ffmpeg Stdout Pipe Streaming
Stream raw video frames directly from ffmpeg without intermediate files.
Pattern
csharp
var psi = new ProcessStartInfo
{
FileName = "ffmpeg",
Arguments = $"-loglevel error -i \"{videoPath}\" -vf scale={width}:{height},format=gray -f rawvideo -pix_fmt gray pipe:1",
RedirectStandardOutput = true,
RedirectStandardError = true,
CreateNoWindow = true
};
var process = Process.Start(psi);
process.BeginErrorReadLine(); // Drain stderr to prevent blocking
var stream = process.StandardOutput.BaseStream;
Read Frame
csharp
public static byte[]? ReadNextFrame(Stream stream, byte[] buffer, int frameSize)
{
int bytesRead = 0;
while (bytesRead < frameSize)
{
int count = stream.Read(buffer, bytesRead, frameSize - bytesRead);
if (count == 0) return null; // EOF
bytesRead += count;
}
return buffer;
}
Loop Playback
Restart ffmpeg process on EOF:
csharp
if (frame == null)
{
reader.Dispose();
reader = FfmpegFrameReader.Start(videoPath);
frame = ReadNextFrame(...);
}