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Old 2nd August 2005, 19:11   #5  |  Link
Sharktooth
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Join Date: Sep 2003
Location: Haddonfield, IL
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Quote:
Originally Posted by skal
Hello Sharktooth,
could you elaborate a little on how you deduce your matrices?
("with my eyes" is ok as an answer
-Skal
well with h264 i had to re-elaborate some of my theories on human eye perception but generally i "draw" a matrix around my initial idea, then i do a set of tests with a set (10 or more) of matrices (usually those are scaled from the "master" matrix with different factors and scaling formula) on 5 different sources.
Then i analyze the source sequencies and for every sequence i assign a score.
After the analysis phase i sum the scores and choose the matrix with the higest one.
This method was pretty fast for xvid, but since AVC is more complex it requires a lot more time...

Quote:
Originally Posted by trbarry
Hi Sharktooth -

When I wanted consistantly high quality and didn't care greatly about a precise bit rate I would often use 1-pass Xvid with a constant quant of 2, but with 2 b-frames, at q=3. Varyingly this would also be with one of your custom matrices. Other options to taste but mostly using more CPU to get better compression efficiency in a single pass. I tend to store things on external USB drives so a precise size is not that important. While I dislike wasting space it's often not worth another pass just to hit a arbitrary size target if quality demands more anyway.

Can you off hand recom
Quote:
Originally Posted by trbarry
Hi Sharktooth -

When I wanted consistantly high quality and didn't care greatly about a precise bit rate I would often use 1-pass Xvid with a constant quant of 2, but with 2 b-frames, at q=3. Varyingly this would also be with one of your custom matrices. Other options to taste but mostly using more CPU to get better compression efficiency in a single pass. I tend to store things on external USB drives so a precise size is not that important. While I dislike wasting space it's often not worth another pass just to hit a arbitrary size target if quality demands more anyway.

Can you off hand recommend any sort of fairly high bit rate X264 equivalent set of fixed quant options?

Sorry if this has been covered before but I've been away for awhile and a search didn't turn up anything with these priorities. I don't yet have much feel for what I can get out of X264 (or Nero?) with fixed quants but you seem to work with these things a bit.

- Tom

PS - These are mostly HD caps, at 720p or 544p though I don't know if it matters here.
Well, you can try with quants from 20 to 24, and you should have the "equivalent" of q2 (or q2+Bs) for xvid (depending on the CQM you used).mend any sort of fairly high bit rate X264 equivalent set of fixed quant options?

Sorry if this has been covered before but I've been away for awhile and a search didn't turn up anything with these priorities. I don't yet have much feel for what I can get out of X264 (or Nero?) with fixed quants but you seem to work with these things a bit.

- Tom

PS - These are mostly HD caps, at 720p or 544p though I don't know if it matters here.
Well, you can try with quants from 20 to 24, and you should have the "equivalent" of q2 (or q2+Bs) for xvid (depending on the CQM you used).

Last edited by Sharktooth; 2nd August 2005 at 19:14.
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