render.cc

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/* SPDX-FileCopyrightText: 2001-2002 NaN Holding BV. All rights reserved.
 * SPDX-FileCopyrightText: 2003-2024 Blender Authors
 * SPDX-FileCopyrightText: 2005-2006 Peter Schlaile <peter [at] schlaile [dot] de>
 *
 * SPDX-License-Identifier: GPL-2.0-or-later */
 
#include <ctime>
 
#include "MEM_guardedalloc.h"
 
#include "DNA_defaults.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_math_geom.h"
#include "BLI_math_rotation.h"
#include "BLI_path_utils.hh"
#include "BLI_rect.h"
#include "BLI_task.hh"
 
#include "BKE_anim_data.hh"
#include "BKE_animsys.h"
#include "BKE_fcurve.hh"
#include "BKE_global.hh"
#include "BKE_image.hh"
#include "BKE_layer.hh"
#include "BKE_lib_id.hh"
#include "BKE_main.hh"
#include "BKE_mask.h"
#include "BKE_movieclip.h"
#include "BKE_scene.hh"
#include "BKE_sequencer_offscreen.h"
 
#include "DEG_depsgraph.hh"
#include "DEG_depsgraph_query.hh"
 
#include "IMB_colormanagement.hh"
#include "IMB_imbuf.hh"
#include "IMB_imbuf_types.hh"
#include "IMB_metadata.hh"
 
#include "RNA_prototypes.hh"
 
#include "RE_engine.h"
#include "RE_pipeline.h"
 
#include "SEQ_channels.hh"
#include "SEQ_effects.hh"
#include "SEQ_iterator.hh"
#include "SEQ_modifier.hh"
#include "SEQ_proxy.hh"
#include "SEQ_relations.hh"
#include "SEQ_render.hh"
#include "SEQ_sequencer.hh"
#include "SEQ_time.hh"
#include "SEQ_transform.hh"
#include "SEQ_utils.hh"
 
#include "effects.hh"
#include "image_cache.hh"
#include "multiview.hh"
#include "prefetch.hh"
#include "proxy.hh"
#include "render.hh"
#include "utils.hh"
 
#include <algorithm>
 
using namespace blender;
 
static ImBuf *seq_render_strip_stack(const SeqRenderData *context,
                                     SeqRenderState *state,
                                     ListBase *channels,
                                     ListBase *seqbasep,
                                     float timeline_frame,
                                     int chanshown);
 
static ThreadMutex seq_render_mutex = BLI_MUTEX_INITIALIZER;
SequencerDrawView sequencer_view3d_fn = nullptr; /* nullptr in background mode */
 
/* -------------------------------------------------------------------- */
void seq_imbuf_assign_spaces(const Scene *scene, ImBuf *ibuf)
{
#if 0
  /* Byte buffer is supposed to be in sequencer working space already. */
  if (ibuf->rect != nullptr) {
    IMB_colormanagement_assign_byte_colorspace(ibuf, scene->sequencer_colorspace_settings.name);
  }
#endif
  if (ibuf->float_buffer.data != nullptr) {
    IMB_colormanagement_assign_float_colorspace(ibuf, scene->sequencer_colorspace_settings.name);
  }
}
 
void seq_imbuf_to_sequencer_space(const Scene *scene, ImBuf *ibuf, bool make_float)
{
  /* Early output check: if both buffers are nullptr we have nothing to convert. */
  if (ibuf->float_buffer.data == nullptr && ibuf->byte_buffer.data == nullptr) {
    return;
  }
  /* Get common conversion settings. */
  const char *to_colorspace = scene->sequencer_colorspace_settings.name;
  /* Perform actual conversion logic. */
  if (ibuf->float_buffer.data == nullptr) {
    /* 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(ibuf->byte_buffer.data,
                                                  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, 4, false);
      IMB_colormanagement_transform_from_byte_threaded(ibuf->float_buffer.data,
                                                       ibuf->byte_buffer.data,
                                                       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 == nullptr || 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->byte_buffer.data != nullptr) {
      imb_freerectImBuf(ibuf);
    }
    IMB_colormanagement_transform_threaded(ibuf->float_buffer.data,
                                           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->float_buffer.data) {
    return;
  }
 
  if (to_colorspace && to_colorspace[0] != '\0') {
    IMB_colormanagement_transform_threaded(ibuf->float_buffer.data,
                                           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(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,
                                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->ignore_missing_media = false;
  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 = nullptr;
  r_context->gpu_viewport = nullptr;
  r_context->task_id = SEQ_TASK_MAIN_RENDER;
  r_context->is_prefetch_render = false;
}
 
StripElem *SEQ_render_give_stripelem(const Scene *scene, const 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 = round_fl_to_int(SEQ_give_frame_index(scene, seq, timeline_frame));
 
    if (frame_index == -1 || se == nullptr) {
      return nullptr;
    }
 
    se += frame_index + seq->anim_startofs;
  }
  return se;
}
 
Vector<Sequence *> seq_get_shown_sequences(const Scene *scene,
                                           ListBase *channels,
                                           ListBase *seqbase,
                                           const int timeline_frame,
                                           const int chanshown)
{
  Vector<Sequence *> result;
  VectorSet strips = SEQ_query_rendered_strips(
      scene, channels, seqbase, timeline_frame, chanshown);
  const int strip_count = strips.size();
 
  if (UNLIKELY(strip_count > SEQ_MAX_CHANNELS)) {
    BLI_assert_msg(0, "Too many strips, this shouldn't happen");
    return result;
  }
 
  result.reserve(strips.size());
  for (Sequence *seq : strips) {
    result.append(seq);
  }
 
  /* Sort strips by channel. */
  std::sort(result.begin(), result.end(), [](const Sequence *a, const Sequence *b) {
    return a->machine < b->machine;
  });
  return result;
}
 
StripScreenQuad get_strip_screen_quad(const SeqRenderData *context, const Sequence *seq)
{
  Scene *scene = context->scene;
  const int x = context->rectx;
  const int y = context->recty;
  float2 offset{x * 0.5f, y * 0.5f};
 
  float quad[4][2];
  SEQ_image_transform_final_quad_get(scene, seq, quad);
  return StripScreenQuad{quad[0] + offset, quad[1] + offset, quad[2] + offset, quad[3] + offset};
}
 
/* Is quad `a` fully contained (i.e. covered by) quad `b`? For that to happen,
 * all corners of `a` have to be inside `b`. */
static bool is_quad_a_inside_b(const StripScreenQuad &a, const StripScreenQuad &b)
{
  return isect_point_quad_v2(a.v0, b.v0, b.v1, b.v2, b.v3) &&
         isect_point_quad_v2(a.v1, b.v0, b.v1, b.v2, b.v3) &&
         isect_point_quad_v2(a.v2, b.v0, b.v1, b.v2, b.v3) &&
         isect_point_quad_v2(a.v3, b.v0, b.v1, b.v2, b.v3);
}
 
/* Tracking of "known to be opaque" strip quad coordinates, along with their
 * order index within visible strips during rendering. */
 
struct OpaqueQuad {
  StripScreenQuad quad;
  int order_index;
};
 
struct OpaqueQuadTracker {
  Vector<OpaqueQuad, 4> opaques;
 
  /* Determine if the input strip is completely behind opaque strips that are
   * above it. Current implementation is simple and only checks if strip is
   * completely covered by any other strip. It does not detect case where
   * a strip is not covered by a single strip, but is behind of the union
   * of the strips above. */
  bool is_occluded(const SeqRenderData *context, const Sequence *seq, int order_index) const
  {
    StripScreenQuad quad = get_strip_screen_quad(context, seq);
    if (quad.is_empty()) {
      /* Strip size is not initialized/valid, we can't know if it is occluded. */
      return false;
    }
    for (const OpaqueQuad &q : opaques) {
      if (q.order_index > order_index && is_quad_a_inside_b(quad, q.quad)) {
        return true;
      }
    }
    return false;
  }
 
  void add_occluder(const SeqRenderData *context, const Sequence *seq, int order_index)
  {
    StripScreenQuad quad = get_strip_screen_quad(context, seq);
    if (!quad.is_empty()) {
      opaques.append({quad, order_index});
    }
  }
};
 
/* -------------------------------------------------------------------- */
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 /*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;
}
 
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_matrix(const Sequence *seq,
                                                  const ImBuf *in,
                                                  const ImBuf *out,
                                                  const float image_scale_factor,
                                                  const float preview_scale_factor,
                                                  float r_transform_matrix[4][4])
{
  const StripTransform *transform = seq->strip->transform;
  const float scale_x = transform->scale_x * image_scale_factor;
  const float scale_y = transform->scale_y * image_scale_factor;
  const float image_center_offs_x = (out->x - in->x) / 2;
  const float image_center_offs_y = (out->y - in->y) / 2;
  const float translate_x = transform->xofs * preview_scale_factor + image_center_offs_x;
  const float translate_y = transform->yofs * preview_scale_factor + image_center_offs_y;
  const float pivot[3] = {in->x * transform->origin[0], in->y * transform->origin[1], 0.0f};
 
  float rotation_matrix[3][3];
  axis_angle_to_mat3_single(rotation_matrix, 'Z', transform->rotation);
  loc_rot_size_to_mat4(r_transform_matrix,
                       float3{translate_x, translate_y, 0.0f},
                       rotation_matrix,
                       float3{scale_x, scale_y, 1.0f});
  transform_pivot_set_m4(r_transform_matrix, pivot);
  invert_m4(r_transform_matrix);
}
 
static void sequencer_image_crop_init(const Sequence *seq,
                                      const ImBuf *in,
                                      float crop_scale_factor,
                                      rctf *r_crop)
{
  const StripCrop *c = seq->strip->crop;
  const int left = c->left * crop_scale_factor;
  const int right = c->right * crop_scale_factor;
  const int top = c->top * crop_scale_factor;
  const int bottom = c->bottom * crop_scale_factor;
 
  BLI_rctf_init(r_crop, left, in->x - right, bottom, in->y - top);
}
 
static bool is_strip_covering_screen(const SeqRenderData *context, const Sequence *seq)
{
  /* The check is done by checking whether all corners of viewport fit inside
   * of the transformed strip. If they do not, the strip does not cover
   * whole screen. */
  float x0 = 0.0f;
  float y0 = 0.0f;
  float x1 = float(context->rectx);
  float y1 = float(context->recty);
  float x_aspect = context->scene->r.xasp / context->scene->r.yasp;
  if (x_aspect != 1.0f) {
    float xmid = (x0 + x1) * 0.5f;
    x0 = xmid - (xmid - x0) * x_aspect;
    x1 = xmid + (x1 - xmid) * x_aspect;
  }
  StripScreenQuad quad = get_strip_screen_quad(context, seq);
  StripScreenQuad screen{float2(x0, y0), float2(x1, y0), float2(x0, y1), float2(x1, y1)};
 
  return is_quad_a_inside_b(screen, quad);
}
 
/* Automatic filter:
 * - No scale, no rotation and non-fractional position: nearest.
 * - Scale up by more than 2x: cubic mitchell.
 * - Scale down by more than 2x: box.
 * - Otherwise: bilinear. */
static eIMBInterpolationFilterMode get_auto_filter(const StripTransform *transform)
{
  const float sx = fabsf(transform->scale_x);
  const float sy = fabsf(transform->scale_y);
  if (sx > 2.0f && sy > 2.0f) {
    return IMB_FILTER_CUBIC_MITCHELL;
  }
  if (sx < 0.5f && sy < 0.5f) {
    return IMB_FILTER_BOX;
  }
  const float px = transform->xofs;
  const float py = transform->yofs;
  const float rot = transform->rotation;
  if (sx == 1.0f && sy == 1.0f && roundf(px) == px && roundf(py) == py && rot == 0.0f) {
    return IMB_FILTER_NEAREST;
  }
  return IMB_FILTER_BILINEAR;
}
 
static void sequencer_preprocess_transform_crop(
    ImBuf *in, ImBuf *out, const SeqRenderData *context, Sequence *seq, const bool is_proxy_image)
{
  const Scene *scene = context->scene;
  const float preview_scale_factor = context->preview_render_size == SEQ_RENDER_SIZE_SCENE ?
                                         float(scene->r.size) / 100 :
                                         SEQ_rendersize_to_scale_factor(
                                             context->preview_render_size);
  const bool do_scale_to_render_size = seq_need_scale_to_render_size(seq, is_proxy_image);
  const float image_scale_factor = do_scale_to_render_size ? 1.0f : preview_scale_factor;
 
  float transform_matrix[4][4];
  sequencer_image_crop_transform_matrix(
      seq, in, out, image_scale_factor, preview_scale_factor, transform_matrix);
 
  /* Proxy image is smaller, so crop values must be corrected by proxy scale factor.
   * Proxy scale factor always matches preview_scale_factor. */
  rctf source_crop;
  const float crop_scale_factor = do_scale_to_render_size ? preview_scale_factor : 1.0f;
  sequencer_image_crop_init(seq, in, crop_scale_factor, &source_crop);
 
  const StripTransform *transform = seq->strip->transform;
  eIMBInterpolationFilterMode filter = IMB_FILTER_NEAREST;
  switch (transform->filter) {
    case SEQ_TRANSFORM_FILTER_AUTO:
      filter = get_auto_filter(seq->strip->transform);
      break;
    case SEQ_TRANSFORM_FILTER_NEAREST:
      filter = IMB_FILTER_NEAREST;
      break;
    case SEQ_TRANSFORM_FILTER_BILINEAR:
      filter = IMB_FILTER_BILINEAR;
      break;
    case SEQ_TRANSFORM_FILTER_CUBIC_BSPLINE:
      filter = IMB_FILTER_CUBIC_BSPLINE;
      break;
    case SEQ_TRANSFORM_FILTER_CUBIC_MITCHELL:
      filter = IMB_FILTER_CUBIC_MITCHELL;
      break;
    case SEQ_TRANSFORM_FILTER_BOX:
      filter = IMB_FILTER_BOX;
      break;
  }
 
  IMB_transform(in, out, IMB_TRANSFORM_MODE_CROP_SRC, filter, transform_matrix, &source_crop);
 
  if (is_strip_covering_screen(context, seq)) {
    out->planes = in->planes;
  }
  else {
    /* Strip is not covering full viewport, which means areas with transparency
     * are introduced for sure. */
    out->planes = R_IMF_PLANES_RGBA;
  }
}
 
static void multiply_ibuf(ImBuf *ibuf, const float fmul, const bool multiply_alpha)
{
  const size_t pixel_count = IMB_get_rect_len(ibuf);
  if (ibuf->byte_buffer.data != nullptr) {
    threading::parallel_for(IndexRange(pixel_count), 64 * 1024, [&](IndexRange range) {
      uchar *ptr = ibuf->byte_buffer.data + range.first() * 4;
      const int imul = int(256.0f * fmul);
      for ([[maybe_unused]] const int64_t i : range) {
        ptr[0] = min_ii((imul * ptr[0]) >> 8, 255);
        ptr[1] = min_ii((imul * ptr[1]) >> 8, 255);
        ptr[2] = min_ii((imul * ptr[2]) >> 8, 255);
        if (multiply_alpha) {
          ptr[3] = min_ii((imul * ptr[3]) >> 8, 255);
        }
        ptr += 4;
      }
    });
  }
 
  if (ibuf->float_buffer.data != nullptr) {
    threading::parallel_for(IndexRange(pixel_count), 64 * 1024, [&](IndexRange range) {
      float *ptr = ibuf->float_buffer.data + range.first() * 4;
      for ([[maybe_unused]] const int64_t i : range) {
        ptr[0] *= fmul;
        ptr[1] *= fmul;
        ptr[2] *= fmul;
        if (multiply_alpha) {
          ptr[3] *= fmul;
        }
        ptr += 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 = nullptr;
 
  /* 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->float_buffer.data ? IB_rectfloat : IB_rect);
 
    sequencer_preprocess_transform_crop(ibuf, preprocessed_ibuf, context, seq, is_proxy_image);
 
    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 == nullptr) {
    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->float_buffer.data) {
      seq_imbuf_to_sequencer_space(scene, preprocessed_ibuf, true);
    }
 
    if (preprocessed_ibuf->byte_buffer.data) {
      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) {
    const bool multiply_alpha = (seq->flag & SEQ_MULTIPLY_ALPHA);
    multiply_ibuf(preprocessed_ibuf, mul, multiply_alpha);
  }
 
  if (seq->modifiers.first) {
    SEQ_modifier_apply_stack(context, seq, preprocessed_ibuf, timeline_frame);
  }
 
  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 non-generator effect strips are not stored in cache. */
  const bool is_effect_with_inputs = (seq->type & SEQ_TYPE_EFFECT) != 0 &&
                                     SEQ_effect_get_num_inputs(seq->type) != 0;
  if (!is_proxy_image && !is_effect_with_inputs) {
    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;
}
 
struct RenderEffectInitData {
  SeqEffectHandle *sh;
  const SeqRenderData *context;
  Sequence *seq;
  float timeline_frame, fac;
  ImBuf *ibuf1, *ibuf2;
 
  ImBuf *out;
};
 
struct RenderEffectThread {
  SeqEffectHandle *sh;
  const SeqRenderData *context;
  Sequence *seq;
  float timeline_frame, fac;
  ImBuf *ibuf1, *ibuf2;
 
  ImBuf *out;
  int start_line, tot_line;
};
 
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->fac = init_data->fac;
  handle->ibuf1 = init_data->ibuf1;
  handle->ibuf2 = init_data->ibuf2;
  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->fac,
                                 thread_data->ibuf1,
                                 thread_data->ibuf2,
                                 thread_data->start_line,
                                 thread_data->tot_line,
                                 thread_data->out);
 
  return nullptr;
}
 
ImBuf *seq_render_effect_execute_threaded(SeqEffectHandle *sh,
                                          const SeqRenderData *context,
                                          Sequence *seq,
                                          float timeline_frame,
                                          float fac,
                                          ImBuf *ibuf1,
                                          ImBuf *ibuf2)
{
  RenderEffectInitData init_data;
  ImBuf *out = sh->init_execution(context, ibuf1, ibuf2);
 
  init_data.sh = sh;
  init_data.context = context;
  init_data.seq = seq;
  init_data.timeline_frame = timeline_frame;
  init_data.fac = fac;
  init_data.ibuf1 = ibuf1;
  init_data.ibuf2 = ibuf2;
  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;
  int i;
  SeqEffectHandle sh = SEQ_effect_handle_get(seq);
  const FCurve *fcu = nullptr;
  ImBuf *ibuf[2];
  Sequence *input[2];
  ImBuf *out = nullptr;
 
  ibuf[0] = ibuf[1] = nullptr;
 
  input[0] = seq->seq1;
  input[1] = seq->seq2;
 
  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(scene, seq, timeline_frame, &fac);
  }
  else {
    fcu = id_data_find_fcurve(&scene->id, seq, &RNA_Sequence, "effect_fader", 0, nullptr);
    if (fcu) {
      fac = evaluate_fcurve(fcu, timeline_frame);
    }
    else {
      fac = seq->effect_fader;
    }
  }
 
  StripEarlyOut early_out = sh.early_out(seq, fac);
 
  switch (early_out) {
    case StripEarlyOut::NoInput:
      out = sh.execute(context, seq, timeline_frame, fac, nullptr, nullptr);
      break;
    case StripEarlyOut::DoEffect:
      for (i = 0; i < 2; 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(scene, seq, timeline_frame, i);
 
          /* Only convert to int when interpolation is not used. */
          SpeedControlVars *s = reinterpret_cast<SpeedControlVars *>(seq->effectdata);
          if ((s->flags & SEQ_SPEED_USE_INTERPOLATION) != 0) {
            target_frame = std::floor(target_frame);
          }
 
          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, ibuf[0], ibuf[1]);
        }
        else {
          out = sh.execute(context, seq, timeline_frame, fac, ibuf[0], ibuf[1]);
        }
      }
      break;
    case StripEarlyOut::UseInput1:
      if (input[0]) {
        out = seq_render_strip(context, state, input[0], timeline_frame);
      }
      break;
    case StripEarlyOut::UseInput2:
      if (input[1]) {
        out = seq_render_strip(context, state, input[1], timeline_frame);
      }
      break;
  }
 
  for (i = 0; i < 2; i++) {
    IMB_freeImBuf(ibuf[i]);
  }
 
  if (out == nullptr) {
    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 *filepath,
                                          char *prefix,
                                          const char *ext,
                                          int view_id)
{
  ImBuf *ibuf = nullptr;
 
  int flag = IB_rect | IB_metadata;
  if (seq->alpha_mode == SEQ_ALPHA_PREMUL) {
    flag |= IB_alphamode_premul;
  }
 
  if (prefix[0] == '\0') {
    ibuf = IMB_loadiffname(filepath, flag, seq->strip->colorspace_settings.name);
  }
  else {
    char filepath_view[FILE_MAX];
    BKE_scene_multiview_view_prefix_get(context->scene, filepath, prefix, &ext);
    seq_multiview_name(context->scene, view_id, prefix, ext, filepath_view, FILE_MAX);
    ibuf = IMB_loadiffname(filepath_view, flag, seq->strip->colorspace_settings.name);
  }
 
  if (ibuf == nullptr) {
    return nullptr;
  }
 
  /* We don't need both (speed reasons)! */
  if (ibuf->float_buffer.data != nullptr && ibuf->byte_buffer.data != nullptr) {
    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,
                                                const char *filepath,
                                                char *r_prefix,
                                                const char *r_ext)
{
  if (totfiles > 1) {
    BKE_scene_multiview_view_prefix_get(scene, filepath, 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 *create_missing_media_image(const SeqRenderData *context, int width, int height)
{
  if (context->ignore_missing_media) {
    return nullptr;
  }
  if (context->scene == nullptr || context->scene->ed == nullptr ||
      (context->scene->ed->show_missing_media_flag & SEQ_EDIT_SHOW_MISSING_MEDIA) == 0)
  {
    return nullptr;
  }
 
  ImBuf *ibuf = IMB_allocImBuf(max_ii(width, 1), max_ii(height, 1), 32, IB_rect);
  float col[4] = {0.85f, 0.0f, 0.75f, 1.0f};
  IMB_rectfill(ibuf, col);
  return ibuf;
}
 
static ImBuf *seq_render_image_strip(const SeqRenderData *context,
                                     Sequence *seq,
                                     int timeline_frame,
                                     bool *r_is_proxy_image)
{
  char filepath[FILE_MAX];
  const char *ext = nullptr;
  char prefix[FILE_MAX];
  ImBuf *ibuf = nullptr;
 
  StripElem *s_elem = SEQ_render_give_stripelem(context->scene, seq, timeline_frame);
  if (s_elem == nullptr) {
    return nullptr;
  }
 
  BLI_path_join(filepath, sizeof(filepath), seq->strip->dirpath, s_elem->filename);
  BLI_path_abs(filepath, ID_BLEND_PATH_FROM_GLOBAL(&context->scene->id));
 
  /* Try to get a proxy image. */
  ibuf = seq_proxy_fetch(context, seq, timeline_frame);
  if (ibuf != nullptr) {
    *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, filepath, prefix, ext);
 
  if (is_multiview_render) {
    int totviews = BKE_scene_multiview_num_views_get(&context->scene->r);
    ImBuf **ibufs_arr = static_cast<ImBuf **>(
        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, filepath, prefix, ext, view_id);
    }
 
    if (ibufs_arr[0] == nullptr) {
      return nullptr;
    }
 
    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, filepath, prefix, ext, context->view_id);
  }
 
  blender::seq::media_presence_set_missing(context->scene, seq, ibuf == nullptr);
  if (ibuf == nullptr) {
    return create_missing_media_image(context, s_elem->orig_width, s_elem->orig_height);
  }
 
  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 filepath[PROXY_MAXFILE];
  StripProxy *proxy = seq->strip->proxy;
 
  if (proxy->anim == nullptr) {
    if (seq_proxy_get_custom_file_filepath(seq, filepath, context->view_id)) {
      proxy->anim = openanim(filepath, IB_rect, 0, seq->strip->colorspace_settings.name);
    }
    if (proxy->anim == nullptr) {
      return nullptr;
    }
  }
 
  int frameno = round_fl_to_int(SEQ_give_frame_index(context->scene, seq, timeline_frame)) +
                seq->anim_startofs;
  return IMB_anim_absolute(proxy->anim, frameno, IMB_TC_NONE, IMB_PROXY_NONE);
}
 
static IMB_Timecode_Type seq_render_movie_strip_timecode_get(Sequence *seq)
{
  bool use_timecodes = (seq->flag & SEQ_USE_PROXY) != 0;
  if (!use_timecodes) {
    return IMB_TC_NONE;
  }
  return IMB_Timecode_Type(seq->strip->proxy ? IMB_Timecode_Type(seq->strip->proxy->tc) :
                                               IMB_TC_NONE);
}
 
static ImBuf *seq_render_movie_strip_view(const SeqRenderData *context,
                                          Sequence *seq,
                                          float timeline_frame,
                                          StripAnim *sanim,
                                          bool *r_is_proxy_image)
{
  ImBuf *ibuf = nullptr;
  IMB_Proxy_Size psize = IMB_Proxy_Size(SEQ_rendersize_to_proxysize(context->preview_render_size));
  const int frame_index = round_fl_to_int(
      SEQ_give_frame_index(context->scene, seq, timeline_frame));
 
  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_render_movie_strip_timecode_get(seq),
                               psize);
    }
 
    if (ibuf != nullptr) {
      *r_is_proxy_image = true;
    }
  }
 
  /* Fetching for requested proxy size failed, try fetching the original instead. */
  if (ibuf == nullptr) {
    ibuf = IMB_anim_absolute(sanim->anim,
                             frame_index + seq->anim_startofs,
                             seq_render_movie_strip_timecode_get(seq),
                             IMB_PROXY_NONE);
  }
  if (ibuf == nullptr) {
    return nullptr;
  }
 
  seq_imbuf_to_sequencer_space(context->scene, ibuf, false);
 
  /* We don't need both (speed reasons)! */
  if (ibuf->float_buffer.data != nullptr && ibuf->byte_buffer.data != nullptr) {
    imb_freerectImBuf(ibuf);
  }
 
  return ibuf;
}
 
static ImBuf *seq_render_movie_strip(const SeqRenderData *context,
                                     Sequence *seq,
                                     float timeline_frame,
                                     bool *r_is_proxy_image)
{
  /* Load all the videos. */
  seq_open_anim_file(context->scene, seq, false);
 
  ImBuf *ibuf = nullptr;
  StripAnim *sanim = static_cast<StripAnim *>(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_is_equal_to(&seq->anims, totfiles);
 
  if (is_multiview_render) {
    ImBuf **ibuf_arr;
    int totviews = BKE_scene_multiview_num_views_get(&context->scene->r);
    ibuf_arr = static_cast<ImBuf **>(
        MEM_callocN(sizeof(ImBuf *) * totviews, "Sequence Image Views Imbufs"));
    int ibuf_view_id;
 
    for (ibuf_view_id = 0, sanim = static_cast<StripAnim *>(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, timeline_frame, sanim, r_is_proxy_image);
      }
    }
 
    if (seq->views_format == R_IMF_VIEWS_STEREO_3D) {
      if (ibuf_arr[0] == nullptr) {
        /* Probably proxy hasn't been created yet. */
        MEM_freeN(ibuf_arr);
        return nullptr;
      }
 
      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]) {
        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, timeline_frame, sanim, r_is_proxy_image);
  }
 
  blender::seq::media_presence_set_missing(context->scene, seq, ibuf == nullptr);
  if (ibuf == nullptr) {
    return create_missing_media_image(
        context, seq->strip->stripdata->orig_width, seq->strip->stripdata->orig_height);
  }
 
  if (*r_is_proxy_image == false) {
    if (sanim && sanim->anim) {
      short fps_denom;
      float fps_num;
      IMB_anim_get_fps(sanim->anim, true, &fps_denom, &fps_num);
      seq->strip->stripdata->orig_fps = fps_denom / fps_num;
    }
    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 = nullptr;
  float tloc[2], tscale, tangle;
  if (seq->clip_flag & SEQ_MOVIECLIP_RENDER_STABILIZED) {
    ibuf = BKE_movieclip_get_stable_ibuf(seq->clip, &user, 0, tloc, &tscale, &tangle);
  }
  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 = nullptr;
  MovieClipUser user = *DNA_struct_default_get(MovieClipUser);
  IMB_Proxy_Size psize = IMB_Proxy_Size(SEQ_rendersize_to_proxysize(context->preview_render_size));
 
  if (!seq->clip) {
    return nullptr;
  }
 
  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 clip doesn't use proxies, it will fallback to full size render of original file. */
  if (ibuf != nullptr && psize != IMB_PROXY_NONE && BKE_movieclip_proxy_enabled(seq->clip)) {
    *r_is_proxy_image = true;
  }
 
  /* If proxy is not found, grab full-size frame. */
  if (ibuf == nullptr) {
    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 = nullptr;
  float *maskbuf;
  int i;
 
  if (!mask) {
    return nullptr;
  }
 
  AnimData *adt;
  Mask *mask_temp;
  MaskRasterHandle *mr_handle;
 
  mask_temp = (Mask *)BKE_id_copy_ex(
      nullptr, &mask->id, nullptr, 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 = static_cast<float *>(
      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(nullptr, &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 | IB_uninitialized_pixels);
 
    fp_src = maskbuf;
    fp_dst = ibuf->float_buffer.data;
    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;
    uchar *ub_dst;
 
    ibuf = IMB_allocImBuf(context->rectx, context->recty, 32, IB_rect | IB_uninitialized_pixels);
 
    fp_src = maskbuf;
    ub_dst = ibuf->byte_buffer.data;
    i = context->rectx * context->recty;
    while (--i) {
      ub_dst[0] = ub_dst[1] = ub_dst[2] = uchar(*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 = nullptr;
  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/image-window
   *
   * 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;
  bool is_preview = !context->for_render && (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;
 
  /* don't refer to seq->scene above this point!, it can be nullptr */
  if (seq->scene == nullptr) {
    return create_missing_media_image(context, context->rectx, context->recty);
  }
 
  /* Prevent rendering scene recursively. */
  if (seq->scene == context->scene) {
    return nullptr;
  }
 
  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 nullptr when doing rendering. */
  Depsgraph *depsgraph = nullptr;
 
  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 == nullptr) {
    goto finally;
  }
 
  if (seq->flag & SEQ_SCENE_NO_ANNOTATION) {
    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 && is_preview && camera && BLI_thread_is_main()) {
    char err_out[256] = "unknown";
    int width, height;
    BKE_render_resolution(&scene->r, false, &width, &height);
    const char *viewname = BKE_scene_multiview_render_view_name_get(&scene->r, context->view_id);
 
    uint 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 (nullptr when scrubbing) */
        depsgraph,
        scene,
        &context->scene->display.shading,
        eDrawType(context->scene->r.seq_prev_type),
        camera_eval,
        width,
        height,
        IB_rect,
        eV3DOffscreenDrawFlag(draw_flags),
        scene->r.alphamode,
        viewname,
        context->gpu_offscreen,
        context->gpu_viewport,
        err_out);
    if (ibuf == nullptr) {
      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;
 
    /*
     * XXX: this if can be removed when sequence preview rendering uses the job system
     *
     * Disable rendered preview for sequencer while rendering - invoked render job will
     * conflict with already running 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_preview && (is_rendering && !G.background)) {
      goto finally;
    }
 
    ibufs_arr = static_cast<ImBuf **>(
        MEM_callocN(sizeof(ImBuf *) * totviews, "Sequence Image Views Imbufs"));
 
    if (re == nullptr) {
      re = RE_NewSceneRender(scene);
    }
 
    const float subframe = frame - floorf(frame);
 
    RE_RenderFrame(re,
                   context->bmain,
                   scene,
                   have_comp ? nullptr : view_layer,
                   camera,
                   floorf(frame),
                   subframe,
                   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);
 
      /* TODO: Share the pixel data with the original image buffer from the render result using
       * implicit sharing. */
      if (rres.ibuf && rres.ibuf->float_buffer.data) {
        ibufs_arr[view_id] = IMB_allocImBuf(rres.rectx, rres.recty, 32, IB_rectfloat);
        memcpy(ibufs_arr[view_id]->float_buffer.data,
               rres.ibuf->float_buffer.data,
               sizeof(float[4]) * 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.ibuf && rres.ibuf->byte_buffer.data) {
        ibufs_arr[view_id] = IMB_allocImBuf(rres.rectx, rres.recty, 32, IB_rect);
        memcpy(ibufs_arr[view_id]->byte_buffer.data,
               rres.ibuf->byte_buffer.data,
               4 * rres.rectx * rres.recty);
      }
      else {
        ibufs_arr[view_id] = IMB_allocImBuf(rres.rectx, rres.recty, 32, IB_rect);
      }
 
      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 != nullptr)) {
    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 = nullptr;
  ListBase *seqbase = nullptr;
  ListBase *channels = nullptr;
  int offset;
 
  seqbase = SEQ_get_seqbase_from_sequence(seq, &channels, &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,
                                  channels,
                                  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 = nullptr;
  float frame_index = SEQ_give_frame_index(context->scene, 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{};
          scene_parent.next = state->scene_parents;
          scene_parent.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 nullptr 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, timeline_frame, r_is_proxy_image);
      break;
    }
 
    case SEQ_TYPE_MOVIE: {
      ibuf = seq_render_movie_strip(context, seq, timeline_frame, r_is_proxy_image);
      break;
    }
 
    case SEQ_TYPE_MOVIECLIP: {
      ibuf = seq_render_movieclip_strip(
          context, seq, round_fl_to_int(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->float_buffer.data) {
          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 = nullptr;
  bool use_preprocess = false;
  bool is_proxy_image = false;
 
  ibuf = seq_cache_get(context, seq, timeline_frame, SEQ_CACHE_STORE_PREPROCESSED);
  if (ibuf != nullptr) {
    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 == nullptr) {
    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 == nullptr) {
    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 StripEarlyOut seq_get_early_out_for_blend_mode(Sequence *seq)
{
  SeqEffectHandle sh = seq_effect_get_sequence_blend(seq);
  float fac = seq->blend_opacity / 100.0f;
  StripEarlyOut early_out = sh.early_out(seq, fac);
 
  if (ELEM(early_out, StripEarlyOut::DoEffect, StripEarlyOut::NoInput)) {
    return early_out;
  }
 
  if (seq_must_swap_input_in_blend_mode(seq)) {
    if (early_out == StripEarlyOut::UseInput2) {
      return StripEarlyOut::UseInput1;
    }
    if (early_out == StripEarlyOut::UseInput1) {
      return StripEarlyOut::UseInput2;
    }
  }
  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;
  SeqEffectHandle sh = seq_effect_get_sequence_blend(seq);
  float fac = 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, fac, ibuf2, ibuf1);
    }
    else {
      out = sh.execute(context, seq, timeline_frame, fac, ibuf2, ibuf1);
    }
  }
  else {
    if (sh.multithreaded) {
      out = seq_render_effect_execute_threaded(
          &sh, context, seq, timeline_frame, fac, ibuf1, ibuf2);
    }
    else {
      out = sh.execute(context, seq, timeline_frame, fac, ibuf1, ibuf2);
    }
  }
 
  return out;
}
 
static bool is_opaque_alpha_over(const Sequence *seq)
{
  if (seq->blend_mode != SEQ_TYPE_ALPHAOVER) {
    return false;
  }
  if (seq->blend_opacity < 100.0f) {
    return false;
  }
  if (seq->mul < 1.0f && (seq->flag & SEQ_MULTIPLY_ALPHA) != 0) {
    return false;
  }
  LISTBASE_FOREACH (SequenceModifierData *, smd, &seq->modifiers) {
    /* Assume result is not opaque if there is an enabled Mask modifier. */
    if ((smd->flag & SEQUENCE_MODIFIER_MUTE) == 0 && smd->type == seqModifierType_Mask) {
      return false;
    }
  }
  return true;
}
 
static ImBuf *seq_render_strip_stack(const SeqRenderData *context,
                                     SeqRenderState *state,
                                     ListBase *channels,
                                     ListBase *seqbasep,
                                     float timeline_frame,
                                     int chanshown)
{
  Vector<Sequence *> strips = seq_get_shown_sequences(
      context->scene, channels, seqbasep, timeline_frame, chanshown);
  if (strips.is_empty()) {
    return nullptr;
  }
 
  OpaqueQuadTracker opaques;
 
  int64_t i;
  ImBuf *out = nullptr;
  for (i = strips.size() - 1; i >= 0; i--) {
    Sequence *seq = strips[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;
    }
 
    StripEarlyOut early_out = seq_get_early_out_for_blend_mode(seq);
 
    if (early_out == StripEarlyOut::DoEffect && opaques.is_occluded(context, seq, i)) {
      early_out = StripEarlyOut::UseInput1;
    }
 
    /* "Alpha over" is default for all strips, and it can be optimized in some cases:
     * - If the whole image has no transparency, there's no need to do actual blending.
     * - Likewise, if we are at the bottom of the stack; the input can be used as-is.
     * - If we are rendering a strip that is known to be opaque, we mark it as an occluder,
     *   so that strips below can check if they are completely hidden. */
    if (out == nullptr && early_out == StripEarlyOut::DoEffect && is_opaque_alpha_over(seq)) {
      ImBuf *test = seq_render_strip(context, state, seq, timeline_frame);
      if (ELEM(test->planes, R_IMF_PLANES_BW, R_IMF_PLANES_RGB) || i == 0) {
        early_out = StripEarlyOut::UseInput2;
      }
      else {
        early_out = StripEarlyOut::DoEffect;
      }
      /* Free the image. It is stored in cache, so this doesn't affect performance. */
      IMB_freeImBuf(test);
 
      /* Check whether the raw (before preprocessing, which can add alpha) strip content
       * was opaque. */
      ImBuf *ibuf_raw = seq_cache_get(context, seq, timeline_frame, SEQ_CACHE_STORE_RAW);
      if (ibuf_raw != nullptr) {
        if (ibuf_raw->planes != R_IMF_PLANES_RGBA) {
          opaques.add_occluder(context, seq, i);
        }
        IMB_freeImBuf(ibuf_raw);
      }
    }
 
    switch (early_out) {
      case StripEarlyOut::NoInput:
      case StripEarlyOut::UseInput2:
        out = seq_render_strip(context, state, seq, timeline_frame);
        break;
      case StripEarlyOut::UseInput1:
        if (i == 0) {
          out = IMB_allocImBuf(context->rectx, context->recty, 32, IB_rect);
          seq_imbuf_assign_spaces(context->scene, out);
        }
        break;
      case StripEarlyOut::DoEffect:
        if (i == 0) {
          /* This is an effect at the bottom of the stack, so one of the inputs does not exist yet:
           * create one that is transparent black. Extra optimization for an alpha over strip at
           * the bottom, we can just return it instead of blending with black. */
          ImBuf *ibuf2 = seq_render_strip(context, state, seq, timeline_frame);
          const bool use_float = ibuf2 && ibuf2->float_buffer.data;
          ImBuf *ibuf1 = IMB_allocImBuf(
              context->rectx, context->recty, 32, use_float ? IB_rectfloat : IB_rect);
          seq_imbuf_assign_spaces(context->scene, ibuf1);
 
          out = seq_render_strip_stack_apply_effect(context, seq, timeline_frame, ibuf1, ibuf2);
          IMB_metadata_copy(out, ibuf2);
 
          seq_cache_put(context, strips[i], timeline_frame, SEQ_CACHE_STORE_COMPOSITE, out);
 
          IMB_freeImBuf(ibuf1);
          IMB_freeImBuf(ibuf2);
        }
        break;
    }
 
    if (out) {
      break;
    }
  }
 
  i++;
  for (; i < strips.size(); i++) {
    Sequence *seq = strips[i];
 
    if (opaques.is_occluded(context, seq, i)) {
      continue;
    }
 
    if (seq_get_early_out_for_blend_mode(seq) == StripEarlyOut::DoEffect) {
      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, strips[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);
  ListBase *seqbasep;
  ListBase *channels;
 
  if (ed == nullptr) {
    return nullptr;
  }
 
  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;
    channels = ((MetaStack *)BLI_findlink(&ed->metastack, count))->old_channels;
  }
  else {
    seqbasep = ed->seqbasep;
    channels = ed->displayed_channels;
  }
 
  SeqRenderState state;
  ImBuf *out = nullptr;
 
  Vector<Sequence *> strips = seq_get_shown_sequences(
      scene, channels, seqbasep, timeline_frame, chanshown);
 
  if (!strips.is_empty()) {
    out = seq_cache_get(context, strips.last(), timeline_frame, SEQ_CACHE_STORE_FINAL_OUT);
  }
 
  seq_cache_free_temp_cache(context->scene, context->task_id, timeline_frame);
  /* Make sure we only keep the `anim` data for strips that are in view. */
  SEQ_relations_free_all_anim_ibufs(context->scene, timeline_frame);
 
  if (!strips.is_empty() && !out) {
    BLI_mutex_lock(&seq_render_mutex);
    out = seq_render_strip_stack(context, &state, channels, seqbasep, timeline_frame, chanshown);
 
    if (context->is_prefetch_render) {
      seq_cache_put(context, strips.last(), timeline_frame, SEQ_CACHE_STORE_FINAL_OUT, out);
    }
    else {
      seq_cache_put_if_possible(
          context, strips.last(), 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 *channels,
                                    ListBase *seqbasep)
{
  SeqRenderState state;
 
  return seq_render_strip_stack(context, &state, channels, seqbasep, timeline_frame, chan_shown);
}
 
ImBuf *SEQ_render_give_ibuf_direct(const SeqRenderData *context,
                                   float timeline_frame,
                                   Sequence *seq)
{
  SeqRenderState state;
 
  ImBuf *ibuf = seq_render_strip(context, &state, seq, timeline_frame);
  return ibuf;
}
 
bool SEQ_render_is_muted(const ListBase *channels, const Sequence *seq)
{
 
  SeqTimelineChannel *channel = SEQ_channel_get_by_index(channels, seq->machine);
  return seq->flag & SEQ_MUTE || SEQ_channel_is_muted(channel);
}