> -----Original Message----- > From: ffmpeg-devel <ffmpeg-devel-boun...@ffmpeg.org> On Behalf Of > Ronald S. Bultje > Sent: Friday, June 30, 2023 1:27 AM > To: FFmpeg development discussions and patches <ffmpeg- > de...@ffmpeg.org> > Subject: Re: [FFmpeg-devel] [PATCH v3] avformat/ivfenc: Set the "number of > frames" in IVF header > > Hi, > > On Thu, Jun 29, 2023 at 8:54 AM Dai, Jianhui J < jianhui.j.dai-at- > intel....@ffmpeg.org> wrote: > > > Should set "number of frames" to bytes 24-27 of IVF header, not > > duration. > > It is described by [1], and confirmed by parsing all IVF files in [2]. > > > > This commit also updates the md5sum of refs to pass fate-cbs. > > > > [1] Duck IVF - MultimediaWiki > > https://wiki.multimedia.cx/index.php/Duck_IVF > > > > [2] webm/vp8-test-vectors > > https://chromium.googlesource.com/webm/vp8-test-vectors > > > > Signed-off-by: Jianhui Dai <jianhui.j....@intel.com> > > --- > > libavformat/ivfdec.c | 6 +++--- > > libavformat/ivfenc.c | 13 +++++-------- > > tests/ref/fate/cbs-vp9-vp90-2-03-deltaq | 2 +- > > tests/ref/fate/cbs-vp9-vp90-2-06-bilinear | 2 +- > > tests/ref/fate/cbs-vp9-vp90-2-09-lf_deltas | 2 +- > > .../ref/fate/cbs-vp9-vp90-2-10-show-existing-frame | 2 +- > > .../ref/fate/cbs-vp9-vp90-2-10-show-existing-frame2 | 2 +- > > tests/ref/fate/cbs-vp9-vp90-2-segmentation-aq-akiyo | 2 +- > > tests/ref/fate/cbs-vp9-vp90-2-segmentation-sf-akiyo | 2 +- > > tests/ref/fate/cbs-vp9-vp90-2-tiling-pedestrian | 2 +- > > tests/ref/fate/cbs-vp9-vp91-2-04-yuv440 | 2 +- > > tests/ref/fate/cbs-vp9-vp91-2-04-yuv444 | 2 +- > > tests/ref/fate/cbs-vp9-vp92-2-20-10bit-yuv420 | 2 +- > > tests/ref/fate/cbs-vp9-vp93-2-20-10bit-yuv422 | 2 +- > > tests/ref/fate/cbs-vp9-vp93-2-20-12bit-yuv444 | 2 +- > > 15 files changed, 21 insertions(+), 24 deletions(-) > > > > diff --git a/libavformat/ivfdec.c b/libavformat/ivfdec.c index > > 511f2387ed..c71a28e0d3 100644 > > --- a/libavformat/ivfdec.c > > +++ b/libavformat/ivfdec.c > > @@ -51,9 +51,9 @@ static int read_header(AVFormatContext *s) > > st->codecpar->codec_id = ff_codec_get_id(ff_codec_bmp_tags, > > st->codecpar->codec_tag); > > st->codecpar->width = avio_rl16(s->pb); > > st->codecpar->height = avio_rl16(s->pb); > > - time_base.den = avio_rl32(s->pb); > > - time_base.num = avio_rl32(s->pb); > > - st->duration = avio_rl32(s->pb); > > + time_base.den = avio_rl32(s->pb); > > + time_base.num = avio_rl32(s->pb); > > + st->nb_frames = avio_rl32(s->pb); > > avio_skip(s->pb, 4); // unused > > > > ffstream(st)->need_parsing = AVSTREAM_PARSE_HEADERS; > > > > Is the removal of the st->duration assignment necessary? Applications using > this field will now see a regression.
Thanks. It's good for me to set both st->nb_frames and st->duration. The accuracy of `duration` cannot be guaranteed. Luckily, the duration is often correct, because it is popular configure that time_base.den/time_base.num == fps. > > Ronald > _______________________________________________ > 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". _______________________________________________ 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".
