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16th May 2008, 20:23 | #21 | Link |
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*AQ or *LUMGAIN ?
I did a couple of test encodes using either *AQ 3 or *LUMGAIN 3. The source was quite dark, average bitrate a little over 5000 kbps. The matrix I used comes from manono:
8, 8, 8, 9,11,13,14,17, 8, 8, 9,11,13,13,14,17, 8, 8,11,12,13,14,17,94, 9,11,13,13,14,17,17,94, 11,11,13,13,14,17,94,94, 13,13,14,16,17,20,94,94, 13,13,14,17,94,94,94,94, 13,14,17,94,94,94,94,94 12,12,13,14,15,16,22,26, 12,13,14,15,16,22,26,32, 13,14,15,16,22,26,32,41, 14,15,16,22,26,32,41,53, 15,16,22,26,32,41,53,94, 16,22,26,32,41,53,70,94, 22,26,32,41,53,70,94,94, 26,32,41,53,94,94,94,94 To make it short: I could not detect any differences between the two encodes. Maybe the bitrate was too high. AQ 3 did compress slightly better than LUMGAIN 3, but this probably depends on the source. So more testing needed, I guess... Cheers manolito |
19th May 2008, 17:17 | #22 | Link |
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Try sources with flat areas versus sharper edges..the bits should be shifted from the edges towards the more flat areas of the frames. Also scenes with grass or similar texture are quite good.
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30th May 2008, 05:27 | #26 | Link |
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AQ Setting in HCenc23
Can someone please explain the 4 settings in AQ vs the 4 settings in LUMGAIN? I am trying to understand what to look for. I have previously used LUMGAIN 4 and liked the video. AQ has me puzzled, I saw the comments of Boulder but am still puzzled. I mainly compress/encode TV captures movies at a bitrate of 4K/S with small compression % like 82% with DVD-RB. I do notice that the detail on a face isn't real good it looks kinda flat. I am learning and would welcome opinions. Thanks in advance.
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30th May 2008, 06:09 | #28 | Link |
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AQ adapts the quantization, LUMGAIN affects the quantization matrix. hank posted the code related to LUMGAIN in the HC Encoder thread which shows how it works. Basically LUMGAIN lowers the coefficients of the base quantization matrix depending on the luminance levels. The strength affects the factor used in determining the new coefficients.
If I'm not entirely mistaken, AQ is meant for shifting bits inside one frame - from sharp edges to the more flat areas. LUMGAIN is supposed to shift bits to low-luminance frames from the brighter ones to prevent blocking in dark frames.
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31st May 2008, 01:26 | #29 | Link |
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So Boulder, then is it OK to use them at the same time or is it best to pick 1 or the other? In the past you have sugested I use LUMGAIN 4 and i like the output but was wondering if AQ would produce better results then LUMGAIN. What I recently encoded didn't have many dark sections. What do you use to make the decision as to use LUMGAIN or AQ?
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31st May 2008, 17:52 | #30 | Link |
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I use 3 for both AQ and LUMGAIN. They are two different things so they can be used together.
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31st May 2008, 23:42 | #31 | Link | ||
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Quote:
QMB is adjusted by the variance of the MacroBlock --> AQ. Qmatrix(i,j) is adjusted by the average luminance of the frames in a GOP --> LUMGAIN. Quote:
This picture shows the Quants of the same frame for different AQ values.
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31st May 2008, 23:50 | #32 | Link | |
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Quote:
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1st June 2008, 08:18 | #34 | Link |
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The matrix depends entirely on the source. Use the search, there are quite a few threads about this issue.
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7th June 2008, 14:33 | #35 | Link |
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hank, first let me say this is a very nice tool. i just started using it and the results are so far pretty good. but there are some open question for me in fully understanding the usage and some minor issues. i hope you or somebody else can help with this.
1. i currently set aq to 0 and the luminance gain to 0 , is this good or should i raise it? i encode from br/hd-dvd sources at 18mbps 2. i experienced that hcenc seams to lower the colors by a bit. i re-encoded the simpsons movie and saw how the skin colors faded a bit, which kinda bugs me 3. is there a way to scale hd sources to dvd res (pal and ntsc)? 4. is it possible to import .dga files from dgavcindex besides using avisynth? Last edited by zeropc; 7th June 2008 at 16:21. |
7th June 2008, 22:50 | #36 | Link |
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1. I say leave it on, especially at the bitrate you are using.
2. I never heard of that before, but maybe, how/what program are you using, what kind of file (DVD,XVID), essentially what I'm saying is you need to provide more information. 3. Yes 4. Not sure. I wouldn't think so. Hank, I get this mismatch error with v23. "Error, large source mismatch found in pass 2 starting at frame:0, count :1 frames." I'm using FAVC 1.06. Just thought I'd point that out. It seems to be only this program that experiences this problem, as I use DVD Rebuilder and it never happened. |
7th June 2008, 23:35 | #37 | Link |
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gizzin i remember that i came across this error before or something similar and after a bit of searching found that ticking reload avisynth during second pass under the settings 3 tab in the HCGUI fixed the problem, remember to save HC Ini in main tab or any settings changes won't take effect
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8th June 2008, 00:34 | #38 | Link |
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Quality is good as long as I keep AQ off. Not much different than HC022.
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8th June 2008, 03:26 | #39 | Link |
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Probs with zones
Zones don't seem to work for me
Code:
*ZONE 3 1 0.2 1200 1.0 163500 0.2 For testing I've set end frame to 2000 ... could that be causing trouble? |
13th June 2008, 18:28 | #40 | Link |
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I've found a bug that cause Ifoedit to crash when muxing.
I encoded some 352x240 video. I found out that Ifoedit will crashed at the beginning if the video bitrate is below ~256kbps. I notice video having a black fade in. When the black is usually low bitrate that's where the Ifoedit crashed. If I encode the video starting frames of 100 where there's no black screen. Ifoedit mux just fine when the bitrate is > 256kbps. Can HCenc have minimum bitrate settings? Last edited by lithoc; 13th June 2008 at 18:41. |
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