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-   -   FFMPEG: Ffvfw VIDEO CODEC (http://www.digitalfaq.com/archives/encode/7913-ffmpeg-ffvfw-video.html)

incredible 02-03-2004 05:16 PM

BTW: At all my last samples I did NOT add noise! just the script and their diff. resizers acording to final resolution!

Here now 480x576 at 1164CBR and again the better quantize value of 2!
So its not FIX by this:"yes" the screwing on the CBR Bitrate does compensate a bit. But you have to screw a lot and thats risky.

As you see Kwag I choosed the same quantizer as in case of 352x576 but had to lower the CBR to archive almost the same final size of these 1% at 480x576 compared to the 352x576 sample above.

Final size on 1% is 6.464kbit

(as I understood right Kwag, the VBV 20 below in the screen stand for a real double value like VBV40 in TmpgENc??)

http://www.digitalfaq.com/archives/error.gif

Anerboda 02-03-2004 05:25 PM

So, I got to get this straight: do we have to change both the min and max Quantizer to be the same value or can we have different values in the min and max settings??

Anerboda

incredible 02-03-2004 05:26 PM

I always have quantize max to 25 or even 30 and I ONLY change at the min quantizer from 2 to 3 depends on the final wanted filesize and resolution!

The max value in all my cases did cause nothing as the CBR encode refers to the min Quatize value. You can se that in the FFvfw Graph which you can open during encoding below right at your desctop left hand to the little watch!

Anerboda 02-03-2004 05:29 PM

Quote:

Originally Posted by incredible
I always have quantize max to 25 or even 30 and I ONLY change at the min quantizer from 2 to 3 depends on the final wanted filesize and resolution!

The max value in all my cases did cause nothing as the CBR encode refers to the min Quatize value. You can se that in the FFvfw Graph which you can open during encoding below right at your desctop left hand to the little watch!

But then the Q-level won't be linear, but perhaps it doesn't have to be??

incredible 02-03-2004 05:41 PM

At my KDVD sample 704x576 where I set that high bitrate the Q Level was Linear, but in case of OneCD encodings it isn't as I lower the CBR Bitrate at least to get the right VBV.

Linear Q curve is luxury and means nothing, you just should keep the Q curve about 3 or better below. And thats only a numeral value, only your eyes will tell you the truth.

DO open a TmpgENc CQ encoding and there also even at high CQ Values the Q curve won't be linear.

On the other hand as I said that often: Bitrateviewer and also its Q curve is not a garant for real viewable quality!

Let me quote KIKA from his GOP DCT/ Matrix Guide:

Quote:

Originally Posted by Kika
The force of expression of the q-level with the popular Bitrateviewer is to be enjoyed with caution. Because a high level means only that a block contained many same values after quantization, and which also could mean a result of a perfect interaction of quantization and RLE coding!!! And that again means that in such a case highly one quantized, the image quality however on the highest possible level was! Since however hardly someone really understands, what has it with the q-level actually on itself, I leave rather the fingers of interpretation attempts.

(Googles translation engine just used)

Means: If You encode crap and after reassembling the stream when the player again uses the matrix to descramble and the SAME crap comes out, the result is a 1:1 copy of that crap = "....could mean a result of a perfect interaction of quantization and RLE coding" and means a good Q value in Bitrateviewer. (If I understood KIKA in his guide right)

Anerboda 02-03-2004 05:48 PM

But do you gain anything by not keeping the same min and max values?

incredible 02-03-2004 05:51 PM

These are my first encodings on CBR mode in ffvfw and so as I said I do not recommend anything ;-) It was just set and I did let it run and as my logic told me that only the min value of quantize makes sense to modify (I figured that out in the ffvfw graph!), so now that was it what I actually did ;-)

Anerboda 02-03-2004 05:54 PM

Ok, thanks.

I guess more testing will be done, I don't think we're finished yet :D

Anerboda

incredible 02-03-2004 05:58 PM

We just just figured out "how to drive that car" but we still don't now which type of gas is the best and how fast it could drive then! :D :lol:

kwag 02-03-2004 06:00 PM

Quote:

Originally Posted by Anerboda
I don't think we're finished yet :D

I'm not :mrgreen:
I'm trying to find a way to encode with 9 bits precision, but that's probably impossible at this moment :)

-kwag

kwag 02-03-2004 06:02 PM

Quote:

Originally Posted by incredible
We just just figured out "how to drive that car" but we still don't now which type of gas is the best and how fast it could drive then! :D :lol:

But we've come from a "Go Kart" to a Porche in a matter of hours :mrgreen: :rotf:
:driveby:

-kwag

Hydeus 02-03-2004 06:03 PM

Quote:

Originally Posted by kwag
I'm trying to find a way to encode with 9 bits precision, but that's probably impossible at this moment :)

And what will be benefit of this?? Yes, yes .. I'm newbie :)

kwag 02-03-2004 06:12 PM

Quote:

Originally Posted by Hydeus
Quote:

Originally Posted by kwag
I'm trying to find a way to encode with 9 bits precision, but that's probably impossible at this moment :)

And what will be benefit of this?? Yes, yes .. I'm newbie :)

Higher quality on bitrates above ~4Mbps.

-kwag

incredible 02-03-2004 06:43 PM

Next Step a full action flashing long Movie at 480x576

"The Core" 130mins!, ... very hard to get good result:

Min Quantizers I=3, P=3, B=4, 84 Frames within a GOP! CBR 1165, 1B Frame (yes it decreased filesize), noise added via ffvfw.

And a little extra Unfilter(-8,-8 ) below the MA Command in my script.
... that little unsharpen the movie does make wonder according to an acceptable quantisation on THAT kind of movie.
Merge/Chroma/Luma Blur would do it also but I don't had that command now in mind and I was just too lazy to look in the orig MA ;-))))

8O We're still at mpeg2 one CDencoding ;-)

690kbit AVG Bitrate!!

Look at the Q curve, it seems the encoder after some Frames does get calm ;-)


http://www.digitalfaq.com/archives/i...2004/02/19.jpg

Hydeus 02-04-2004 05:41 AM

I'm starting to be lost in posts :)

Two questions to Incredible:
1st few post ago by Dialhot
Quote:

Originally Posted by Dialhot
WHO actually set the matrix in bbmpeg ?
:arrow: If I follow you correctly, if you do not do that, all the KVCD muxed with bbmpeg will be unscramble with the wrong key :!:

2nd
Quote:

Originally Posted by Incredible
Min Quantizers I=3, P=3, B=4, 84 Frames within a GOP! CBR 1165, 1B Frame (yes it decreased filesize), noise added via ffvfw.

And what will be with no B frames at all?

Krassi 02-04-2004 06:23 AM

I've done 3 screenshots.
Some details:
DVB-Capture mpeg2, small adapted MA-script, q=4 (all).
1 min. equals 18.283 KB.

Bitrate
Pic1
Pic2

In the last picture on the top right corner you can see some blocks. However, TMPGEnc's image is alot worse :roll:

EDIT: The screenshots above had SADT, adaptive 3. The following is done with "normal" settings:
Pic3

EDIT2: Converted image links to normal links to clean up thread.

Dialhot 02-04-2004 06:44 AM

CAN ANYONE TELL ME WHY ME Q CURVE ISN'T CONSTANT :?: :?:

Krassi have a perfect line, Inc have a "near constant" curve and mine is like the yellow line of Krassi snapshot !

Whatever the settings I put (I even set to 100% all the paremeters in Rate control and put "0" for "Max Quantizer difference"

This sucks ! :-(

Note: Inc and all, still snapshots are worthless. They only permit to see if there is macro blocks default. But all other defaults have a temporal aspect (dancing block, ants, mosquitos).

What are we doing there ? Photo or video ? You can have perfect (or awfull) stills but awfull (or good) video.

The last sample of Kwag is a perfect example of what I want to say. I'm sorry to say that but it was very bad !
(see my post in the other thread talking about ffvfw).

Krassi 02-04-2004 06:52 AM

Quote:

Originally Posted by Dialhot
Krassi have a perfect line, Inc have a "near constant" curve and mine is like the yellow line of Krassi snapshot !

Maybe the registry settings are damaged. Have you tried a reinstall? If i remember well you have already installed the latest build, right :?:

Dialhot 02-04-2004 07:00 AM

Quote:

Originally Posted by Krassi
if i remember well you have already installed the latest build, right :?:

Yes. And I will have to purge manually the register because I already uninstall/reinstall a lot with no real results. I was using ffdshow since months, that can be tied.

Note for Krassi: don't miss the ep. 10-11 tomorrow ;-)

rds_correia 02-04-2004 07:30 AM

Quote:

Originally Posted by Dialhot
CAN ANYONE TELL ME WHY ME Q CURVE ISN'T CONSTANT :?: :?:

Krassi have a perfect line, Inc have a "near constant" curve and mine is like the yellow line of Krassi snapshot !

Hi guys,
Sorry to say but I have the same problem that Phil has about the Q curve not being constant.
Mine is looking like krassi's yellow one too...
Anyway I am having very good encoding results with ffvfw's settings posted on the other
thread, apart from this Q curve prob.
Has anyone noticed that speed decreased since we changed to constant bitrate?
Maybe not much on some PCs but I went from 17 hours encoding to 22 hours
encoding a 115 minutes movie.
Yep my pc is needing new brains :oops:
I'll be seeing u guys tonight.


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