x264 deblocking settings

[fatxy]

hallo, i have problems to find proper deblocking settings with x264

i used sharktooths hq slow profil with 1500 bitrate and
alpha deblockin -2
beta deblocking -1

but compared to the source it smooths a little to much imo, so did anyone found already some good settings or do i have to increase the bitrate?

sample pics (ie. look at the couch pattern between the fur and the mic, or the fur itself)

http://people.freenet.de/fatxyz/vlcsnap-3505035_source.png

http://people.freenet.de/fatxyz/vlcsnap-3505035.png


fatxy

[Oline 61]

If it smooths too much set it lower until you find it agreeable with your tastes.

[berrinam]

It doesn't actualy look like your source has much detail -- it's mostly noise. Maybe you should try running it through a denoiser first. That would also increase compressibility -> lower QP -> decrease smoothing.

[CEC]

It isn't that bad! It looks really good to my eyes! And yes it has a lot of noise and you must be really happy that you don't have blocky issues with such a noisy source!!!;)

And I really believe that you should at least resize it to make it something like 672x512 or just crop to make it 672x496!

You have 672x508 and this is baaaad!!! Remember the magic number is 16!

[foxyshadis]

I like how the AVC provides a bit of an airbrushing to their skin. :p

[kotrtim]

the deblocker settings at -2,-1 could turn a grassland into a piece of smooth green cloth.....try -3,-3 ......I've seen people using -6,-6 too

[bob0r]

What mic?

[spinstate]

What mic?

I think he mean's the microphone the lady on the right is holding ;)

[fatxy]

ok thanks for your infos im gonna play around with -3/-6

cant see much noise at the source tho? (dvb capture)

[Archimedes]

It looks like, i have the same problem. I’ve encoded some interlaced DV Avi sources (PAL) for test purposes. I’ve used the “HQ-Slow” profile as it is, but with a bitrate of 6500 kbps. Some regions of the video looks like the following example. Changing the deplocking values to (-3, -3) or (-6, -6) doesn’t work well. Ideally, i want to see the noise from the source also on the encoded video. Any recommendations? I’ve also added the results from Nero Recode 2. The pictures are scaled by 150 %.

Original
http://img70.imageshack.us/img70/3668/original0540x04325wr.jpg

X264, „HQ-Slow“ profile, 6500 kbps
http://img82.imageshack.us/img82/6663/x26465000540x04324cr.jpg

Nero Recode 2, 6,52 Mbps
http://img5.imageshack.us/img5/369/nero65000540x04321ux.jpg

Best regards
Josef

[fatxy]

yup clearly visible @ flagstones

i use now -6, 2000 bitrate, and a 3rd pass
result is quite good

haven't compared with nero tho your sample pics looks quite good

[Soulhunter]

look at the couch pattern...
Its very hard, for some reason my eyes always drift to the left... XD


Bye

[kotrtim]

>>>Any recommendations? I’ve also added the results from Nero Recode 2. The pictures are scaled by 150 %.

How about increasing the bitrate? and turn off deblocking????

[bob0r]

...and turn off deblocking????

My thoughts exactly when i read this, please try
--nf Disable loop filter (uncheck "enable deblocking in megui")

[akupenguin]

It looks like, i have the same problem. I’ve encoded some interlaced DV Avi sources (PAL) for test purposes.
How about not encoding interlaced stuff with x264?

[Archimedes]

The basic problem was not the interlaced stuff, which isn’t supported by the x264 encoder. Calculating the SSIM values over all frames (through AviSynth script) tells me, that the x264 video has the better quality than the Nero file. After analyzing the following frames after each 1st frame of a new scene, i realized, that Nero also soften some areas. I was impressed a little bit too much when comparing some Nero i frames with x264 i frames. So, H.264/AVC encoders in common can't do it much better with such sources. Thanks for your help.

Best regards
Josef

[xyloy]

0,0 is the safest.

Positive values tends to smooth the edges, negative values intensify them too much... Not a very good idea with a "clean" source(such as a DVD. Deinterlaced if needed).

[loki03]

which bitrate do the dvb-recordings have? i record analog german tv to mpeg2 at vbr 6,4mbps(>5,8mbps<7,4mbps) and i need 4000kbps for the x264 recodes to make it look good at d1-res, deblocking -1,-1.

[nm]

Here in Finland we have about 3.5 Mbps as an average in DVB-T, sometimes lower. That is not enough for good quality since they encode on the fly.

Perhaps you need some better filtering (especially noise reduction) before encoding to x264. Analog sources tend to be a bit dirty.

[*.mp4 guy]

negative values intensify them too much... Not a very good idea with a "clean" source(such as a DVD. Deinterlaced if needed).
Where did you get that Idea? Negative deblocking values just smooth less then positive ones, they don't intensify anything.

[Shinjite]

I thought negative values are use to make the output video sharper

[dude051]

Theoritically, it doesn't 'sharpen the source', it simply stops the encoder from softening it more (with negitive values). As apose to positive values that smooth more, in order to help deblocking.

[xyloy]

Where did you get that Idea? Negative deblocking values just smooth less then positive ones, they don't intensify anything.
It's only my personnal feeling. ;)

Anyway, using other values than 0,0 is a bad idea.

[Backflip]

Its very hard, for some reason my eyes always drift to the left... XD

Lol, this also affects me for some reason too. Something quite titillating seems to attract my attention.. (pun intended ;) )

Tend to agree with the 0,0. If in doubt use the 0.

[Oline 61]

Just out of curiosity, shouldn't it be 0:0 instead of 0,0?

[bob0r]

Just out of curiosity, shouldn't it be 0:0 instead of 0,0?

Read http://forum.doom9.org/showthread.php?p=772901#post772901 and below, what akupenguin said.

[Oline 61]

Hmm. So I shouldn't use MeGUI to encode, because it uses "," instead of ":". No big deal, just copy MeGUI's commandline into a BAT file and run it. Maybe even save a few minutes because there is no GUI taking up CPU cycles :).

[Sharktooth]

Read http://forum.doom9.org/showthread.php?p=772901#post772901 and below, what akupenguin said.
it was addressed with a recent revision.