From: Mark Reid <mindm...@gmail.com> The current behaviour ends up squaring the avg_frame_rate if the conter mode flag is set. This messes up the timecode calculation, and looks to me as a regression that seems to have been introduced 428b4aac.
The new behaviour is use the "Number of frames" field for avg_frame_rate from the timecode atom as describe here: https://developer.apple.com/library/archive/documentation/QuickTime/QTFF/QTFFChap3/qtff3.html#//apple_ref/doc/uid/TP40000939-CH205-69831 Number of frames An 8-bit integer that contains the number of frames per second for the timecode format. If the time is a counter, this is the number of frames for each counter tick. Here is a sample mov file with the counter flag set https://www.dropbox.com/s/5l4fucb9lhq523s/timecode_counter_mode.mov before the patch ffmpeg will report the timecode as: 00:37:11:97 and warns that the timecode framerate is 576000000/1002001 after patch: 14:50:55:02 --- libavformat/mov.c | 17 +++++------------ 1 file changed, 5 insertions(+), 12 deletions(-) diff --git a/libavformat/mov.c b/libavformat/mov.c index 2b90e31170..76c1ceb82a 100644 --- a/libavformat/mov.c +++ b/libavformat/mov.c @@ -2336,24 +2336,17 @@ static int mov_parse_stsd_data(MOVContext *c, AVIOContext *pb, tmcd_ctx->tmcd_flags = val; st->avg_frame_rate.num = AV_RB32(st->codecpar->extradata + 8); /* timescale */ st->avg_frame_rate.den = AV_RB32(st->codecpar->extradata + 12); /* frameDuration */ -#if FF_API_LAVF_AVCTX -FF_DISABLE_DEPRECATION_WARNINGS - st->codec->time_base = av_inv_q(st->avg_frame_rate); -FF_ENABLE_DEPRECATION_WARNINGS -#endif + /* adjust for per frame dur in counter mode */ if (tmcd_ctx->tmcd_flags & 0x0008) { - int timescale = AV_RB32(st->codecpar->extradata + 8); - int framedur = AV_RB32(st->codecpar->extradata + 12); - st->avg_frame_rate.num *= timescale; - st->avg_frame_rate.den *= framedur; + st->avg_frame_rate.num = st->codecpar->extradata[16] /* fps, frames per counter tick in counter mode */; + st->avg_frame_rate.den = 1; + } #if FF_API_LAVF_AVCTX FF_DISABLE_DEPRECATION_WARNINGS - st->codec->time_base.den *= timescale; - st->codec->time_base.num *= framedur; + st->codec->time_base = av_inv_q(st->avg_frame_rate); FF_ENABLE_DEPRECATION_WARNINGS #endif - } if (size > 30) { uint32_t len = AV_RB32(st->codecpar->extradata + 18); /* name atom length */ uint32_t format = AV_RB32(st->codecpar->extradata + 22); -- 2.29.2 _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".