[FFmpeg-trac] #2686(avcodec:open): Native AAC encoder collapses at high bitrates on some samples
FFmpeg
trac at avcodec.org
Fri Jul 19 17:12:16 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):
[[Image(http://i44.tinypic.com/2s805y0.png)]]
I used tx->frame_bits = FFMIN(2560, and psymodel.h line 32:
{{{
#define AAC_CUTOFF(s) (s->bit_rate ?
FFMIN3(FFMIN3(s->bit_rate/s->channels/2, 4000 + s->bit_rate/s->channels/4,
12000 + s->bit_rate/s->channels/16), 20000, s->sample_rate / 2):
(s->sample_rate / 2))
}}}
This is better on mono, surround, and on very low bitrates(such as 32kbps
stereo).
truncut.wav has few HF content, so the bitrate saturates in 172kbps.
--
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/2686#comment:53>
FFmpeg <http://ffmpeg.org>
FFmpeg issue tracker
More information about the FFmpeg-trac
mailing list