[FFmpeg-user] VBR setting is unsupported in libfdk_aac

[Ashish Jha]

Hi,

I am trying to encode audio file .wav into HE-AAC. I am able to encode, However, when trying to encode in VBR, I am getting an error stating "[libfdk_aac @ 0x29c5c00] Note, the VBR setting is unsupported and only works with some parameter combinations" and its encoding into CBR.

How can I encode into vbr for HE-AAC. I am using the below mentioned command.

ffmpeg -i input.wav -c:a libfdk_aac -profile:a aac_he -vbr 3 -ar 48000 output.m4a

Error I am getting is: ffmpeg -i Bera_Jaal.wav -c:a libfdk_aac -profile:a aac_he -vbr 2 Bera_vbr.m4a
ffmpeg version N-95890-gdf62505 Copyright (c) 2000-2019 the FFmpeg developers
  built with gcc 5.4.0 (Ubuntu 5.4.0-6ubuntu1~16.04.12) 20160609
  configuration: --prefix=/home/ashish/ffmpeg_build --pkg-config-flags=--static --extra-cflags=-I/home/ashish/ffmpeg_build/include --extra-ldflags=-L/home/ashish/ffmpeg_build/lib --bindir=/home/ashish/bin --enable-libass --enable-libfdk-aac --enable-libfreetype --enable-libtheora --enable-libvorbis --enable-libmp3lame --enable-nonfree --enable-gpl
  libavutil      56. 36.101 / 56. 36.101
  libavcodec     58. 64.101 / 58. 64.101
  libavformat    58. 35.100 / 58. 35.100
  libavdevice    58.  9.101 / 58.  9.101
  libavfilter     7. 67.100 /  7. 67.100
  libswscale      5.  6.100 /  5.  6.100
  libswresample   3.  6.100 /  3.  6.100
  libpostproc    55.  6.100 / 55.  6.100
Guessed Channel Layout for Input Stream #0.0 : stereo
Input #0, wav, from 'Bera_Jaal.wav':
  Duration: 00:02:44.04, bitrate: 1411 kb/s
    Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 44100 Hz, stereo, s16, 1411 kb/s
File 'Bera_vbr.m4a' already exists. Overwrite? [y/N] y
Stream mapping:
  Stream #0:0 -> #0:0 (pcm_s16le (native) -> aac (libfdk_aac))
Press [q] to stop, [?] for help
[libfdk_aac @ 0x2345c00] Note, the VBR setting is unsupported and only works with some parameter combinations
Output #0, ipod, to 'Bera_vbr.m4a':
  Metadata:
    encoder         : Lavf58.35.100
    Stream #0:0: Audio: aac (libfdk_aac) (HE-AAC) (mp4a / 0x6134706D), 44100 Hz, stereo, s16
    Metadata:
      encoder         : Lavc58.64.101 libfdk_aac
size=    1415kB time=00:02:44.05 bitrate=  70.7kbits/s speed=  27x
video:0kB audio:1401kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 1.043005%

Please help me on this.

--
Ashish