Comments

vonhosen wrote on 6/22/2002, 7:45 PM
Then that's what you'll get.

As a general rule the higher the bitrate the higher the quality.
But with CBR where there is little action to benefit from all that bitrate the encoder will just be padding out the stream to fill it to that rate.

With your video only elementary stream at 8Mbs added to PCM audio at 1600Kbs you will be getting close to your max 9.8Mbs for DVD.

You could get about 1 hr 2mins on your project with PCM audio & allow room for menus, navigation data etc.

PeterMac wrote on 6/23/2002, 2:18 PM
Is that right? Are you implying that if I set my render params to be 8Mbits (constant), I might end up with an overall 9Mbits plus?

Surely not... Isn't the sound component factored in to the encoder's machinations so that the elementary streams, when added together, approximate 8Mbits?

-Pete
vonhosen wrote on 6/23/2002, 3:33 PM
My understanding is that if you select 8Mbs with program (Video & Audio) stream then your program stream will be the 8Mbs for video + 224Kbs for audio (if that is the rate you slected for your MPEG audio (range is 112-384)), but if you were to select 8Mbs then uncheck the include audio box on audio tab, you would get 8Mbs for video only as the encoder would not be able to second guess what rate audio you would want.

What leads me to believe this is that if you select 8Mbs and then go to the system tab, look towards the bottom at system bitrate & you will see 8,224,000.

The scenario I am painting is that if you have encoded Video only at 8Mbs (having unchecked the audio tab) for your authoring program, then you bring your .wav file rendered from the time line to it at 1600Kbs you are going to be approaching DVD limits. I bring my files in seperately to save the authoring program having to first demultiplex the program stream & then convert the audio to PCM.

Unless you are using DVDit PE or higher end authoring program you can't use compressed audio for NTSC projects & be sure that your distribution is going to be compatible which leaves you with PCM audio.

Even if you take in a program stream of 8,224,000bps the authoring program will convert the 224,000bps of MPEG audio to PCM at 1600Kbs