关于System.Diagnostics.Process中的重定向标准输出

Question

I've been recently working on a program that convert flac files to mp3 in C# using flac.exe and lame.exe, here are the code that do the job:

ProcessStartInfo piFlac = new ProcessStartInfo( "flac.exe" );
piFlac.CreateNoWindow = true;
piFlac.UseShellExecute = false;
piFlac.RedirectStandardOutput = true;
piFlac.Arguments = string.Format( flacParam, SourceFile );

ProcessStartInfo piLame = new ProcessStartInfo( "lame.exe" );
piLame.CreateNoWindow = true;
piLame.UseShellExecute = false;
piLame.RedirectStandardInput = true;
piLame.RedirectStandardOutput = true;
piLame.Arguments = string.Format( lameParam, QualitySetting, ExtractTag( SourceFile ) );

Process flacp = null, lamep = null;
byte[] buffer = BufferPool.RequestBuffer();


flacp = Process.Start( piFlac );
lamep = new Process();
lamep.StartInfo = piLame;
lamep.OutputDataReceived += new DataReceivedEventHandler( this.ReadStdout );
lamep.Start();
lamep.BeginOutputReadLine();

int count = flacp.StandardOutput.BaseStream.Read( buffer, 0, buffer.Length );

while ( count != 0 )
{
    lamep.StandardInput.BaseStream.Write( buffer, 0, count );

    count = flacp.StandardOutput.BaseStream.Read( buffer, 0, buffer.Length );
}

Here I set the command line parameters to tell lame.exe to write its output to stdout, and make use of the Process.OutPutDataRecerved event to gather the output data, which is mostly binary data, but the DataReceivedEventArgs.Data is of type "string" and I have to convert it to byte[] before put it to cache, I think this is ugly and I tried this approach but the result is incorrect.

Is there any way that I can read the raw redirected stdout stream, either synchronously or asynchronously, bypassing the OutputDataReceived event?

PS: the reason why I don't use lame to write to disk directly is that I'm trying to convert several files in parallel, and direct writing to disk will cause severe fragmentation.

Thanks a lot!

Answer 1

I don't think lame and flac uses Stdout to output its converted data. I think they write the converted files directly to disk. The StdOut is only used to output info/error messages.