diff options
Diffstat (limited to 'source/blender/imbuf')
| -rw-r--r-- | source/blender/imbuf/intern/anim_movie.c | 53 |
1 files changed, 52 insertions, 1 deletions
diff --git a/source/blender/imbuf/intern/anim_movie.c b/source/blender/imbuf/intern/anim_movie.c index 785f27c53e4..d75a81e79f9 100644 --- a/source/blender/imbuf/intern/anim_movie.c +++ b/source/blender/imbuf/intern/anim_movie.c @@ -1124,6 +1124,49 @@ static void ffmpeg_decode_video_frame_scan(struct anim *anim, int64_t pts_to_sea } } +/* Wrapper over av_seek_frame(), for formats that doesn't have it's own read_seek() or read_seek2() + * functions defined. When seeking in these formats, rule to seek to last necessary I-frame is not + * honored. It is not even guaranteed that I-frame, that must be decoded will be read. See + * https://trac.ffmpeg.org/ticket/1607 and https://developer.blender.org/T86944. */ +static int ffmpeg_generic_seek_workaround(struct anim *anim, int64_t requested_pos) +{ + AVStream *v_st = anim->pFormatCtx->streams[anim->videoStream]; + double frame_rate = av_q2d(av_guess_frame_rate(anim->pFormatCtx, v_st, NULL)); + int64_t current_pos = requested_pos; + + /* This time offset maximum limit is arbitrary. If some files fails to decode it may be + * increased. Seek performance will be negatively affected. Small initial offset is necessary + * because encoder can re-arrange frames as it needs but within it's delay, which is usually + * small. */ + for (int offset = 5; offset < 25; offset++) { + current_pos = requested_pos - ((int64_t)(offset)*AV_TIME_BASE / frame_rate); + + /* Seek to timestamp. */ + if (av_seek_frame(anim->pFormatCtx, -1, current_pos, AVSEEK_FLAG_BACKWARD) < 0) { + break; + } + + /* Read first video stream packet. */ + AVPacket read_packet = {0}; + while (av_read_frame(anim->pFormatCtx, &read_packet) >= 0) { + if (anim->next_packet.stream_index != anim->videoStream) { + continue; + } + else { + break; + } + } + + /* If this packet contains I-frame, exit loop. This should be the frame that we need. */ + if (read_packet.flags & AV_PKT_FLAG_KEY) { + break; + } + } + + /* Re-seek to timestamp that gave I-frame, so it can be read by decode function. */ + return av_seek_frame(anim->pFormatCtx, -1, current_pos, AVSEEK_FLAG_BACKWARD); +} + /* Seek to last necessary I-frame and scan-decode until requested frame is found. */ static void ffmpeg_seek_and_decode(struct anim *anim, int position, struct anim_index *tc_index) { @@ -1176,7 +1219,15 @@ static void ffmpeg_seek_and_decode(struct anim *anim, int position, struct anim_ av_log(anim->pFormatCtx, AV_LOG_DEBUG, "NO INDEX final seek pos = %" PRId64 "\n", pos); - ret = av_seek_frame(anim->pFormatCtx, -1, pos, AVSEEK_FLAG_BACKWARD); + AVFormatContext *format_ctx = anim->pFormatCtx; + + /* Condition based on av_seek_frame() code. */ + if (format_ctx->iformat->read_seek2 && !format_ctx->iformat->read_seek) { + ret = av_seek_frame(anim->pFormatCtx, -1, pos, AVSEEK_FLAG_BACKWARD); + } + else { + ret = ffmpeg_generic_seek_workaround(anim, pos); + } } if (ret < 0) { |