OT: Pro 8 DVD bitrates: what was Sony thinking?

rs170a wrote on 6/11/2008, 4:02 AM

I always use custom templates for my DVD renders so I never noticed this until someone I was helping with DVD burning issues mentioned it.
The default bitrate for all the various MPEG-2 templates in Vegas Pro 8 is as follows:
Max: 9,500,000
Average: 6,000,000
Min: 192,000

By way of comparison, the numbers for Vegas 7 are:
Max: 8,000,000
Average: 6,000,000
Min: 192,000

9,500,000??
All the articles I've read over the years have said not to exceed a max of 8,000,000.
Is my thinking flawed or did Sony mess up?
I wonder if people (especially newbies) are running into burning issues due to these new numbers.

Mike

Comments

John_Cline wrote on 6/11/2008, 4:42 AM

The DVD spec says that the absolute maximum combined audio, video and subtitle bitrate is 10.08 Mbits/second. 9.5Mbit video with 448k 5.1 .AC3 audio pretty much hits the limit. Some DVD players choke on data rates that high, but they are supposed to meet that spec. Keeping the video at 8Mbps max is a good idea.

corug7 wrote on 6/11/2008, 11:45 AM

All of the DVDA templates create a muxed mpeg stream as well, regardless if the audio checkbox is checked or not. As a result, I had a hang of a time trying to import these "elementary" video streams into other programs. Took me awhile to figure out that the "create separate .m2v and .mpa" checkbox should be checked (not to mention the full first gop checkbox).

riredale wrote on 6/11/2008, 4:40 PM

Also, keep in mind that this is the MAX bitrate, while the average is much lower. This means that the encoder will only hit the max bitrate for the most demanding parts of the video, so it shouldn't be all that hard for the player to keep up.

johnmeyer wrote on 6/11/2008, 6:36 PM

Time for my usual link to one form of the MPEG-2 DVD spec:

mpeg.org

(Document describing DVD spec)

The key quote from this spec is as follows:

"ALL DVD PLAYERS MUST SUSTAIN A 9.8 MBIT/SEC VIDEO DECODE RATE!!!!!!!"

They put this in all caps, not me.

video777 wrote on 6/12/2008, 8:28 PM

I read on one of the forums (probably from my previous life with Avid) that 8500 is quite safe. I've used it for about 2 years and not once have I had a problem. BTW - I burn thousands of DVDs. In fact I'm burning 150 for just one order right now. Some day I plan on getting a DVD duplicator/printer.