What's the easiest way to merge two videos into one?

Kasun Lee

2y717C#

I tried the FFmpeg library but the code seems not working.

    public void MergeVideos(string[] videoPaths, string outputFilePath)
    {
        // Combine video paths into FFmpeg command
        string command = "ffmpeg -i concat:" + string.Join("|", videoPaths[0]) + " -c copy " + outputFilePath;

        // Execute FFmpeg command
        ExecuteFFmpegCommand(command);
    }

       private void ExecuteFFmpegCommand(string command)
       {
           try
           {
               // Start the FFmpeg process
               Process ffmpegProcess = new Process
               {
                   StartInfo =
                   {
                       FileName = "ffmpeg.exe", // Assuming ffmpeg.exe is in the PATH environment variable
                       Arguments = command,
                       UseShellExecute = false,
                       RedirectStandardOutput = true,
                       RedirectStandardError = true,
                       CreateNoWindow = false
                   }
               };

               // Subscribe to process output data events
               ffmpegProcess.OutputDataReceived += (sender, e) => Console.WriteLine(e.Data);
               ffmpegProcess.ErrorDataReceived += (sender, e) => Console.WriteLine(e.Data);

               // Start process and redirect output
               ffmpegProcess.Start();
               ffmpegProcess.BeginOutputReadLine();
               ffmpegProcess.BeginErrorReadLine();

               // Wait for process to exit
               ffmpegProcess.WaitForExit();
           }

Are there bugs in the above code? Or Is there some other easier way to do it?

Thanks.

3 Replies

Know the answer? Post it — somebody with the same question will find it here.

Tuhin Paul2y ago
To correctly concatenate all video paths in the array, we should use string.Join on the entire videoPaths array, not just videoPaths[0].
```
public void MergeVideos(string[] videoPaths, string outputFilePath)
{
    if (videoPaths == null || videoPaths.Length == 0)
    {
        throw new ArgumentException("Video paths array is empty or null.");
    }

    // Combine all video paths into FFmpeg command
    string command = "ffmpeg -i concat:" + string.Join("|", videoPaths) + " -c copy " + outputFilePath;

    // Execute FFmpeg command
    ExecuteFFmpegCommand(command);
}
```
In this improvement:
1. I added a check to ensure that the videoPaths array is not null or empty before attempting to concatenate the paths. If the array is empty or null, an ArgumentException is thrown to indicate the error.
2. I updated string.Join to concatenate all video paths in the videoPaths array, ensuring that the correct FFmpeg command is generated with all video paths included in the concatenation.
With this improvement, the MergeVideos method will correctly concatenate all video paths provided in the videoPaths array when generating the FFmpeg command.
+1
Kasun Lee2y ago
>> I think when joining the video paths into a single command, you are using string.Join on videoPaths[0], which would only concatenate the first video path. You should concatenate all video paths in the array.

Yes, my bad, fixed it, but still it's not working. ffmpeg.exe is being executed, but the video merging does not happen...
+2

Amit Mohanty2y ago

I think when joining the video paths into a single command, you are using string.Join on videoPaths[0], which would only concatenate the first video path. You should concatenate all video paths in the array.

public void MergeVideos(string[] videoPaths, string outputFilePath)
{
    // Combine all video paths into FFmpeg command
    string command = "ffmpeg -i concat:" + string.Join("|", videoPaths) + " -c copy " + outputFilePath;

    // Execute FFmpeg command
    ExecuteFFmpegCommand(command);
}