[FFmpeg-trac] #5233(undetermined:new): ffmpeg native aac encoder does not uses sensible default values to bitrate on multchannel audios

[FFmpeg]

#5233: ffmpeg native aac encoder does not uses sensible default values to bitrate
on multchannel audios
-------------------------------------+-------------------------------------
             Reporter:  myleal       |                     Type:  defect
               Status:  new          |                 Priority:  normal
            Component:               |                  Version:
  undetermined                       |  unspecified
             Keywords:               |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 The native ffmpeg native aac encoder defaults do 128kbps bitrate,
 regardless of the input audio is stereo or an AC3 / DTS multichannel
 audio.

 The fdk_aac compiled ffmpeg defaults to 489kbps bitrate when the input is
 a 5.1 channel audio.

 It would be nice if the ffmpeg aac native encoder uses 'sensible defaults'
 like the fdk_aac counterpart.

 How to reproduce:

 C:\Users\marcu\Downloads\ffmpeg-20160212-git-6973846-win64-static\ffmpeg-20160212-git-6973846-win64-static\bin>ffmpeg
 -i http://www.mysurround.com/test/TestMySurround-en.dbr.wma audio.mp4
 ffmpeg version N-78395-g6973846 Copyright (c) 2000-2016 the FFmpeg
 developers
   built with gcc 5.3.0 (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-libdcadec --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-amrwbenc --enable-
 libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-
 libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-
 libzimg --enable-lzma --enable-decklink --enable-zlib
   libavutil      55. 17.100 / 55. 17.100
   libavcodec     57. 24.102 / 57. 24.102
   libavformat    57. 25.100 / 57. 25.100
   libavdevice    57.  0.101 / 57.  0.101
   libavfilter     6. 31.100 /  6. 31.100
   libswscale      4.  0.100 /  4.  0.100
   libswresample   2.  0.101 /  2.  0.101
   libpostproc    54.  0.100 / 54.  0.100
 Input #0, asf, from 'http://www.mysurround.com/test/TestMySurround-
 en.dbr.wma':
   Metadata:
     WMFSDKNeeded    : 0.0.0.0000
     DeviceConformanceTemplate: M3
     WM/WMADRCPeakReference: 32767
     WM/WMADRCPeakTarget: 32767
     WM/WMADRCAverageReference: 3822
     WM/WMADRCAverageTarget: 3822
     WMFSDKVersion   : 11.0.5721.5145
     IsVBR           : 1
   Duration: 00:00:54.04, start: 0.000000, bitrate: 297 kb/s
     Stream #0:0(fre): Audio: wmapro (b[1][0][0] / 0x0162), 48000 Hz, 5.1,
 fltp, 384 kb/s
 Output #0, mp4, to 'audio.mp4':
   Metadata:
     WMFSDKNeeded    : 0.0.0.0000
     DeviceConformanceTemplate: M3
     WM/WMADRCPeakReference: 32767
     WM/WMADRCPeakTarget: 32767
     WM/WMADRCAverageReference: 3822
     WM/WMADRCAverageTarget: 3822
     WMFSDKVersion   : 11.0.5721.5145
     IsVBR           : 1
     encoder         : Lavf57.25.100
     Stream #0:0(fre): Audio: aac (LC) ([64][0][0][0] / 0x0040), 48000 Hz,
 5.1, fltp, 128 kb/s
     Metadata:
       encoder         : Lavc57.24.102 aac
 Stream mapping:
   Stream #0:0 -> #0:0 (wmapro (native) -> aac (native))
 Press [q] to stop, [?] for help
 [aac @ 0000020f47e6a8c0] Queue input is backward in timepeed=12.6x
 [mp4 @ 0000020f47da4d60] Non-monotonous DTS in output stream 0:0;
 previous: 1199103, current: 1198080; changing to 1199104. This may result
 in incorrect timestamps in the output file.
 [aac @ 0000020f47e6a8c0] Queue input is backward in timepeed= 9.8x
 [mp4 @ 0000020f47da4d60] Non-monotonous DTS in output stream 0:0;
 previous: 2561007, current: 2559984; changing to 2561008. This may result
 in incorrect timestamps in the output file.
 size=     473kB time=00:00:54.05 bitrate=  71.6kbits/s speed=9.97x
 video:0kB audio:461kB subtitle:0kB other streams:0kB global headers:0kB
 muxing overhead: 2.587044%
 [aac @ 0000020f47e6a8c0] Qavg: 53019.391


 ------------- Mediainfo -----------------
 Geral
 Nome completo :
 C:\Users\marcu\Downloads\ffmpeg-20160212-git-6973846-win64-static\ffmpeg-20160212-git-6973846-win64-static\bin\audio.mp4
 Formato : MPEG-4
 Perfil do Formato : Base Media
 ID do Codec : isom
 Tamanho do arquivo : 473 KiB
 Duração : 54s 80ms
 Taxa de Bits Total, Modo : Variável
 Taxa de Bits Total : 71.6 Kbps
 Programa usado : Lavf57.25.100

 Áudio
 ID : 1
 Formato : AAC
 Formato/Informações : Advanced Audio Codec
 Perfil do Formato : LC
 ID do Codec : 40
 Duração : 54s 80ms
 Modo da taxa de bits : Variável
 Taxa de bits : 69.8 Kbps
 Taxa de bits máxima : 128 Kbps
 Nº de canais : 2 canais
 Channel(s)_Original : 6 canais
 Posições dos canais : Front: L C R, Side: L R, LFE
 Taxa de amostragem : 48.0 KHz
 Tamanho da Faixa : 461 KiB (97%)
 Idioma : Francês

--
Ticket URL: <https://trac.ffmpeg.org/ticket/5233>
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