Bug 401723 – media-libs/libaacplus USE=fftw causes segmentation faults - ?

• Product: Gentoo Linux
• Status: RESOLVED WONTFIX

[Description Reuben Martin 2012-02-01 00:22:44 UTC]

libaacplus segfaults when using fftw when fftw is built with SSE(2) SIMD options enabled due to alignment issues.

libaacplus does work when fftw is built without SSE(2) options enabled, but at that point there is no benefit gained in using fftw over the built-in FFT code.

This also causes ffmpeg to segfault when it tries to use the lib for aac+ encoding.

Reproducible: Always

[Comment 1 Jeroen Roovers (RETIRED) 2012-02-01 15:09:57 UTC]

1) Please post your `emerge --info media-libs/libaacplus' output in a comment.
2) Please post the failing command line and its output too.

[Comment 2 Reuben Martin 2012-02-01 17:08:31 UTC]

Created attachment 300681 [details]
Ebuild Info

Emerge info attached. (currently with fftw USE option turned off)

[Comment 3 Reuben Martin 2012-02-01 17:14:37 UTC]

With FFTW option turned off:

===========

$ ffmpeg -i test.wav -acodec libaacplus -ab 64k -f mp4 test.m4a
ffmpeg version 0.10 Copyright (c) 2000-2012 the FFmpeg developers
  built on Jan 30 2012 12:09:12 with gcc 4.5.3
  configuration: --prefix=/usr --libdir=/usr/lib64 --shlibdir=/usr/lib64 --mandir=/usr/share/man --enable-shared --cc=x86_64-pc-linux-gnu-gcc --cxx=x86_64-pc-linux-gnu-g++ --ar=x86_64-pc-linux-gnu-ar --optflags='-O2 -march=native -mfpmath=sse -ftree-vectorize -fomit-frame-pointer -pipe -fprefetch-loop-arrays -floop-block -floop-strip-mine -floop-interchange' --extra-cflags='-O2 -march=native -mfpmath=sse -ftree-vectorize -fomit-frame-pointer -pipe -fprefetch-loop-arrays -floop-block -floop-strip-mine -floop-interchange' --extra-cxxflags='-O2 -march=native -mfpmath=sse -ftree-vectorize -fomit-frame-pointer -pipe -fprefetch-loop-arrays -floop-block -floop-strip-mine -floop-interchange -fvisibility-inlines-hidden' --disable-static --enable-gpl --enable-version3 --enable-postproc --enable-avfilter --disable-stripping --disable-debug --disable-doc --enable-openssl --enable-nonfree --enable-gnutls --enable-libmp3lame --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-libtheora --enable-libvorbis --enable-libx2  libavutil      51. 34.101 / 51. 34.101
  libavcodec     53. 60.100 / 53. 60.100
  libavformat    53. 31.100 / 53. 31.100
  libavdevice    53.  4.100 / 53.  4.100
  libavfilter     2. 60.100 /  2. 60.100
  libswscale      2.  1.100 /  2.  1.100
  libswresample   0.  6.100 /  0.  6.100
  libpostproc    52.  0.100 / 52.  0.100
[wav @ 0x1c9cc70] max_analyze_duration 5000000 reached at 5015510
Input #0, wav, from 'test.wav':
  Duration: 00:03:23.22, bitrate: 1411 kb/s
    Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 44100 Hz, 2 channels, s16, 1411 kb/s
Output #0, mp4, to 'test.m4a':
  Metadata:
    encoder         : Lavf53.31.100
    Stream #0:0: Audio: aac (@[0][0][0] / 0x0040), 44100 Hz, 2 channels, s16, 64 kb/s
Stream mapping:
  Stream #0:0 -> #0:0 (pcm_s16le -> libaacplus)
Press [q] to stop, [?] for help
size=    1606kB time=00:03:23.22 bitrate=  64.7kbits/s    
video:0kB audio:1588kB global headers:0kB muxing overhead 1.123113%


===========

With FFTW option turned on:

===========

$ ffmpeg -i test.wav -acodec libaacplus -ab 64k -f mp4 test2.m4a
ffmpeg version 0.10 Copyright (c) 2000-2012 the FFmpeg developers
  built on Jan 30 2012 12:09:12 with gcc 4.5.3
  configuration: --prefix=/usr --libdir=/usr/lib64 --shlibdir=/usr/lib64 --mandir=/usr/share/man --enable-shared --cc=x86_64-pc-linux-gnu-gcc --cxx=x86_64-pc-linux-gnu-g++ --ar=x86_64-pc-linux-gnu-ar --optflags='-O2 -march=native -mfpmath=sse -ftree-vectorize -fomit-frame-pointer -pipe -fprefetch-loop-arrays -floop-block -floop-strip-mine -floop-interchange' --extra-cflags='-O2 -march=native -mfpmath=sse -ftree-vectorize -fomit-frame-pointer -pipe -fprefetch-loop-arrays -floop-block -floop-strip-mine -floop-interchange' --extra-cxxflags='-O2 -march=native -mfpmath=sse -ftree-vectorize -fomit-frame-pointer -pipe -fprefetch-loop-arrays -floop-block -floop-strip-mine -floop-interchange -fvisibility-inlines-hidden' --disable-static --enable-gpl --enable-version3 --enable-postproc --enable-avfilter --disable-stripping --disable-debug --disable-doc --enable-openssl --enable-nonfree --enable-gnutls --enable-libmp3lame --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-libtheora --enable-libvorbis --enable-libx2  libavutil      51. 34.101 / 51. 34.101
  libavcodec     53. 60.100 / 53. 60.100
  libavformat    53. 31.100 / 53. 31.100
  libavdevice    53.  4.100 / 53.  4.100
  libavfilter     2. 60.100 /  2. 60.100
  libswscale      2.  1.100 /  2.  1.100
  libswresample   0.  6.100 /  0.  6.100
  libpostproc    52.  0.100 / 52.  0.100
[wav @ 0x19f6c70] max_analyze_duration 5000000 reached at 5015510
Input #0, wav, from 'test.wav':
  Duration: 00:03:23.22, bitrate: 1411 kb/s
    Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 44100 Hz, 2 channels, s16, 1411 kb/s
Output #0, mp4, to 'test2.m4a':
  Metadata:
    encoder         : Lavf53.31.100
    Stream #0:0: Audio: aac (@[0][0][0] / 0x0040), 44100 Hz, 2 channels, s16, 64 kb/s
Stream mapping:
  Stream #0:0 -> #0:0 (pcm_s16le -> libaacplus)
Press [q] to stop, [?] for help
Segmentation fault

[Comment 4 Reuben Martin 2012-02-01 17:18:24 UTC]

The bug referenced in the URL given in the original report includes a gdb trace with the relevant debug into turned on, in case you want an example showing the segfault taking place in the FFTW3 lib.