[FFmpeg-trac] #2686(avcodec:open): Native AAC encoder collapses at high bitrates on some samples
FFmpeg
trac at avcodec.org
Tue Jul 16 14:37:54 CEST 2013
#2686: Native AAC encoder collapses at high bitrates on some samples
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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 |
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Comment (by Kamedo2):
I've got it. When the native aac encoder calcs a masking curve, almost
inaudible sounds like 18kHz, 20kHz, 22kHz is taking into account, and
audible sound like 14kHz is masked by the inaudibles. Add the inaudible
noise above to the source sound and the encoded sound will be
significantly degraded. I recommend that any signals above 16kHz is
disregarded in psychoacoustic engines.
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Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/2686#comment:32>
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