Help me understand something about instantcopy..

[JoeB]

I'm in the process of converting DIEHARD 1 & 2 from DVD-9 to DVD-R.
I used IFOEdit and ripped the movie only, and am now using IC7 to convert it down to DVD-R size.

The one thing I noticed (main movie in both cases is about 5.5GB) is that the files IC7 tosses out are really SMALL! I even set the quality bar to 99.90% and the movie came out (in both cases) to less than 4GB!

So I decided to run the first VOB's through Bitrate viewer, and here's what I found:

Original:

Peak bitrate: 8861
Avg bitrate: 6529
Peak Q: 2.38
Avg Q: 1.32

After IC7:

Peak bitrate: 8246
Avg bitrate: 3505
Peak Q: 28.03
Avg Q: 28.02

So my questions are:

1) Why did IC7 chop the avg bitrate by 1/2!? Doesn't this mean that the image quality is now 50% rather than 99.90%?

2) What exactly is "Q" and why has it jumped so much??

Thanks.

[padre]

JoeB, just curious - is it a letterbox/widescreen movie?

[JoeB]

widescreen version...

[Ollie W. Holmes]

I think IC squashes the black areas of a picture. It must use the "close enough for government work" principle and sacrifices shadow detail when the YUV values are close to each other and the Y-value is low. Unless you own a big projection tv, you may not notice this.

[Grover]

I've come across this same "feature" of IC7 a number of times. It only seems to occur on moives with the "built-in" black bars.

All you can do is set it to 99.99% and live with that output or try using DVDShrink for that movie.

I've had a couple of DVD's where IC7 could not get above about 3.7GB. Instead I used Level 1 compression in DVDShrink and got that up to about 4.2 to 4.3GB.

Cheers...