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

FFmpeg trac at avcodec.org
Sun Sep 29 18:56:09 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 Kamedo2):

 My current plan:
 {{{
 bin\ffmpeg55212_v4patch -y -i in.wav -c:a aac -strict experimental -b:a
 128k out.mp4

 bin\ffmpeg56667_v6patch_c185 -y -i in.wav -c:a aac -strict experimental
 -b:a 128k out.mp4

 bin\ffmpeg56667_v6patch_c185 -y -i in.wav -c:a aac -strict experimental
 -q:a 0.7 out.mp4

 bin\ffmpeg56667 -y -i in.wav -c:a libfdk_aac -vbr 3 out.mp4

 bin\ffmpeg56667 -y -i in.wav -c:a libfaac -q:a 97 out.mp4

 bin\ffmpeg56667 -y -i in.wav -c:a libmp3lame -q:a 5 out.mp3

 bin\ffmpeg56667 -y -i in.wav -c:a ac3 -b:a 128k out.ac3
 }}}
 Many people were asking the quality of faac. Weird, but maybe I should
 include it if many people are wondering. Expect the test to slow down.

 The bitrate distribution of vbr encoders. Even when the comment:185 was
 applied, the speech samples takes up a lot of space.
 [[Image(http://i39.tinypic.com/2h8be3o.png)]]


 My current FFmpeg configuration:
 {{{
 $ ./configure --enable-gpl --enable-version3 --enable-nonfree --enable-
 libfdk-a
 ac --enable-libfaac --enable-libmp3lame --extra-ldflags=-static --extra-
 cflags=
 '-march=nocona -mfpmath=sse' --optflags=-O2
 }}}
 Is there a way to expose more bugs so that we can fix it before the test?

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/2686#comment:192>
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