BitRate Calculator Variable Question

kentwolf wrote on 7/13/2003, 9:03 AM

I am going to try to start pre-rendering video files right out of Vegas so as to speed up my DVD Architect project creation. Nothing is more frustrating than waiting 4 to 7 hours for DVD-A to render a project with AVI file input only to see a typo on a DVD menu…

I found a Java app bit rate calculator on DVDhelp.com. It looks pretty good, but I am curious as to the sound bit rate to enter.

Seeing I am not interested in 5.1 sound, I would just want to use Stereo sound… or so I think.

According to the DVD-A manual:

AC3 Audio:

Number of channels: stereo or 5.1 surround
Bit rate: 64 kbps to 448 kbps inclusive

Question:

1.) Does this mean that if I desired stereo sound, this would be rendered from Vegas at 64 kbps and that if I desired 5.1 surround sound, that would be rendered from Vegas at 448 kbps?

2.) What are the ramifications of the “inclusive” term here?

(Number of channels is also a variable for this particular bit rate calculator.)

3.) If I did decide to go with 5.1 sound, would this be a single (1) channel of 5.1 sound? Six (6) channels?

4.) Would stereo sound be two (2) channels?

I have always let DVD-A do these calculations automatically, but now I am going to try to start doing them myself.

Thank you very much for any help you can offer.

Comments

JSWTS wrote on 7/13/2003, 4:51 PM

1.) Does this mean that if I desired stereo sound, this would be rendered from Vegas at 64 kbps and that if I desired 5.1 surround sound, that would be rendered from Vegas at 448 kbps?

I believe the default bitrate for stereo ac3 within DVD-A is 192 kbps and if you choose 5.1 SS it is 448 kbps.

2.) What are the ramifications of the “inclusive” term here?

You can create your own 2 ch or 5.1 ac3 audio files outside of DVD-A and if the bitrates are between 64 to 448 (including the high and low limits), they will be accepted.

3.) If I did decide to go with 5.1 sound, would this be a single (1) channel of 5.1 sound? Six (6) channels?

You would have a single file with all 6 (5.1) channels included (it will ultimately be multi-plexed with your video when the VOB files are created into a single dvd file containing all of the audio, video, subtitles, etc in one file).

4.) Would stereo sound be two (2) channels?

Yes, one file with 2 channels of sound.

When using a bitrate calculator, you would just enter the combined bitrate for the single audio file (whether it contains 2 channels or 6 of information). A 5.1 file at 448 kbps represents the combined total bitrate of all channels, not each channel at 448 kbps. In this case you would just enter the 448 kbps.
For stereo projects, a bitrate that high would just be a waste of disc space. 192 is the default in DVD-A, I typically bump it up to 224 myself. The disc space required for the 'bump' is only a few mb at most.

I find this bitrate calc. helpful, but it requires you to have excel on your computer:

http://www.daileycreative.com/ReelDVD/DVDCalc.XLS

Jim