native vorbis encoder produces noise

[hxuanyu]

Converted a 5.1 channel video into webm with latest ffmpeg (using native vorbis for audio encoder). But can hear noise not exists in source video.

Was able to reproduce this issue with 2 videos.

Below is the command used to convert.

$ ffmpeg.exe -i Stereotest.mp4 -acodec vorbis -strict -2 test.webm
ffmpeg version N-66289-gb76d613 Copyright (c) 2000-2014 the FFmpeg developers
  built on Sep 15 2014 22:02:10 with gcc 4.8.3 (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-libbs2b --enable-libcaca --enable-libfreetype --enable-libgme --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-libvidstab --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-decklink --enable-zlib
  libavutil      54.  7.100 / 54.  7.100
  libavcodec     56.  1.100 / 56.  1.100
  libavformat    56.  4.101 / 56.  4.101
  libavdevice    56.  0.100 / 56.  0.100
  libavfilter     5.  1.100 /  5.  1.100
  libswscale      3.  0.100 /  3.  0.100
  libswresample   1.  1.100 /  1.  1.100
  libpostproc    53.  0.100 / 53.  0.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'Stereotest.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: isommp42
    creation_time   : 2013-12-23 05:20:05
  Duration: 00:00:20.04, start: 0.000000, bitrate: 159 kb/s
    Stream #0:0(und): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p, 480x360, 60 kb/s, 29.97 fps, 29.97 tbr, 60k tbn, 59.94 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 95 kb/s (default)
    Metadata:
      creation_time   : 2013-12-23 05:20:05
      handler_name    : IsoMedia File Produced by Google, 5-11-2011
File 'test.webm' already exists. Overwrite ? [y/N] y
[libvpx @ 04404a60] v1.3.0
Output #0, webm, to 'test.webm':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: isommp42
    encoder         : Lavf56.4.101
    Stream #0:0(und): Video: vp8 (libvpx), yuv420p, 480x360, q=-1--1, 200 kb/s, 29.97 fps, 1k tbn, 29.97 tbc (default)
    Metadata:
      handler_name    : VideoHandler
      encoder         : Lavc56.1.100 libvpx
    Stream #0:1(und): Audio: vorbis, 44100 Hz, stereo, fltp (default)
    Metadata:
      creation_time   : 2013-12-23 05:20:05
      handler_name    : IsoMedia File Produced by Google, 5-11-2011
      encoder         : Lavc56.1.100 vorbis
Stream mapping:
  Stream #0:0 -> #0:0 (h264 (native) -> vp8 (libvpx))
  Stream #0:1 -> #0:1 (aac (native) -> vorbis (native))
Press [q] to stop, [?] for help
frame=  600 fps=145 q=0.0 Lsize=     560kB time=00:00:20.06 bitrate= 228.5kbits/s
video:130kB audio:416kB subtitle:0kB other streams:0kB global headers:3kB muxing overhead: 2.403836%



$ ffmpeg.exe -i Original51.mkv -acodec vorbis -strict -2 test.webm
ffmpeg version N-66289-gb76d613 Copyright (c) 2000-2014 the FFmpeg developers
  built on Sep 15 2014 22:02:10 with gcc 4.8.3 (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-libbs2b --enable-libcaca --enable-libfreetype --enable-libgme --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-libvidstab --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-decklink --enable-zlib
  libavutil      54.  7.100 / 54.  7.100
  libavcodec     56.  1.100 / 56.  1.100
  libavformat    56.  4.101 / 56.  4.101
  libavdevice    56.  0.100 / 56.  0.100
  libavfilter     5.  1.100 /  5.  1.100
  libswscale      3.  0.100 /  3.  0.100
  libswresample   1.  1.100 /  1.  1.100
  libpostproc    53.  0.100 / 53.  0.100
Input #0, matroska,webm, from 'Original51.mkv':
  Metadata:
    ENCODER         : Lavf55.33.100
  Duration: 00:00:46.63, start: 0.000000, bitrate: 605 kb/s
    Stream #0:0: Video: h264 (High), yuv420p, 800x600 [SAR 1:1 DAR 4:3], 8 fps, 8 tbr, 1k tbn, 16 tbc (default)
    Stream #0:1: Audio: aac, 44100 Hz, stereo, fltp (default)
File 'test.webm' already exists. Overwrite ? [y/N] y
[libvpx @ 037d47e0] v1.3.0
Output #0, webm, to 'test.webm':
  Metadata:
    encoder         : Lavf56.4.101
    Stream #0:0: Video: vp8 (libvpx), yuv420p, 800x600 [SAR 1:1 DAR 4:3], q=-1--1, 200 kb/s, 8 fps, 1k tbn, 8 tbc (default)
    Metadata:
      encoder         : Lavc56.1.100 libvpx
    Stream #0:1: Audio: vorbis, 44100 Hz, stereo, fltp (default)
    Metadata:
      encoder         : Lavc56.1.100 vorbis
Stream mapping:
  Stream #0:0 -> #0:0 (h264 (native) -> vp8 (libvpx))
  Stream #0:1 -> #0:1 (aac (native) -> vorbis (native))
Press [q] to stop, [?] for help
frame=  373 fps= 49 q=0.0 Lsize=     944kB time=00:00:46.62 bitrate= 165.8kbits/s
video:421kB audio:503kB subtitle:0kB other streams:0kB global headers:3kB muxing overhead: 2.077811%

[hxuanyu]

another test video is here: ​https://dl.dropboxusercontent.com/u/89678527/Original51.mkv

[Timothy Gu]

The native vorbis encoder is full of bugs so don't use it. Also don't expect this bug to be fixed anytime soon.

[Elon Musk]

Known issue, codec is experimental and should be removed from FFmpeg.