Quality problem (again)

[neutrogenik]

Thanks to Foxyshadis and Teegedeck i found how to greatly improve the quality of my vids using xvid, however i ran some other test today and i'm still not 100% satisfied with the results that i'm getting.

I used MPEG-custom with eqm v3ehr matrix @ q2 single-pass with no filters (null transform) and the difference between original and encoded is still visible, just save the following screenshot and open them in fullscreen and you'll see ^^

(first is original, second is xvid)

http://denibob.free.fr/test1.bmp

http://denibob.free.fr/test2.bmp


I highlighted the most visible transformations here (it looks like a "pixellisation effect"), but you can also notice that the averall brightness also changed on the encoded one :

http://denibob.free.fr/test3.bmp


I know this is only some minor changes but i really'd like to get the best results so is there something else that can be done or should i say to myself that it's the best i can have and be happy with it ? ;)

I also tried to encode in mpeg2 but i was getting even worse results.

:thanks: in advance :)

[scharfis_brain]

you've just stumbled over the yuv 4:2:0 chroma subsampling.
there is nothing you can do about it, except encoding in the native resolution given by your source.

(btw.: the resizing you used looks a little bit weird)

[neutrogenik]

you've just stumbled over the yuv 4:2:0 chroma subsampling

omg what does that mean ? :D

I encoded in the native resolution and i get exactly the same problem, i just rezised the screenshots to fit to 4:3 but i can give you the original ones if you need.

danke sehr für die Hilfe ^^

[scharfis_brain]

yuv 420 == a block of 2x2 pixels only has ONE chroma information
the decoder of your source smoothes that out
the decoder of xvid doesn't. that's why you see the chroma stairstepping at high saturated edges.

It will help to enable the high quality rgb conversion in the ffdshow video decoder.
But this of course won't help the image you're taking from vdub, cause vdub is using vfw decoders.

btw.: why are search for such small deviations on an LOSSY encoding model?
I think, you'd better stick with lossless encoding then, or leave the original is it is..

[sysKin]

1. For God's sake, don't post bmp's on forums... or anywhere else ;_;

2. I highly recommend cropping all black borders if you want better compression. Unless you need to keep the resolution exact, of course :/

[neutrogenik]

It will help to enable the high quality rgb conversion in the ffdshow video decoder.

How do i do that ?

I think, you'd better stick with lossless encoding then, or leave the original is it is..

The original is interlaced, have black borders to be removed and must be cut at some points so i must reencode it.

And i'm trying to encode with a lossless model but i can't find one :(


1. For God's sake, don't post bmp's on forums... or anywhere else ;_;

It's small details so i was afraid that it'd be gone with Jpeg :D

2. I highly recommend cropping all black borders if you want better compression. Unless you need to keep the resolution exact, of course :/

I'll try that now :thanks:

[Soulhunter]

@ neutrogenik

Read this... (http://forum.doom9.org/showthread.php?t=106111)


Bye

[neutrogenik]

This article is very interessting !

So if i understand well the problem is not encoding but decoding right ?

Two others questions :

you have to force YV12 output in its decoder config

1°) How do i do that ? :)

2°) Seems like the "3. Use Overlay + a graphicscard with inbuild HQ YV12 to RGB conversation" is the best one for quality and speed (i have a 6800Ultra so that should do it) but same question : how do i do that ? ^^

Thanks again 4 the help :)

[Soulhunter]

1°) Like this -> XviDs decoder (http://img82.imageshack.us/img82/3792/xvid7ai.png) / FFDshow (http://img126.imageshack.us/img126/2915/ffdshow0qc.png)

2°) First: You dont "DO IT" it happens automatically inside the card! Second: Just because you have a relative new card it doesnt mean it has internal HQ chroma upsampling! My GeForce 6600GT (released ~ the same time as your 6800Ultra iirc) fails, while my Radeon 9200 (much older than the 6600GT) is able to do it correctly...


Bye

[neutrogenik]

First: You dont "DO IT" it happens automatically inside the card!

Ok thanks for the explanation :)

Also am i using an old xvid version ? Because i only have this pannel for Xvids decoder :

http://img345.imageshack.us/img345/3659/clipboard013hf.jpg

And i don't know where the hell did you find this FFDshow option pannel :/

[Soulhunter]

Sure its the "real" decoder config and not the config in the encoder setup? Both configs (XviDs decoder and FFDShow) should be somewhere in your Start menu...


Bye

[neutrogenik]

It is the config in the encoders options (Virtualdubmod) but i can promess you that i don't have anything in my start menu, as in my Xvid installation directory :

http://img364.imageshack.us/img364/2338/clipboard019io.jpg

I downloaded it on xvid.org so i don't understand why i'm missing some stuff :??:

[Soulhunter]

Since when XviD.org offers binarys? Anyway, I just did a fresh install of Koepis build with this (http://img307.imageshack.us/img307/2645/unbenannt9vc.png)
result... So, there must be something wrong on your end! But you can call the config also via Start -> Run -> C:\WINDOWS\system32\rundll32.exe xvid.ax,Configure


Bye

[neutrogenik]

I checked 'n was running the old 1.03 version, i'm surprised that xvid version are released with 1 month intervals only :o

I'm gonna look at the decoders options and see the results, thanks again for all the help, it's always a pleasure to get some advices from skilled ppl like you ;)

[neutrogenik]

I tried like you said :

http://img323.imageshack.us/img323/5828/xvid6dm.jpg

http://img444.imageshack.us/img444/69/ffdshow6sk.jpg

but the result is almost the same :

http://denibob.free.fr/yv12.bmp

Maybe my 6800Ultra doesn't do its job ...

I uploaded the original video so you can make some tests on it and show me if you get better results that i do :

http://rapidshare.de/files/17046879/original.m2v.html (30 Mb)

[foxyshadis]

Then probably the only way it'll work is switching to ffdshow and using its high quality rgb upsampling.

Scharfis, I thought vdub did hq upsampling in its native yv12->rgb?

[neutrogenik]

i can try out fox if you tell me out to do so :)

[Soulhunter]

Erm, what renderer have you used?


Bye

[neutrogenik]

you mean the FourCC used ? I took the default one : xvid

[Sirber]

seems your FFSHOW is old...

[neutrogenik]

i downloaded the latest one avariable on sourceforge : ffdshow-alpha (ffdshow-20041012)

http://sourceforge.net/project/showfiles.php?group_id=53761

[Soulhunter]

you mean the FourCC used?
Nope, go to MPCs config, under "output" there are this options... (http://img431.imageshack.us/img431/8074/newsnap001850ge.png) Depending on the abilitys of your card you have to use "Overlay" or "VMR9 windowed" (but test "VMR9 renderless" as well) And yes, your FFDShow version looks outdated, grab a recent version here... (http://x264.nl/)


Bye

[shon3i]

Practicly if you install both ffdshow and xvid, ffdshow have higher merit and his decode video, try to unistall ffdshow or find some newer version like this http://mirror01.x264.nl/x264/ffdshow-20051221-gcc4.0.2-sse-x264.nl.exe

[Soulhunter]

Practicly if you install both ffdshow and xvid, ffdshow have higher merit and his decode video...
Well, if you set FFDShow to decode XviD via XviD (http://img431.imageshack.us/img431/6245/newsnap001864uw.png) it will use XviDs decoder! <- Wow, what a sentence... XD


Bye

[neutrogenik]

Nope, go to MPCs config, under "output" there are this options... (http://img431.imageshack.us/img431/8074/newsnap001850ge.png) Depending on the abilitys of your card you have to use "Overlay" or "VMR9 windowed" (but test "VMR9 renderless" as well) And yes, your FFDShow version looks outdated, grab a recent version here... (http://x264.nl/)


Bye

Thanks for the link, i can't belive that sourceforge is outdated lol

I'll download MPC right now :)

Edit : well it seems like that the pixellisation problem is indeed gone, also i can't really see it because when i try to make a screenshot i got this weird error :

http://img382.imageshack.us/img382/665/clipboard010rd.jpg

But now there is a second problem : the black areas have a shining effect, like it's moving, i don't know how to describe it well.

edit 2 : i checked the "overlay" box in ffshow decoder config and it seems to be good, but i'd still like to make a screenshot to see the differences.

Anyway Soulhunter did you try to get it work with your own config ?

[shon3i]

Well, if you set FFDShow to decode XviD via XviD (http://img431.imageshack.us/img431/6245/newsnap001864uw.png) it will use XviDs decoder! <- Wow, what a sentence... XD


Bye
But this sometimes have some problems, I have this problems something like gain in brightness

[Soulhunter]

@ neutrogenik

About the error: You get this message only if you use "Overlay" for the ouput, right? Thats normal... You cant make screenshots of the overlay, but for VMR9 it should work! For the black areas: If you mean that they're brighter now its probably the 0-255 -> 16-235 Level conversation I mentioned in the article... Try the latest beta drivers from Nvidia (link is in the article thread) and see if they fix ya problem! About my config: For the box with the GF 6600GT I use FFDShows HQ YV12 to RGB32 conversation + Overlay, for the box with the Radeon (btw, the 9200 VIVO died last week, now I use a 9600 as replacement) I use YV12 output + Overlay... this way both configs produce proper upsampled chroma and non altered levels! ^^


Bye

[neutrogenik]

Sorry for your 9200 :(

Well i don't have time to test this now because i'm going to work tomorrow but anyway a big THANKS for all these informations, everything is very interesting and your knowledge is impressive :)

[neutrogenik]

i'd also like to know if i understood the stuff from your article well :

1. Use "VMR9" as renderer

like this (http://img80.imageshack.us/img80/5665/newsnap001850ge5xj.png), without using the overlay mixer from ffdshow


2. Use "Overlay" as renderer + FFDShows HQ YV12 to RGB32 conversation

like this (http://img80.imageshack.us/img80/7195/ffdshow0qc4px.png), using "system default" output in MPC

3. Use Overlay + a graphicscard with inbuild HQ YV12 to RGB conversation

like this (http://img126.imageshack.us/img126/2915/ffdshow0qc.png) with "system default" output in MPC


So the question is : why is it needed to specify to MPC that it has to use the overlay mixer ? I thought that ffdshow was already doing it when you check the "use overlay mixer" box http://smileyonline.free.fr/images/gif/pascompris/vignette/thumbnails/Question3_gif.gif

[Soulhunter]

If you set VMR9 in MPC, VMR9 is used, no matter if overlay mixer is activated in ffdshow or not! So, you use 1.) FFDShows HQ YV12 to RGB output (btw, you have to uncheck YV12 and check RGB32 then) + Overlay in MPC or 2.) FFDShows YV12 output + Overlay in MPC or 3.) FFDShows YV12 output + VMR9 in MPC...


Bye

[bratao]

Man !
I have to tune my eyes ! i cant see ANY difference

[Soulhunter]

Yeah, Im still not sure if my eyes are a bless or a curse... :D


Bye

[neutrogenik]

http://img145.imageshack.us/img145/1053/clipboard013fs.png http://img145.imageshack.us/img145/8213/clipboard022gs.png

It's not an eye thing, it's a zoom thing ^^

Anyway Soulhunter the thing that i don't understand is why do we have to set "overlay mixer" output in MPC since it's already done in FFdshow ? In fact, what's the difference between activating overlay mixer in ffdshow and activating it in MPC ?

[Soulhunter]

Well, as I wrote... Its doesnt matter if you activate overlay mixer in FFDShow or not, the renderer you set in MPC is used! (Example: Overlay (http://img334.imageshack.us/img334/4519/overlay2wv.png) / VMR9 (http://img51.imageshack.us/img51/5118/vmr98hv.png)). The only use for FFDShows setting is the transfer of PAR info etc. to the overlay mixer iirc, but which renderer is used depends on the player!


Bye

[neutrogenik]

what i think is :

directshow default output in MPC + overlay mixer in ffdshow <=> directshow overlay mixer in MPC + nothing in ffdshow.

I'm I wrong ? ^^

[Soulhunter]

Erm, the tooltip in MPC says the "system default" renderer is VMR7, not overlay mixer (at least for WinXP). But, VMR9 output in MPC + overlay mixer in ffdshow = VMR9 in MPC + no overlay mixer in ffdshow... Except that the PAR info wont be send to the renderer, so its better to keep overlay mixer activated in FFDShow!


Bye

[neutrogenik]

so the correction is :

1. Use "VMR9" as renderer

VMR9 windowed in MPC ; overlay mixer and YV12 in ffdshow


2. Use "Overlay" as renderer + FFDShows HQ YV12 to RGB32 conversation

Overlay mixer in MPC ; overlay mixer, RGB32 and high quality YV12->RGB conversion in ffdshow

3. Use Overlay + a graphicscard with inbuild HQ YV12 to RGB conversation

Overlay mixer in MPC ; overlay mixer, YV12 in ffdshow

right ? ;)

[Soulhunter]

Yeah, one of the three... which depends on the capability's of your graphicscard!


Bye

[neutrogenik]

Well you should add these info to your article for the newbies like me ! :D

Anyway do you know by chance a way to do screenshot in overlay mode with another software maybe ? Because it's hard to check the differences between each mode without frames per frame checking :)

[Soulhunter]

No, but to test if the chroma is upsampled correctly simply use something like this! (http://www.sendspace.com/file/2danxj) If it looks like this (http://img440.imageshack.us/img440/7383/good9ra.png) it works, if it looks like this (http://img440.imageshack.us/img440/7400/bad6dq.png) it doesnt work... Note: You have to close/reload the video each time you change the render mode in MPC!


Bye

[neutrogenik]

It is working great, when i compare original picture and the same frame in MPC it looks 100% identical, it's really near lossless quality without huge filesize like others lossless codecs, it's magic ! :D

But i'll take my camera and snapshot my screen (i know i'm crazy), i'd really enjoy to see if the differences between each chroma unsampling method looks visually identical.

And even if you find that i repeat it too much : thanks you a billion !!!

One more question (yeah again lol) : i saw in your sig that you make CQMs, do you have one that is similar or better than eqm v3uhr rev2 or/and eqm v3ehr ? And don't be modest ^^

[Soulhunter]

No problem, Im jobless atm, so I have nuff free time to "waste" lol! For the CQM: You could give my Soulhunters v3 (http://www.webalice.it/f.corriga/CQMs/Soulhunters%20V3.xcm) a try, its for usual DVD content at ~4000kbps... ^^


Bye

[neutrogenik]

I'm jobless too (in school = same :D ) lol

I'll give it a try after i tried the latest Forceware 84.21 WHQL to see if i got some changes with it because the brightness looks different when i use chroma upsampling and not.

I keep you up-to-date :)

[neutrogenik]

Well i tried all the 3 rendering mode :

first is original / second is ffd YV12 -> RGB / third is VM9

(i suggest saving them in a folder and opening in fullscreen to see the differences)

http://img400.imageshack.us/img400/3340/original5nf.png

http://img432.imageshack.us/img432/213/encodeeavecrgbconversion1qc.png

http://img333.imageshack.us/img333/5005/vm93gb.png


http://img432.imageshack.us/img432/7595/orig4kw.png http://img432.imageshack.us/img432/3276/rgb0jj.png http://img98.imageshack.us/img98/2374/vm921ph.png


As you can see the chroma upsampling is amazing, fd YV12 -> RGB and VM9 looks almost the same but i prefer VM9 ;)

The final result is still not 100% matching original because i didn't use the best EHR settings when encoding so there is a very few quality loss, but i'll try it tomorrow with the best settings and with your "Soulhunters v3" to see if i can reach 100% ^^

=> so far it's 96% :D

Otherwise i can't have something good with Overlay inbuild HQ conversation : the colors become weird (clearly different from the original ones) and the image is much more blurried (quality loss).

Maybe my 6800 Ultra is not good for this :/

I'll try to add pictures from my camera since it's impossible to make screenshots with this rendering mode.

To be continued (and finished i hope) tomorrow :)