View Full Version : Encoding for DVD with Vegas Question


Dan Measel
June 2nd, 2003, 06:23 PM
I have a superficial understanding about encoding principles and am relatively new to DVD authoring, but have a question regarding Vegas.

I am making a DVD using Vegas for editing and rendering the video and ReelDVD for authoring. My video is less than an hour so if I understand correctly I would get the best video quality by encoding at a constant bit rate, and at the maximum for DVD (9.8MBps). I have done several projects with the default settings in Vegas (Variable Bit Rate with 6M max and average 4M) which have turned out nicely, but tried to set the Constant Bit Rate to around 9M, but that wasn't an option.

Does anyone know if the video quality would be much improved with a higher constant bit rate (especially if some high action scenes are present)? And does anyone know if you can set Vegas to render at a CBR higher than 6M?

As always, any comments are greatly appreciated.

Edward Troxel
June 2nd, 2003, 08:38 PM
The next issue of Vegas Tips, Trick, and Scripts talks all about this topic http://www.jetdv.com/tts. I hope to post it either Tuesday or Wednesday.

Technically, VBR should be better because it can use a higher bitrate for areas where there is a lot of action and lower bitrates for areas of less action. However, if your video is small enough to use the rates you are indicating then there should be no difference between CBR and VBR.

Remember that the bitrate has to also include the audio. To get the audio as small as possible, render it to AC-3. Try rendering to CBR at 8,000,000 and see if you like the results. Also, you could try some other encoder such as TMPGenc to see if you like its results better.

Dan Measel
June 2nd, 2003, 09:21 PM
Edward, Thanks for the feedback. When I tried to select a CBR in Vegas it only gave me 3 options 6,000,000 - 4,000,000 & 192,000. I'm sure there's a way to select 8,000,000 but it wasn't apparent to me. Do you know how to do that?

Edward Troxel
June 2nd, 2003, 09:50 PM
I don't know which pre-set you are using. However, you should be able to just type it in.

Glen Elliott
June 3rd, 2003, 04:54 AM
Yeah I've heard never to render at the limit because it'll have inherent spikes that go over the limit and cause the file to be non-compliant. Try 8mb, that'll give you enough headroom.

Speaking of encoding in Vegas- how is it? I have Procoder and love it. Is it good enough to not even have to use Procoder- and if I'm looking to encode progressive scan 24p DVDs do I have to encode with Vegas w/DVD arcitect?

Dan Measel
June 3rd, 2003, 06:56 AM
Edward,

Thanks again, that was easy, sometimes the obvious escapes me, sorry.

Do you use another encoder with Vegas? If so, is the quality better or is it for speed?

Edward Troxel
June 3rd, 2003, 07:53 AM
I always encode directly from Vegas. That way I can do it directly from the timeline (although with Satish's new frameserver, any could be used directly from the timeline)

Rob Lohman
June 4th, 2003, 02:00 PM
I had some good results with VBR 0-5000-8000 in other MPEG
encoders.

Edward Troxel
June 4th, 2003, 02:51 PM
The newsletter containing info about encoding in Vegas and authoring in DVD Architect is now available at www.jetdv.com/tts/archive/TTS01-07.pdf

Aaron Koolen
June 4th, 2003, 09:30 PM
Edward, what's this about the frameserver? I'm looking at upgrading my machine in the near future and was hoping I could use my old machine to help render the timeline if that was possible.

Cheers
Aaron

Dan Measel
June 5th, 2003, 06:06 AM
Just for some feedback. I encoded the DVD (about 50 minutes all together) at a CBR of 8,000,000 and converted the Wav files to AC-3. It looks great. Whether it is much improved over the Vegas default of VBR 196k - 4,000,000 - 6,000,000 I can't tell. But anyway thanks for all the help.

Edward Troxel
June 5th, 2003, 07:55 AM
Go to http://www.debugmode.com to find information about the frameserver plugin that Satish wrote for Vegas.

Rob Lohman
June 5th, 2003, 09:03 AM
The frameserver can be found here (http://www.debugmode.com/pluginpac/frameserver.php)