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

FFmpeg trac at avcodec.org
Sat Dec 12 11:01:11 CET 2015


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

Comment (by Kamedo2):

 The new AAC output cannot be decoded properly by the faad decoder.

 {{{
 ffmpeg77208 -y -i abc\compilation2.wav -c:a aac -b:a 96k out.mp4
 }}}
 {{{
 faad -b 1 out.mp4 out.wav
 }}}
 results in collapsed sounds.

 {{{
 ffmpeg77208 -y -i abc\compilation2.wav -c:a aac -b:a 96k out.mp4
 }}}
 {{{
 faad -q -b 4 out.mp4 out.wav
 }}}
 decoding to 32bit float also results in collapsed sounds.

 {{{
 ffmpeg77208 -y -i abc\compilation2.wav -c:a aac -b:a 96k out.mp4
 }}}
 {{{
 ffmpeg77208 -y -i out.mp4 -c:a pcm_s16le out.wav
 }}}
 The same AAC output decoded by the new FFmpeg is OK.

 {{{
 ffmpeg77208 -y -i abc\compilation2.wav -c:a aac -b:a 96k out.mp4
 }}}
 {{{
 ffmpeg72585 -y -i out.mp4 -c:a pcm_s16le out.wav
 }}}
 The same AAC output decoded by older FFmpeg is also OK.




 {{{
 ffmpeg76735 -y -i abc\compilation2.wav -c:a aac -b:a 96k -strict -2
 out.mp4
 }}}
 {{{
 faad -b 1 out.mp4 out.wav
 }}}
 72585, 76735 was OK, but the 76851, 76877, 76976, 77208 suffer the same
 problem.

--
Ticket URL: <https://trac.ffmpeg.org/ticket/2686#comment:459>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker


More information about the FFmpeg-trac mailing list