Recherche avancée

Sur d’autres sites (7010)

• FFmpeg can't find AV_CODEC_ID_WMAV2

  17 novembre 2015, par chaoqi

  I want decode the wma type file use the FFmpeg,
  compiled it with options

  --enable-decoder=wmav1 --enable-decoder=wmav2, --enable-encoder=wmav1, --enable-encoder=wmav2 --enable-demuxer=xwma

  and the source code i use it like this :

          av_register_all();
  
          //avcodec_register_all();
  
  
  
          if ((ret = avformat_open_input(&fmt_ctx, src_filename, 0, 0)) < 0) {
  
              LOG("Could not open source file %s, ret:%d", src_filename, ret);
  
              return;
  
          }
  
  
  
          if ((ret = avformat_find_stream_info(fmt_ctx, 0)) < 0) {
  
              LOG("Could not find stream information---ret:%d", ret);
  
              return;
  
          }

  and avformat_find_stream_info fail with ret:-541478725

  and add ffmpeg -i <inputfile></inputfile> commandline log :

  D:\Downloads\ffmpeg-static\bin>ffmpeg.exe -i ring.wma
  
  ffmpeg version N-76684-g1fe82ab Copyright (c) 2000-2015 the FFmpeg developers
  
    built with gcc 5.2.0 (GCC)
  
    configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-av
  
  isynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enab
  
  le-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --
  
  enable-libdcadec --enable-libfreetype --enable-libgme --enable-libgsm --enable-l
  
  ibilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enab
  
  le-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --en
  
  able-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --ena
  
  ble-libtwolame --enable-libvidstab --enable-libvo-aacenc --enable-libvo-amrwbenc
  
   --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enabl
  
  e-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libzimg --
  
  enable-lzma --enable-decklink --enable-zlib
  
    libavutil      55.  6.100 / 55.  6.100
  
    libavcodec     57. 15.100 / 57. 15.100
  
    libavformat    57. 14.100 / 57. 14.100
  
    libavdevice    57.  0.100 / 57.  0.100
  
    libavfilter     6. 15.100 /  6. 15.100
  
    libswscale      4.  0.100 /  4.  0.100
  
    libswresample   2.  0.101 /  2.  0.101
  
    libpostproc    54.  0.100 / 54.  0.100
  
  Guessed Channel Layout for  Input Stream #0.0 : stereo
  
  Input #0, asf, from 'ring.wma':
  
    Metadata:
  
      WMFSDKNeeded    : 0.0.0.0000
  
      DeviceConformanceTemplate: L3
  
      WMFSDKVersion   : 11.0.6001.7001
  
      IsVBR           : 0
  
      PeakValue       : 18081
  
      AverageLevel    : 1915
  
    Duration: 00:00:07.80, start: 0.000000, bitrate: 206 kb/s
  
      Stream #0:0: Audio: wmav2 (a[1][0][0] / 0x0161), 44100 Hz, 2 channels, fltp,
  
   192 kb/s

  any tips ?

  And which option must be include when i want to decode a special type file ?

  thank you.

• swresample/resample : improve bessel function accuracy and speed

  2 novembre 2015, par Ganesh Ajjanagadde

  swresample/resample : improve bessel function accuracy and speed
  This improves accuracy for the bessel function at large arguments, and this in turn
  
  should improve the quality of the Kaiser window. It also improves the
  
  performance of the bessel function and hence build_filter by 20%.
  
  Details are given below.
  Algorithm : taken from the Boost project, who have done a detailed
  
  investigation of the accuracy of their method, as compared with e.g the
  
  GNU Scientific Library (GSL) :
  
  http://www.boost.org/doc/libs/1_52_0/libs/math/doc/sf_and_dist/html/math_toolkit/special/bessel/mbessel.html.
  
  Boost source code (also cited and licensed in the code) :
  
  https://searchcode.com/codesearch/view/14918379/.
  Accuracy : sample values may be obtained as follows. i0 denotes the old bessel code,
  
  i0_boost the approach here, and i0_real an arbitrary precision result (truncated) from Wolfram Alpha :
  
  type "bessel i0(6.0)" to reproduce. These are evaluation points that occur for
  
  the default kaiser_beta = 9.
  Some illustrations :
  
  bessel(8.0)
  
  i0      (8.000000) = 427.564115721804739678191254
  
  i0_boost(8.000000) = 427.564115721804796521610115
  
  i0_real (8.000000) = 427.564115721804785177396791
  bessel(6.0)
  
  i0      (6.000000) = 67.234406976477956163762428
  
  i0_boost(6.000000) = 67.234406976477970374617144
  
  i0_real (6.000000) = 67.234406976477975326188025
  Reason for accuracy : Main accuracy benefits come at larger bessel arguments, where the
  
  Taylor-Maclaurin method is not that good : 23+ iterations
  
  (at large arguments, since the series is about 0) can cause
  
  significant floating point error accumulation.
  Benchmarks : Obtained on x86-64, Haswell, GNU/Linux via a loop calling
  
  build_filter 1000 times :
  
  test : fate-swr-resample-dblp-44100-2626
  new :
  
  995894468 decicycles in build_filter(loop 1000),     256 runs,      0 skips
  
  1029719302 decicycles in build_filter(loop 1000),     512 runs,      0 skips
  
  984101131 decicycles in build_filter(loop 1000),    1024 runs,      0 skips
  old :
  
  1250020763 decicycles in build_filter(loop 1000),     256 runs,      0 skips
  
  1246353282 decicycles in build_filter(loop 1000),     512 runs,      0 skips
  
  1220017565 decicycles in build_filter(loop 1000),    1024 runs,      0 skips
  A further 5% may be squeezed by enabling -ftree-vectorize. However,
  
  this is a separate issue from this patch.
  Reviewed-by : Michael Niedermayer <michael@niedermayer.cc>
  
  Signed-off-by : Ganesh Ajjanagadde <gajjanagadde@gmail.com>
  

  • [DH] libswresample/resample.c

• Bash script to convert imgs in subfolders to video (using ffmpeg and Ubuntu)

  2 novembre 2015, par mcExchange

  I’m trying to convert all files in folders given by

   allFolders.txt
  
  > head folderNames.txt
  
  0001 
  
  0002 
  
  0003 
  
  0004 
  
  0005 
  
  ...

  to a video using ffmpeg

  ffmpeg version 2.2.3 Copyright (c) 2000-2014 the FFmpeg developers  built on Apr 20 2015 13:38:52 with gcc 4.8 (Ubuntu 4.8.2-19ubuntu1)
  
  configuration: --prefix=/home/myUsername/usr/local --enable-nonfree --enable-gpl --enable-pic --enable-shared --enable-libx264 --disable-vaapi

  According to some answers here on stackoverflow I wrote the following bash script :

  #!/bin/bash
  
  while read p; do
  
      cd "$p"
  
      ffmpeg -f concat -i "allImgNames.txt" -framerate 30 -c:v libx264 -profile:v high -crf 20 -pix_fmt yuv420p output.mp4
  
      cd -
  
  done < folderNames.txt

  where allImgNames.txt is a text file containing all the image names.

  The strange thing is that it works for a few videos but for the rest of the filelist it fails saying allImgNames.txt: No such file or directory, which is not true. I checked all paths several times. Also I can execute the ffmpeg ... command above manually without problems.
  I don’t know what I’m doing wrong. All file / folder names are normal (no special characters). Maybe I don’t understand enough about bash or ffmpeg.