Surround sound in only part of movie?

RoyBU wrote on 2/2/2007, 5:20 AM
I am helping my kids make a movie and we realized that one of the many scenes would be much better in surround (to make a sfx move from front to back). I haven't used surround before and have two questions:

1. Can I set just the one scene to surround sound and leave the rest in stereo? Will that encode and play back properly?

2. When we give a copy of the DVD to friends who will watch it on a regular, non-surround player, will the surround scene play back properly in stereo?

Thanks,
Roy

Comments

blink3times wrote on 2/2/2007, 6:02 AM
1) Yes and no.
When you encode for dvd you either encode in AC3 (dolby digital) or you don't. If you don't then you won't get suround sound. But having said that. you can adjust your panning system during the edit phase to reflect suround sound for one scene, and then re pan for stereo for the next scene. Your final result will be stereo sound from within a dolby digital encoding.

2) yes.
riredale wrote on 2/2/2007, 8:27 AM
To amplify what Blink said a bit:

You will need to set audio properties to 5.1 so you get the surround panners. I don't bother with 5.1 and am happy with 4 channels. When rendering I choose 2/2 ac-3 and a bitrate of 384Kb/sec.

In the ac-3 encoding menus you can pick the mixdown level for the rear channels in a stereo environment, 0, -3, or -6db--probably 0 in your situation.
mikkie wrote on 2/2/2007, 10:25 PM
FWIW on a DVD you can have multiple switchable audio tracks, but each track has to be the same, i.e. 5.1 or 2... One way around it would be to encode separate titles, one for the 5.1 scene, 1 each before and after segments in stereo. Chain the result together with end actions or playlist. Player should honor the clips, i.e. proj setting for 5.1 or stereo should be moot.

Another option would be to fake 5.1 for portions where you don't have it.

Generally the player determines mixdown, normalization etc... There are settings in the custom dialog for the ac3 encoder, but beware & test the results before doing a final burn -- the settings are not intuitive, and have read of players rejecting ac3 too far from the usual, default settings in the Sony ac3 encoder.

Really FWIW... During a discussion some time ago in another forum, consensus was you could fake 5.1 using this: http://www.stevethomson.ca/vi/ better than deriving it using the Vegas panners.
TeetimeNC wrote on 2/3/2007, 4:43 AM
Mikkie, thanks much for posting about the Steve Thomson converter. I found this thread that links to a 10 page tutorial on converting stereo to 5.1 using SoundForge and Vegas. I'm going to give it a try.

Jerry