[FFmpeg-devel] [PATCH v7] Add SUP/PGS subtitle demuxer

[Petri Hintukainen]

Hello,

Missing DTS combined with non-monotonic PTS seems to cause some
problems. This is with the file from ticket #2208 (I added dumping
timestamps to demuxer and muxer):


$ ../ffmpeg -i orig/track_06\ -\ Subtitle.sup -scodec copy 6.sup
ffmpeg version N-66546-gea74007 Copyright (c) 2000-2014 the FFmpeg
developers
  built on Sep 30 2014 11:10:08 with gcc 4.8 (Ubuntu 4.8.2-19ubuntu1)
  configuration: 
  libavutil      54.  7.101 / 54.  7.101
  libavcodec     56.  1.101 / 56.  1.101
  libavformat    56.  7.101 / 56.  7.101
  libavdevice    56.  1.100 / 56.  1.100
  libavfilter     5.  1.102 /  5.  1.102
  libswscale      3.  1.100 /  3.  1.100
  libswresample   1.  1.100 /  1.  1.100
IN  pts 00255314 dts 00000000
Input #0, sup, from 'orig/track_06 - Subtitle.sup':
  Duration: N/A, start: 2.836822, bitrate: N/A
    Stream #0:0: Subtitle: hdmv_pgs_subtitle, 1920x1080
Output #0, sup, to '6.sup':
  Metadata:
    encoder         : Lavf56.7.101
    Stream #0:0: Subtitle: hdmv_pgs_subtitle, 1920x1080
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
Press [q] to stop, [?] for help
OUT pts 00000000 dts 00000000
IN  pts 00255037 dts 00000000
OUT pts 00000000 dts 00000000
IN  pts 00249205 dts 00000000
[sup @ 0x241f4e0] Application provided invalid, non monotonically
increasing dts to muxer in stream 0: -277 >= -6109
av_interleaved_write_frame(): Invalid argument
size=       0kB time=00:00:00.00 bitrate=N/A    
video:0kB audio:0kB subtitle:1kB other streams:0kB global headers:0kB
muxing overhead: unknown
Conversion failed!


Also note that timestamps are re-positioned to start from 0. This may be
problematic, it requires manually synchronizing subtitles to the video.

Remuxing from the original .m2ts file works just well:


$ ffmpeg -i orig/00038.m2ts -map 0:6 -scodec copy 6.sup
ffmpeg version N-66546-gea74007 Copyright (c) 2000-2014 the FFmpeg developers
  built on Sep 30 2014 11:10:08 with gcc 4.8 (Ubuntu 4.8.2-19ubuntu1)
  configuration: 
  libavutil      54.  7.101 / 54.  7.101
  libavcodec     56.  1.101 / 56.  1.101
  libavformat    56.  7.101 / 56.  7.101
  libavdevice    56.  1.100 / 56.  1.100
  libavfilter     5.  1.102 /  5.  1.102
  libswscale      3.  1.100 /  3.  1.100
  libswresample   1.  1.100 /  1.  1.100
[NULL @ 0x1bf9ba0] start time for stream 6 is not set in estimate_timings_from_pts
[NULL @ 0x1c146e0] start time for stream 7 is not set in estimate_timings_from_pts
[NULL @ 0x1c151c0] start time for stream 8 is not set in estimate_timings_from_pts
[mpegts @ 0x1bf1ca0] 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 @ 0x1bf1ca0] 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 @ 0x1bf1ca0] 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
Input #0, mpegts, from 'orig/00038.m2ts':
  Duration: 00:00:43.90, start: 11.650667, bitrate: 35145 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: truehd (AC-3 / 0x332D4341), 48000 Hz, 7.1, s32 (24 bit)
    Stream #0:2[0x1100]: Audio: ac3 (AC-3 / 0x332D4341), 48000 Hz, 5.1(side), fltp, 640 kb/s
    Stream #0:3[0x1101]: Audio: ac3 (AC-3 / 0x332D4341), 48000 Hz, stereo, fltp, 320 kb/s
    Stream #0:4[0x1102]: Audio: ac3 (AC-3 / 0x332D4341), 48000 Hz, stereo, fltp, 320 kb/s
    Stream #0:5[0x1200]: Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090), 1920x1080
    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)
Output #0, sup, to '6.sup':
  Metadata:
    encoder         : Lavf56.7.101
    Stream #0:0: Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)
Stream mapping:
  Stream #0:6 -> #0:0 (copy)
Press [q] to stop, [?] for help
OUT pts 00255255 dts 00249146
OUT pts 00254978 dts 00249146
OUT pts 00249146 dts 00249146
OUT pts 00249699 dts 00249146
OUT pts 00249699 dts 00249699
...


Also, remuxing this file again (.sup->.sup) with ffmpeg works. Well,
except that timestamps are again repositioned.


Is this something that can be handled in muxer ?


- Petri