Calculating size for MPEG render

smashguy37 wrote on 7/14/2008, 6:38 AM

Hey guys, I have a project that is about an hour and 40 minutes long. It's a pretty basic edit, but the beginning and end has some composite work with filters. I want to get this on one DVD, so I was wondering a good way to calculate how to get the end size under 4.47 gigs instead of trial and error (because it takes my computer a crazy amount of time to render it out).

Comments

up_north wrote on 7/14/2008, 6:54 AM

Try this bit rate calculator:

http://www.createspace.com/bitbudget

Ian

rs170a wrote on 7/14/2008, 6:55 AM

You'll need to use a bitrate calculator to get the numbers.
There's one on the VideoHelp site.
Here's a link to the one I use (Note: link is to a zipped file).

Mike

smashguy37 wrote on 7/14/2008, 7:08 AM

With that first calculator posted, it says 5.76 mbps...sorry I've always been terrible at math -- that would be a CBR of 5,076,000?

rs170a wrote on 7/14/2008, 7:29 AM

It would be a CBR of 5,760,000

Mike

Aegis Kleais wrote on 7/14/2008, 7:32 AM

5.76 Mbps = 5,898.2 Kbps = 6,039,798 bits/sec

I'm not sure how CBR works, but if constant bit rate is the actual amount of bits, it's 6,039,798 (rounded up)

1 Megabit = 1,024 Kilobits (not 1,000) and 1 Kilobit = 1,024 bits.

rs170a wrote on 7/14/2008, 7:51 AM

The above math is why I like the calculator I linked to :-)
In the Settings screen, there's an option to have 1 kilobit = 1024 bits so you don't need to worry about it.
There's also a Safety Margin option which I've bumped up to 5% (from the default 1%).
BTW, this calculator says the CBR is 5,528,000 (assuming AC-3 audio @ the default of 192 Kb/s).
If it's PCM (WAV) audio, then the CBR drops to 4,184,000.

Mike

Stringer wrote on 7/14/2008, 11:25 AM

Another option you might consider, is authoring a DVD image file ( without regard to size ), then use http://www.doom9.org/index.html?/mpg/dvdshrink31-main.htmDVD Shrink[/link] to get it under 4.47g ..