2 CDs questions

[augi]

I wanted to compress a 90min movie to 2CDs .I used jonny's compressibility tool and it gave me a value near 100% at the highest resolution possible (704x...).What should I do then?This means that the targeted filezise (1.4Gbytes) won't be reached?And I can't do anything about it as the resolution is maximum!What now?Maybe this means I gave more bitrate to the codec than needed?

And another thing.WHY does the targeted filesize vary?If I say to the codec to use A Kbits/sec , the targeted filesize should be A*(movie length)/8 Kbytes.DivX uses variable bitrate?

[jonny]

Are you using DivX5Enc or CompTest?

[Mac Sidewinder]

With the compressability test, if you get anything above about 80% you are going to get undersized files. It won't matter what bitrate you set since everything is being compressed at quant 2 anyway. If you maxed the resolution then the only thing you can do is use the space left on the disc for other things such as better audio, extras, etc.

See the sticky above on undersized files for more info.

Mac

[jonny]

It won't matter what bitrate you set since everything is being compressed at quant 2 anyway.


I think this is not always true. If you have, for example, 85%, you'll obtain undersized file... but i think the average quant is not 2. If you obtain 80%-90%, you can lower the max quant to 4, this help a lot to don't go undersized.

[theReal]

...or you can just encode at 100% quality and see what filesize you get. And use sharp bicubic resizing, of course.