Opened 4 years ago

Last modified 4 years ago

#2758 open defect

DVD-A LPCM in vob cannot be decoded

Reported by: Underground78 Owned by:
Priority: normal Component: avformat
Version: git-master Keywords: mpegps
Cc: Blocked By:
Blocking: Reproduced by developer: yes
Analyzed by developer: no

Description

Summary of the bug:
Sample: http://mpchc.omertabeyond.com/incorrect_audio_stream.AOB

This AOB sample is incorrectly detected as PCM audio.

How to reproduce:

% ffplay.exe incorrect_audio_stream.AOB
ffplay version N-54277-gff130d7 Copyright (c) 2003-2013 the FFmpeg developers
  built on Jun 30 2013 01:20:12 with gcc 4.7.3 (GCC)
  configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libcaca --enable-libfreetype --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxavs --enable-libxvid --enable-zlib
  libavutil      52. 37.101 / 52. 37.101
  libavcodec     55. 17.100 / 55. 17.100
  libavformat    55. 10.100 / 55. 10.100
  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
Input #0, mpeg, from 'incorrect_audio_stream.AOB':sq=    0B f=0/0
  Duration: 00:04:18.27, start: 0.006500, bitrate: 6141 kb/s
    Stream #0:0[0xa0]: Audio: pcm_s16be, 44100 Hz, 2 channels, s16, 1411 kb/s
[pcm_s16be @ 0464b240] Invalid PCM packet, data has size 8 but at least a size of 16 was expected
[pcm_s16be @ 0464b240] Invalid PCM packet, data has size 13 but at least a size of 16 was expected
    Last message repeated 10 times
    ...

Attachments (1)

patchpcm16dvd.diff (816 bytes) - added by cehoyos 4 years ago.

Download all attachments as: .zip

Change History (13)

comment:1 follow-up: Changed 4 years ago by heleppkes

To elaborate, the stream is actually supposed to be MLP instead of PCM.

comment:2 Changed 4 years ago by Underground78

  • Summary changed from AOB file detected as PCM file to MLP audio detected as PCM

comment:3 Changed 4 years ago by cehoyos

  • Keywords mpegps thd added

Which application plays the sample / are you sure it is not encrypted?

comment:4 Changed 4 years ago by Underground78

VLC works fine for example.

comment:5 in reply to: ↑ 1 Changed 4 years ago by cehoyos

Replying to heleppkes:

To elaborate, the stream is actually supposed to be MLP instead of PCM.

Why do you think so?
From a quick look, this is 16bit PCM DVD-Audio, unsupported by FFmpeg.

comment:6 Changed 4 years ago by heleppkes

Hm right, i tried to confirm its really MLP but i couldn't find the usual markers.
Thats what i get for believing the downstream error report.

Changed 4 years ago by cehoyos

comment:7 Changed 4 years ago by cehoyos

  • Component changed from undetermined to avformat
  • Reproduced by developer set
  • Status changed from new to open
  • Summary changed from MLP audio detected as PCM to 16bit PCM in vob cannot be decoded

PoC attached.

comment:8 Changed 4 years ago by cehoyos

  • Keywords thd removed

comment:9 Changed 4 years ago by richardpl

What created such sample?

comment:10 Changed 4 years ago by Underground78

I honestly don't know and I'm afraid I can't get that info either. :/

comment:11 Changed 4 years ago by cehoyos

  • Summary changed from 16bit PCM in vob cannot be decoded to DVD-A LPCM in vob cannot be decoded

comment:12 Changed 4 years ago by cehoyos

I had sent a patch once that shows how this could be done (the detection is definitely wrong):

http://thread.gmane.org/gmane.comp.video.ffmpeg.devel/166791

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