On Mon, Sep 21, 2020 at 1:12 PM Martin Storsjö <mar...@martin.st> wrote: > > On Sun, 20 Sep 2020, Jan Ekström wrote: > > > This is utilized by various media ingests to figure out the bit > > rate of the content you are pushing towards it, so write it by > > default for video, audio and subtitle tracks. It is only mentioned > > for timed metadata sample descriptions in QTFF, so limit it only to > > ISOBMFF (MODE_MP4). > > > > Updates the FATE tests which have their results changed due to the > > 20 extra bytes being written per track. > > --- > > libavformat/movenc.c | 29 ++++++++ > > tests/fate/mov.mak | 2 +- > > tests/ref/fate/binsub-movtextenc | 2 +- > > tests/ref/fate/copy-trac3074 | 4 +- > > tests/ref/fate/movenc | 102 ++++++++++++++--------------- > > tests/ref/lavf-fate/av1.mp4 | 4 +- > > tests/ref/lavf-fate/h264.mp4 | 4 +- > > tests/ref/lavf/mp4 | 12 ++-- > > tests/ref/vsynth/vsynth1-mpeg4 | 4 +- > > tests/ref/vsynth/vsynth2-mpeg4 | 4 +- > > tests/ref/vsynth/vsynth3-mpeg4 | 4 +- > > tests/ref/vsynth/vsynth_lena-mpeg4 | 4 +- > > 12 files changed, 102 insertions(+), 73 deletions(-) > > Not familiar with the box or its use, but the change looks pretty sensible > to me. >
As far as I understand, its most common use cases are to either show a per-track bit rate in an mp4 file's stats, or to read the incoming fragmented mp4 stream's bit rate so it can be advertised when HLS/DASH etc are being generated from it. > Are there cases where there's really no sensible information about > bitrates to write, where it would be preferrable to just drop it, instead > of writing a box with bogus values? > Yea, I basically decided that if maxrate, average bit rate and bufsize are all zero, then the box is absolutely useless and should be skipped. Thanks for reviews, I have applied various improvements and will in a bit post a v2. Jan _______________________________________________ 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".
