[FFmpeg-trac] #10456(undetermined:new): Example decode_filter_audio.c produces noise

[FFmpeg]

#10456: Example decode_filter_audio.c produces noise
-------------------------------------+-------------------------------------
             Reporter:  Mahyar       |                    Owner:  (none)
                 Type:  defect       |                   Status:  new
             Priority:  normal       |                Component:
                                     |  undetermined
              Version:  git-master   |               Resolution:
             Keywords:               |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------

Old description:

> Summary of the bug:
>
> The decode_filter_audio.c example of the nightly trunk and of version 6.0
> produces noise on the output. The example is supposed to read in an audio
> file, decode it, apply a filter, and output 16-bit LE PCM audio. The
> output audio is mostly noise, but the original music can just about be
> heard.
>
> This issue occured with all the audio files that I tried, including flac,
> m4a (aac), and ogg. The input file and the output PCM audio will be
> attached to this bug report.
>
> How to reproduce:
> {{{
> % ./decode_filter_audio.exe Muriel-Nguyen-Xuan-Brahms-rhapsody-
> opus79-snippet.ogg | ffplay -f s16le -ar 8000 -ac 1 -
> }}}
>
> This bug occurs on Windows 10 Version 21H2 within an Mingw-w64
> (w64devkit) environment.
>
> Playing the input audio files work correctly with ffplay.
>
> ffmpeg version summary:
> {{{
> ffprobe version N-111378-g13e9899014-20230708 Copyright (c) 2007-2023 the
> FFmpeg developers
>   built with gcc 13.1.0 (crosstool-NG 1.25.0.196_227d99d)
>   configuration: --prefix=/ffbuild/prefix --pkg-config-flags=--static
> --pkg-config=pkg-config --cross-prefix=x86_64-w64-mingw32- --arch=x86_64
> --target-os=mingw32 --enable-gpl --enable-version3 --disable-debug
> --enable-shared --disable-static --disable-w32threads --enable-pthreads
> --enable-iconv --enable-libxml2 --enable-zlib --enable-libfreetype
> --enable-libfribidi --enable-gmp --enable-lzma --enable-fontconfig
> --enable-libvorbis --enable-opencl --disable-libpulse --enable-libvmaf
> --disable-libxcb --disable-xlib --enable-amf --enable-libaom --enable-
> libaribb24 --enable-avisynth --enable-chromaprint --enable-libdav1d
> --enable-libdavs2 --disable-libfdk-aac --enable-ffnvcodec --enable-cuda-
> llvm --enable-frei0r --enable-libgme --enable-libkvazaar --enable-libass
> --enable-libbluray --enable-libjxl --enable-libmp3lame --enable-libopus
> --enable-librist --enable-libssh --enable-libtheora --enable-libvpx
> --enable-libwebp --enable-lv2 --enable-libvpl --enable-openal --enable-
> libopencore-amrnb --enable-libopencore-amr  libavutil      58. 14.100 /
> 58. 14.100
>   libavcodec     60. 22.100 / 60. 22.100
>   libavformat    60. 10.100 / 60. 10.100
>   libavdevice    60.  2.101 / 60.  2.101
>   libavfilter     9.  8.102 /  9.  8.102
>   libswscale      7.  3.100 /  7.  3.100
>   libswresample   4. 11.100 /  4. 11.100
>   libpostproc    57.  2.100 / 57.  2.100
> }}}

New description:

 Summary of the bug:

 The decode_filter_audio.c example of the nightly trunk,
 https://ffmpeg.org/doxygen/trunk/decode_filter_audio_8c-example.html, and
 of version 6.0, https://ffmpeg.org/doxygen/6.0/decode_filter_audio_8c-
 example.html, produces noise on the output. The example is supposed to
 read in an audio file, decode it, apply a filter, and output 16-bit LE PCM
 audio. The output audio is mostly noise, but the original music can just
 about be heard.

 This issue occured with all the audio files that I tried, including flac,
 m4a (aac), and ogg. The input file and the output PCM audio will be
 attached to this bug report.

 How to reproduce:
 {{{
 % ./decode_filter_audio.exe Muriel-Nguyen-Xuan-Brahms-rhapsody-
 opus79-snippet.ogg | ffplay -f s16le -ar 8000 -ac 1 -
 }}}

 This bug occurs on Windows 10 Version 21H2 within an Mingw-w64 (w64devkit)
 environment.

 Playing the input audio files work correctly with ffplay.

 ffmpeg version summary:
 {{{
 ffprobe version N-111378-g13e9899014-20230708 Copyright (c) 2007-2023 the
 FFmpeg developers
   built with gcc 13.1.0 (crosstool-NG 1.25.0.196_227d99d)
   configuration: --prefix=/ffbuild/prefix --pkg-config-flags=--static
 --pkg-config=pkg-config --cross-prefix=x86_64-w64-mingw32- --arch=x86_64
 --target-os=mingw32 --enable-gpl --enable-version3 --disable-debug
 --enable-shared --disable-static --disable-w32threads --enable-pthreads
 --enable-iconv --enable-libxml2 --enable-zlib --enable-libfreetype
 --enable-libfribidi --enable-gmp --enable-lzma --enable-fontconfig
 --enable-libvorbis --enable-opencl --disable-libpulse --enable-libvmaf
 --disable-libxcb --disable-xlib --enable-amf --enable-libaom --enable-
 libaribb24 --enable-avisynth --enable-chromaprint --enable-libdav1d
 --enable-libdavs2 --disable-libfdk-aac --enable-ffnvcodec --enable-cuda-
 llvm --enable-frei0r --enable-libgme --enable-libkvazaar --enable-libass
 --enable-libbluray --enable-libjxl --enable-libmp3lame --enable-libopus
 --enable-librist --enable-libssh --enable-libtheora --enable-libvpx
 --enable-libwebp --enable-lv2 --enable-libvpl --enable-openal --enable-
 libopencore-amrnb --enable-libopencore-amr  libavutil      58. 14.100 /
 58. 14.100
   libavcodec     60. 22.100 / 60. 22.100
   libavformat    60. 10.100 / 60. 10.100
   libavdevice    60.  2.101 / 60.  2.101
   libavfilter     9.  8.102 /  9.  8.102
   libswscale      7.  3.100 /  7.  3.100
   libswresample   4. 11.100 /  4. 11.100
   libpostproc    57.  2.100 / 57.  2.100
 }}}

--
Comment (by Mahyar):

 Added URL to example in ffmpeg documentation.
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/10456#comment:1>
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