Capturing FFmpeg Progress with Progress Bar in C#

Question

I'm working on a C# application where I'm using FFmpeg to encode multiple video files. I want to display a progress bar to show the encoding progress for each video. I have tried using the Process.OutputDataReceived event to capture FFmpeg's progress updates, but it doesn't seem to work reliably.

Here's the relevant part of my code:

// Code snippet
int i = 1;
if (openFileDialog1.ShowDialog() == DialogResult.OK)
{
    progressBar1.Maximum = openFileDialog1.FileNames.Length;

    foreach (string file in openFileDialog1.FileNames)
    {
        // Output file naming code here

        Process process = new Process();
        process.StartInfo.FileName = "ffmpeg.exe";
        process.StartInfo.CreateNoWindow = true;
        process.StartInfo.RedirectStandardError = true;
        process.StartInfo.UseShellExecute = false;

        process.OutputDataReceived += (sender, e) =>
        {
            // Progress parsing code here
            // This part doesn't seem to receive any data
        };

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

        i++;
    }
}

However, the OutputDataReceived event doesn't seem to receive any data from FFmpeg's stderr, and the progress bar doesn't update as expected.

Is there a better way to capture FFmpeg's progress updates for encoding videos and use them to update the progress bar in C#? How can I achieve this?

Any help or suggestions would be greatly appreciated. Thank you!