[FFmpeg-user] Why is there a Guide on libfdk_aac VBR AAC when it is not supported and working?

[Albert Scholtalbers]

Hi,

I found this very nice webpage:
https://ffmpeg.org/trac/ffmpeg/wiki/AACEncodingGuide
But when you try the code you get messages like:
Note, the VBR setting is unsupported and only works with some parameter
combinations

total output:
[2013-02-20 10:34:03] The transcode cmd is: /usr/local/bin/ffmpeg -i
/home/test/sample.avi -y -c:v libx264 -b:v 2000k -vf scale=-1:480 -flags
+ildct+ilme -x264opts tff=1 -strict -2 -c:a libfdk_aac -vbr 4
/home/test/sample-result.mp4
ffmpeg version git-2013-01-12-15daa8f Copyright (c) 2000-2013 the FFmpeg
developers
  built on Jan 12 2013 10:05:11 with gcc 4.6 (Ubuntu/Linaro 4.6.3-1ubuntu5)
  configuration: --enable-gpl --enable-libass --enable-libfaac
--enable-libfdk-aac --enable-libmp3lame --enable-libopencore-amrnb
--enable-libopencore-amrwb --enable-librtmp --enable-libtheora
--enable-libvorbis --enable-libvpx --enable-libx264 --enable-nonfree
--enable-version3
  libavutil      52. 13.100 / 52. 13.100
  libavcodec     54. 86.100 / 54. 86.100
  libavformat    54. 59.107 / 54. 59.107
  libavdevice    54.  3.102 / 54.  3.102
  libavfilter     3. 32.100 /  3. 32.100
  libswscale      2.  1.103 /  2.  1.103
  libswresample   0. 17.102 /  0. 17.102
  libpostproc    52.  2.100 / 52.  2.100
[avi @ 0xaded0e0] non-interleaved AVI
Guessed Channel Layout for  Input Stream #0.1 : stereo
Input #0, avi, from '/home/test/sample.avi':
  Metadata:
    date            : 2011-08-22T13:41:25.00032-03:00
    encoder         : Lavf54.37.100
  Duration: 00:00:10.01, start: 0.000000, bitrate: 30331 kb/s
    Stream #0:0: Video: dvvideo (dvsd / 0x64737664), yuv411p, 720x480 [SAR
32:27 DAR 16:9], 29.97 tbr, 29.97 tbn, 29.97 tbc
    Stream #0:1: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 48000 Hz,
stereo, s16, 1536 kb/s
[libx264 @ 0xadf4da0] interlace + weightp is not implemented
[libx264 @ 0xadf4da0] using SAR=32/27
[libx264 @ 0xadf4da0] using cpu capabilities: MMX2 SSE2Fast SSSE3
FastShuffle SSEMisalign LZCNT BMI1
[libx264 @ 0xadf4da0] profile High 4:2:2, level 3.0, 4:2:2 8-bit
[libx264 @ 0xadf4da0] 264 - core 129 r2 bc13772 - H.264/MPEG-4 AVC codec -
Copyleft 2003-2013 - http://www.videolan.org/x264.html - options: cabac=1
ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00
mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11
fast_pskip=1 chroma_qp_offset=-2 threads=1 lookahead_threads=1
sliced_threads=0 nr=0 decimate=1 interlaced=tff bluray_compat=0
constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1
weightb=1 open_gop=0 weightp=0 keyint=250 keyint_min=25 scenecut=40
intra_refresh=0 rc_lookahead=40 rc=abr mbtree=1 bitrate=2000 ratetol=1.0
qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
[libfdk_aac @ 0xadfdf80] Note, the VBR setting is unsupported and only
works with some parameter combinations


Your sincerely,

Albert