[FFmpeg-trac] #2686(avcodec:open): Native AAC encoder collapses at high bitrates on some samples
FFmpeg
trac at avcodec.org
Wed Aug 5 17:30:20 CEST 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):
{{{-aac_coder faac}}} induces infinite loop whenever the bitrate is
clamped to max. It never induces infinite loop when the bitrate is below
the max.
This bug is reproducible on any samples on any channel/sampling freq.
settings.
{{{
ffmpeg74294 -y -i Whitenoise.flac -c:a aac -strict experimental -b:a 530k
-ac 2 -ar 44100 -aac_coder faac whitenoise.mp4
ffmpeg version N-74294-g45d9d16 Copyright (c) 2000-2015 the FFmpeg
developers
built with gcc 5.2.0 (GCC)
configuration: --enable-gpl --enable-version3 --enable-nonfree --enable-
libmp3
lame --enable-libvo-aacenc --enable-libvorbis --enable-libfdk-aac
--enable-w32th
reads --extra-ldflags=-static --extra-cflags='-mtune=nocona'
--optflags=-O2
libavutil 54. 30.100 / 54. 30.100
libavcodec 56. 57.100 / 56. 57.100
libavformat 56. 40.101 / 56. 40.101
libavdevice 56. 4.100 / 56. 4.100
libavfilter 5. 32.100 / 5. 32.100
libswscale 3. 1.101 / 3. 1.101
libswresample 1. 2.101 / 1. 2.101
libpostproc 53. 3.100 / 53. 3.100
Input #0, flac, from 'Whitenoise.flac':
Duration: 00:00:05.00, start: 0.000000, bitrate: 1550 kb/s
Stream #0:0: Audio: flac, 48000 Hz, stereo, s16
[aac @ 01e37760] Too many bits per frame requested, clamping to max
Output #0, mp4, to 'whitenoise.mp4':
Metadata:
encoder : Lavf56.40.101
Stream #0:0: Audio: aac ([64][0][0][0] / 0x0040), 44100 Hz, stereo,
fltp (16
bit), 529 kb/s
Metadata:
encoder : Lavc56.57.100 aac
Stream mapping:
Stream #0:0 -> #0:0 (flac (native) -> aac (native))
Press [q] to stop, [?] for help
size= 86kB time=00:00:01.48 bitrate= 475.6kbits/s
}}}
{{{[aac @ 01e37760] Too many bits per frame requested, clamping to max}}}
is the sign it fails.
{{{
ffmpeg74294 -y -i Whitenoise.flac -c:a aac -strict experimental -b:a 133k
-ac 1 -ar 22050 -aac_coder faac whitenoise.m
p4
ffmpeg version N-74294-g45d9d16 Copyright (c) 2000-2015 the FFmpeg
developers
built with gcc 5.2.0 (GCC)
configuration: --enable-gpl --enable-version3 --enable-nonfree --enable-
libmp3
lame --enable-libvo-aacenc --enable-libvorbis --enable-libfdk-aac
--enable-w32th
reads --extra-ldflags=-static --extra-cflags='-mtune=nocona'
--optflags=-O2
libavutil 54. 30.100 / 54. 30.100
libavcodec 56. 57.100 / 56. 57.100
libavformat 56. 40.101 / 56. 40.101
libavdevice 56. 4.100 / 56. 4.100
libavfilter 5. 32.100 / 5. 32.100
libswscale 3. 1.101 / 3. 1.101
libswresample 1. 2.101 / 1. 2.101
libpostproc 53. 3.100 / 53. 3.100
Input #0, flac, from 'Whitenoise.flac':
Duration: 00:00:05.00, start: 0.000000, bitrate: 1550 kb/s
Stream #0:0: Audio: flac, 48000 Hz, stereo, s16
[aac @ 01997760] Too many bits per frame requested, clamping to max
Output #0, mp4, to 'whitenoise.mp4':
Metadata:
encoder : Lavf56.40.101
Stream #0:0: Audio: aac ([64][0][0][0] / 0x0040), 22050 Hz, mono, fltp
(16 b
it), 132 kb/s
Metadata:
encoder : Lavc56.57.100 aac
Stream mapping:
Stream #0:0 -> #0:0 (flac (native) -> aac (native))
Press [q] to stop, [?] for help
}}}
--
Ticket URL: <https://trac.ffmpeg.org/ticket/2686#comment:401>
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