On Tue, 2019-10-01 at 21:41 +0200, Carl Eugen Hoyos wrote: > Am Di., 1. Okt. 2019 um 21:35 Uhr schrieb Raphaël Zumer < > rzu...@tebako.net>: > > On Tue, 2019-10-01 at 20:09 +0100, Derek Buitenhuis wrote: > > > On 01/10/2019 18:25, James Almer wrote: > > > > The value in the unused field will be 0xFFFFFFFF after this > > > > change > > > > instead of 0, since you're writing 32 bits as duration instead > > > > of > > > > 64 > > > > where the high 32 bits (corresponding to the unused field) are > > > > zeroed. > > > > That means the ivf demuxer prior to this patch will read bogus > > > > duration > > > > values from ivf files created after this patch. > > > > > > > > Just leave the muxer as is. > > > > > > Why not just write zero? > > > > > > It's, to me, worse to leave a bogus 64-bit write to appease bugs > > > in > > > our > > > own demuxer. It's confusing and misleading for any readers of the > > > code. > > > > In that case I would prefer changing the initial written value to 0 > > rather than 0xFFFFFFFFFFFFFFFFULL. Writing over the unused bytes > > twice > > to get around an old error is a bit odd as well. > > That may needlessly break non-seekable output.
Writing a 0 as the initial value is consistent with the behaviour of libvpx. libvpx writes 0 initially: https://github.com/webmproject/libvpx/blob/v1.8.1/vpxenc.c#L1191 then updates afterwards with the length (if output is seekable): https://github.com/webmproject/libvpx/blob/v1.8.1/vpxenc.c#L1209 (for reference, the ivf_write_file_header function is here: https://github.com/webmproject/libvpx/blob/v1.8.1/ivfenc.c#L16 ) So we need to make sure that ffmpeg can handle 0 values in this field regardless. -- Calvin Walton <calvin.wal...@kepstin.ca> _______________________________________________ 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".