dvda1 - why is the highest quality only 9.8

scottshackrock wrote on 4/25/2004, 11:58 AM
I got a .avi (uncompressed) that I made with vegas 4. It's about 13 min. long. And the file is like 2.2 GIG or something around there.

Anyway, I would expect dvda to just put the entire thing on there full quality - since it's under 4.6GB...wouldn't you? How come the highest RE-RENDERING it will do is 9.8, when it should just not even need to re render.
does it HAVE to be mpeg2 or somethin before it can burn it? shoot...haha

Also - I am planning to make a long movie soon, probably about an hour long. At the end of this, when I burn it onto a dvd with dvda - will I have to significantly reduce the quality of the video??

Comments

johnmeyer wrote on 4/25/2004, 12:20 PM
The 9.8 doesn't refer to some scale that goes from zero to ten, but instead refers to the megabytes per second of encoding. The maximum allowed by the DVD standard is 9.8 Mbit/sec (see this link for information on the standard):

mpeg.org

Generally, for best compatibility with a wide range of DVD players, you should keep the average bitrate below 8 Mbit/sec, and use only high-quality (major name branded) DVD media. Some people recommend bitrates lower than this for best compatibility, but I have never seen any reliable testing results that really prove that this makes a difference.

(Part of me just wants to say, "It goes to 11," but no one would get it.)

As to your "uncompressed" AVI file, if it is 13 minutes and is 2.2 Gbytes, then it is not uncompressed. Most likely it is DV video, which takes up about 4 Gbytes for every 18 minutes.
scottshackrock wrote on 4/25/2004, 12:33 PM
yeah, you got me..i did check that out after you said that, it is dvd video!! haha.

anyway, so will I notice a difference with it being at 8 instead of 9.8? I mean, will it look worse..NOTICEABLY?
johnmeyer wrote on 4/25/2004, 2:09 PM
First of all, you should not use an average above 8.0. For best quality:

Maximum (bps): 9,800,000
Average (bps) : 8,000,000
Minimum (bps) : 192,000

Check "Two-pass" (which will double the encoding time). Set video quality to High (31). Leave everything else at default. This will give you the best quality you can get from this encoder.
farss wrote on 4/25/2004, 4:06 PM
How it will look depends as much on the quality of the source as anything. Hollywood DVDs use musch lower bitrates and can look excellent but they have much better material to start with.
Noise can be the big killer, the less motion the better and noise is a LOT of motion. Dissolves between two scenes each with motion are a real test too.
johnmeyer wrote on 4/25/2004, 4:10 PM
And Hollywood DVDs are usually from 24p film source. This gives them a 25% advantage (video is 25% more frames per second). Also, the lack of interlacing makes the encoding easier (there are actually 60 different positional changes per second in video, vs. 24 for film). And, as Farss points out, the quality is far, far better than most video.