[FFmpeg-trac] #2686(avcodec:open): Native AAC encoder collapses at high bitrates on some samples

[FFmpeg]

#2686: Native AAC encoder collapses at high bitrates on some samples
-------------------------------------+-------------------------------------
             Reporter:  Kamedo2      |                    Owner:
                 Type:  defect       |                   Status:  open
             Priority:  normal       |                Component:  avcodec
              Version:  git-master   |               Resolution:
             Keywords:  aac          |               Blocked By:
  regression                         |  Reproduced by developer:  1
             Blocking:               |
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------

Comment (by Kamedo2):

 > However, you can get (I think) a similar result by specifying both -q:a
 and -b:a, like so:
 >
 > {{{
 > ffmpeg -i somefile.flac -c:a aac -b:a 256k -q:a 1 -strict experimental
 somefile.aac
 > }}}
 >
 > Although that seldom gives you 256k. The bitrate there is like a lower
 bound (aim for 256k, spend more if needed).

 I tried it over 128 different songs and the result was:

 {{{-b:a 256k -q:a 1}}}
 - Average 247kbps
 - SD +/-33kbps
 - Min 161kbps
 - Max 300kbps
 {{{-q:a 1}}}
 - Average 235kbps
 - SD +/-30kbps
 - Min 154kbps
 - Max 287kbps

 (comment:160 change is not applied in this test.)

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/2686#comment:175>
FFmpeg <http://ffmpeg.org>
FFmpeg issue tracker