Losing soundtrack, but the commentary is there

[SMB]

I have ripped quite a few dvd's and burned to dvd-r's. However I've just realised that the last half a doz have a problem. The films have the directors commentary and not the proper audio.
What I did start doing was to remove the 5.1 sound thinking that I'd save nearly half a Gb in doing so. I only have stereo so the 5.1 would be a waste of space. I was under the impression that there were two audio "channels" one for stereo and one for 5.1 .
It looks like I've been removing the main audio, is this correct?
Do I have to keep the 5.1 even though I don't need it?

Help !

Cheers.

 

[The-poacher]

If thats the only audio channel other than the commentary yes U must

 

[SMB]

um...how do I know? There's usually two, 2 ch and 5.1 . Is there any way of telling what each one is?

 

[celtic_druid]

Most of the time the 2channel stream will be the commentary, only on some DVD's will the main movie audio be available as both. If there is no 2channel stream available if you really wanted you could downmix and re-encode the 5.1.

 

[SMB]

Thanks, I might try that.
On Spiderman there is one 5.1 and two 2 ch 's, so in this case I thought I could leave out the 5.1 as one of the others was bound to be what I wanted, but it didn't work ! Commentary only...