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• avutil/tests/channel_layout : Improve enum range check

  30 mars, par Andreas Rheinhardt

  avutil/tests/channel_layout : Improve enum range check
  Both GCC and Clang use unsigned as underlying type of
  
  an enum with no negative enumeration constants, making
  
  checks like "layout->order >= 0" here tautologically true.
  
  Clang warns about this. Combine both range checks
  
  by casting to unsigned to suppress this warning.
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
  

  • [DH] libavutil/tests/channel_layout.c

• Why convert wav to mp3 get different length

  13 avril 2022, par sybil

  I use NAudio and NAudio.Lame to convert a wav file to mp3 file,code like that :

  


  using var reader = new WaveFileReader(file);
using var ms = new MemoryStream();
var writer = new LameMP3FileWriter(ms, reader.WaveFormat, 32);
reader.CopyTo(writer);
writer.Flush();
File.WriteAllBytes(file.Replace("wav", "mp3"), ms.ToArray());


  


  the wav file length is 1500ms,but the mp3 file length is 1557ms.

  


  And I do the same thing by using ffmpeg.exe,command like that :

  


  ffmpeg -i c:\2\xxx.wav c:\2\xxx.mp3


  


  the output info :

  


  ffmpeg version 5.0.1-essentials_build-www.gyan.dev Copyright (c) 2000-2022 the FFmpeg developers
  built with gcc 11.2.0 (Rev7, Built by MSYS2 project)
  configuration: --enable-gpl --enable-version3 --enable-static --disable-w32threads --disable-autodetect --enable-fontconfig --enable-iconv --enable-gnutls --enable-libxml2 --enable-gmp --enable-lzma --enable-zlib --enable-libsrt --enable-libssh --enable-libzmq --enable-avisynth --enable-sdl2 --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxvid --enable-libaom --enable-libopenjpeg --enable-libvpx --enable-libass --enable-libfreetype --enable-libfribidi --enable-libvidstab --enable-libvmaf --enable-libzimg --enable-amf --enable-cuda-llvm --enable-cuvid --enable-ffnvcodec --enable-nvdec --enable-nvenc --enable-d3d11va --enable-dxva2 --enable-libmfx --enable-libgme --enable-libopenmpt --enable-libopencore-amrwb --enable-libmp3lame --enable-libtheora --enable-libvo-amrwbenc --enable-libgsm --enable-libopencore-amrnb --enable-libopus --enable-libspeex --enable-libvorbis --enable-librubberband
  libavutil      57. 17.100 / 57. 17.100
  libavcodec     59. 18.100 / 59. 18.100
  libavformat    59. 16.100 / 59. 16.100
  libavdevice    59.  4.100 / 59.  4.100
  libavfilter     8. 24.100 /  8. 24.100
  libswscale      6.  4.100 /  6.  4.100
  libswresample   4.  3.100 /  4.  3.100
  libpostproc    56.  3.100 / 56.  3.100
Guessed Channel Layout for Input Stream #0.0 : mono
Input #0, wav, from 'c:\2\xxx.wav':
  Duration: 00:00:01.50, bitrate: 768 kb/s
  Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 48000 Hz, mono, s16, 768 kb/s
Stream mapping:
  Stream #0:0 -> #0:0 (pcm_s16le (native) -> mp3 (libmp3lame))
Press [q] to stop, [?] for help
Output #0, mp3, to 'c:\2\xxx.mp3':
  Metadata:
    TSSE            : Lavf59.16.100
  Stream #0:0: Audio: mp3, 48000 Hz, mono, s16p
    Metadata:
      encoder         : Lavc59.18.100 libmp3lame
size=      12kB time=00:00:01.51 bitrate=  66.2kbits/s speed= 137x
video:0kB audio:12kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 1.928711%


  


  And I get a mp3 file which length is 1536ms.
So,why the length changed ?
Thanks for reading.

  


• Revision 91c222491e : Alternate high bitdepth quantizer changes In this proposal, the qindex range is

  3 juillet 2014, par Peter de Rivaz

  Changed Paths :
   Modify /vp9/common/vp9_onyxc_int.h

  
   Modify /vp9/common/vp9_quant_common.c

  
   Modify /vp9/common/vp9_quant_common.h

  
   Modify /vp9/common/vp9_seg_common.c

  
   Modify /vp9/common/vp9_seg_common.h

  
   Modify /vp9/decoder/vp9_decodeframe.c

  
   Modify /vp9/encoder/vp9_aq_complexity.c

  
   Modify /vp9/encoder/vp9_aq_cyclicrefresh.c

  
   Modify /vp9/encoder/vp9_aq_variance.c

  
   Modify /vp9/encoder/vp9_bitstream.c

  
   Modify /vp9/encoder/vp9_encoder.c

  
   Modify /vp9/encoder/vp9_firstpass.c

  
   Modify /vp9/encoder/vp9_quantize.c

  
   Modify /vp9/encoder/vp9_quantize.h

  
   Modify /vp9/encoder/vp9_ratectrl.c

  
   Modify /vp9/encoder/vp9_rdopt.c

  
   Modify /vp9/vp9_cx_iface.c

  
  
  Alternate high bitdepth quantizer changes

  In this proposal, the qindex range is kept at 0 to 255
  but the values are remapped to cover an extended range of
  quantizer values.

  This simplifies the code and bitstream compared to the 8-bit version.

  Change-Id : I0dda61388cef41e21a0d5c34d817c862de637580