#5641: Support WebVTT according to MKV specs -------------------------------------+------------------------------------- Reporter: RiCON | Type: defect Status: new | Priority: normal Component: avformat | Version: git- Keywords: webvtt | master matroska | Blocked By: Blocking: | Reproduced by developer: 0 Analyzed by developer: 0 | -------------------------------------+------------------------------------- FFmpeg supports the D_WEBVTT/SUBTITLES flavor following WebM specs (http://www.webmproject.org/docs/container/), but not the recent S_TEXT/WEBVTT flavor added to Matroska spec (https://matroska.org/technical/specs/codecid/index.html), likely close to it being added to mkvtoolnix in https://github.com/mbunkus/mkvtoolnix/commit/c0c8ea01 . It should probably also be changed to mux WebVTT tracks as S_TEXT/WEBVTT, at least to Matroska so mkvtoolnix recognizes the track as valid subtitles. {{{ ffmpeg -i cut-vtt.mkv ffmpeg version N-80317-gff53b66-g9da27fb+1 Copyright (c) 2000-2016 the FFmpeg developers built with gcc 5.4.0 (Rev1, Built by MSYS2 project) configuration: --enable-libx264 --enable-libvpx --enable-libopus --disable-postproc --disable-doc --disable-demuxer=asf --disable-ffplay --enable-gpl --disable-debug libavutil 55. 24.100 / 55. 24.100 libavcodec 57. 46.100 / 57. 46.100 libavformat 57. 38.100 / 57. 38.100 libavdevice 57. 0.101 / 57. 0.101 libavfilter 6. 46.101 / 6. 46.101 libswscale 4. 1.100 / 4. 1.100 libswresample 2. 1.100 / 2. 1.100 [matroska,webm @ 000000038f2d1c60] Unknown/unsupported AVCodecID S_TEXT/WEBVTT. [matroska,webm @ 000000038f2d1c60] Could not find codec parameters for stream 3 (Subtitle: none): unknown codec Consider increasing the value for the 'analyzeduration' and 'probesize' options Input #0, matroska,webm, from 'cut-vtt.mkv': Metadata: encoder : libebml v1.3.3 + libmatroska v1.4.4 creation_time : 2016-06-14 12:56:53 Duration: 00:00:11.28, start: 0.000000, bitrate: 352 kb/s Stream #0:0: Video: vp9 (Profile 2), yuv420p10le(tv), 1280x720, SAR 1:1 DAR 16:9, 23.98 fps, 23.98 tbr, 1k tbn, 1k tbc (default) Metadata: BPS : 291322 BPS-eng : 291322 DURATION : 00:00:09.760000000 DURATION-eng : 00:00:09.760000000 NUMBER_OF_FRAMES: 234 NUMBER_OF_FRAMES-eng: 234 NUMBER_OF_BYTES : 355414 NUMBER_OF_BYTES-eng: 355414 _STATISTICS_WRITING_APP: mkvmerge v9.2.0 ('Photograph') 64bit _STATISTICS_WRITING_APP-eng: mkvmerge v9.2.0 ('Photograph') 64bit _STATISTICS_WRITING_DATE_UTC: 2016-06-14 12:56:53 _STATISTICS_WRITING_DATE_UTC-eng: 2016-06-14 12:56:53 _STATISTICS_TAGS: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES _STATISTICS_TAGS-eng: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES Stream #0:1: Audio: opus, 48000 Hz, stereo, fltp (default) (forced) Metadata: BPS : 107013 BPS-eng : 107013 DURATION : 00:00:09.758000000 DURATION-eng : 00:00:09.758000000 NUMBER_OF_FRAMES: 488 NUMBER_OF_FRAMES-eng: 488 NUMBER_OF_BYTES : 130530 NUMBER_OF_BYTES-eng: 130530 _STATISTICS_WRITING_APP: mkvmerge v9.2.0 ('Photograph') 64bit _STATISTICS_WRITING_APP-eng: mkvmerge v9.2.0 ('Photograph') 64bit _STATISTICS_WRITING_DATE_UTC: 2016-06-14 12:56:53 _STATISTICS_WRITING_DATE_UTC-eng: 2016-06-14 12:56:53 _STATISTICS_TAGS: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES _STATISTICS_TAGS-eng: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES Stream #0:2(eng): Subtitle: webvtt Metadata: title : FFmpeg BPS : 163 BPS-eng : 163 DURATION : 00:00:10.300000000 DURATION-eng : 00:00:10.300000000 NUMBER_OF_FRAMES: 5 NUMBER_OF_FRAMES-eng: 5 NUMBER_OF_BYTES : 211 NUMBER_OF_BYTES-eng: 211 _STATISTICS_WRITING_APP: mkvmerge v9.2.0 ('Photograph') 64bit _STATISTICS_WRITING_APP-eng: mkvmerge v9.2.0 ('Photograph') 64bit _STATISTICS_WRITING_DATE_UTC: 2016-06-14 12:56:53 _STATISTICS_WRITING_DATE_UTC-eng: 2016-06-14 12:56:53 _STATISTICS_TAGS: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES _STATISTICS_TAGS-eng: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES Stream #0:3: Subtitle: none (default) Metadata: title : mkvmerge BPS : 0 BPS-eng : 0 DURATION : 00:00:00.000000000 DURATION-eng : 00:00:00.000000000 NUMBER_OF_FRAMES: 0 NUMBER_OF_FRAMES-eng: 0 NUMBER_OF_BYTES : 0 NUMBER_OF_BYTES-eng: 0 _STATISTICS_WRITING_APP: mkvmerge v9.2.0 ('Photograph') 64bit _STATISTICS_WRITING_APP-eng: mkvmerge v9.2.0 ('Photograph') 64bit _STATISTICS_WRITING_DATE_UTC: 2016-06-14 12:56:53 _STATISTICS_WRITING_DATE_UTC-eng: 2016-06-14 12:56:53 _STATISTICS_TAGS: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES _STATISTICS_TAGS-eng: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES At least one output file must be specified }}} -- Ticket URL: <https://trac.ffmpeg.org/ticket/5641> FFmpeg <https://ffmpeg.org> FFmpeg issue tracker