pgssub -> dvdsub in matroska

[Thomas]

My cam creates mpeg-ts files with h264+ac3+pgs tracks. I need to convert the container and the subtitle track to matroska and vobsub.
I use this command :
ffmpeg -i file.mts -vcodec copy -acodec copy -scodec dvdsub file.mkv

It works but the vobsub track is not CodecPrivate so I can't use it with mkvtoolnix.
I think this is a bug. Sorry for the ticket if it's not.

[Aurélien Jacobs]

I just tried with latest ffmpeg and sample [1]. It stops with the following message:

Subtitle encoding failed

With an old version (0.6.something) it works, and indeed, it doesn't generate extradata.
I guess it is either the pgssub decoder or dvdsub encoder which doesn't decode or
encode extradata, but it requires a deeper analysis.

[1] ​http://samples.mplayerhq.hu/sub/BluRay/sample-dts-not-valid-dca-frame.m2ts

[reimar]

The "Subtitle encoding failed" is due to the decode PGS packets that do not contain any rects, the dvdsub encoder cannot handle them.
If you change the condition to return 0 it will continue to encode, though I don't know if the result is usable/playable.

[Carl Eugen Hoyos]

mkvalidator does not like ffmpeg's output:

$ ffmpeg -i sample-dts-not-valid-dca-frame.m2ts -vcodec copy -acodec copy -scodec copy out.mkv
ffmpeg version N-47403-g7e93b0b Copyright (c) 2000-2012 the FFmpeg developers
  built on Dec  3 2012 11:57:16 with gcc 4.7 (SUSE Linux)
  configuration: --enable-gpl --disable-indev=jack --disable-yasm --disable-asm
  libavutil      52. 11.101 / 52. 11.101
  libavcodec     54. 78.101 / 54. 78.101
  libavformat    54. 42.100 / 54. 42.100
  libavdevice    54.  3.102 / 54.  3.102
  libavfilter     3. 23.105 /  3. 23.105
  libswscale      2.  1.103 /  2.  1.103
  libswresample   0. 17.101 /  0. 17.101
  libpostproc    52.  2.100 / 52.  2.100
[dca @ 0x17365c0] Not a valid DCA frame
    Last message repeated 52 times
[mpegts @ 0x168a150] Stream #5: not enough frames to estimate rate; consider increasing probesize
[mpegts @ 0x168a150] Stream #6: not enough frames to estimate rate; consider increasing probesize
[mpegts @ 0x168a150] Stream #7: not enough frames to estimate rate; consider increasing probesize
[mpegts @ 0x168a150] Stream #8: not enough frames to estimate rate; consider increasing probesize
[mpegts @ 0x168a150] Stream #9: not enough frames to estimate rate; consider increasing probesize
[mpegts @ 0x168a150] Stream #10: not enough frames to estimate rate; consider increasing probesize
[mpegts @ 0x168a150] Stream #11: not enough frames to estimate rate; consider increasing probesize
[mpegts @ 0x168a150] Stream #12: not enough frames to estimate rate; consider increasing probesize
[mpegts @ 0x168a150] Stream #13: not enough frames to estimate rate; consider increasing probesize
[mpegts @ 0x168a150] Stream #14: not enough frames to estimate rate; consider increasing probesize
[mpegts @ 0x168a150] Stream #15: not enough frames to estimate rate; consider increasing probesize
[mpegts @ 0x168a150] Stream #16: not enough frames to estimate rate; consider increasing probesize
[mpegts @ 0x168a150] Stream #17: not enough frames to estimate rate; consider increasing probesize
[mpegts @ 0x168a150] Stream #18: not enough frames to estimate rate; consider increasing probesize
[mpegts @ 0x168a150] Stream #19: not enough frames to estimate rate; consider increasing probesize
[mpegts @ 0x168a150] Stream #20: not enough frames to estimate rate; consider increasing probesize
[mpegts @ 0x168a150] Stream #21: not enough frames to estimate rate; consider increasing probesize
[mpegts @ 0x168a150] Could not find codec parameters for stream 5 (Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options
[mpegts @ 0x168a150] Could not find codec parameters for stream 6 (Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options
[mpegts @ 0x168a150] Could not find codec parameters for stream 7 (Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options
[mpegts @ 0x168a150] Could not find codec parameters for stream 8 (Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options
[mpegts @ 0x168a150] Could not find codec parameters for stream 9 (Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options
[mpegts @ 0x168a150] Could not find codec parameters for stream 10 (Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options
[mpegts @ 0x168a150] Could not find codec parameters for stream 11 (Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options
[mpegts @ 0x168a150] Could not find codec parameters for stream 12 (Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options
[mpegts @ 0x168a150] Could not find codec parameters for stream 13 (Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options
[mpegts @ 0x168a150] Could not find codec parameters for stream 14 (Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options
[mpegts @ 0x168a150] Could not find codec parameters for stream 15 (Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options
[mpegts @ 0x168a150] Could not find codec parameters for stream 16 (Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options
[mpegts @ 0x168a150] Could not find codec parameters for stream 17 (Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options
[mpegts @ 0x168a150] Could not find codec parameters for stream 18 (Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options
[mpegts @ 0x168a150] Could not find codec parameters for stream 19 (Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options
[mpegts @ 0x168a150] Could not find codec parameters for stream 20 (Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options
[mpegts @ 0x168a150] Could not find codec parameters for stream 21 (Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options
[mpegts @ 0x168a150] decoding for stream 22 failed
[mpegts @ 0x168a150] Could not find codec parameters for stream 22 (Audio: dts ([162][0][0][0] / 0x00A2), 0 channels, fltp): unspecified sample rate
Consider increasing the value for the 'analyzeduration' and 'probesize' options
[NULL @ 0x1690730] start time is not set in estimate_timings_from_pts
[NULL @ 0x1690f60] start time is not set in estimate_timings_from_pts
[NULL @ 0x16917e0] start time is not set in estimate_timings_from_pts
[NULL @ 0x1691fd0] start time is not set in estimate_timings_from_pts
[NULL @ 0x16e59b0] start time is not set in estimate_timings_from_pts
[NULL @ 0x16ebcc0] start time is not set in estimate_timings_from_pts
[NULL @ 0x16f2040] start time is not set in estimate_timings_from_pts
[NULL @ 0x16f8350] start time is not set in estimate_timings_from_pts
[NULL @ 0x16fe6e0] start time is not set in estimate_timings_from_pts
[NULL @ 0x17049f0] start time is not set in estimate_timings_from_pts
[NULL @ 0x170ade0] start time is not set in estimate_timings_from_pts
[NULL @ 0x17110f0] start time is not set in estimate_timings_from_pts
[NULL @ 0x17174a0] start time is not set in estimate_timings_from_pts
[NULL @ 0x171d7b0] start time is not set in estimate_timings_from_pts
[NULL @ 0x1723bd0] start time is not set in estimate_timings_from_pts
[NULL @ 0x1729ee0] start time is not set in estimate_timings_from_pts
[NULL @ 0x17302b0] start time is not set in estimate_timings_from_pts
[mpegts @ 0x168a150] PES packet size mismatch
    Last message repeated 3 times
Input #0, mpegts, from 'sample-dts-not-valid-dca-frame.m2ts':
  Duration: 00:00:53.18, start: 11.608967, bitrate: 16276 kb/s
  Program 1
    Stream #0:0[0x1011]: Video: h264 (High) (HDMV / 0x564D4448), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 23.98 fps, 23.98 tbr, 90k tbn, 47.95 tbc
    Stream #0:1[0x1100]: Audio: dts (DTS-HD MA) ([134][0][0][0] / 0x0086), 48000 Hz, 5.1(side), fltp, 1536 kb/s
    Stream #0:2[0x1101]: Audio: ac3 (AC-3 / 0x332D4341), 48000 Hz, 5.1(side), s16, 448 kb/s
    Stream #0:3[0x1102]: Audio: ac3 (AC-3 / 0x332D4341), 48000 Hz, 5.1(side), s16, 448 kb/s
    Stream #0:4[0x1103]: Audio: ac3 (AC-3 / 0x332D4341), 48000 Hz, 5.1(side), s16, 448 kb/s
    Stream #0:5[0x1200]: Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)
    Stream #0:6[0x1201]: Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)
    Stream #0:7[0x1202]: Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)
    Stream #0:8[0x1203]: Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)
    Stream #0:9[0x1204]: Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)
    Stream #0:10[0x1205]: Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)
    Stream #0:11[0x1206]: Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)
    Stream #0:12[0x1207]: Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)
    Stream #0:13[0x1208]: Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)
    Stream #0:14[0x1209]: Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)
    Stream #0:15[0x120a]: Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)
    Stream #0:16[0x120b]: Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)
    Stream #0:17[0x120c]: Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)
    Stream #0:18[0x120d]: Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)
    Stream #0:19[0x120e]: Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)
    Stream #0:20[0x120f]: Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)
    Stream #0:21[0x1210]: Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)
    Stream #0:22[0x1a00]: Audio: dts ([162][0][0][0] / 0x00A2), 0 channels, fltp
    Stream #0:23[0x1b00]: Video: h264 (High) (HDMV / 0x564D4448), yuv420p, 720x480 [SAR 40:33 DAR 20:11], 23.98 fps, 23.98 tbr, 90k tbn, 47.95 tbc
Output #0, matroska, to 'out.mkv':
  Metadata:
    encoder         : Lavf54.42.100
    Stream #0:0: Video: h264 (HDMV / 0x564D4448), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 23.98 fps, 1k tbn, 90k tbc
    Stream #0:1: Audio: dts ([134][0][0][0] / 0x0086), 48000 Hz, 5.1(side), 1536 kb/s
    Stream #0:2: Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
  Stream #0:1 -> #0:1 (copy)
  Stream #0:5 -> #0:2 (copy)
Press [q] to stop, [?] for help
[mpegts @ 0x168a150] PES packet size mismatch
frame= 1273 fps=0.0 q=-1.0 Lsize=   88047kB time=00:00:53.05 bitrate=13595.5kbits/s
video:70275kB audio:17585kB subtitle:134 global headers:0kB muxing overhead 0.059732%

$ mkvalidator out.mkv
ERR0B1: Block at 50661520 track #3 is not a keyframe
ERR0B1: Block at 50661553 track #3 is not a keyframe
ERR0B1: Block at 50661578 track #3 is not a keyframe
ERR0B1: Block at 50661917 track #3 is not a keyframe
ERR0B1: Block at 50707127 track #3 is not a keyframe
ERR0B1: Block at 56486707 track #3 is not a keyframe
ERR0B1: Block at 56486732 track #3 is not a keyframe
ERR0B1: Block at 56486756 track #3 is not a keyframe
ERR0B1: Block at 58281775 track #3 is not a keyframe
ERR0B1: Block at 58281808 track #3 is not a keyframe
ERR0B1: Block at 58281833 track #3 is not a keyframe
ERR0B1: Block at 58282172 track #3 is not a keyframe
ERR0B1: Block at 58322632 track #3 is not a keyframe
ERR0B1: Block at 70426654 track #3 is not a keyframe
ERR0B1: Block at 70426679 track #3 is not a keyframe
ERR0B1: Block at 70426703 track #3 is not a keyframe
ERR0B1: Block at 70946184 track #3 is not a keyframe
ERR0B1: Block at 70946217 track #3 is not a keyframe
ERR0B1: Block at 70946242 track #3 is not a keyframe
ERR0B1: Block at 70946581 track #3 is not a keyframe
ERR0B1: Block at 70974021 track #3 is not a keyframe
ERR0B1: Block at 82469195 track #3 is not a keyframe
ERR0B1: Block at 82469220 track #3 is not a keyframe
ERR0B1: Block at 82469244 track #3 is not a keyframe
ERR0B1: Block at 85421140 track #3 is not a keyframe
ERR0B1: Block at 85421173 track #3 is not a keyframe
ERR0B1: Block at 85421198 track #3 is not a keyframe
ERR0B1: Block at 85421537 track #3 is not a keyframe
ERR0B1: Block at 85461724 track #3 is not a keyframe
....    file created with Lavf54.42.100 / Lavf54.42.100

[Cigaes]

Can you post an excerpt of the output of ffprobe -show_packets on your input file showing the paragraph for a few subtitles packets.

My guess is that the duration field is not set.

[Carl Eugen Hoyos]

I misread the original description last week;-(
Reencoding pgssub -> dvdsub in matroska works fine with current git head (and mkvalidator accepts the output file), fails with earlier versions either completely or leads to slightly broken subtitles.

I opened ticket #2023 for the problem with mkvalidator on remuxing (the duration field is indeed not set), sorry for the mess!