[FFmpeg-trac] #2686(avcodec:open): Native AAC encoder collapses at high bitrates on some samples
FFmpeg
trac at avcodec.org
Thu Jul 18 07:41:15 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):
They go up because twoloop will push all scalefactors down uniformly until
it achieves the desired bitrate, but:
* It won't work with VBR, VBR almost wholly depends on psy to dictate
scalefactor band noise floors. Twoloop will push scalefactors down a bit
more I think but not much at those high bitrates
* It's still suboptimal, it's better to let psy decide, since psy
understands perceptual entropy better
Sadly, I didn't have time today to work on it. Lets hope I can do so
tomorrow. With your analysis I'm confident I can patch psy without having
to cap anything.
--
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/2686#comment:45>
FFmpeg <http://ffmpeg.org>
FFmpeg issue tracker
More information about the FFmpeg-trac
mailing list