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• After transcoding using ffmpeg, I found audio bitrate is not the value I expected

  16 mai 2017, par penny

  I used ffmpeg to transcode some files into new format and with certain parameters. After transcoding, I found some output file’s metadata is not what I expected, the output value is not the same with I set in the cmd line.

  Before transcoding I check the media info of the inputfile :

  ffmpeg -i dz2015082000010.mpg

  ffmpeg version 3.2.4 Copyright (c) 2000-2017 the FFmpeg developers
  built with gcc 4.8.3 (GCC) 20140911 (Red Hat 4.8.3-9)
  configuration : —enable-static —enable-memalign-hack —enable-libx264
  —enable-gpl —enable-pthreads —enable-version3 —enable-avisynth —enable-bzlib —enable-iconv —enable-zlib —enable-nonfree —extra-cflags=-I/usr/local/include/ —extra-ldflags=-L/usr/local/lib —enable-debug=3 —disable-optimizations —enable-nonfree —enable-libmp3lame libavutil 55. 34.101 / 55. 34.101 libavcodec 57. 64.101 / 57. 64.101 libavformat 57. 56.101 /
  57. 56.101 libavdevice 57. 1.100 / 57. 1.100 libavfilter 6. 65.100 / 6. 65.100 libswscale 4. 2.100 / 4. 2.100 libswresample 2. 3.100 / 2. 3.100 libpostproc 54. 1.100 /
  54. 1.100 Input #0, mpeg, from ’dz2015082000010.mpg’ : Duration : 00:01:49.30, start : 0.685389, bitrate : 15723 kb/s
  Stream #0:0[0x1e0] : Video : mpeg2video (Main), yuv420p(tv, top first), 1920x1080 [SAR 1:1 DAR 16:9], 15000 kb/s, 25 fps, 25 tbr,
  90k tbn, 50 tbc
  Stream #0:1[0x1c0] : Audio : mp2, 48000 Hz, stereo, s16p, 384 kb/s At least one output file must be specified

  Next, transcoding with the cmd line :

  ffmpeg -i dz2015082000010.mpg -vcodec libx264 -b:v 4000k -s 1920x1080 -r 25 -g 25  -vprofile main -acodec aac -strict -2 -b:a 128k -ac 2 -ar 44100 -y output.ts

  After transcoding, I check the media info of the output file :

  ffmpeg -i output.ts    

  ffmpeg version 3.2.4 Copyright (c) 2000-2017 the FFmpeg developers built with gcc 4.8.3 (GCC) 20140911 (Red Hat
  4.8.3-9) configuration : —enable-static —enable-memalign-hack —enable-libx264 —enable-gpl —enable-pthreads —enable-version3 —enable-avisynth —enable-bzlib —enable-iconv —enable-zlib —enable-nonfree —extra-cflags=-I/usr/local/include/ —extra-ldflags=-L/usr/local/lib —enable-debug=3 —disable-optimizations —enable-nonfree —enable-libmp3lame libavutil 55. 34.101 / 55. 34.101 libavcodec 57. 64.101
  / 57. 64.101 libavformat 57. 56.101 / 57. 56.101
  libavdevice 57. 1.100 / 57. 1.100 libavfilter 6. 65.100
  / 6. 65.100 libswscale 4. 2.100 / 4. 2.100
  libswresample 2. 3.100 / 2. 3.100 libpostproc 54. 1.100
  / 54. 1.100 Input #0, mpegts, from ’full-2.ts’ : Duration :
  00:01:49.30, start : 1.456778, bitrate : 4455 kb/s Program 1
  Metadata :
  service_name : Service01
  service_provider : FFmpeg
  Stream #0:0[0x100] : Video : h264 (Main) ([27][0][0][0] / 0x001B), yuv420p(progressive), 1920x1080 [SAR 1:1 DAR 16:9], 25 fps, 25 tbr,
  90k tbn, 50 tbc
  Stream #0:1[0x101] : Audio : aac (LC) ([15][0][0][0] / 0x000F), 44100 Hz, stereo, fltp, 4 kb/s At least one output file must be
  specified

  I don’t know why the audio bitrate is changed to 4 kb/s after transcoding, I set the value with -b:a 128k before, anybody can help me ? BTW, the output file sounds all right.

• Why is the external executable I bundled with my azure function not being found at runtime, despite it being present in the expected location ?

  6 septembre 2023, par Cristian Camilo Garcia Barrera

  I have a group of Azure functions that I publish to a functions app. One of these is a blob triggered function, meant to extract thumbnails from videos uploaded to Azure storage, and to do so, uses ffmpeg.exe.

  


  I have published the project via Visual Studio, adding the executable in a directory in the root of the project. The relative path is exe/ffmpeg.exe. To include the executable in the published bundle I followed the instructions in this Microsoft Developer instructional video.

  


  After publication, If I enter the Kudu debug console for this function app, I can find the file under C:\home\site\wwwroot\exe\ffmpeg.exe, as expected. I can even use that absolute path to execute ffmpeg inside the Kudu console.

  


  This is the code I use to call the ffmpeg executable in the blob function :

  


  using (var process = new Process())
{
    process.StartInfo = new ProcessStartInfo
    {
        FileName = @"C:\home\site\wwwroot\exe\ffmpeg.exe",
        Arguments = $"-hide_banner -loglevel error -i {videoTempPath} -frames:v 1 {thumbTempPath}",
        UseShellExecute = false,
        RedirectStandardOutput = true,
        RedirectStandardError = true,
        CreateNoWindow = true
    };

    process.Start();
    await process.WaitForExitAsync();
}


  


  However, this does not work. I get the following error in the logs :

  


  


  An error occurred trying to start process 'C :\home\site\wwwroot\exe\ffmpeg.exe' with working directory 'C :\Program Files (x86)\SiteExtensions\Functions 4.25.2132bit. The system cannot find the file specified.

  


  


  And indeed my thumbnails are never created. How can I solve this, or why does it happen ?

  


• avformat/hlsenc : resend full url of the init fragment mp4

  4 mai 2020, par Steven Liu

  avformat/hlsenc : resend full url of the init fragment mp4
  fix ticket : 8651
  
  because the init fragment mp4 file name is without base url name,
  
  so just modify it use the full url which splice after init function.
  Tested-by : matclayton
  
  Signed-off-by : Steven Liu <liuqi05@kuaishou.com>
  

  • [DH] libavformat/hlsenc.c