Changing Bitrate Settings for Render

[Mike Hammond]

Hi all,

I'm rendering out to DVD NTSC DVDA. I have a film that is 2 hours, 5 minutes, 4 seconds long. I did some research about making sure the file will fit onto a standard DVD and used Mark's Bitrate Calculator to get my settings.

I've gone into Vegas' custom area for this render and tried messing with the Max., Avg., and Min. bitrates. I think I'm doing it correctly but it seems like Vegas won't allow for different values in those boxed. The calculator indicates to use min 2752, avg 4592 and max 8040, and when I choose VBR and put my first value into the minimum bitrate box (2,752,000), and then try to enter the avg rate of 4,592,000, the avg rate for right to 2,752,000.

Can someone tell me what I may be doing wrong?

[Mike Hammond]

Here's a screenshot of my settings and the calculator.

[Mike Kujbida]

Mike, I just tried it and it worked for me so I don't know why you're having problems.
All I can suggest is try entering the numbers from the top (Max first) down and see if that helps.
Also, can we see the entire Custom screen instead of it being partially obscured by the bitrate calculator?

[Mike Hammond]

Hi Mike,

Thanks and here you go.

I did try to input the values from the top down (and bottom up) with the same result. You can see from the screen shot that Vegas has automatically inupt the avg number to match the max number I put in. That's after I manually tried to enter the avg value myself.

[Edward Troxel]

You entered the "minimum" value in the "Maximum" box. Therefore, average can't exceed that "maximum" that you entered. Put the minimum value in the BOTTOM box.

[Mike Hammond]

Oh for crying out....

Thanks Ed. You know, I got to tell you - it's a little embarrassing. Anyway, all the calculations look right for 2hrs, 5mins, 4secs, yes? I don't want to render out and then find out I didn't put the right values in there. It's kind of surprising that Vegas doesn't show you what you'll end up with, in terms of file size, when you customize your bit rates.

[Arkady Bolotin]

Theoretically speaking, the VBR encoding method, which you chose, allows you to specify only a bitrate range - a minimum and maximum allowed bitrate – determining the range in which the bitrate may vary.

The disadvantage of such settings is that the average bitrate (the file size) will not be known ahead of time. Therefore, some encoders (including MainConcept MPEG-2) allow the user to set additionally an average bitrate (ABR) (just to ensure the output stream achieves a predictable long-term average bitrate, i.e. the file size).

The settled ABR can be achieved in a single pass, but a multi-pass ABR encoding is highly recommended because the multi-pass ABR is more similar to fixed quantizer VBR: a higher average will really increase the final quality.

[Edward Troxel]

Mike, yes those numbers sound about right for 2 hours 5 minutes. If I was doing it, I would use about 4,620,000. From my chart, the number you listed is between 125 and 130 minutes so you're definitely in the right ballpark. If you're using a menu, the smaller number will give you a little more wiggle room.

[Bruce Phung]

I try to download Mark's DVD biterate calculator but got nowhere, to many redirect links for BS stuffs. Finally I found it seem to be the place to download it, when I clicked download there is nothing, keep bouncing back and forth to the same site. It is not my computer blocking it.

Can someone nice enough to .zip your Marks dvd calculator here. I appreciate if anyone can help.

[Mike Kujbida]

Here you go Bruce.

http://www.johncline.com/bitcalc110.zip

[Bruce Phung]

Mike,
It all good. Thank you very much.

[Mike Hammond]

Thanks very much everyone. I'm rendering now with those values (in the right order) with a 2-pass, and I'm looking forward to finishing it up.

I really appreciate the assitance.