Opened 6 years ago

Last modified 5 weeks ago

#1958 open defect

mp3 24khz (in wav): overreads

Reported by: ami_stuff Owned by:
Priority: normal Component: undetermined
Version: git-master Keywords: mp3
Cc: Blocked By:
Blocking: Reproduced by developer: no
Analyzed by developer: no

Description

This happens only with 24khz mode.

I can hear some distortions.

C:\>ffmpeg -i 24khz_2ch_160kbps.wav -t 2 -f null -
ffmpeg version N-46755-ge70144c Copyright (c) 2000-2012 the FFmpeg developers
  built on Nov 15 2012 02:38:20 with gcc 4.5.0 (GCC) 20100414 (Fedora MinGW 4.5.
0-1.fc14)
  configuration: --prefix=/var/www/users/research/ffmpeg/snapshots/build --arch=
x86 --target-os=mingw32 --cross-prefix=i686-pc-mingw32- --cc='ccache i686-pc-min
gw32-gcc' --enable-w32threads --enable-memalign-hack --enable-runtime-cpudetect
--enable-cross-compile --enable-static --disable-shared --extra-libs='-lws2_32 -
lwinmm -lpthread' --extra-cflags='--static -I/var/www/users/research/ffmpeg/snap
shots/build/include' --extra-ldflags='-static -L/var/www/users/research/ffmpeg/s
napshots/build/lib' --enable-bzlib --enable-zlib --enable-gpl --enable-version3
--enable-nonfree --enable-libx264 --enable-libspeex --enable-libtheora --enable-
libvorbis --enable-libfaac --enable-libxvid --enable-libopencore-amrnb --enable-
libopencore-amrwb --enable-libmp3lame --enable-libvpx --disable-decoder=libvpx
  libavutil      52.  6.100 / 52.  6.100
  libavcodec     54. 71.100 / 54. 71.100
  libavformat    54. 36.100 / 54. 36.100
  libavdevice    54.  3.100 / 54.  3.100
  libavfilter     3. 23.100 /  3. 23.100
  libswscale      2.  1.102 /  2.  1.102
  libswresample   0. 16.100 /  0. 16.100
  libpostproc    52.  1.100 / 52.  1.100
[wav @ 0x1edc3c0] max_analyze_duration 5000000 reached at 5016000
[wav @ 0x1edc3c0] Estimating duration from bitrate, this may be inaccurate
Input #0, wav, from '24khz_2ch_160kbps.wav':
  Duration: 00:00:33.12, bitrate: 127 kb/s
    Stream #0:0: Audio: mp3 (U[0][0][0] / 0x0055), 24000 Hz, stereo, s16, 128 kb
/s
Output #0, null, to 'pipe:':
  Metadata:
    encoder         : Lavf54.36.100
    Stream #0:0: Audio: pcm_s16le, 24000 Hz, stereo, s16, 768 kb/s
Stream mapping:
  Stream #0:0 -> #0:0 (mp3 -> pcm_s16le)
Press [q] to stop, [?] for help
[mp3 @ 0x1edcb60] overread, skip -7 enddists: -6 -6
[mp3 @ 0x1edcb60] overread, skip -6 enddists: -5 -5
[mp3 @ 0x1edcb60] overread, skip -9 enddists: -1 -1
[mp3 @ 0x1edcb60] overread, skip -7 enddists: -3 -3
    Last message repeated 1 times
[mp3 @ 0x1edcb60] overread, skip -6 enddists: -2 -2
[mp3 @ 0x1edcb60] overread, skip -6 enddists: -4 -4
[mp3 @ 0x1edcb60] overread, skip -7 enddists: -4 -4
size=       0kB time=00:00:02.01 bitrate=   0.0kbits/s
video:0kB audio:189kB subtitle:0 global headers:0kB muxing overhead -100.000000%

Attachments (5)

22khz_2ch_160kbps.wav (521.9 KB) - added by ami_stuff 6 years ago.
24khz_2ch_160kbps.wav (517.4 KB) - added by ami_stuff 6 years ago.
32khz_2ch_160kbps.wav (563.6 KB) - added by ami_stuff 6 years ago.
24khz_1ch_160kbps.wav (536.8 KB) - added by ami_stuff 6 years ago.
resample_24000_V_0.mp3 (281.3 KB) - added by ami_stuff 21 months ago.

Change History (10)

Changed 6 years ago by ami_stuff

Changed 6 years ago by ami_stuff

Changed 6 years ago by ami_stuff

comment:1 Changed 6 years ago by ami_stuff

with mono 24khz there is only 1 overread

Changed 6 years ago by ami_stuff

comment:2 Changed 6 years ago by cehoyos

  • Keywords mp3 added
  • Status changed from new to open
  • Version changed from unspecified to git-master

comment:3 Changed 6 years ago by ami_stuff

the same problem can be reproduced with file generated by lame

lame --resample 24000 test.wav

or

lame --resample 24000 -V 0 test.wav

Last edited 6 years ago by ami_stuff (previous) (diff)

Changed 21 months ago by ami_stuff

comment:4 Changed 21 months ago by ami_stuff

attached better sample

comment:5 Changed 5 weeks ago by m.dmt

I'm also affected by this bug.
To try to narrow it down, I've encoded PCM16 wav with LAME 3.100 at various sample rates and qualities. Out of all valid MP3 sample rates only 24 kHz is affected. If LAME encoding quality (-q) is <= 4, overread messages appear during decoding. If quality is >= 5, these messages do not appear, but distortions can still be heard. mpg123 1.25.10 decodes without audible distortions in both cases.

Last edited 5 weeks ago by m.dmt (previous) (diff)
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