/* get memory buffer for first uncached frame within prefetch frame range */
static unsigned char *prefetch_thread_next_frame(
PrefetchQueue *queue, MovieClip *clip,
size_t *r_size, int *r_current_frame)
{
unsigned char *mem = NULL;
BLI_spin_lock(&queue->spin);
if (!*queue->stop && !check_prefetch_break() &&
IN_RANGE_INCL(queue->current_frame, queue->start_frame, queue->end_frame))
{
int current_frame;
if (queue->forward) {
current_frame = prefetch_find_uncached_frame(clip, queue->current_frame + 1, queue->end_frame,
queue->render_size, queue->render_flag, 1);
/* switch direction if read frames from current up to scene end frames */
if (current_frame > queue->end_frame) {
queue->current_frame = queue->initial_frame;
queue->forward = false;
}
}
if (!queue->forward) {
current_frame = prefetch_find_uncached_frame(clip, queue->current_frame - 1, queue->start_frame,
queue->render_size, queue->render_flag, -1);
}
if (IN_RANGE_INCL(current_frame, queue->start_frame, queue->end_frame)) {
int frames_processed;
mem = prefetch_read_file_to_memory(clip, current_frame, queue->render_size,
queue->render_flag, r_size);
*r_current_frame = current_frame;
queue->current_frame = current_frame;
if (queue->forward) {
frames_processed = queue->current_frame - queue->initial_frame;
}
else {
frames_processed = (queue->end_frame - queue->initial_frame) +
(queue->initial_frame - queue->current_frame);
}
*queue->do_update = 1;
*queue->progress = (float)frames_processed / (queue->end_frame - queue->start_frame);
}
}
BLI_spin_unlock(&queue->spin);
return mem;
}
static bool prefetch_movie_frame(MovieClip *clip, int frame, short render_size,
short render_flag, short *stop)
{
MovieClipUser user = {0};
ImBuf *ibuf;
if (check_prefetch_break() || *stop)
return false;
user.framenr = frame;
user.render_size = render_size;
user.render_flag = render_flag;
if (!BKE_movieclip_has_cached_frame(clip, &user)) {
ibuf = BKE_movieclip_anim_ibuf_for_frame(clip, &user);
if (ibuf) {
int result;
result = BKE_movieclip_put_frame_if_possible(clip, &user, ibuf);
if (!result) {
/* no more space in the cache, we could stop prefetching here */
*stop = 1;
}
IMB_freeImBuf(ibuf);
}
else {
/* error reading frame, fair enough stop attempting further reading */
*stop = 1;
}
}
return true;
}
