Subject:5.1 Encoding

Posted by: jkb242

Date:12/7/2003 8:08:57 AM

I am always impressed by the friendly and knowledgeable professionals who freely share valuable informaiton with those of us who are less talented.

My question to the forum: while using Vegas 4 with the caputre interface provided, I would like to take a video event captured from either VHS or my camcorder (basically an AVI file) which does not have surround sound or 5.1 Dolby digital capabilities and set up Vegas to "fill in" or just divide the sound channel of the original forcing surround sound to be encoded so that play back on a DVD compatible player will in fact play audio on the surround sound spakers.

I attempted to do this using the Audio PAN localizer in the audio track setting it roughly in the center of the front and rear speakers but when played back, there was nothing sent to the rear or center channel speakers. It's like starting with monoral and attempting to get "sudo" stereo. I know that I will not get true surround sound with phasing and delays that accompany the "real" effects but not to have the center and rear speakers active leaves the production sorta of empty and at best a two channel (front speakes only) production which is not really desirable. Can anyone assist me with this??

Subject:RE: 5.1 Encoding

Reply by: vonhosen

Date:12/7/2003 10:28:36 AM

What you are wanting is quite possible to do

IYou must have your audio settings for your Vegas project as 5.1 surround(which you must have aleady or you wouldn't get the "Surround Pan" adjustment available.)

The default position for the orange diamond which you use to position sound would leave you with audio from on the front left & right channels.

First click on the "panner" on the track header, to open the surround panner.

Then you will see the slider for the centre channel at the bottom , drag this to the right & you will see the db level for centre channel increase.

Drag the orange diamond to position your audio. (The relative db for each channel will be visible by them) You can keyframe this positioning to match your video by right clicking on the track header and selecting Insert/Remove Envelope>Surround Pan Keyframes.

Of course if you are using special sound effects they will be on their own track for positioning.

You should also duplicate your audio track , right click on the duplicates track header & choose "LFE only" . That track will then provide your .1 audio in your 5.1.

Then render fron Vegas as AC3 file with 5.1 Surround DVD template.

Of course if you are not using DVD Architect then make sure your authoring program supports AC3 5.1

With DVD-A you are going to need that AC3 render and a seperate .mpg render for the video (try to use same file name & save to the same directory for both files so it's easier for DVD-A to deal with them)

Subject:RE: 5.1 Encoding

Reply by: jkb242

Date:12/7/2003 3:54:43 PM

Thank you bvery much for the thorough comments and suggestions.

I would not have dfigured this one out for a long time to come without your assistance.

I do have the Media concepts MPG2 codec/encoder and the AC3 coded and encoder as I have been using DVD A on previous projects. Is there an additional renderer needed to support what I am attempting to do?

Thanks again as I will be trying this again today.

Jerry

Subject:RE: 5.1 Encoding

Reply by: vonhosen

Date:12/7/2003 3:57:01 PM

No Everything you need is in Vegas & the Main Concept encoder.

Subject:RE: 5.1 Encoding Attention Vonhosen

Reply by: jkb242

Date:12/8/2003 6:09:28 PM

I tried your suggestions and I thought things went per your recommendations although I did not understand your comment "You can keyframe this positioning to match your video by right clicking on the track header and selecting Insert/Remove Envelope>Surround Pan Keyframes." but the end results is that wben played back in a surround sound home theater system there was no sound from the rear left or right speakers.

I did not understand the step to render the audio and Video separately or at least that is what I believe you stated. I rendered to an MPEG 2 movie using the surround sound settings with the EFE in a separate track as you suggested. I was nota ble to get the center speaker to play either. Relative levels for the front left and right speakers were equal and within 3.0dB of the center and rear speakers. I did get good SW (subwoffer) response but cannont figure out why the other speakers/channels were missing.

Can you please post a bit more guidence? Much thanks for everything thus far. Is it possible that the Main Concepts MPEG 2 encoder is an issue?

DVD was also set up to provide surround sound 5.1 channels to matched the rendered MPEG 2 output from Vegas 4.

Subject:RE: 5.1 Encoding Attention Vonhosen

Reply by: vonhosen

Date:12/8/2003 11:01:48 PM

Do a search in the help files within the program for keyframing. What this allows is accurate positioning to he timecode matching your video. For instance say at timecode 1:23:01 a car appears stage front right & at timecode 1:24:17 it disappears stage front left. You can create a keyframe at the first timecode & postion your audio (for car) with the panner close to the front right speaker. Then create another keyframe at the 2nd timecode & with this one postion the audio by the front left speaker. If you do this the sound will travel across the stage from the first point to the second between those timecodes (as the car does on screen) But beware the audio for the track containing the car would remain focused on front left until you keyframe to another point.

You must do two seperate renders before going to DVD-A for authoring.

The MPEG-2 render does not contian your 5.1 audio. That is gained with the 2nd render & the married together in DVD-A.

First render select to save for the file type MPEG-2 and choose a template for DVD Architect (NTSC , PAL which ever you are using).

When that is done render again , this time saving to a Dolby Digital AC3 file type using the 5.1 surround DVD template.

Then in DVD-A load both the files .

Sounds to me like you are just doing a one render to the standard MPEG-2 template. This will give you video with MPEG-1 layer II audio in stereo, not 5.1 Dolby.

Subject:RE: 5.1 Encoding Attention Vonhosen

Reply by: jkb242

Date:12/10/2003 7:55:26 AM

Thanks again for the great feedback. You are correct, I am only rendering once and obtaining a MPE2 file which I am using DVD-A to burn the CD. Is there a location in the manual where I can read up on this subject to which you can refer me? I think I need to study this a bit more but I do so very much appreciate your input. Hopefully, I can consult with you again with more specific questions.

Thanks again,

Jerry

Subject:RE: 5.1 Encoding Attention Vonhosen

Reply by: vonhosen

Date:12/10/2003 10:05:03 AM

Which bit ? The rendering ? (just use the "MPEG-2 for DVD Architect" & "AC3 5.1 surround DVD" templates) The importing ? (Just make sure that the "Myproject.mpg" video file & the "Myproject.ac3" audio file are rendered to be saved inside the same folder & when you import the video file DVD-A will automatically attach the audio file)

I'd spend time reading the whole manual before you start & hopefully the things we have discussed will fall into place.

Edit:
----
Are you really trying to burn to CD or was that a misprint ?