[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 klaussfreire):

 Replying to [comment:87 Kamedo2]:
 > Replying to [comment:86 klaussfreire]:
 > > I just want to preserve the HF component of transients. There might be
 better ways of doing that. I guess I'll keep iterating on it. However, I
 believe the way it's being done now works well. If you check, the LP
 cutoff is chosen from the allocation given by psy. Psy contains bit
 reservoir logic, which means it will momentarily increase bits (and
 cutoff) for some difficult transients. Right now, it works wonders for hi-
 hats.
 >
 > So, if there is a group of beat sounds that is on the threshold of
 tonal/transients, the LPF is sometimes on and sometimes off? Currently,
 the on/off switch itself is audible and is quite annoying. It sounds like
 a stopwatch.

 No, the cutoff moves up and down, but the LP remains on.

 I'll have to check the sample

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/2686#comment:88>
FFmpeg <http://ffmpeg.org>
FFmpeg issue tracker