DVB subtitles not shown

[Carl Eugen Hoyos]

(videolan ticket 10655, I don't think this is a duplicate of ticket #2161)
A vlc user provided a sample that contains a dvbsub subtitle streams that can be shown with mplayer -demuxer mpegts (and vlc):

$ mplayer video_subs_ttxt+dvbsub.ts -demuxer mpegts -sid 0x138c

ffplay and ffmpeg -filter_complex overlay do not show subtitles, but the following command line shows the expected subtitles:

$ ffmpeg -f lavfi -i testsrc=s=pal -i video_subs_ttxt+dvbsub.ts -filter_complex [0:0][1:12]overlay -an -qscale 2 -t 140 out.avi

The following command produces an output file that does not show any subtitles:

$ ffmpeg -i video_subs_ttxt+dvbsub.ts -filter_complex [0:0][0:12]overlay -an -qscale 2 -t 140 out.avi
ffmpeg version N-60739-g3734c3e Copyright (c) 2000-2014 the FFmpeg developers
  built on Feb 19 2014 18:55:39 with gcc 4.7 (SUSE Linux)
  configuration: --enable-gpl
  libavutil      52. 64.100 / 52. 64.100
  libavcodec     55. 52.102 / 55. 52.102
  libavformat    55. 33.100 / 55. 33.100
  libavdevice    55. 10.100 / 55. 10.100
  libavfilter     4.  1.103 /  4.  1.103
  libswscale      2.  5.101 /  2.  5.101
  libswresample   0. 17.104 /  0. 17.104
  libpostproc    52.  3.100 / 52.  3.100
[mpeg2video @ 0x1aa3460] Invalid frame dimensions 0x0.
    Last message repeated 3 times
[NULL @ 0x1aa5a60] start time is not set in estimate_timings_from_pts
[NULL @ 0x1aa64e0] start time is not set in estimate_timings_from_pts
[NULL @ 0x1ac12c0] start time is not set in estimate_timings_from_pts
[NULL @ 0x1ac1b40] start time is not set in estimate_timings_from_pts
[NULL @ 0x1ac25a0] start time is not set in estimate_timings_from_pts
[NULL @ 0x1ac3000] start time is not set in estimate_timings_from_pts
[NULL @ 0x1ac3a60] start time is not set in estimate_timings_from_pts
[NULL @ 0x1ac44c0] start time is not set in estimate_timings_from_pts
[mpegts @ 0x1a9e9a0] PES packet size mismatch
    Last message repeated 1 times
[mpegts @ 0x1a9e9a0] Could not find codec parameters for stream 4 (Unknown: none ([5][0][0][0] / 0x0005)): unknown codec
Consider increasing the value for the 'analyzeduration' and 'probesize' options
[mpegts @ 0x1a9e9a0] Could not find codec parameters for stream 5 (Unknown: none ([5][0][0][0] / 0x0005)): unknown codec
Consider increasing the value for the 'analyzeduration' and 'probesize' options
[mpegts @ 0x1a9e9a0] Could not find codec parameters for stream 6 (Unknown: none ([5][0][0][0] / 0x0005)): unknown codec
Consider increasing the value for the 'analyzeduration' and 'probesize' options
[mpegts @ 0x1a9e9a0] Could not find codec parameters for stream 7 (Unknown: none ([5][0][0][0] / 0x0005)): unknown codec
Consider increasing the value for the 'analyzeduration' and 'probesize' options
[mpegts @ 0x1a9e9a0] Could not find codec parameters for stream 8 (Unknown: none ([5][0][0][0] / 0x0005)): unknown codec
Consider increasing the value for the 'analyzeduration' and 'probesize' options
[mpegts @ 0x1a9e9a0] Could not find codec parameters for stream 9 (Unknown: none ([5][0][0][0] / 0x0005)): unknown codec
Consider increasing the value for the 'analyzeduration' and 'probesize' options
[mpegts @ 0x1a9e9a0] Could not find codec parameters for stream 10 (Unknown: none ([5][0][0][0] / 0x0005)): unknown codec
Consider increasing the value for the 'analyzeduration' and 'probesize' options
[mpegts @ 0x1a9e9a0] Could not find codec parameters for stream 11 (Unknown: none ([5][0][0][0] / 0x0005)): unknown codec
Consider increasing the value for the 'analyzeduration' and 'probesize' options
Input #0, mpegts, from 'video_subs_ttxt+dvbsub.ts':
  Duration: 00:02:21.72, start: 458.712200, bitrate: 6010 kb/s
  Program 6301
    Metadata:
      service_name    : BBC 1 London
      service_provider: BSkyB
    Stream #0:0[0x1388]: Video: mpeg2video (Main) ([2][0][0][0] / 0x0002), yuv420p(tv), 720x576 [SAR 64:45 DAR 16:9], max. 7980 kb/s, 25 fps, 25 tbr, 90k tbn, 50 tbc
    Stream #0:1[0x1389](eng): Audio: mp2 ([3][0][0][0] / 0x0003), 48000 Hz, stereo, s16p, 254 kb/s
    Stream #0:2[0x138a](NAR): Audio: mp2 ([3][0][0][0] / 0x0003), 48000 Hz, stereo, s16p, 254 kb/s
    Stream #0:3[0x138b](eng,eng): Subtitle: dvb_teletext ([6][0][0][0] / 0x0006)
    Stream #0:4[0x902]: Unknown: none ([5][0][0][0] / 0x0005)
    Stream #0:5[0x903]: Unknown: none ([5][0][0][0] / 0x0005)
    Stream #0:6[0x904]: Unknown: none ([5][0][0][0] / 0x0005)
    Stream #0:7[0x905]: Unknown: none ([5][0][0][0] / 0x0005)
    Stream #0:8[0x907]: Unknown: none ([5][0][0][0] / 0x0005)
    Stream #0:9[0x908]: Unknown: none ([5][0][0][0] / 0x0005)
    Stream #0:10[0x909]: Unknown: none ([5][0][0][0] / 0x0005)
    Stream #0:11[0x90a]: Unknown: none ([5][0][0][0] / 0x0005)
    Stream #0:12[0x138c](eng): Subtitle: dvb_subtitle ([6][0][0][0] / 0x0006)
  Program 6318
    Metadata:
      service_name    : CBeebies
      service_provider: BSkyB
  Program 6319
    Metadata:
      service_name    : BBC THREE
      service_provider: BSkyB
  Program 6331
    Metadata:
      service_name    : BBC 1 NI
      service_provider: BSkyB
  Program 6363
    Metadata:
      service_name    : BBC R Cymru
      service_provider: BSkyB
  Program 6302
    Metadata:
      service_name    : BBC 2 England
      service_provider: BSkyB
  Program 6304
    Metadata:
      service_name    : BBC NEWS 24
      service_provider: BSkyB
  Program 6306
    Metadata:
      service_name    : ETV
      service_provider: BSkyB
  Program 6308
    Metadata:
      service_name    : BBC TES Test
      service_provider: BSkyB
  Program 6309
    Metadata:
      service_name    : BBC TES 2
      service_provider: BSkyB
  Program 6315
    Metadata:
      service_name    : BBC TES 3
      service_provider: BSkyB
  Program 6316
    Metadata:
      service_name    : BBC FOUR
      service_provider: BSkyB
  Program 6317
    Metadata:
      service_name    : CBBC Channel
      service_provider: BSkyB
Please use -q:a or -q:v, -qscale is ambiguous
[mpegts @ 0x1a9e9a0] sub2video: using 720x576 canvas
Output #0, avi, to 'out.avi':
  Metadata:
    ISFT            : Lavf55.33.100
    Stream #0:0: Video: mpeg4 (FMP4 / 0x34504D46), yuv420p, 720x576 [SAR 64:45 DAR 16:9], q=2-31, 200 kb/s, 25 tbn, 25 tbc (default)
Stream mapping:
  Stream #0:0 (mpeg2video) -> overlay:main
  Stream #0:12 (dvbsub) -> overlay:overlay
  overlay -> Stream #0:0 (mpeg4)
Press [q] to stop, [?] for help
frame= 3493 fps=233 q=2.0 Lsize=   65424kB time=00:02:20.00 bitrate=3828.2kbits/s
video:65335kB audio:0kB subtitle:0 data:0 global headers:0kB muxing overhead 0.136851%

[Carl Eugen Hoyos]

Sample uploaded to ​http://samples.ffmpeg.org/ffmpeg-bugs/trac/ticket3401/

[Carl Eugen Hoyos]

Please ignore, the subtitles work fine, I don't know what I originally tested.