[FFmpeg-trac] #2686(avcodec:open): Native AAC encoder collapses at high bitrates on some samples
FFmpeg
trac at avcodec.org
Sat Jul 20 17:53:09 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 |
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Comment (by Kamedo2):
Recommended cutoff frequency for FFmpeg AAC.
[[Image(http://i41.tinypic.com/28al1fn.png)]]
psymodel.h line 32:
{{{
#define AAC_CUTOFF(s) (s->bit_rate ?
FFMIN3(FFMIN3(s->bit_rate/s->channels/2, 3000 + s->bit_rate/s->channels/4,
12000 + s->bit_rate/s->channels/16), 20000, s->sample_rate / 2):
(s->sample_rate / 2))
}}}
The LPF is not applied in VBR now, resulting in noticeably poor quality.
--
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/2686#comment:57>
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