x264 dark scenes

[Ma-Xell]

http://img3.uploadhouse.com/fileuploads/3477/3477383fd0a6ac46a85211fff3e2a537f2c3d7b.jpg
What causes all those blocks in dark areas.
I had fast pskip disabled.

[LoRd_MuldeR]

Is AQ enabled? You should post your entire commandline. Also you should post a screenshot of the same frame from the unprocessed original video.

[Ma-Xell]

I used MediaCoder but here

cabac=1 / ref=6 / deblock=1:-1:-1 / analyse=0x3:0x113 / me=umh / subme=7 / brdo=1 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=1 / cqm=0 / deadzone=21,11 / chroma_qp_offset=0 / threads=6 / nr=0 / decimate=1 / mbaff=0 / bframes=16 / b_pyramid=1 / b_adapt=1 / b_bias=0 / direct=3 / wpredb=1 / bime=1 / keyint=250 / keyint_min=25 / scenecut=40(pre) / rc=2pass / bitrate=2194 / ratetol=1.0 / rceq='blurCplx^(1-qComp)' / qcomp=0.60 / qpmin=10 / qpmax=51 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / ip_ratio=1.40 / pb_ratio=1.30

Source frame:
http://img9.uploadhouse.com/fileuploads/3477/3477439efa6dc43432e32b8824325bb26c850d0.jpg

[LoRd_MuldeR]

I can't see "aq" or "psy_rd" in your settings. What revision of x264 was used to create that clip?

If you use MediaInfo to read out the encoder settings, which I assume, then look for the "Writing library" line...

[Ma-Xell]

x264 core 65 r1057

Here are the settings in MediaCoder
http://img5.uploadhouse.com/fileuploads/3477/34775156b1d6aa872029bfb5af425c07d7a3d56.gif

[LoRd_MuldeR]

x264 core 65 r1057

That's not the latest revision, but not too old either. I'd update anyway...

Here are the settings in MediaCoder
http://img5.uploadhouse.com/fileuploads/3477/34775156b1d6aa872029bfb5af425c07d7a3d56.gif

Can't see any settings for Psy-RDO or VAQ. Doesn't MediaCoder offer these options?

:confused:

[lexor]

OK, I don't see any blocks (without boosting brightness way up), are you sure your monitor is calibrated correctly? Looks like a smooth image to me.

[LoRd_MuldeR]

OK, I don't see any blocks (without boosting brightness way up), are you sure your monitor is calibrated correctly? Looks like a smooth image to me.

I can hardly see them. But if he really didn't use AQ, there's a great chance to reduce the blocks with the help of AQ.

Also Psy-RDO and/or Psy-Trellis may help to better retain the noise in the dark area...

[Dark Shikari]

x264 core 65 r1057

Here are the settings in MediaCoder
http://img5.uploadhouse.com/fileuploads/3477/34775156b1d6aa872029bfb5af425c07d7a3d56.gifWrong. That settings line cannot possibly originate from r1057.

I'm going to guess you're using a version at least 1 year old, pre-AQ.

[DVFs_DrinkOrDie]

That's weird. I don't see any blocks. EDIT: (in your picture) Just pure consistent black. I know that I can have a video that looks like I just described, but if I set my decoder settings to alter the gamma, then blocks show up.

[Ma-Xell]

Well I've updated MediaCoder and x264. Now I can see the options for Psy-RDO and VAQ.
I've enabled them and I'll recode the video overnight and I'll see tomorrow. Thanks for the help.

note: The blocks are more visible when in fullscreen mode and the bright colours of doom9 aren't distracting your eyes.

[Snowknight26]

If you can see blocking you're using an LCD. Time to get a proper monitor (S-IPS or better!). :P

[burfadel]

I can't see blocking either, on an LCD, but I can imagine on certain brands with bad contrast ratio you could! I've got an Asus VW222u that I go just over a year ago, 22 inch, 2ms response, great picture (it does require a bit of changing of the settings though) but couldn't be happier.

You don't need a new monitor, just check your monitor settings. The doom9 page isn't blinding bright, I would suggest to check your monitor settings. There are brightness/contrast adjuster programmes you can download where it just shows shades of grey, and you adjust your monitor to suit the description of the grey shading depicted on the screen. I highly suggest you do that as it sounds you have (most likely the brightness) set way too high. It could even be the display driver settings too, you can adjust brightness/contrast & gamma on a driver level. Some people perfect the settings as much as possible on the screen, then tweak it through the driver which often works with excellent results!

[Audionut]

The jpeg compression has soften these images.

http://img153.imageshack.us/img153/3124/adjustedqm5.jpg

The source is crap also
http://img18.imageshack.us/img18/55/sourcehx4.jpg


These areas of blocking are so dark, imo, the codecs are doing a good job of reducing the bitrate in these areas that will never be seen under normal circumstances.

[Sharktooth]

btw if you can see those blocks during playback, your monitor is way too much uncalibrated... or crappy... :)

[Shinigami-Sama]

these last ones I can see and would annoy me, and my monitor is on dark settings and definitively not crap

[burfadel]

I think the last pics were brightened to highlight the issue described!

[Audionut]

Indeed

[Chengbin]

btw if you can see those blocks during playback, your monitor is way too much uncalibrated... or crappy... :)

Isn't that the opposite? His screen is either uncalibrated or it uses a very GOOD LCD that unforunately is unforgiving. I can see those blocks easily on my Dell Ultrasharp 22''

[Sharktooth]

if a monitor/TV shows artifacts that they were NOT meant to be visible, then it doesnt mean it is a good monitor/TV...
for example some non-black matrix panels easily show those artifacts, but non-black panels are crap... ;)

[Rumbah]

You could try setting deblocking to 0,0 .

In addition to that try to play back the video with ffdshow and let ffdshow do the YV12 to RGB conversion. Perhaps you are suffering from wrong colorspace conversion done by your graphics card when playing the video (VMR for ATI, nVidia, overlay for nVidia, for non HD resolution and most drivers).

[Ma-Xell]

I have a Benq T2200HD 22inch LCD monitor which i just recently bought so I wont be buying a new one anytime soon..
I recalibrated the monitor and the gamma was too high.. It looks much better now

[Sagittaire]

Blocking are really visible in dark area. Codec like Mainconcept SDK or Microsoft VC1 SDK use special masking for that with AQ (I don't know for x264).

[DVFs_DrinkOrDie]

I have a Benq T2200HD 22inch LCD monitor which i just recently bought so I wont be buying a new one anytime soon..
I recalibrated the monitor and the gamma was too high.. It looks much better now

Well that explains it. Your picture looked perfect to me. No blocks. And, like I already mentioned, if you increase the gamma you can get almost any video to start showing blocks. This goes not only for the monitor, but also your decoder (such as ffdshow) settings.

[*.mp4 guy]

My trinitron fw900 shows me blocking. I believe it. Use Aq. Denoise+deband your source.