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    13 avril 2011, par

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  • Le plugin : Podcasts.

    14 juillet 2010, par

    Le problème du podcasting est à nouveau un problème révélateur de la normalisation des transports de données sur Internet.
    Deux formats intéressants existent : Celui développé par Apple, très axé sur l’utilisation d’iTunes dont la SPEC est ici ; Le format "Media RSS Module" qui est plus "libre" notamment soutenu par Yahoo et le logiciel Miro ;
    Types de fichiers supportés dans les flux
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Sur d’autres sites (5693)

  • ffmpeg audio conversion : encoder pcm_u8 working pcm_s8 not

    14 novembre 2018, par patszn

    I need to convert audio inside video to 8 Bit signed PCM. I try it like this :

    C:\Users\E\Desktop\ffmpeg-20160731-04da20e-win32-static\bin>ffmpeg -i minions.mp4 -vcodec mjpeg -s 800x480 -acodec pcm_s8 -ac 1 out.avi

    output :

    ffmpeg version N-81192-g04da20e Copyright (c) 2000-2016 the FFmpeg developers
    
  built with gcc 5.4.0 (GCC)
    
  configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-dxva2 --enable-libmfx --enable-nvenc --enable-avisynth --enable-bzlib --enable-lib
    
ebur128 --enable-fontconfig --enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libfree
    
type --enable-libgme --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-lib
    
openjpeg --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame
    
 --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-
    
libxavs --enable-libxvid --enable-libzimg --enable-lzma --enable-decklink --enable-zlib
    
  libavutil      55. 28.100 / 55. 28.100
    
  libavcodec     57. 51.100 / 57. 51.100
    
  libavformat    57. 44.100 / 57. 44.100
    
  libavdevice    57.  0.102 / 57.  0.102
    
  libavfilter     6. 49.100 /  6. 49.100
    
  libswscale      4.  1.100 /  4.  1.100
    
  libswresample   2.  1.100 /  2.  1.100
    
  libpostproc    54.  0.100 / 54.  0.100
    
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'minions.mp4':
    
  Metadata:
    
    major_brand     : mp42
    
    minor_version   : 0
    
    compatible_brands: isommp42
    
    creation_time   : 2016-03-17 10:06:57
    
  Duration: 00:03:18.72, start: 0.000000, bitrate: 1869 kb/s
    
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 1675 kb/s, 23.98 fps, 23.98 tbr, 24k tbn, 47.95 tbc (default
    
)
    
    Metadata:
    
      handler_name    : VideoHandler
    
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 192 kb/s (default)
    
    Metadata:
    
      creation_time   : 2016-03-17 10:06:58
    
      handler_name    : IsoMedia File Produced by Google, 5-11-2011
    
[swscaler @ 04821880] deprecated pixel format used, make sure you did set range correctly
    
[avi @ 048c0460] Using AVStream.codec to pass codec parameters to muxers is deprecated, use AVStream.codecpar instead.
    
    Last message repeated 1 times
    
Output #0, avi, to 'out.avi':
    
  Metadata:
    
    major_brand     : mp42
    
    minor_version   : 0
    
    compatible_brands: isommp42
    
    encoder         : Lavf57.44.100
    
    Stream #0:0(und): Video: mjpeg (MJPG / 0x47504A4D), yuvj420p(pc), 800x480 [SAR 16:15 DAR 16:9], q=2-31, 200 kb/s, 23.98 fps, 23.98 tbn, 23.98 tbc (default)
    
    Metadata:
    
      handler_name    : VideoHandler
    
      encoder         : Lavc57.51.100 mjpeg
    
    Side data:
    
      cpb: bitrate max/min/avg: 0/0/200000 buffer size: 0 vbv_delay: -1
    
    Stream #0:1(und): Audio: pcm_s8, 44100 Hz, mono, u8, 352 kb/s (default)
    
    Metadata:
    
      creation_time   : 2016-03-17 10:06:58
    
      handler_name    : IsoMedia File Produced by Google, 5-11-2011
    
      encoder         : Lavc57.51.100 pcm_s8
    
Stream mapping:
    
  Stream #0:0 -> #0:0 (h264 (native) -> mjpeg (native))
    
  Stream #0:1 -> #0:1 (aac (native) -> pcm_s8 (native))
    
Could not write header for output file #0 (incorrect codec parameters ?): Operation not permitted

    ffmpeg can not write a header for output file. I want to mention that if audio encoder is selected to pcm_u8 everything works fine.

    C:\Users\E\Desktop\ffmpeg-20160731-04da20e-win32-static\bin>ffmpeg -i minions.mp4 -vcodec mjpeg -s 800x480 -acodec pcm_u8 -ac 1 out.avi

    output :

    ffmpeg version N-81192-g04da20e Copyright (c) 2000-2016 the FFmpeg developers
    
  built with gcc 5.4.0 (GCC)
    
  configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-dxva2 --enable-libmfx --enable-nvenc --enable-avisynth --enable-bzlib --enable-lib
    
ebur128 --enable-fontconfig --enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libfree
    
type --enable-libgme --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-lib
    
openjpeg --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame
    
 --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-
    
libxavs --enable-libxvid --enable-libzimg --enable-lzma --enable-decklink --enable-zlib
    
  libavutil      55. 28.100 / 55. 28.100
    
  libavcodec     57. 51.100 / 57. 51.100
    
  libavformat    57. 44.100 / 57. 44.100
    
  libavdevice    57.  0.102 / 57.  0.102
    
  libavfilter     6. 49.100 /  6. 49.100
    
  libswscale      4.  1.100 /  4.  1.100
    
  libswresample   2.  1.100 /  2.  1.100
    
  libpostproc    54.  0.100 / 54.  0.100
    
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'minions.mp4':
    
  Metadata:
    
    major_brand     : mp42
    
    minor_version   : 0
    
    compatible_brands: isommp42
    
    creation_time   : 2016-03-17 10:06:57
    
  Duration: 00:03:18.72, start: 0.000000, bitrate: 1869 kb/s
    
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 1675 kb/s, 23.98 fps, 23.98 tbr, 24k tbn, 47.95 tbc (default
    
)
    
    Metadata:
    
      handler_name    : VideoHandler
    
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 192 kb/s (default)
    
    Metadata:
    
      creation_time   : 2016-03-17 10:06:58
    
      handler_name    : IsoMedia File Produced by Google, 5-11-2011
    
File 'out.avi' already exists. Overwrite ? [y/N] y
    
[swscaler @ 030a1880] deprecated pixel format used, make sure you did set range correctly
    
[avi @ 04a10460] Using AVStream.codec to pass codec parameters to muxers is deprecated, use AVStream.codecpar instead.
    
    Last message repeated 1 times
    
Output #0, avi, to 'out.avi':
    
  Metadata:
    
    major_brand     : mp42
    
    minor_version   : 0
    
    compatible_brands: isommp42
    
    ISFT            : Lavf57.44.100
    
    Stream #0:0(und): Video: mjpeg (MJPG / 0x47504A4D), yuvj420p(pc), 800x480 [SAR 16:15 DAR 16:9], q=2-31, 200 kb/s, 23.98 fps, 23.98 tbn, 23.98 tbc (default)
    
    Metadata:
    
      handler_name    : VideoHandler
    
      encoder         : Lavc57.51.100 mjpeg
    
    Side data:
    
      cpb: bitrate max/min/avg: 0/0/200000 buffer size: 0 vbv_delay: -1
    
    Stream #0:1(und): Audio: pcm_u8 ([1][0][0][0] / 0x0001), 44100 Hz, mono, u8, 352 kb/s (default)
    
    Metadata:
    
      creation_time   : 2016-03-17 10:06:58
    
      handler_name    : IsoMedia File Produced by Google, 5-11-2011
    
      encoder         : Lavc57.51.100 pcm_u8
    
Stream mapping:
    
  Stream #0:0 -> #0:0 (h264 (native) -> mjpeg (native))
    
  Stream #0:1 -> #0:1 (aac (native) -> pcm_u8 (native))
    
Press [q] to stop, [?] for help
    
frame= 4764 fps=250 q=24.8 Lsize=   74247kB time=00:03:18.71 bitrate=3060.8kbits/s speed=10.4x
    
video:65364kB audio:8558kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.438745%

    What is the problem ? Why conversion does not work for signed pcm ?

    Encoders for both unsigned and signed pcm are avaible :

    C:\Users\E\Desktop\ffmpeg-20160731-04da20e-win32-static\bin>ffmpeg -encoders

     .
    
 .
    
 A..... pcm_f32be            PCM 32-bit floating point big-endian
    
 A..... pcm_f32le            PCM 32-bit floating point little-endian
    
 A..... pcm_f64be            PCM 64-bit floating point big-endian
    
 A..... pcm_f64le            PCM 64-bit floating point little-endian
    
 A..... pcm_mulaw            PCM mu-law / G.711 mu-law
    
 A..... pcm_s16be            PCM signed 16-bit big-endian
    
 A..... pcm_s16be_planar     PCM signed 16-bit big-endian planar
    
 A..... pcm_s16le            PCM signed 16-bit little-endian
    
 A..... pcm_s16le_planar     PCM signed 16-bit little-endian planar
    
 A..... pcm_s24be            PCM signed 24-bit big-endian
    
 A..... pcm_s24daud          PCM D-Cinema audio signed 24-bit
    
 A..... pcm_s24le            PCM signed 24-bit little-endian
    
 A..... pcm_s24le_planar     PCM signed 24-bit little-endian planar
    
 A..... pcm_s32be            PCM signed 32-bit big-endian
    
 A..... pcm_s32le            PCM signed 32-bit little-endian
    
 A..... pcm_s32le_planar     PCM signed 32-bit little-endian planar
    
 A..... pcm_s8               PCM signed 8-bit
    
 A..... pcm_s8_planar        PCM signed 8-bit planar
    
 A..... pcm_u16be            PCM unsigned 16-bit big-endian
    
 A..... pcm_u16le            PCM unsigned 16-bit little-endian
    
 A..... pcm_u24be            PCM unsigned 24-bit big-endian
    
 A..... pcm_u24le            PCM unsigned 24-bit little-endian
    
 A..... pcm_u32be            PCM unsigned 32-bit big-endian
    
 A..... pcm_u32le            PCM unsigned 32-bit little-endian
    
 A..... pcm_u8               PCM unsigned 8-bit
    
 .
    
 .

  • ffmpeg audio conversion : encoder pcm_u8 working pcm_s8 not

    1er août 2016, par patszn

    I need to convert audio inside video to 8 Bit signed PCM. I try it like this :

    C:\Users\E\Desktop\ffmpeg-20160731-04da20e-win32-static\bin>ffmpeg -i minions.mp4 -vcodec mjpeg -s 800x480 -acodec pcm_s8 -ac 1 out.avi

    output :

    ffmpeg version N-81192-g04da20e Copyright (c) 2000-2016 the FFmpeg developers
    
  built with gcc 5.4.0 (GCC)
    
  configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-dxva2 --enable-libmfx --enable-nvenc --enable-avisynth --enable-bzlib --enable-lib
    
ebur128 --enable-fontconfig --enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libfree
    
type --enable-libgme --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-lib
    
openjpeg --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame
    
 --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-
    
libxavs --enable-libxvid --enable-libzimg --enable-lzma --enable-decklink --enable-zlib
    
  libavutil      55. 28.100 / 55. 28.100
    
  libavcodec     57. 51.100 / 57. 51.100
    
  libavformat    57. 44.100 / 57. 44.100
    
  libavdevice    57.  0.102 / 57.  0.102
    
  libavfilter     6. 49.100 /  6. 49.100
    
  libswscale      4.  1.100 /  4.  1.100
    
  libswresample   2.  1.100 /  2.  1.100
    
  libpostproc    54.  0.100 / 54.  0.100
    
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'minions.mp4':
    
  Metadata:
    
    major_brand     : mp42
    
    minor_version   : 0
    
    compatible_brands: isommp42
    
    creation_time   : 2016-03-17 10:06:57
    
  Duration: 00:03:18.72, start: 0.000000, bitrate: 1869 kb/s
    
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 1675 kb/s, 23.98 fps, 23.98 tbr, 24k tbn, 47.95 tbc (default
    
)
    
    Metadata:
    
      handler_name    : VideoHandler
    
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 192 kb/s (default)
    
    Metadata:
    
      creation_time   : 2016-03-17 10:06:58
    
      handler_name    : IsoMedia File Produced by Google, 5-11-2011
    
[swscaler @ 04821880] deprecated pixel format used, make sure you did set range correctly
    
[avi @ 048c0460] Using AVStream.codec to pass codec parameters to muxers is deprecated, use AVStream.codecpar instead.
    
    Last message repeated 1 times
    
Output #0, avi, to 'out.avi':
    
  Metadata:
    
    major_brand     : mp42
    
    minor_version   : 0
    
    compatible_brands: isommp42
    
    encoder         : Lavf57.44.100
    
    Stream #0:0(und): Video: mjpeg (MJPG / 0x47504A4D), yuvj420p(pc), 800x480 [SAR 16:15 DAR 16:9], q=2-31, 200 kb/s, 23.98 fps, 23.98 tbn, 23.98 tbc (default)
    
    Metadata:
    
      handler_name    : VideoHandler
    
      encoder         : Lavc57.51.100 mjpeg
    
    Side data:
    
      cpb: bitrate max/min/avg: 0/0/200000 buffer size: 0 vbv_delay: -1
    
    Stream #0:1(und): Audio: pcm_s8, 44100 Hz, mono, u8, 352 kb/s (default)
    
    Metadata:
    
      creation_time   : 2016-03-17 10:06:58
    
      handler_name    : IsoMedia File Produced by Google, 5-11-2011
    
      encoder         : Lavc57.51.100 pcm_s8
    
Stream mapping:
    
  Stream #0:0 -> #0:0 (h264 (native) -> mjpeg (native))
    
  Stream #0:1 -> #0:1 (aac (native) -> pcm_s8 (native))
    
Could not write header for output file #0 (incorrect codec parameters ?): Operation not permitted

    ffmpeg can not write a header for output file. I want to mention that if audio encoder is selected to pcm_u8 everything works fine.

    C:\Users\E\Desktop\ffmpeg-20160731-04da20e-win32-static\bin>ffmpeg -i minions.mp4 -vcodec mjpeg -s 800x480 -acodec pcm_u8 -ac 1 out.avi

    output :

    ffmpeg version N-81192-g04da20e Copyright (c) 2000-2016 the FFmpeg developers
    
  built with gcc 5.4.0 (GCC)
    
  configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-dxva2 --enable-libmfx --enable-nvenc --enable-avisynth --enable-bzlib --enable-lib
    
ebur128 --enable-fontconfig --enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libfree
    
type --enable-libgme --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-lib
    
openjpeg --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame
    
 --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-
    
libxavs --enable-libxvid --enable-libzimg --enable-lzma --enable-decklink --enable-zlib
    
  libavutil      55. 28.100 / 55. 28.100
    
  libavcodec     57. 51.100 / 57. 51.100
    
  libavformat    57. 44.100 / 57. 44.100
    
  libavdevice    57.  0.102 / 57.  0.102
    
  libavfilter     6. 49.100 /  6. 49.100
    
  libswscale      4.  1.100 /  4.  1.100
    
  libswresample   2.  1.100 /  2.  1.100
    
  libpostproc    54.  0.100 / 54.  0.100
    
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'minions.mp4':
    
  Metadata:
    
    major_brand     : mp42
    
    minor_version   : 0
    
    compatible_brands: isommp42
    
    creation_time   : 2016-03-17 10:06:57
    
  Duration: 00:03:18.72, start: 0.000000, bitrate: 1869 kb/s
    
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 1675 kb/s, 23.98 fps, 23.98 tbr, 24k tbn, 47.95 tbc (default
    
)
    
    Metadata:
    
      handler_name    : VideoHandler
    
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 192 kb/s (default)
    
    Metadata:
    
      creation_time   : 2016-03-17 10:06:58
    
      handler_name    : IsoMedia File Produced by Google, 5-11-2011
    
File 'out.avi' already exists. Overwrite ? [y/N] y
    
[swscaler @ 030a1880] deprecated pixel format used, make sure you did set range correctly
    
[avi @ 04a10460] Using AVStream.codec to pass codec parameters to muxers is deprecated, use AVStream.codecpar instead.
    
    Last message repeated 1 times
    
Output #0, avi, to 'out.avi':
    
  Metadata:
    
    major_brand     : mp42
    
    minor_version   : 0
    
    compatible_brands: isommp42
    
    ISFT            : Lavf57.44.100
    
    Stream #0:0(und): Video: mjpeg (MJPG / 0x47504A4D), yuvj420p(pc), 800x480 [SAR 16:15 DAR 16:9], q=2-31, 200 kb/s, 23.98 fps, 23.98 tbn, 23.98 tbc (default)
    
    Metadata:
    
      handler_name    : VideoHandler
    
      encoder         : Lavc57.51.100 mjpeg
    
    Side data:
    
      cpb: bitrate max/min/avg: 0/0/200000 buffer size: 0 vbv_delay: -1
    
    Stream #0:1(und): Audio: pcm_u8 ([1][0][0][0] / 0x0001), 44100 Hz, mono, u8, 352 kb/s (default)
    
    Metadata:
    
      creation_time   : 2016-03-17 10:06:58
    
      handler_name    : IsoMedia File Produced by Google, 5-11-2011
    
      encoder         : Lavc57.51.100 pcm_u8
    
Stream mapping:
    
  Stream #0:0 -> #0:0 (h264 (native) -> mjpeg (native))
    
  Stream #0:1 -> #0:1 (aac (native) -> pcm_u8 (native))
    
Press [q] to stop, [?] for help
    
frame= 4764 fps=250 q=24.8 Lsize=   74247kB time=00:03:18.71 bitrate=3060.8kbits/s speed=10.4x
    
video:65364kB audio:8558kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.438745%

    What is the problem ? Why conversion does not work for signed pcm ?

    Encoders for both unsigned and signed pcm are avaible :

    C:\Users\E\Desktop\ffmpeg-20160731-04da20e-win32-static\bin>ffmpeg -encoders

     .
    
 .
    
 A..... pcm_f32be            PCM 32-bit floating point big-endian
    
 A..... pcm_f32le            PCM 32-bit floating point little-endian
    
 A..... pcm_f64be            PCM 64-bit floating point big-endian
    
 A..... pcm_f64le            PCM 64-bit floating point little-endian
    
 A..... pcm_mulaw            PCM mu-law / G.711 mu-law
    
 A..... pcm_s16be            PCM signed 16-bit big-endian
    
 A..... pcm_s16be_planar     PCM signed 16-bit big-endian planar
    
 A..... pcm_s16le            PCM signed 16-bit little-endian
    
 A..... pcm_s16le_planar     PCM signed 16-bit little-endian planar
    
 A..... pcm_s24be            PCM signed 24-bit big-endian
    
 A..... pcm_s24daud          PCM D-Cinema audio signed 24-bit
    
 A..... pcm_s24le            PCM signed 24-bit little-endian
    
 A..... pcm_s24le_planar     PCM signed 24-bit little-endian planar
    
 A..... pcm_s32be            PCM signed 32-bit big-endian
    
 A..... pcm_s32le            PCM signed 32-bit little-endian
    
 A..... pcm_s32le_planar     PCM signed 32-bit little-endian planar
    
 A..... pcm_s8               PCM signed 8-bit
    
 A..... pcm_s8_planar        PCM signed 8-bit planar
    
 A..... pcm_u16be            PCM unsigned 16-bit big-endian
    
 A..... pcm_u16le            PCM unsigned 16-bit little-endian
    
 A..... pcm_u24be            PCM unsigned 24-bit big-endian
    
 A..... pcm_u24le            PCM unsigned 24-bit little-endian
    
 A..... pcm_u32be            PCM unsigned 32-bit big-endian
    
 A..... pcm_u32le            PCM unsigned 32-bit little-endian
    
 A..... pcm_u8               PCM unsigned 8-bit
    
 .
    
 .

  • .mp4 audio(mpeg aac audio (mp4a)) dosen't play well with sdl2_audio

    18 février 2016, par jijijijiji

    I’m making video player in
    https://github.com/mpenkov/ffmpeg-tutorial/blob/master/tutorial03.c

    but I have problem when playing sound. I can hear high pitch sound.

     aCodecCtx=pFormatCtx->streams[audioStream]->codec;
    
  // Set audio settings from codec info
    
  wanted_spec.freq = aCodecCtx->sample_rate;
    
  wanted_spec.format = AUDIO_S16SYS;
    
  wanted_spec.channels = aCodecCtx->channels;
    
  wanted_spec.silence = 0;
    
  wanted_spec.samples = SDL_AUDIO_BUFFER_SIZE;
    
  wanted_spec.callback = audio_callback;
    
  wanted_spec.userdata = aCodecCtx;

    this is part of source code. to solve the problem, I changed value of
    wanted_spec.format.
    when format is AUDIO_S16SYS, I can’t hear what audio says. because sound is like
    slow and high pitch. but I can hear what audio says when I change the value to
    AUDIO_F32SYS. this means 32-bit floating point samples in native byte order. but sound is still high pitch not normal sound.

    other audio file plays well. but only mpeg aac audio (mp4a) codec is not well played.

    you can hear sound in https://soundcloud.com/nickd6ibdksy/sets/sdl2-sound.

    sdl2 cannot support mpeg aac audio (mp4a) codec ? or how can I solve this problem ?

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