Cannot extract proper audio from video using pipes

[ruliworst]

Hi everyone!

I am trying to extract audio from video using pipes unsuccessfully. Here is the code:

... ExtractAudioFromVideoUsingPipes(byte[] video)
{
  MemoryStream videoStream = new MemoryStream(video);
  MemoryStream audioStream = new MemoryStream();
  
  StreamPipeSource input = new StreamPipeSource(videoStream);
  StreamPipeSink output = new StreamPipeSink(audioStream);
  
  FFMpegArguments
    .FromPipeInput(input)
    .OutputToPipe(output, options =>
    {
       options.DisableChannel(Channel.Video).ForceFormat("mp3");
    })
    .ProcessSynchronously();
  
    byte[] outputByteArray = new byte[audioStream.Length];
  
    audioStream.Position = 0;
    audioStream.Read(outputByteArray, 0, outputByteArray.Length);
  
  ...
}

That code produces a result but it is wrong. The resulting outputByteArray should have a length of approximately 223000, but a length of 148 is provided instead. However, if I use the original method, everything is fine:

public static bool ExtractAudio(string input, string output)
{
     FFMpegHelper.ExtensionExceptionCheck(output, FileExtension.Mp3);

      return FFMpegArguments
                .FromFileInput(input)
                .OutputToFile(output, true, options => options
                    .DisableChannel(Channel.Video))
                .ProcessSynchronously();
}

FFMpeg version used: 2022-10-24-git-d79c240196-full_build-www.gyan.dev.

Processing video and audio in memory is a requirement so, I cannot use file system. Has anyone had to deal with this before?

Any help is really appreciated. Thanks in advance.