Hi Thanks for the feedback.
I'll try to capture at least some of these in tickets, and reply on this thread as I go along. Async not working with damaged audio input is https://trac.ffmpeg.org/ticket/2693 (existing ticket) Sub2video not working with negative timestamps is https://trac.ffmpeg.org/ticket/4062 (new ticket) Mika On 27 October 2014 01:00, Michael Niedermayer <michae...@gmx.at> wrote: > On Wed, Sep 24, 2014 at 10:43:40AM +0300, Mika Raento wrote: > > Dear all > > > > This mail is meant mainly as a note to other potential users, but > > possibly as input to development - time allowing I might be able to pick > > up some of the pieces myself. It's also a thank-you for all the hard > > work in ffmpeg. > > > > I've successfully implemented a transcoding pipeline for producing > > multi-bitrate fragmented mp4 files from broadcast DVB input. More > > concretely, I'm taking in broadcast TS captures with either mpeg2 video > > and mp2 audio (SD, varying aspect ratio) or h264 video and aac audio, > > both potentially with dvbsub. From that I'm producing ISMV output with > > multiple bitrate h264 video at fixed 16:9 aspect ratio and multiple > > bitrate aac audio, with burned subtitles. The ISMV outputs are > > post-processed with tools/ismindex and with the hls muxer. > > > > There are number of limitations in ffmpeg that I've had to work around: > > > > - I haven't gotten sub2video or async working without reasonably > > monotonous DTS. Broadcast TS streams can easily contain backward jumps > > in time (e.g., a cheapo source that plays mp4 files and starts each > file > > at 0). The fix is to cut the TS into pieces at timestamp jump locations > > and using '-itsoffset' to rewrite the timestamps and then concatenate. > > I'm using the segment and concat muxers for that. > > - Sub2video doesn't work with negative timestamps, so I use '-itsoffset' > > to get positive timestamps > > - For HD streams, I need to scale up the sub2video results from SD to > > HD. Sub2video doesn't handle the HD subtitle geometries. I'm not > > enough of an expert to know whether that's the issue, or whether that's > > just the way it's supposed to work with SD subs (typical) with HD > video. > > - For columnboxing, I use the scale, pad and setdar video filters. These > > work fine, but their parameters are only evaluated at start, so I need > > to cut the video into pieces with a single aspect ratio first and > > concatenate later. > > - Audio sync (using aresample) gets confused if the input contains > > errors, so I need to first re-encode audio (with '-copyts') and only > > after that synchronize. > > - The TS PIDs are not kept over the segment muxer, so I given them on > > the command line with '-streamid'. > > a bit late reply but > bug reports or feature requests for all these are welcome unless there > are already tickets for them assuming these issues still exist > > thx > > [...] > > -- > Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB > > Why not whip the teacher when the pupil misbehaves? -- Diogenes of Sinope > > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > http://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel