Different xvid matrix for second pass?

[Henry The Ripper]

Hi!

I've tried to search the forum, but haven't find my answer.

I remember that someone suggested ('think it was Koepi) that it would be better to use different matrix for 2nd pass with xvid.

What was the case? I that much of a newbie and an average computer user that I have still not understood the quant stuff completely.

I know that some matricies blend the picture to archive better compressibility and others sharpen at the cost of size.

Should I, for example, use H.263 for the first pass and then the hvs.good.picture for the second?


Thanks in advance!

[manono]

Hi-

Ordinarily you'd use the same Matrix for both passes. However, if the movie doesn't compress as I thought it would, I'll change Matrices for the second pass (switch to a softer or sharper Matrix). I don't see much point in switching from the H.263 Matrix to HVS_Good, though, since they have similar compressibility.

And you'd have to point out where Koepi said such a thing, as it doesn't sound like something he'd say.

[Henry The Ripper]

Thanks manono, I give it a try.

I'm sorry, but I didn't find that comment from the forum anymore.

I have this one question also. Have I understood this correctly:

B-frames are the ones that are encoded completely and then there are just changes before the next B-frame?

This would be good stuff for the newbie guide: What are I-,P-,B-frames in lamens terms?

[manono]

Hi-

Here's an explanation of I, P, and B Frames:

http://forum.doom9.org/showthread.php?s=&threadid=19436

[Bogalvator]

Also be aware that changing the matrix for second pass will muck up the file size prediction a bit (probably not by much more than a few MB mind).