Hi all:
I am very happy to announce new settings and new templates.
The changes were inspired by many questions and suggestions from many of you.
One of the most talked topics is re-encoding a movie twice in order to increase quality, because the first encode was 100MB less than the CD-R's max size, etc. and there was a lot of space left.
Then users increase CQ and find that the second encode was way over 800MB!
This was getting tired, for me too!, so I decided to investigate the posibility of increasing the quality to a point where there is no more quality increase by tweaking parameters, but still maintain the 120 minute goal per CD-R
And I did
Here are the changes that were made to the templates, with a description of the changes:
1) The CQ is now 80 instead of 70.
Of all the test's I've done, increasing above 80, increases the file size. But the visual quality is barely noticeable.
2) The MAX bit rate was brought down from 2,300Kbps to 1,450Kbps
I hear you! This is going to cause a blocky picture!
That's what I thought, and I was wrong.
For the current resolution, 1,450Kbps is visually blockless up to fast scenes. On very high speed scenes, the macro blocks are present, but the eye can barely distinguish them. The very high speed scenes on a DVD will look blurred anyway, and on a KVCD you'll also see a blurred scene.
If you were to do a "Pause" on a very high speed scene on a KVCD, then of course you'll see some unaligned macroblocks, but for practical purposes, they're invisible. Actually on a regular VCD there are more visible blocks on a high speed scene than on a KVCD.
3) Because the CQ was increased to 80, I was able to increase th GOP again a little, to gain compression. The new GOP structure is now 1-18-3-1-0. Before it was 1-12-3-1-0.
4) Detect scene change dropped. Why? There is no visual increase in quality with TMPEG and this option set. It just inserts I frames, even at non-scene change points, as I have been able to observe.
This actually kills the advantage of the large GOP structure, because every time an I frame is inserted, there are no predictive frames to compare.
5) Audio. ( Thanks Luis! )
It has been changed to Dual Channel. Before, we were using "Joint Stereo" to compress more data.
The results were great, but "Dolby Surround" would be lost!.
Changing this to dual channel solves the problem.
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What do we accomplish with all of this changes? What are the results?
It is now possible to encode a movie, and never worry if the final size will fit or not in one CD-R.
You won't see a quality increase if you raise the CQ from 80 to 100.
Visually speaking. So If your final size came out to 700MB, don't bother to re-encode at a higher CQ, because you won't see the difference.
If you raise your MAX bit rate above 1,450Kbps, you'll increase the file size, but the same applies to the visual quality. You'll barely see a difference.
And if your encode was way over 800MB you have two choices:
1) Just cut the movie in half and burn in 2 CD-R's
2) Lower your resolution to 352x240(28
and re-encode. If you still want to try to get it in one CD-R.
My choice is #1. Because the quality is now saturated to the maximum that TMPEG can make at the current settings, it makes more sense to just put the movie in 2 CD-R's.
And because this method still maintains an average of 90 to 120 minutes per CD-R, we can easily fit a 3+ hour movie in 2 CD-R's.
And please, If anyone says something like"I finished my encode, and I had 100+MB unused in the CD-R, this is a waste of space".
My answer right now is this:
"For the price of a CD-R ( about 20 cents or less ), you'll loose more than 20 cents re-encoding at a higher CQ and/or bitrate to end up with the same quality"
So it's not really a waste of space. It will be a waste of time to try to use those extra MB left.
Conclusion:
We can now just encode, and forget about the unpredictable file sizes generated by CQ encoding.
If it fits in one CD-R, fine. If not, cut the MPEG and burn in 2 CD-R's.
No more hassles.
If you still feel that you can live with a lower quality, then either start lowering the CQ or lower your resolution to increase your time per CD-R.
And I want feedback!. Yes I do. I finished Matrix last night with the new parameters, and I just had to cut the last 1 1/2 minute of credits to burn it.
I have posted a small sample here:
http://ns1.shidima.com/kwag/sample.mpg
The new templates are available at the main page now.
It's 2.8MB and about 20 seconds.
The quality of this sample is the one retained throughout the complete movie in a single CD-R.
The results viewed on a HDTV are now amazing.
kwag