Support scrambled / customised mpeg program streams from Karaoke hardware

[Carl Eugen Hoyos]

(videolan ticket 8819)
A videolan user uploaded three samples from a Karaoke player. The program streams are not auto-detected by FFmpeg, MPlayer does auto-detect them. All players show massive visual artefacts, audio is slightly better with MPlayer than FFmpeg but still damaged.

$ ffmpeg -f mpeg -i 81391.mpg
ffmpeg version N-54166-g5dba888 Copyright (c) 2000-2013 the FFmpeg developers
  built on Jun 24 2013 08:54:40 with gcc 4.7 (SUSE Linux)
  configuration: --enable-gpl --disable-indev=jack
  libavutil      52. 37.101 / 52. 37.101
  libavcodec     55. 16.100 / 55. 16.100
  libavformat    55.  9.100 / 55.  9.100
  libavdevice    55.  2.100 / 55.  2.100
  libavfilter     3. 77.101 /  3. 77.101
  libswscale      2.  3.100 /  2.  3.100
  libswresample   0. 17.102 /  0. 17.102
  libpostproc    52.  3.100 / 52.  3.100
[mpeg @ 0x2b5d060] pes_ext B4 is invalid
[mpeg @ 0x2b5d060] pes_ext 97 is invalid
[mpeg @ 0x2b5d060] pes_ext 8B is invalid
[mpeg @ 0x2b5d060] pes_ext B9 is invalid
[mpeg @ 0x2b5d060] pes_ext EE is invalid
[mpeg @ 0x2b5d060] pes_ext 20 is invalid
[mpeg @ 0x2b5d060] pes_ext 24 is invalid
[mpeg @ 0x2b5d060] pes_ext E4 is invalid
[mpeg @ 0x2b5d060] pes_ext 0 is invalid
[mpeg @ 0x2b5d060] pes_ext 29 is invalid
[mpeg @ 0x2b5d060] pes_ext F is invalid
[mpeg @ 0x2b5d060] pes_ext 25 is invalid
[mpeg @ 0x2b5d060] pes_ext D7 is invalid
[mpeg @ 0x2b5d060] pes_ext 2B is invalid
[mpeg @ 0x2b5d060] pes_ext 2D is invalid
[mpeg @ 0x2b5d060] pes_ext D1 is invalid
[mpeg @ 0x2b5d060] pes_ext 23 is invalid
[mpeg @ 0x2b5d060] pes_ext EC is invalid
[mpeg2video @ 0x2b65d40] ignoring pic cod ext after 0
[mpeg2video @ 0x2b65d40] warning: first frame is no keyframe
[mpeg2video @ 0x2b65d40] invalid cbp -1 at 7 2
[mpeg2video @ 0x2b65d40] skip with previntra
[mpeg2video @ 0x2b65d40] ac-tex damaged at 14 16
[mpeg2video @ 0x2b65d40] ac-tex damaged at 0 19
[mpeg2video @ 0x2b65d40] ac-tex damaged at 2 23
[mpeg2video @ 0x2b65d40] ac-tex damaged at 4 13
[mpeg2video @ 0x2b65d40] mb incr damaged
[mpeg2video @ 0x2b65d40] slice mismatch

...

[mpeg @ 0x2b5d060] pes_ext B4 is invalid
[mpeg @ 0x2b5d060] pes_ext 59 is invalid
[mpeg @ 0x2b5d060] pes_ext 31 is invalid
Input #0, mpeg, from '81391.mpg':
  Duration: 00:01:10.87, start: 0.415833, bitrate: 5807 kb/s
    Stream #0:0[0x1e0]: Video: mpeg2video (Main), yuv420p, 720x480 [SAR 8:9 DAR 4:3], 29.83 fps, 29.97 tbr, 90k tbn, 59.94 tbc
    Stream #0:1[0x1c0]: Audio: mp2, 48000 Hz, stereo, s16p, 224 kb/s
    Stream #0:2[0x1ce]: Audio: mp3, 0 channels, s16p
At least one output file must be specified

Samples are in ​http://samples.ffmpeg.org/ffmpeg-bugs/trac/ticket2705/

[compn]

testing with an old mplayer with libmpeg2, result is similar to lavc mpeg2.