```
$ gpac -i input.mp4 @ -o output.mp4:frag
Unknown argument ":frag" set but not used by any filter - possible matches
- range in filters httpin fin
```

Here it proposes ```range``` but not ```frag``` which is available in ```mp4mx```.
gpac reporting unknown argument but unable to find match
This is a GitHub Issue
repo:gpac
owner:gpac
Title : gpac reporting unknown argument but unable to find match
Issue date:

--- start body ---
```
$ gpac -i input.mp4 @ -o output.mp4:frag
Unknown argument ":frag" set but not used by any filter - possible matches
- range in filters httpin fin
```

Here it proposes ```range``` but not ```frag``` which is available in ```mp4mx```.
--- end body ---
