Bitrate question

Hi guys.
Just a question on bitrates. I finally sorted out my dvd writer and did a test. I compressed at the highest bitrate setting (9 something) and the quality was really good on the dvd. I really could not see a different with the dvd quality and the original (DV) footage, really nice. Although, this was just a 5min seq to test the writer, I have read here that one should compress at the highest, at about 8mbps. What is the reason for this, and why can I not keep it at the max of 9.8? I understand that most dvd burns would be far longer than 5min, but surely if a seq is under and hour, can I compress at max bitrates? thanks

Sean,

You may find that a bit rate of 5.0 is just as pristine as 9.0. Depends on the motion content of you clips. There maybe issues with using disks burned with high bit rate MPEG files playing in some set top DVD players. Information on these issues is spotty and hard to find.
The 2 pass VBR compression takes a look at the content before it encodes it and tries to give the very best results from the content given it.
Then again, using an 8.0 Mbps bit rate will limit the DVD content to around 30 minutes.

Thanks for the info John. I am still running DVDSP 1.5.2 so I am not sure about VBR and more than 1 Pass ( I presume on DVDSP2), but it's a pity that there is no set-rate for set-time article. It seems a waste to toast a whole of of dics to find the 'optimum' for a project.
I must say that I tested the 9 bitrate disc on my Pioneer set-top (quite new - 3 months) and an older 2 year old Harmon Kardon set-top player, and they both looked great! Thanks again and your thoughts are appreciated!!

Sean,
There is a way to determine the bitrate. Here is a bit rate calculator that's easy to use and very accurate: [www.dvdrhelp.com]

Not only will some set-top players have a problem with high bit rates, but PCs can stall and stutter with bit rates that are too high. I have found anything under 8 to be pretty safe.

<<I am still running DVDSP 1.5.2 so I am not sure about VBR and more than 1 Pass>>

My last project was done in DVDSP 1.5.2 as I just recently received DVDSP 2.
The MPEG-2 encoder loaded by DVDSP 1.5 into Quicktime is VBR but only one pass. The docs recommend you set the base rate somewhat lower than the max rate so that the Variable encode has room to "swing" as it see fit.

As I said, I did a long encode at 4.5 Mbps in Quicktime (at the time that was the only way to save Chapter Markers into DVDSP 1.5) and the content looks very good. Perhaps the tight space I had to get a 22 Gig video file and a 1 Gig audio file onto 4.37 Gigs was a driver to get down to 4.5 Mbps.
And I couldn't have done that without AC3 compression help either.