System.Diagnostics.Process pipe (vertical bar) not accepted as argument

Question

I'm trying to execute this code using System.Diagnostics.Process. It works fine in command line. But in C# it's failing on the | character.

var myProcess = new Process();
var p = new ProcessStartInfo();

var sArgs = " -i emp.mp3 -f wav - | neroAacEnc -ignorelength -q 0.5 -if - -of emp.mp4";
p.FileName = "ffmpeg.exe";
p.CreateNoWindow = false;
p.RedirectStandardOutput = false;
p.UseShellExecute = false;
p.Arguments = sArgs;

myProcess.StartInfo = p;

myProcess.Start();
myProcess.WaitForExit();

It gives the following error:

Unable to find a suitable output format for '|': Invalid argument

I've looked around on stackoverflow and found the following hint but it is also not working:

var psi = new ProcessStartInfo("ffmpeg.exe");
psi.Arguments = 
    "\"-i emp.mp3 -f wav -\" | \"neroAacEnc -ignorelength -q 0.5 -if - -of emp.mp4\"";
psi.CreateNoWindow = false;
psi.UseShellExecute = false;

var process = new Process { StartInfo = psi };

process.Start();
process.WaitForExit();

gives the following error:

Unrecognized option 'i emp.mp3 -f wav -'
Failed to set value '|' for option 'i emp.mp3 -f wav -'

Answer 1

Thanks to Lee his comments, the problem has been resolved. Just invoke cmd.exe and pass it the full command:

var myProcess = new Process();
var p = new ProcessStartInfo("cmd.exe");
var sArgs = "/C ffmpeg.exe -i emp.mp3 -f wav - | neroAacEnc -ignorelength -q 0.5 -if - -of emp.mp4";
p.CreateNoWindow = false;
p.RedirectStandardOutput = false;
p.UseShellExecute = false;
p.Arguments = sArgs;
myProcess.StartInfo = p;
myProcess.Start();
myProcess.WaitForExit();