_from_byte_threaded(ibuf->rect_float,
                                                       (unsigned char *)ibuf->rect,
                                                       ibuf->x,
                                                       ibuf->y,
                                                       ibuf->channels,
                                                       from_colorspace,
                                                       to_colorspace);
      /* We don't need byte buffer anymore. */
      imb_freerectImBuf(ibuf);
    }
  }
  else {
    const char *from_colorspace = IMB_colormanagement_get_float_colorspace(ibuf);
    /* Unknown input color space, can't perform conversion. */
    if (from_colorspace == NULL || from_colorspace[0] == '\0') {
      return;
    }
    /* We don't want both byte and float buffers around: they'll either run
     * out of sync or conversion of byte buffer will lose precision in there.
     */
    if (ibuf->rect != NULL) {
      imb_freerectImBuf(ibuf);
    }
    IMB_colormanagement_transform_threaded(
        ibuf->rect_float, ibuf->x, ibuf->y, ibuf->channels, from_colorspace, to_colorspace, true);
  }
  seq_imbuf_assign_spaces(scene, ibuf);
}
 
void SEQ_render_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 SEQ_render_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);
  }
}
 
/* -------------------------------------------------------------------- */
void SEQ_render_new_render_data(Main *bmain,
                                struct Depsgraph *depsgraph,
                                Scene *scene,
                                int rectx,
                                int recty,
                                int preview_render_size,
                                int for_render,
                                SeqRenderData *r_context)
{
  r_context->bmain = bmain;
  r_context->depsgraph = depsgraph;
  r_context->scene = scene;
  r_context->rectx = rectx;
  r_context->recty = recty;
  r_context->preview_render_size = preview_render_size;
  r_context->for_render = for_render;
  r_context->motion_blur_samples = 0;
  r_context->motion_blur_shutter = 0;
  r_context->skip_cache = false;
  r_context->is_proxy_render = false;
  r_context->view_id = 0;
  r_context->gpu_offscreen = NULL;
  r_context->task_id = SEQ_TASK_MAIN_RENDER;
  r_context->is_prefetch_render = false;
}
 
void seq_render_state_init(SeqRenderState *state)
{
  state->scene_parents = NULL;
}
 
StripElem *SEQ_render_give_stripelem(Sequence *seq, int timeline_frame)
{
  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 frame_index = (int)seq_give_frame_index(seq, timeline_frame);
 
    if (frame_index == -1 || se == NULL) {
      return NULL;
    }
 
    se += frame_index + seq->anim_startofs;
  }
  return se;
}
 
static int evaluate_seq_frame_gen(Sequence **seq_arr,
                                  ListBase *seqbase,
                                  int timeline_frame,
                                  int chanshown)
{
  /* Use arbitrary sized linked list, the size could be over MAXSEQ. */
  LinkNodePair effect_inputs = {NULL, NULL};
  int totseq = 0;
 
  memset(seq_arr, 0, sizeof(Sequence *) * (MAXSEQ + 1));
 
  LISTBASE_FOREACH (Sequence *, seq, seqbase) {
    if ((seq->startdisp <= timeline_frame) && (seq->enddisp > timeline_frame)) {
      if ((seq->type & SEQ_TYPE_EFFECT) && !(seq->flag & SEQ_MUTE)) {
 
        if (seq->seq1) {
          BLI_linklist_append_alloca(&effect_inputs, seq->seq1);
        }
 
        if (seq->seq2) {
          BLI_linklist_append_alloca(&effect_inputs, seq->seq2);
        }
 
        if (seq->seq3) {
          BLI_linklist_append_alloca(&effect_inputs, seq->seq3);
        }
      }
 
      seq_arr[seq->machine] = seq;
      totseq++;
    }
  }
 
  /* 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 (LinkNode *seq_item = effect_inputs.list; seq_item; seq_item = seq_item->next) {
    Sequence *seq = seq_item->link;
    /* It's possible that effect strip would be placed to the same
     * 'machine' as its inputs. We don't want to clear such strips
     * from the stack. */
    if (seq_arr[seq->machine] && seq_arr[seq->machine]->type & SEQ_TYPE_EFFECT) {
      continue;
    }
    /* If we're shown a specified channel, then we want to see the strips
     * which belongs to this machine. */
    if (chanshown != 0 && chanshown <= seq->machine) {
      continue;
    }
    seq_arr[seq->machine] = NULL;
  }
 
  return totseq;
}
 
int SEQ_render_evaluate_frame(ListBase *seqbase, int timeline_frame)
{
  Sequence *seq_arr[MAXSEQ + 1];
  return evaluate_seq_frame_gen(seq_arr, seqbase, timeline_frame, 0);
}
 
static bool video_seq_is_rendered(Sequence *seq)
{
  return (seq && !(seq->flag & SEQ_MUTE) && seq->type != SEQ_TYPE_SOUND_RAM);
}
 
int seq_get_shown_sequences(ListBase *seqbasep,
                            int timeline_frame,
                            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, timeline_frame, chanshown)) {
    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;
}
 
/* -------------------------------------------------------------------- */
/*
 * 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
 */
 
static bool sequencer_use_transform(const Sequence *seq)
{
  const StripTransform *transform = seq->strip->transform;
 
  if (transform->xofs != 0 || transform->yofs != 0 || transform->scale_x != 1 ||
      transform->scale_y != 1 || transform->rotation != 0) {
    return true;
  }
 
  return false;
}
 
static bool sequencer_use_crop(const Sequence *seq)
{
  const StripCrop *crop = seq->strip->crop;
  if (crop->left > 0 || crop->right > 0 || crop->top > 0 || crop->bottom > 0) {
    return true;
  }
 
  return false;
}
 
static bool seq_input_have_to_preprocess(const SeqRenderData *context,
                                         Sequence *seq,
                                         float UNUSED(timeline_frame))
{
  float mul;
 
  if (context && context->is_proxy_render) {
    return false;
  }
 
  if ((seq->flag & (SEQ_FILTERY | SEQ_FLIPX | SEQ_FLIPY | SEQ_MAKE_FLOAT)) ||
      sequencer_use_crop(seq) || sequencer_use_transform(seq)) {
    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;
}
 
typedef struct ImageTransformThreadInitData {
  ImBuf *ibuf_source;
  ImBuf *ibuf_out;
  Sequence *seq;
  float preview_scale_factor;
  bool is_proxy_image;
  bool for_render;
} ImageTransformThreadInitData;
 
typedef struct ImageTransformThreadData {
  ImBuf *ibuf_source;
  ImBuf *ibuf_out;
  Sequence *seq;
  /* image_scale_factor is used to scale proxies to correct preview size. */
  float image_scale_factor;
  /* Preview scale factor is needed to correct translation to match preview size. */
  float preview_scale_factor;
  float crop_scale_factor;
  bool for_render;
  int start_line;
  int tot_line;
} ImageTransformThreadData;
 
static bool seq_need_scale_to_render_size(const Sequence *seq, bool is_proxy_image)
{
  if (is_proxy_image) {
    return true;
  }
  if ((seq->type & SEQ_TYPE_EFFECT) != 0 || seq->type == SEQ_TYPE_MASK ||
      seq->type == SEQ_TYPE_META ||
      (seq->type == SEQ_TYPE_SCENE && ((seq->flag & SEQ_SCENE_STRIPS) != 0))) {
    return true;
  }
  return false;
}
 
static void sequencer_image_crop_transform_init(void *handle_v,
                                                int start_line,
                                                int tot_line,
                                                void *init_data_v)
{
  ImageTransformThreadData *handle = (ImageTransformThreadData *)handle_v;
  const ImageTransformThreadInitData *init_data = (ImageTransformThreadInitData *)init_data_v;
 
  handle->ibuf_source = init_data->ibuf_source;
  handle->ibuf_out = init_data->ibuf_out;
  handle->seq = init_data->seq;
 
  handle->preview_scale_factor = init_data->preview_scale_factor;
  if (seq_need_scale_to_render_size(init_data->seq, init_data->is_proxy_image)) {
    handle->image_scale_factor = 1.0f;
  }
  else {
    handle->image_scale_factor = handle->preview_scale_factor;
  }
 
  /* Proxy image is smaller, so crop values must be corrected by proxy scale factor.
   * Proxy scale factor always matches preview_scale_factor. */
  handle->crop_scale_factor = seq_need_scale_to_render_size(init_data->seq,
                                                            init_data->is_proxy_image) ?
                                  init_data->preview_scale_factor :
                                  1.0f;
 
  handle->for_render = init_data->for_render;
  handle->start_line = start_line;
  handle->tot_line = tot_line;
}
 
static void *sequencer_image_crop_transform_do_thread(void *data_v)
{
  const ImageTransformThreadData *data = (ImageTransformThreadData *)data_v;
  const StripTransform *transform = data->seq->strip->transform;
  const float scale_x = transform->scale_x * data->image_scale_factor;
  const float scale_y = transform->scale_y * data->image_scale_factor;
  const float image_center_offs_x = (data->ibuf_out->x - data->ibuf_source->x) / 2;
  const float image_center_offs_y = (data->ibuf_out->y - data->ibuf_source->y) / 2;
  const float translate_x = transform->xofs * data->preview_scale_factor + image_center_offs_x;
  const float translate_y = transform->yofs * data->preview_scale_factor + image_center_offs_y;
  const float pivot[2] = {data->ibuf_source->x / 2, data->ibuf_source->y / 2};
  float transform_matrix[3][3];
  loc_rot_size_to_mat3(transform_matrix,
                       (const float[]){translate_x, translate_y},
                       transform->rotation,
                       (const float[]){scale_x, scale_y});
  transform_pivot_set_m3(transform_matrix, pivot);
  invert_m3(transform_matrix);
 
  /* Image crop is done by offsetting image boundary limits. */
  const StripCrop *c = data->seq->strip->crop;
  const int left = c->left * data->crop_scale_factor;
  const int right = c->right * data->crop_scale_factor;
  const int top = c->top * data->crop_scale_factor;
  const int bottom = c->bottom * data->crop_scale_factor;
 
  const float source_pixel_range_max[2] = {data->ibuf_source->x - right,
                                           data->ibuf_source->y - top};
  const float source_pixel_range_min[2] = {left, bottom};
 
  const int width = data->ibuf_out->x;
  for (int yi = data->start_line; yi < data->start_line + data->tot_line; yi++) {
    for (int xi = 0; xi < width; xi++) {
      float uv[2] = {xi, yi};
      mul_v2_m3v2(uv, transform_matrix, uv);
 
      if (source_pixel_range_min[0] >= uv[0] || uv[0] >= source_pixel_range_max[0] ||
          source_pixel_range_min[1] >= uv[1] || uv[1] >= source_pixel_range_max[1]) {
        continue;
      }
 
      if (data->for_render) {
        bilinear_interpolation(data->ibuf_source, data->ibuf_out, uv[0], uv[1], xi, yi);
      }
      else {
        nearest_interpolation(data->ibuf_source, data->ibuf_out, uv[0], uv[1], xi, yi);
      }
    }
  }
 
  return NULL;
}
 
static void multibuf(ImBuf *ibuf, const float fmul)
{
  char *rt;
  float *rt_float;
 
  int a;
 
  rt = (char *)ibuf->rect;
  rt_float = ibuf->rect_float;
 
  if (rt) {
    const int imul = (int)(256.0f * fmul);
    a = ibuf->x * ibuf->y;
    while (a--) {
      rt[0] = min_ii((imul * rt[0]) >> 8, 255);
      rt[1] = min_ii((imul * rt[1]) >> 8, 255);
      rt[2] = min_ii((imul * rt[2]) >> 8, 255);
      rt[3] = min_ii((imul * rt[3]) >> 8, 255);
 
      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 ImBuf *input_preprocess(const SeqRenderData *context,
                               Sequence *seq,
                               float timeline_frame,
                               ImBuf *ibuf,
                               const bool is_proxy_image)
{
  Scene *scene = context->scene;
  ImBuf *preprocessed_ibuf = NULL;
 
  /* Deinterlace. */
  if ((seq->flag & SEQ_FILTERY) && !ELEM(seq->type, SEQ_TYPE_MOVIE, SEQ_TYPE_MOVIECLIP)) {
    /* Change original image pointer to avoid another duplication in SEQ_USE_TRANSFORM. */
    preprocessed_ibuf = IMB_makeSingleUser(ibuf);
    ibuf = preprocessed_ibuf;
 
    IMB_filtery(preprocessed_ibuf);
  }
 
  if (sequencer_use_crop(seq) || sequencer_use_transform(seq) || context->rectx != ibuf->x ||
      context->recty != ibuf->y) {
    const int x = context->rectx;
    const int y = context->recty;
    preprocessed_ibuf = IMB_allocImBuf(x, y, 32, ibuf->rect_float ? IB_rectfloat : IB_rect);
 
    ImageTransformThreadInitData init_data = {NULL};
    init_data.ibuf_source = ibuf;
    init_data.ibuf_out = preprocessed_ibuf;
    init_data.seq = seq;
    init_data.is_proxy_image = is_proxy_image;
 
    /* Get scale factor if preview resolution doesn't match project resolution. */
    if (context->preview_render_size == SEQ_RENDER_SIZE_SCENE) {
      init_data.preview_scale_factor = (float)scene->r.size / 100;
    }
    else {
      init_data.preview_scale_factor = SEQ_rendersize_to_scale_factor(
          context->preview_render_size);
    }
 
    init_data.for_render = context->for_render;
    IMB_processor_apply_threaded(context->recty,
                                 sizeof(ImageTransformThreadData),
                                 &init_data,
                                 sequencer_image_crop_transform_init,
                                 sequencer_image_crop_transform_do_thread);
    seq_imbuf_assign_spaces(scene, preprocessed_ibuf);
    IMB_metadata_copy(preprocessed_ibuf, ibuf);
    IMB_freeImBuf(ibuf);
  }
 
  /* Duplicate ibuf if we still have original. */
  if (preprocessed_ibuf == NULL) {
    preprocessed_ibuf = IMB_makeSingleUser(ibuf);
  }
 
  if (seq->flag & SEQ_FLIPX) {
    IMB_flipx(preprocessed_ibuf);
  }
 
  if (seq->flag & SEQ_FLIPY) {
    IMB_flipy(preprocessed_ibuf);
  }
 
  if (seq->sat != 1.0f) {
    IMB_saturation(preprocessed_ibuf, seq->sat);
  }
 
  if (seq->flag & SEQ_MAKE_FLOAT) {
    if (!preprocessed_ibuf->rect_float) {
      seq_imbuf_to_sequencer_space(scene, preprocessed_ibuf, true);
    }
 
    if (preprocessed_ibuf->rect) {
      imb_freerectImBuf(preprocessed_ibuf);
    }
  }
 
  float mul = seq->mul;
  if (seq->blend_mode == SEQ_BLEND_REPLACE) {
    mul *= seq->blend_opacity / 100.0f;
  }
 
  if (mul != 1.0f) {
    multibuf(preprocessed_ibuf, mul);
  }
 
  if (seq->modifiers.first) {
    ImBuf *ibuf_new = SEQ_modifier_apply_stack(context, seq, preprocessed_ibuf, timeline_frame);
 
    if (ibuf_new != preprocessed_ibuf) {
      IMB_metadata_copy(ibuf_new, preprocessed_ibuf);
      IMB_freeImBuf(preprocessed_ibuf);
      preprocessed_ibuf = ibuf_new;
    }
  }
 
  return preprocessed_ibuf;
}
 
static ImBuf *seq_render_preprocess_ibuf(const SeqRenderData *context,
                                         Sequence *seq,
                                         ImBuf *ibuf,
                                         float timeline_frame,
                                         bool use_preprocess,
                                         const bool is_proxy_image)
{
  if (context->is_proxy_render == false &&
      (ibuf->x != context->rectx || ibuf->y != context->recty)) {
    use_preprocess = true;
  }
 
  /* Proxies and effect strips are not stored in cache. */
  if (!is_proxy_image && (seq->type & SEQ_TYPE_EFFECT) == 0) {
    seq_cache_put(context, seq, timeline_frame, SEQ_CACHE_STORE_RAW, ibuf);
  }
 
  if (use_preprocess) {
    ibuf = input_preprocess(context, seq, timeline_frame, ibuf, is_proxy_image);
  }
 
  seq_cache_put(context, seq, timeline_frame, SEQ_CACHE_STORE_PREPROCESSED, ibuf);
  return ibuf;
}
 
typedef struct RenderEffectInitData {
  struct SeqEffectHandle *sh;
  const SeqRenderData *context;
  Sequence *seq;
  float timeline_frame, facf0, facf1;
  ImBuf *ibuf1, *ibuf2, *ibuf3;
 
  ImBuf *out;
} RenderEffectInitData;
 
typedef struct RenderEffectThread {
  struct SeqEffectHandle *sh;
  const SeqRenderData *context;
  Sequence *seq;
  float timeline_frame, 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->timeline_frame = init_data->timeline_frame;
  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->timeline_frame,
                                 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;
}
 
ImBuf *seq_render_effect_execute_threaded(struct SeqEffectHandle *sh,
                                          const SeqRenderData *context,
                                          Sequence *seq,
                                          float timeline_frame,
                                          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.timeline_frame = timeline_frame;
  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,
                                           SeqRenderState *state,
                                           Sequence *seq,
                                           float timeline_frame)
{
  Scene *scene = context->scene;
  float fac, facf;
  int early_out;
  int i;
  struct SeqEffectHandle sh = SEQ_effect_handle_get(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, timeline_frame, &fac, &facf);
    facf = fac;
  }
  else {
    fcu = id_data_find_fcurve(&scene->id, seq, &RNA_Sequence, "effect_fader", 0, NULL);
    if (fcu) {
      fac = facf = evaluate_fcurve(fcu, timeline_frame);
    }
    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, timeline_frame, fac, facf, NULL, NULL, NULL);
      break;
    case EARLY_DO_EFFECT:
      for (i = 0; i < 3; i++) {
        /* Speed effect requires time remapping of `timeline_frame` for input(s). */
        if (input[0] && seq->type == SEQ_TYPE_SPEED) {
          float target_frame = seq_speed_effect_target_frame_get(context, seq, timeline_frame, i);
          ibuf[i] = seq_render_strip(context, state, input[0], target_frame);
        }
        else { /* Other effects. */
          if (input[i]) {
            ibuf[i] = seq_render_strip(context, state, input[i], timeline_frame);
          }
        }
      }
 
      if (ibuf[0] && (ibuf[1] || SEQ_effect_get_num_inputs(seq->type) == 1)) {
        if (sh.multithreaded) {
          out = seq_render_effect_execute_threaded(
              &sh, context, seq, timeline_frame, fac, facf, ibuf[0], ibuf[1], ibuf[2]);
        }
        else {
          out = sh.execute(context, seq, timeline_frame, fac, facf, ibuf[0], ibuf[1], ibuf[2]);
        }
      }
      break;
    case EARLY_USE_INPUT_1:
      if (input[0]) {
        out = seq_render_strip(context, state, input[0], timeline_frame);
      }
      break;
    case EARLY_USE_INPUT_2:
      if (input[1]) {
        out = seq_render_strip(context, state, input[1], timeline_frame);
      }
      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_image_strip_view(const SeqRenderData *context,
                                          Sequence *seq,
                                          char *name,
                                          char *prefix,
                                          const char *ext,
                                          int view_id)
{
 
  ImBuf *ibuf = NULL;
 
  int flag = IB_rect | IB_metadata;
  if (seq->alpha_mode == SEQ_ALPHA_PREMUL) {
    flag |= IB_alphamode_premul;
  }
 
  if (prefix[0] == '\0') {
    ibuf = IMB_loadiffname(name, flag, seq->strip->colorspace_settings.name);
  }
  else {
    char str[FILE_MAX];
    BKE_scene_multiview_view_prefix_get(context->scene, name, prefix, &ext);
    seq_multiview_name(context->scene, view_id, prefix, ext, str, FILE_MAX);
    ibuf = IMB_loadiffname(str, flag, seq->strip->colorspace_settings.name);
  }
 
  if (ibuf == NULL) {
    return NULL;
  }
 
  /* We don't need both (speed reasons)! */
  if (ibuf->rect_float != NULL && ibuf->rect != NULL) {
    imb_freerectImBuf(ibuf);
  }
 
  /* All sequencer color is done in SRGB space, linear gives odd cross-fades. */
  seq_imbuf_to_sequencer_space(context->scene, ibuf, false);
 
  return ibuf;
}
 
static bool seq_image_strip_is_multiview_render(
    Scene *scene, Sequence *seq, int totfiles, char *name, char *r_prefix, const char *r_ext)
{
  if (totfiles > 1) {
    BKE_scene_multiview_view_prefix_get(scene, name, r_prefix, &r_ext);
    if (r_prefix[0] == '\0') {
      return false;
    }
  }
  else {
    r_prefix[0] = '\0';
  }
 
  return (seq->flag & SEQ_USE_VIEWS) != 0 && (scene->r.scemode & R_MULTIVIEW) != 0;
}
 
static ImBuf *seq_render_image_strip(const SeqRenderData *context,
                                     Sequence *seq,
                                     float UNUSED(frame_index),
                                     float timeline_frame,
                                     bool *r_is_proxy_image)
{
  char name[FILE_MAX];
  const char *ext = NULL;
  char prefix[FILE_MAX];
  ImBuf *ibuf = NULL;
 
  StripElem *s_elem = SEQ_render_give_stripelem(seq, timeline_frame);
  if (s_elem == NULL) {
    return NULL;
  }
 
  BLI_join_dirfile(name, sizeof(name), seq->strip->dir, s_elem->name);
  BLI_path_abs(name, BKE_main_blendfile_path_from_global());
 
  /* Try to get a proxy image. */
  ibuf = seq_proxy_fetch(context, seq, timeline_frame);
  if (ibuf != NULL) {
    *r_is_proxy_image = true;
    return ibuf;
  }
 
  /* Proxy not found, render original. */
  const int totfiles = seq_num_files(context->scene, seq->views_format, true);
  bool is_multiview_render = seq_image_strip_is_multiview_render(
      context->scene, seq, totfiles, name, prefix, ext);
 
  if (is_multiview_render) {
    int totviews = BKE_scene_multiview_num_views_get(&context->scene->r);
    ImBuf **ibufs_arr = MEM_callocN(sizeof(ImBuf *) * totviews, "Sequence Image Views Imbufs");
 
    for (int view_id = 0; view_id < totfiles; view_id++) {
      ibufs_arr[view_id] = seq_render_image_strip_view(context, seq, name, prefix, ext, view_id);
    }
 
    if (ibufs_arr[0] == NULL) {
      return NULL;
    }
 
    if (seq->views_format == R_IMF_VIEWS_STEREO_3D) {
      IMB_ImBufFromStereo3d(seq->stereo3d_format, ibufs_arr[0], &ibufs_arr[0], &ibufs_arr[1]);
    }
 
    for (int view_id = 0; view_id < totviews; view_id++) {
      SeqRenderData localcontext = *context;
      localcontext.view_id = view_id;
 
      if (view_id != context->view_id) {
        ibufs_arr[view_id] = seq_render_preprocess_ibuf(
            &localcontext, seq, ibufs_arr[view_id], timeline_frame, true, false);
      }
    }
 
    /* Return the original requested ImBuf. */
    ibuf = ibufs_arr[context->view_id];
 
    /* Remove the others (decrease their refcount). */
    for (int view_id = 0; view_id < totviews; view_id++) {
      if (ibufs_arr[view_id] != ibuf) {
        IMB_freeImBuf(ibufs_arr[view_id]);
      }
    }
 
    MEM_freeN(ibufs_arr);
  }
  else {
    ibuf = seq_render_image_strip_view(context, seq, name, prefix, ext, context->view_id);
  }
 
  if (ibuf == NULL) {
    return NULL;
  }
 
  s_elem->orig_width = ibuf->x;
  s_elem->orig_height = ibuf->y;
 
  return ibuf;
}
 
static ImBuf *seq_render_movie_strip_custom_file_proxy(const SeqRenderData *context,
                                                       Sequence *seq,
                                                       int timeline_frame)
{
  char name[PROXY_MAXFILE];
  StripProxy *proxy = seq->strip->proxy;
 
  if (proxy->anim == NULL) {
    if (seq_proxy_get_custom_file_fname(seq, name, context->view_id)) {
      proxy->anim = openanim(name, IB_rect, 0, seq->strip->colorspace_settings.name);
    }
    if (proxy->anim == NULL) {
      return NULL;
    }
  }
 
  int frameno = (int)seq_give_frame_index(seq, timeline_frame) + seq->anim_startofs;
  return IMB_anim_absolute(proxy->anim, frameno, IMB_TC_NONE, IMB_PROXY_NONE);
}
 
static ImBuf *seq_render_movie_strip_view(const SeqRenderData *context,
                                          Sequence *seq,
                                          float frame_index,
                                          float timeline_frame,
                                          StripAnim *sanim,
                                          bool *r_is_proxy_image)
{
  ImBuf *ibuf = NULL;
  IMB_Proxy_Size psize = SEQ_rendersize_to_proxysize(context->preview_render_size);
 
  if (SEQ_can_use_proxy(context, seq, psize)) {
    /* Try to get a proxy image.
     * Movie proxies are handled by ImBuf module with exception of `custom file` setting. */
    if (context->scene->ed->proxy_storage != SEQ_EDIT_PROXY_DIR_STORAGE &&
        seq->strip->proxy->storage & SEQ_STORAGE_PROXY_CUSTOM_FILE) {
      ibuf = seq_render_movie_strip_custom_file_proxy(context, seq, timeline_frame);
    }
    else {
      ibuf = IMB_anim_absolute(sanim->anim,
                               frame_index + seq->anim_startofs,
                               seq->strip->proxy ? seq->strip->proxy->tc : IMB_TC_RECORD_RUN,
                               psize);
    }
 
    if (ibuf != NULL) {
      *r_is_proxy_image = true;
    }
  }
 
  /* Fetching for requested proxy size failed, try fetching the original instead. */
  if (ibuf == NULL) {
    ibuf = IMB_anim_absolute(sanim->anim,
                             frame_index + seq->anim_startofs,
                             seq->strip->proxy ? seq->strip->proxy->tc : IMB_TC_RECORD_RUN,
                             IMB_PROXY_NONE);
  }
  if (ibuf == NULL) {
    return NULL;
  }
 
  seq_imbuf_to_sequencer_space(context->scene, ibuf, false);
 
  /* We don't need both (speed reasons)! */
  if (ibuf->rect_float != NULL && ibuf->rect != NULL) {
    imb_freerectImBuf(ibuf);
  }
 
  return ibuf;
}
 
static ImBuf *seq_render_movie_strip(const SeqRenderData *context,
                                     Sequence *seq,
                                     float frame_index,
                                     float timeline_frame,
                                     bool *r_is_proxy_image)
{
  /* Load all the videos. */
  seq_open_anim_file(context->scene, seq, false);
 
  ImBuf *ibuf = NULL;
  StripAnim *sanim = seq->anims.first;
  const int totfiles = seq_num_files(context->scene, seq->views_format, true);
  bool is_multiview_render = (seq->flag & SEQ_USE_VIEWS) != 0 &&
                             (context->scene->r.scemode & R_MULTIVIEW) != 0 &&
                             BLI_listbase_count_at_most(&seq->anims, totfiles + 1) == totfiles;
 
  if (is_multiview_render) {
    ImBuf **ibuf_arr;
    int totviews = BKE_scene_multiview_num_views_get(&context->scene->r);
    ibuf_arr = MEM_callocN(sizeof(ImBuf *) * totviews, "Sequence Image Views Imbufs");
    int ibuf_view_id;
 
    for (ibuf_view_id = 0, sanim = seq->anims.first; sanim; sanim = sanim->next, ibuf_view_id++) {
      if (sanim->anim) {
        ibuf_arr[ibuf_view_id] = seq_render_movie_strip_view(
            context, seq, frame_index, timeline_frame, sanim, r_is_proxy_image);
      }
    }
 
    if (seq->views_format == R_IMF_VIEWS_STEREO_3D) {
      if (ibuf_arr[0] == NULL) {
        /* Probably proxy hasn't been created yet. */
        MEM_freeN(ibuf_arr);
        return NULL;
      }
 
      IMB_ImBufFromStereo3d(seq->stereo3d_format, ibuf_arr[0], &ibuf_arr[0], &ibuf_arr[1]);
    }
 
    for (int view_id = 0; view_id < totviews; view_id++) {
      SeqRenderData localcontext = *context;
      localcontext.view_id = view_id;
 
      if (view_id != context->view_id) {
        ibuf_arr[view_id] = seq_render_preprocess_ibuf(
            &localcontext, seq, ibuf_arr[view_id], timeline_frame, true, false);
      }
    }
 
    /* Return the original requested ImBuf. */
    ibuf = ibuf_arr[context->view_id];
 
    /* Remove the others (decrease their refcount). */
    for (int view_id = 0; view_id < totviews; view_id++) {
      if (ibuf_arr[view_id] != ibuf) {
        IMB_freeImBuf(ibuf_arr[view_id]);
      }
    }
 
    MEM_freeN(ibuf_arr);
  }
  else {
    ibuf = seq_render_movie_strip_view(
        context, seq, frame_index, timeline_frame, sanim, r_is_proxy_image);
  }
 
  if (ibuf == NULL) {
    return NULL;
  }
 
  if (*r_is_proxy_image == false) {
    seq->strip->stripdata->orig_width = ibuf->x;
    seq->strip->stripdata->orig_height = ibuf->y;
  }
 
  return ibuf;
}
 
static ImBuf *seq_get_movieclip_ibuf(Sequence *seq, MovieClipUser user)
{
  ImBuf *ibuf = NULL;
  float tloc[2], tscale, tangle;
  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, seq->clip->flag, MOVIECLIP_CACHE_SKIP);
  }
  return ibuf;
}
 
static ImBuf *seq_render_movieclip_strip(const SeqRenderData *context,
                                         Sequence *seq,
                                         float frame_index,
                                         bool *r_is_proxy_image)
{
  ImBuf *ibuf = NULL;
  MovieClipUser user;
  IMB_Proxy_Size psize = SEQ_rendersize_to_proxysize(context->preview_render_size);
 
  if (!seq->clip) {
    return NULL;
  }
 
  memset(&user, 0, sizeof(MovieClipUser));
 
  BKE_movieclip_user_set_frame(&user, frame_index + seq->anim_startofs + seq->clip->start_frame);
 
  user.render_size = MCLIP_PROXY_RENDER_SIZE_FULL;
  switch (psize) {
    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;
  }
 
  /* Try to get a proxy image. */
  ibuf = seq_get_movieclip_ibuf(seq, user);
 
  if (ibuf != NULL && psize != IMB_PROXY_NONE) {
    *r_is_proxy_image = true;
  }
 
  /* If proxy is not found, grab full-size frame. */
  if (ibuf == NULL) {
    user.render_flag |= MCLIP_PROXY_RENDER_USE_FALLBACK_RENDER;
    ibuf = seq_get_movieclip_ibuf(seq, user);
  }
 
  return ibuf;
}
 
ImBuf *seq_render_mask(const SeqRenderData *context,
                       Mask *mask,
                       float frame_index,
                       bool make_float)
{
  /* TODO - add option to rasterize to alpha imbuf? */
  ImBuf *ibuf = NULL;
  float *maskbuf;
  int i;
 
  if (!mask) {
    return NULL;
  }
 
  AnimData *adt;
  Mask *mask_temp;
  MaskRasterHandle *mr_handle;
 
  mask_temp = (Mask *)BKE_id_copy_ex(
      NULL, &mask->id, NULL, LIB_ID_COPY_LOCALIZE | LIB_ID_COPY_NO_ANIMDATA);
 
  BKE_mask_evaluate(mask_temp, mask->sfra + frame_index, true);
 
  /* anim-data */
  adt = BKE_animdata_from_id(&mask->id);
  const AnimationEvalContext anim_eval_context = BKE_animsys_eval_context_construct(
      context->depsgraph, mask->sfra + frame_index);
  BKE_animsys_evaluate_animdata(&mask_temp->id, adt, &anim_eval_context, ADT_RECALC_ANIM, false);
 
  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_id_free(NULL, &mask_temp->id);
 
  BKE_maskrasterize_buffer(mr_handle, context->rectx, context->recty, maskbuf);
 
  BKE_maskrasterize_handle_free(mr_handle);
 
  if (make_float) {
    /* pixels */
    const 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 */
    const 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 frame_index)
{
  bool make_float = (seq->flag & SEQ_MAKE_FLOAT) != 0;
 
  return seq_render_mask(context, seq->mask, frame_index, make_float);
}
 
static ImBuf *seq_render_scene_strip(const SeqRenderData *context,
                                     Sequence *seq,
                                     float frame_index,
                                     float timeline_frame)
{
  ImBuf *ibuf = NULL;
  double frame;
  Object *camera;
 
  struct {
    int scemode;
    int timeline_frame;
    float subframe;
 
#ifdef DURIAN_CAMERA_SWITCH
    int mode;
#endif
  } orig_data;
 
  /* 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_prev_type) != OB_RENDER;
  bool have_comp = false;
  bool use_gpencil = true;
  /* do we need to re-evaluate the frame after rendering? */
  bool is_frame_update = 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;
  }
 
  /* Prevent rendering scene recursively. */
  if (seq->scene == context->scene) {
    return NULL;
  }
 
  scene = seq->scene;
  frame = (double)scene->r.sfra + (double)frame_index + (double)seq->anim_startofs;
 
#if 0 /* UNUSED */
  have_seq = (scene->r.scemode & R_DOSEQ) && scene->ed && scene->ed->seqbase.first);
#endif
  have_comp = (scene->r.scemode & R_DOCOMP) && scene->use_nodes && scene->nodetree;
 
  /* Get view layer for the strip. */
  ViewLayer *view_layer = BKE_view_layer_default_render(scene);
  /* Depsgraph will be NULL when doing rendering. */
  Depsgraph *depsgraph = NULL;
 
  orig_data.scemode = scene->r.scemode;
  orig_data.timeline_frame = scene->r.cfra;
  orig_data.subframe = scene->r.subframe;
#ifdef DURIAN_CAMERA_SWITCH
  orig_data.mode = scene->r.mode;
#endif
 
  BKE_scene_frame_set(scene, 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) {
    goto finally;
  }
 
  if (seq->flag & SEQ_SCENE_NO_GPENCIL) {
    use_gpencil = false;
  }
 
  /* prevent eternal loop */
  scene->r.scemode &= ~R_DOSEQ;
 
#ifdef DURIAN_CAMERA_SWITCH
  /* stooping to new low's in hackyness :( */
  scene->r.mode |= R_NO_CAMERA_SWITCH;
#endif
 
  is_frame_update = (orig_data.timeline_frame != scene->r.cfra) ||
                    (orig_data.subframe != scene->r.subframe);
 
  if ((sequencer_view3d_fn && do_seq_gl && camera) && is_thread_main) {
    char err_out[256] = "unknown";
    const int width = (scene->r.xsch * scene->r.size) / 100;
    const int height = (scene->r.ysch * scene->r.size) / 100;
    const char *viewname = BKE_scene_multiview_render_view_name_get(&scene->r, context->view_id);
 
    unsigned int draw_flags = V3D_OFSDRAW_NONE;
    draw_flags |= (use_gpencil) ? V3D_OFSDRAW_SHOW_ANNOTATION : 0;
    draw_flags |= (context->scene->r.seq_flag & R_SEQ_OVERRIDE_SCENE_SETTINGS) ?
                      V3D_OFSDRAW_OVERRIDE_SCENE_SETTINGS :
                      0;
 
    /* for old scene 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 */
    depsgraph = BKE_scene_ensure_depsgraph(context->bmain, scene, view_layer);
    BKE_scene_graph_update_for_newframe(depsgraph);
    Object *camera_eval = DEG_get_evaluated_object(depsgraph, camera);
    ibuf = sequencer_view3d_fn(
        /* set for OpenGL render (NULL when scrubbing) */
        depsgraph,
        scene,
        &context->scene->display.shading,
        context->scene->r.seq_prev_type,
        camera_eval,
        width,
        height,
        IB_rect,
        draw_flags,
        scene->r.alphamode,
        viewname,
        context->gpu_offscreen,
        err_out);
    if (ibuf == NULL) {
      fprintf(stderr, "seq_render_scene_strip failed to get opengl buffer: %s\n", err_out);
    }
  }
  else {
    Render *re = RE_GetSceneRender(scene);
    const int totviews = BKE_scene_multiview_num_views_get(&scene->r);
    ImBuf **ibufs_arr;
 
    ibufs_arr = MEM_callocN(sizeof(ImBuf *) * totviews, "Sequence Image Views Imbufs");
 
    /* 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 || context->for_render) {
      if (re == NULL) {
        re = RE_NewSceneRender(scene);
      }
 
      RE_RenderFrame(
          re, context->bmain, scene, have_comp ? NULL : view_layer, camera, frame, false);
 
      /* restore previous state after it was toggled on & off by RE_RenderFrame */
      G.is_rendering = is_rendering;
    }
 
    for (int view_id = 0; view_id < totviews; view_id++) {
      SeqRenderData localcontext = *context;
      RenderResult rres;
 
      localcontext.view_id = view_id;
 
      RE_AcquireResultImage(re, &rres, view_id);
 
      if (rres.rectf) {
        ibufs_arr[view_id] = IMB_allocImBuf(rres.rectx, rres.recty, 32, IB_rectfloat);
        memcpy(ibufs_arr[view_id]->rect_float,
               rres.rectf,
               sizeof(float[4]) * rres.rectx * rres.recty);
 
        if (rres.rectz) {
          addzbuffloatImBuf(ibufs_arr[view_id]);
          memcpy(
              ibufs_arr[view_id]->zbuf_float, rres.rectz, sizeof(float) * rres.rectx * rres.recty);
        }
 
        /* float buffers in the sequencer are not linear */
        seq_imbuf_to_sequencer_space(context->scene, ibufs_arr[view_id], false);
      }
      else if (rres.rect32) {
        ibufs_arr[view_id] = IMB_allocImBuf(rres.rectx, rres.recty, 32, IB_rect);
        memcpy(ibufs_arr[view_id]->rect, rres.rect32, 4 * rres.rectx * rres.recty);
      }
 
      if (view_id != context->view_id) {
        seq_cache_put(&localcontext, seq, timeline_frame, SEQ_CACHE_STORE_RAW, ibufs_arr[view_id]);
      }
 
      RE_ReleaseResultImage(re);
    }
 
    /* return the original requested ImBuf */
    ibuf = ibufs_arr[context->view_id];
 
    /* "remove" the others (decrease their refcount) */
    for (int view_id = 0; view_id < totviews; view_id++) {
      if (ibufs_arr[view_id] != ibuf) {
        IMB_freeImBuf(ibufs_arr[view_id]);
      }
    }
    MEM_freeN(ibufs_arr);
  }
 
finally:
  /* restore */
  scene->r.scemode = orig_data.scemode;
  scene->r.cfra = orig_data.timeline_frame;
  scene->r.subframe = orig_data.subframe;
 
  if (is_frame_update && (depsgraph != NULL)) {
    BKE_scene_graph_update_for_newframe(depsgraph);
  }
 
#ifdef DURIAN_CAMERA_SWITCH
  /* stooping to new low's in hackyness :( */
  scene->r.mode &= orig_data.mode | ~R_NO_CAMERA_SWITCH;
#endif
 
  return ibuf;
}
 
static ImBuf *do_render_strip_seqbase(const SeqRenderData *context,
                                      SeqRenderState *state,
                                      Sequence *seq,
                                      float frame_index)
{
  ImBuf *ibuf = NULL;
  ListBase *seqbase = NULL;
  int offset;
 
  seqbase = SEQ_get_seqbase_from_sequence(seq, &offset);
 
  if (seqbase && !BLI_listbase_is_empty(seqbase)) {
 
    if (seq->flag & SEQ_SCENE_STRIPS && seq->scene) {
      BKE_animsys_evaluate_all_animation(context->bmain, context->depsgraph, frame_index + offset);
    }
 
    ibuf = seq_render_strip_stack(context,
                                  state,
                                  seqbase,
                                  /* scene strips don't have their start taken into account */
                                  frame_index + offset,
                                  0);
  }
 
  return ibuf;
}
/* -------------------------------------------------------------------- */
static ImBuf *do_render_strip_uncached(const SeqRenderData *context,
                                       SeqRenderState *state,
                                       Sequence *seq,
                                       float timeline_frame,
                                       bool *r_is_proxy_image)
{
  ImBuf *ibuf = NULL;
  float frame_index = seq_give_frame_index(seq, timeline_frame);
  int type = (seq->type & SEQ_TYPE_EFFECT) ? SEQ_TYPE_EFFECT : seq->type;
  switch (type) {
    case SEQ_TYPE_META: {
      ibuf = do_render_strip_seqbase(context, state, seq, frame_index);
      break;
    }
 
    case SEQ_TYPE_SCENE: {
      if (seq->flag & SEQ_SCENE_STRIPS) {
        if (seq->scene && (context->scene != seq->scene)) {
          /* recursive check */
          if (BLI_linklist_index(state->scene_parents, seq->scene) != -1) {
            break;
          }
          LinkNode scene_parent = {
              .next = state->scene_parents,
              .link = seq->scene,
          };
          state->scene_parents = &scene_parent;
          /* end check */
 
          /* Use the Scene sequence-strip's scene for the context when rendering the
           * scene's sequences (necessary for multi-cam selector among others). */
          SeqRenderData local_context = *context;
          local_context.scene = seq->scene;
          local_context.skip_cache = true;
 
          ibuf = do_render_strip_seqbase(&local_context, state, seq, frame_index);
 
          /* step back in the list */
          state->scene_parents = state->scene_parents->next;
        }
      }
      else {
        /* scene can be NULL after deletions */
        ibuf = seq_render_scene_strip(context, seq, frame_index, timeline_frame);
      }
 
      break;
    }
 
    case SEQ_TYPE_EFFECT: {
      ibuf = seq_render_effect_strip_impl(context, state, seq, timeline_frame);
      break;
    }
 
    case SEQ_TYPE_IMAGE: {
      ibuf = seq_render_image_strip(context, seq, frame_index, timeline_frame, r_is_proxy_image);
      break;
    }
 
    case SEQ_TYPE_MOVIE: {
      ibuf = seq_render_movie_strip(context, seq, frame_index, timeline_frame, r_is_proxy_image);
      break;
    }
 
    case SEQ_TYPE_MOVIECLIP: {
      ibuf = seq_render_movieclip_strip(context, seq, frame_index, r_is_proxy_image);
 
      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) {
          seq_imbuf_to_sequencer_space(context->scene, ibuf, false);
        }
      }
 
      break;
    }
 
    case SEQ_TYPE_MASK: {
      /* ibuf is always new */
      ibuf = seq_render_mask_strip(context, seq, frame_index);
      break;
    }
  }
 
  if (ibuf) {
    seq_imbuf_assign_spaces(context->scene, ibuf);
  }
 
  return ibuf;
}
 
ImBuf *seq_render_strip(const SeqRenderData *context,
                        SeqRenderState *state,
                        Sequence *seq,
                        float timeline_frame)
{
  ImBuf *ibuf = NULL;
  bool use_preprocess = false;
  bool is_proxy_image = false;
 
  ibuf = seq_cache_get(context, seq, timeline_frame, SEQ_CACHE_STORE_PREPROCESSED);
  if (ibuf != NULL) {
    return ibuf;
  }
 
  /* Proxies are not stored in cache. */
  if (!SEQ_can_use_proxy(
          context, seq, SEQ_rendersize_to_proxysize(context->preview_render_size))) {
    ibuf = seq_cache_get(context, seq, timeline_frame, SEQ_CACHE_STORE_RAW);
  }
 
  if (ibuf == NULL) {
    ibuf = do_render_strip_uncached(context, state, seq, timeline_frame, &is_proxy_image);
  }
 
  if (ibuf) {
    use_preprocess = seq_input_have_to_preprocess(context, seq, timeline_frame);
    ibuf = seq_render_preprocess_ibuf(
        context, seq, ibuf, timeline_frame, use_preprocess, is_proxy_image);
  }
 
  if (ibuf == NULL) {
    ibuf = IMB_allocImBuf(context->rectx, context->recty, 32, IB_rect);
    seq_imbuf_assign_spaces(context->scene, ibuf);
  }
 
  return ibuf;
}
 
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 (ELEM(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 = seq_effect_get_sequence_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;
    }
    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 timeline_frame, ImBuf *ibuf1, ImBuf *ibuf2)
{
  ImBuf *out;
  struct SeqEffectHandle sh = seq_effect_get_sequence_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, timeline_frame, facf, facf, ibuf2, ibuf1, NULL);
    }
    else {
      out = sh.execute(context, seq, timeline_frame, facf, facf, ibuf2, ibuf1, NULL);
    }
  }
  else {
    if (sh.multithreaded) {
      out = seq_render_effect_execute_threaded(
          &sh, context, seq, timeline_frame, facf, facf, ibuf1, ibuf2, NULL);
    }
    else {
      out = sh.execute(context, seq, timeline_frame, facf, facf, ibuf1, ibuf2, NULL);
    }
  }
 
  return out;
}
 
static ImBuf *seq_render_strip_stack(const SeqRenderData *context,
                                     SeqRenderState *state,
                                     ListBase *seqbasep,
                                     float timeline_frame,
                                     int chanshown)
{
  Sequence *seq_arr[MAXSEQ + 1];
  int count;
  int i;
  ImBuf *out = NULL;
 
  count = seq_get_shown_sequences(seqbasep, timeline_frame, chanshown, (Sequence **)&seq_arr);
 
  if (count == 0) {
    return NULL;
  }
 
  for (i = count - 1; i >= 0; i--) {
    int early_out;
    Sequence *seq = seq_arr[i];
 
    out = seq_cache_get(context, seq, timeline_frame, SEQ_CACHE_STORE_COMPOSITE);
 
    if (out) {
      break;
    }
    if (seq->blend_mode == SEQ_BLEND_REPLACE) {
      out = seq_render_strip(context, state, seq, timeline_frame);
      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, state, seq, timeline_frame);
        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) {
          ImBuf *ibuf1 = IMB_allocImBuf(context->rectx, context->recty, 32, IB_rect);
          ImBuf *ibuf2 = seq_render_strip(context, state, seq, timeline_frame);
 
          out = seq_render_strip_stack_apply_effect(context, seq, timeline_frame, ibuf1, ibuf2);
 
          seq_cache_put(context, seq_arr[i], timeline_frame, SEQ_CACHE_STORE_COMPOSITE, out);
 
          IMB_freeImBuf(ibuf1);
          IMB_freeImBuf(ibuf2);
        }
        break;
    }
    if (out) {
      break;
    }
  }
 
  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, state, seq, timeline_frame);
 
      out = seq_render_strip_stack_apply_effect(context, seq, timeline_frame, ibuf1, ibuf2);
 
      IMB_freeImBuf(ibuf1);
      IMB_freeImBuf(ibuf2);
    }
 
    seq_cache_put(context, seq_arr[i], timeline_frame, SEQ_CACHE_STORE_COMPOSITE, out);
  }
 
  return out;
}
 
ImBuf *SEQ_render_give_ibuf(const SeqRenderData *context, float timeline_frame, int chanshown)
{
  Scene *scene = context->scene;
  Editing *ed = SEQ_editing_get(scene, false);
  ListBase *seqbasep;
 
  if (ed == NULL) {
    return NULL;
  }
 
  if ((chanshown < 0) && !BLI_listbase_is_empty(&ed->metastack)) {
    int count = BLI_listbase_count(&ed->metastack);
    count = max_ii(count + chanshown, 0);
    seqbasep = ((MetaStack *)BLI_findlink(&ed->metastack, count))->oldbasep;
  }
  else {
    seqbasep = ed->seqbasep;
  }
 
  SeqRenderState state;
  seq_render_state_init(&state);
  ImBuf *out = NULL;
  Sequence *seq_arr[MAXSEQ + 1];
  int count;
 
  count = seq_get_shown_sequences(seqbasep, timeline_frame, chanshown, seq_arr);
 
  if (count) {
    out = seq_cache_get(context, seq_arr[count - 1], timeline_frame, SEQ_CACHE_STORE_FINAL_OUT);
  }
 
  seq_cache_free_temp_cache(context->scene, context->task_id, timeline_frame);
 
  if (count && !out) {
    BLI_mutex_lock(&seq_render_mutex);
    out = seq_render_strip_stack(context, &state, seqbasep, timeline_frame, chanshown);
 
    if (context->is_prefetch_render) {
      seq_cache_put(context, seq_arr[count - 1], timeline_frame, SEQ_CACHE_STORE_FINAL_OUT, out);
    }
    else {
      seq_cache_put_if_possible(
          context, seq_arr[count - 1], timeline_frame, SEQ_CACHE_STORE_FINAL_OUT, out);
    }
    BLI_mutex_unlock(&seq_render_mutex);
  }
 
  seq_prefetch_start(context, timeline_frame);
 
  return out;
}
 
ImBuf *seq_render_give_ibuf_seqbase(const SeqRenderData *context,
                                    float timeline_frame,
                                    int chan_shown,
                                    ListBase *seqbasep)
{
  SeqRenderState state;
  seq_render_state_init(&state);
 
  return seq_render_strip_stack(context, &state, seqbasep, timeline_frame, chan_shown);
}
 
ImBuf *SEQ_render_give_ibuf_direct(const SeqRenderData *context,
                                   float timeline_frame,
                                   Sequence *seq)
{
  SeqRenderState state;
  seq_render_state_init(&state);
 
  ImBuf *ibuf = seq_render_strip(context, &state, seq, timeline_frame);
 
  return ibuf;
}