Extra transcode arguement

[Quaoar]

I've been reading the VLC user guide and the VideoLAN how to documentation and have seen the parameter string that can be supplied to transcode. For example the arguements to define video and audio codecs, bit rate and scale are all quite straightforward.

I cannot find a parameter for specifying aspect ratio. Is there one? I can't find it in the documentation. I realise this may not matter if you are streaming, but if you are writing your stream to disc as an MPEG file, it does matter (especially if the file is going to be played on media players other than VLC).

When I am creating an MRL I would like to be able to add an arguement to transcode that will define aspect ratio in the MPEG file headers. Someing obvious like "ar=N" would do, where N is one of the standard MPEG values for aspect ratio (i.e. ar=3 for 16:9, and ar=8 for 4:3)

Am I making sense here?