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

FFmpeg trac at avcodec.org
Tue Oct 8 22:54:01 CEST 2013

#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):

 Sorry, I've been having trouble making good, provable progress with
 v6b/v7, especially since I've got a few deadlines coming that require lot
 of my time.

 I'll try to fix the crashing, and get performance comparable to v6 without
 the VBR constraints, which I noticed are hurting quality on high bit

 However, it seems the tendency to spend lots of bits on speech stems from
 psy itself, not anything else. It seems to estimate speech has a lot of
 perceptual entropy. It may be true, but there is some inefficiency that's
 hard to fix without deviating from the standards.

 So v7 will probably just address the bugs, crashing, some bugs in tonal
 band priorization in short window blocks, and stuff like that.

 About 7.1ch, there's another ticket for that, IIRC. While I will still
 take a look with the report in this ticket, I'd suggest you post the
 relevant bits on that ticket as well (for traceability you know)

Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/2686#comment:203>
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