Created a feature request to automatically scale subtitles for HD video https://trac.ffmpeg.org/ticket/4066
On 29 October 2014 14:25, Mika Raento <mi...@iki.fi> wrote: > Created a feature request to support columnboxing input that changes > aspect-ratio mid-stream. > > https://trac.ffmpeg.org/ticket/4065 > > On 29 October 2014 13:49, Mika Raento <mi...@iki.fi> wrote: > >> Tickets for sub2video and async not working with non-monotonic input, >> using -copyts: >> >> https://trac.ffmpeg.org/ticket/4062 >> https://trac.ffmpeg.org/ticket/4064 >> >> Hm. Lots of my issues seem to relate to using -copyts. I had trouble >> keeping all video and all audio if there were periods where one or the >> other were missing (esp. in the beginning). Maybe I could make this simpler >> if I'd relax that requirement (I don't know how much happier my users are >> if they get audio but no video, rather than nothing). >> >> Mika >> >> On 29 October 2014 10:38, Mika Raento <mi...@iki.fi> wrote: >> >>> segment muxer PIDs were fixed in >>> https://github.com/FFmpeg/FFmpeg/commit/502fc3b3d4b36015562d19d74f27d0a4ff835c4e >>> by me >>> >>> On 29 October 2014 10:17, Mika Raento <mi...@iki.fi> wrote: >>> >>>> 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