[FFmpeg-user] Dolby E decoder

[Mike Brown]

On Mon, Sep 11, 2017 at 09:23:36AM +0200, Fr?d?ric Busnel-Joncour wrote:
> > Looks like you need to resample audio to sample rate ac3 supports.
> 
> I've just tried to convert two different Dolby E source from wav to u8, then ffprobe recognize them as a Dolby E stream, but it says that they're 44800Hz, I guess it should be 48000Hz. Perhaps there's a bug here ?

Here are the results that I get:

ffprobe out.dat
ffprobe version N-87196-g6cadbb1 Copyright (c) 2007-2017 the FFmpeg developers
  built with gcc 7.1.0 (GCC)
  configuration: --enable-gpl --enable-version3 --enable-cuda --enable-cuvid --enable-d3d11va --enable-dxva2 --enable-libmfx --enable-nvenc --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-libopenh264 --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libzimg --enable-lzma --enable-zlib
  libavutil      55. 74.100 / 55. 74.100
  libavcodec     57.105.100 / 57.105.100
  libavformat    57. 81.100 / 57. 81.100
  libavdevice    57.  8.100 / 57.  8.100
  libavfilter     6.101.100 /  6.101.100
  libswscale      4.  7.103 /  4.  7.103
  libswresample   2.  8.100 /  2.  8.100
  libpostproc    54.  6.100 / 54.  6.100
[dolby_e @ 000000000068bfc0] Stream has 2 programs (configuration 0), channels will be output in native order.
Input #0, s337m, from 'out.dat':
  Duration: N/A, bitrate: N/A
    Stream #0:0: Audio: dolby_e, 53706 Hz, 7.1, fltp


ffprobe out.wav
ffprobe version N-87196-g6cadbb1 Copyright (c) 2007-2017 the FFmpeg developers
  built with gcc 7.1.0 (GCC)
  configuration: --enable-gpl --enable-version3 --enable-cuda --enable-cuvid --enable-d3d11va --enable-dxva2 --enable-libmfx --enable-nvenc --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-libopenh264 --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libzimg --enable-lzma --enable-zlib
  libavutil      55. 74.100 / 55. 74.100
  libavcodec     57.105.100 / 57.105.100
  libavformat    57. 81.100 / 57. 81.100
  libavdevice    57.  8.100 / 57.  8.100
  libavfilter     6.101.100 /  6.101.100
  libswscale      4.  7.103 /  4.  7.103
  libswresample   2.  8.100 /  2.  8.100
  libpostproc    54.  6.100 / 54.  6.100
Input #0, wav, from 'out.wav':
  Metadata:
    encoder         : Lavf57.81.100
  Duration: 00:00:18.92, bitrate: 6874 kb/s
    Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 53706 Hz, 7.1, s16, 6874 kb/s


Notice that I get 53706 Hz, 7.1 and 16bits.  The audio is 5.1.  It is for
broacast, so it is 48kHz.

> But I unfortunately can't use ffplay to play it, there a compilation bug on my fedora 24 box with this last ffmpeg release (very annoying by the way, I must investigate it).
> 

I do not have the audio connected on my Win7 box.  I still tried it and it
complained trying to set up 8, 6 and 4 channels.  The 53706 Hz attempted as
well.

MB
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