I need a little bit help and hope to find that here.

I am using sox for tagging some music with voice tags on my server while user is uploading the file. This is my command which I was using. Everything is working fine.

```
sox -m {voice_tag_loop} {source_file} {output_file}

```

Now I want to change something, but don't know how to do that and find no solution.
So the `{voice_tag_loop}` will be uploaded by user and can have all length e.g. 30 seconds, 20s, 17s or 1 Minute. Don't know that before.

The `{source_file}` is the music file and can have also different length e.g. 3:13 Min, 4:20Min

How can I mix the `{voice_tag_loop}` with the `{source_file}` that the `{output_file}` has the length of `{source_file}` but has the `{voice_tag_loop}` is mixed and looped/ repeated into also with as long the length of the `{source_file}`

I hope I could explain that, that you can understand that.

Best regards