Compressibility test

[Veky]

Hello, I understand what the optimal values should be for bits/pixel*frame and the compressibility percent but I'm trying to backup my "The Medallion" DVD and it gives me a 0,261 bits/pixel and a 49% (at608x256).

Now I read that it should be between 60-80% so 49% isnt good.

Lowering the resolution increases the percent but the bits/pixel goes to 0,3 and higher which I read is bad.

So what do I do now? I'm a newb at this. :D

Thanks in advance.

[piscator]

Originally posted by Veky
Lowering the resolution increases the percent but the bits/pixel goes to 0,3 and higher which I read is bad.


Where did you read that :confused: That is not true.

Comp. check just tells you how well a movie compresses. 60% to 80% just tells you that the quality will be quite good after compressing (so you won't get disapointed with the quality after compressing).

Comp. check in the range 40% to 60% can still give acceptable results. But, as a rule of thumb, if you have a movie with a lot of high motion scenes and a lot of bright day-light scenes, it's unadvisable.

What you also can do instead of decreasing resolution, is to use Neutral Bicubic resize filter instead of Lanczos sharp (usually gives a 5%-10% increase in compressability) or, of course, increase target filesize.

greetz,
Piscator

[Veky]

Originally posted by piscator
Where did you read that :confused:

*snip*

In some crappy guide, apparently. :D

Thank you for the info.

[Soulhunter]

I haven't seen thus DVD till now, but I guess adding Convolution3d("moviehq") to your AVS (before resizing) would help... ;)


Bye

[Veky]

Originally posted by Soulhunter
I haven't seen thus DVD till now, but I guess adding Convolution3d("moviehq") to your AVS (before resizing) would help... ;)


Bye

Hmm, how is a noise filter going to help me? I'm not using any because it's a original DVD and there's no need for it. :confused:

[Soulhunter]

Originally posted by Veky
Hmm, how is a noise filter going to help me? I'm not using any because it's a original DVD and there's no need for it. :confused:

Original DVD... Well, Ive assumed this !!!


Why do you think de-noisers are not made for DVD's ???


99% of all DVD's Ive seen so far had a good amount of noise... :rolleyes:

Removing thus helps to gain compression (less or more) !!!


But as I said before...

I haven't seen this DVD till now, so I can only guess if C3D copes well in this case !!!


Bye

[piscator]

Originally posted by Soulhunter
I haven't seen thus DVD till now, but I guess adding Convolution3d("moviehq") to your AVS (before resizing) would help... ;)

But it would also denoise some details away resulting in lesser quality in some degree.

[Soulhunter]

Originally posted by piscator
But it would also denoise some details away resulting in lesser quality in some degree. But his resolution of 608x256 even more... :D


Bye

[piscator]

Originally posted by Soulhunter
But his resolution of 608x256 even more... :D
You don't need to decrease the resolution. You could just go with the given comp. check. I don't think a denoiser would help a lot for the quality improvement (but I know, filter-happy ;))

btw, do you know how much on average this filter would improve on the comp. check. I don't use it that often.

greetz,
Piscator

[Soulhunter]

Originally posted by piscator
Do you know how much on average this filter would improve on the comp. check. From my experience, C3D's MovieHQ preset gives "only" about 5% compression gain...

But the way it alters the final results (visually) is complete other thing !!!


Bye

[leadman584]

I'm a filter freak. CG animation is only video I don't filter to some degree. Hate seeing pink, blue, and green splotches next to each other in a clear blue sky. That said, It's a good idea to use planned filters in the compressibility test as well. VagueDenoiser, and RemoveDirt are a couple of subtle filters that will also improve compressibility.