On 12/23/16, Soft Works <softwo...@hotmail.com> wrote: > > > ________________________________________ > From: ffmpeg-devel <ffmpeg-devel-boun...@ffmpeg.org> on behalf of Paul B > Mahol <one...@gmail.com> > Sent: Friday, December 23, 2016 12:21 PM > To: FFmpeg development discussions and patches > Subject: Re: [FFmpeg-devel] Serious Regression in matroskaenc: > > On 12/23/16, Soft Works <softwo...@hotmail.com> wrote: >> Hello everybody, >> >> it's been a while since my contribution to matroskaenc in July. In case >> you >> don't remember my scenario - it's about realtime transcoding and and >> streaming of mkv files. >> That means that the header is sent to the client before the ffmpeg process >> is completed. >> >> In this context we discovered that the preliminary mkv header that is >> written initially is corrupted in some way! >> >> When transcoding is aborted or completed, the header is written a second >> time, overwriting a few things. This final header write operation always >> fixes the problem and leaves the file with a correct header. >> >> I haven't investigated yet, what's actually being written wrong. I used >> different parsing implementations (mediainfo, ffprobe, mkvvalidator, >> mkvtoolnix) and all are producing different results. Some report CRC >> error, >> others report unknown or duplicate header elements. Some are able to >> detect >> the stream information others are not. >> >> Now, I'm wondering if one of you guys could take care of this? Or do I >> have >> to find the bug on my own? > >>> Do you have steps to reproduce this? > > To reproduce, transcode an mkv file, even if all streams are simply copied. > > While the transcoding is in progress, I copied the output file to another > file > (works on Windows at least), but probably you can simply kill the ffmpeg > process. > > Only thing that you shouldn't do is breaking the ffmpeg process via key > commands > because in this case the header would still be finalized. > > On the result file, you can run various diagnostics then. I tried mediainfo, > ffprobe, mkvvalidator, mkvtoolnix. All showed different results but > always with errors. > > This doesn't happen with matroskaenc.c from July 17, 2016 and other versions > before that date.
See https://lists.ffmpeg.org/pipermail/ffmpeg-user/2016-December/034770.html This is ticket #5977 Thx _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
