Correct usage of Forced Xvid's sharp matrix!

[azmoth]

I read somewhere that the Xvid sharp matrix is for resolutions of 512 x ... for 4.3 and 608 x ... for 16.9 Could someone please confirm this? So the sharp matrix would kick in 624 x... and above, yes at 2CD encodings? I have never seen it in the log or maybe I missed it.

I had a DVD source and the compression was 50% and final compression quality 55%, but the auto kept giving 608 x 256. Lower resolution 592 x ... gave the same compression values. My video bitrate was not bad 705kb/s. I was hoping that lowering the resolution would increase the compression quality. I reduced my audio using recommended auto and never used fixed horizontal as I read alongside the sharp matrix the results could come out worse.

Is using this forced sharp Xvid matrix of any real benefit on fixed encodings of 1CD 700mb using this auto width? The default I believe for 700mb using softmatrix with soft resizer?

One for the ever knowledgeable and reliably eclectic Big Did:thanks:

[BigDid]

I read somewhere that the Xvid sharp matrix is for resolutions of 512 x ... for 4.3 and 608 x ... for 16.9 Could someone please confirm this? So the sharp matrix would kick in 624 x... and above, yes at 2CD encodings? I have never seen it in the log or maybe I missed it.
Hi,

Yes, from recalling, these numbers are the thresholds.
Log will tell you when forcing sharp matrix or soft matrix. By default it IS sharp matrix :)

Is using this forced sharp Xvid matrix of any real benefit on fixed encodings of 1CD 700mb using this auto width? The default I believe for 700mb using softmatrix with soft resizer?
No the decision process is always the same for AutoGK (from recalling, see the log for exact step by step):
- do a comptest
- see if results percents are enough (65 or 67% ) for sharp matrix
If not use softmatrix (gain +/- 10%)
If not also use softresizer (gain +/- 5%)
- If autowidth combine decreasing width with thresholds and above decisions;
Do a First pass; is percents ok?
If not tune again etc...

With VAQ, sharpmatrix is used more often as compression is better.

What I do. Nowadays I encode to x264 and use Autogk first to get a working avisynth script AND a 1pass encode (70%) as a comparison.
So depending of the size of the 1pass I go 700 - 746 or 896Kb 2pass encode (depending on complexity and length of the movie) so I can get
- sharpmatrix and
- max width; not necessarily 720 but near.

One for the ever knowledgeable and reliably eclectic Big Did:thanks:
You're welcome even if I am back to student levels for x264 actually :)

Did

[azmoth]

I tried lower resolutions to 560, no sharp matrix and compression value went up to 62% increase of +7. In the end I settled for auto 608 x 256 with forced sharp matrix(compression value was 55%) and the quality was vasty greater despite lower compression with higher resolution. Best to let AutoGK decide resolution whatever compression values! I have mostly got away with using sharp matrix on compression value under 60%(resolution not less than 608 x ..) with no degradation in picture quality in fact massive improvements, but width must be auto AND never forced. I think that there is not much difference visually between 55% to 65% compression using a 2pass encoding with VAQ.

Better quality comes through at 70% plus as we know. I encoded a test last week more or less same runtime length as above test 105mins PAL but the compression quality was a superb 75% for a 2pass 700mb, so compression values depend too on how compressible your source material is and correct manipulation of audio.

As always your input is highly appreciated. Thankyou.:thanks: