x264 misses I frame detection...

[Slave01]

Hi, recently with new x264 builds i have seen video artefacts that i haven't seen before. The activated option are weighted b prediction, 2 bframes, 2 ref frames, chroma me and all the options of high profile.
For example one of the errors in video regards i frame detection:
http://img435.imageshack.us/img435/271/grab472848uz.jpg

and :
http://img435.imageshack.us/img435/7805/grab473411zo.jpg

in which there are evident changing in colors (the first before i frame is inclined to green, the second (after i frame) has correct color)

Is this a known problem or i have used bugged release or features?
Greetings
John Slave

[Manao]

It's the same scene, isn't it ? And without the pictures taken from the source, we can't tell whether there are indeed artifacts or not.

[Slave01]

Not the same scene but if you see the pillar you can notice that in the first it is green while the real color is that seen in the second one.

Greetings

[Sharktooth]

post the same screenshots from the source please.

[Slave01]

Original:
http://img75.imageshack.us/img75/9882/grab472844mw.jpg

x264:
http://img435.imageshack.us/img435/271/grab472848uz.jpg

Original:
http://img75.imageshack.us/img75/2492/grab473414lq.jpg

x264:
http://img435.imageshack.us/img435/7805/grab473411zo.jpg

[Sharktooth]

ok, now can you please also identify the frame type for both shoots? (use ffdshow OSD).

[Slave01]

http://img435.imageshack.us/img435/271/grab472848uz.jpg

P frame

http://img435.imageshack.us/img435/7805/grab473411zo.jpg

I frame

Thanks in advance
Ciao

[Manao]

Ok, one more questions ( two actually ) :

* weighted b prediction, 2 bframes, 2 ref frames, chroma me and all the options of high profile <--- does that mean custom matrices ?
* what decoder did you use ( for making the capture ) ?

Oh, and a third one : screenshots (original vs x264) aren't the same frame, why ? ( did you use an avi ? )

And a fourth one : was there two players opened when you took the first two pictures ? especially the second one ( overlay issues happen so quickly... )

[Slave01]

Ok, one more questions ( two actually ) :

* weighted b prediction, 2 bframes, 2 ref frames, chroma me and all the options of high profile <--- does that mean custom matrices ?

all options activated but no custom matrices...

* what decoder did you use ( for making the capture ) ?

ffdshow 20050930

Oh, and a third one : screenshots (original vs x264) aren't the same frame, why ? ( did you use an avi ? )

same frame! I use mp4 output and then put into mkv container.


And a fourth one : was there two players opened when you took the first two pictures ? especially the second one ( overlay issues happen so quickly... )
No no. But there are flaws like old bugged xvid releases, especially chroma issues. Anybody with same problem?

[Manao]

same frame! I use mp4 output and then put into mkv container.No, definitely not the same ( in the second case, the legs have moved ).

Can you make a whole sample available ( from the precedent I to the next one ), so that we can decode it to see if we get also that greenish effect ?

And another question, did you use any postprocessing filters during playback ?

[Kopernikus]

Whose build did you use?

[Slave01]

No, definitely not the same ( in the second case, the legs have moved ).
Yeah it's true....now i can see it in detail maybe one frame of difference but this is not important because the same effect is on previous frames and in next frames until the i frame.

However build 327A
No pp activated.
Yeah for the sample i need to find an mp4 cutting tool.

[Sharktooth]

use mp4box to split the file or download YAMB (a convenient mp4box GUI).

[Slave01]

Tried with last build...same problem...tried in avi with vfw gui...same problem...here is the mp4 file (thanks Sharktooth) http://s5.ultrashare.net/hosting/fs/c05fb075e702265c/


Greetings

[Slave01]

The movie is Sahara...has anyone the same problem?

[dlzinc]

I remember reading somewhere that using VMR9 or VMR7 rendering modes in the player can result in a greenish tint especially with NVidia video cards, any of that apply to you?

[foxyshadis]

A much better title for this thread would be 'x264 causes green chroma drift' or something like that.

[Slave01]

I remember reading somewhere that using VMR9 or VMR7 rendering modes in the player can result in a greenish tint especially with NVidia video cards, any of that apply to you?


No ati and overlay mixer. Did you see it too? The sample posted here (http://s5.ultrashare.net/hosting/fs/c05fb075e702265c/)

[Manao]

I don't seem to notice any drift here (whatever the decoder), but it's hard to tell without the source anyway. I must say I'm rather clueless on what's happening.

[Sharktooth]

the encoded file is ok. No green on my side. Maybe your decoder is b0rked.

[kurt]

do you have the same problems with mplayer or vlc?

[Sharktooth]

However it's not x264... it's a decoding problem.

[Slave01]

Yes it's true! With videolan all it's ok. Strange...i am using zoomplayer+ffdshow 20050930 + reclock...Sharktooth did you try with ateme? What can be the reason?


Thank you
John Slave

[Slave01]

I don't understand now i have installed 20051013 ffdshow and the problem goes away (i have uninstalled for the first time previous version (before maybe a conflict?))

Thank you!
John Slave

[Sharktooth]

probably there was some sort of bug in the previous ffdshow build or maybe libavcodec was compiled with wrong compiler settings.
however, yes, i tried with ateme decoder too and it was all ok.

[Manao]

Not FFDShow, since I used the same version he did, and didn't notice any drift.

[foxyshadis]

Odd, since I did, but if a new version sorts it out then there's no worry. Must be post-processing settings or overlay interface or something like that.

[Slave01]

A friend of mine has that problem too with ffdshow (my same build). I think all this problem was generated because i usually overwrite ffdshow installation instead of uninstall it before. May be so?

Thanks
John Slave

[Slave01]

Problem found. It's the option "skip deblocking always" in codecs window of ffdshow!

Greetings
John Slave

[yidaki]

What does that option do really, and how is it related to the h.264 deblocking options in the post-processing tab?
There's also the "skip deblocking when safe", could that help relieve some cpu without ruining the picture completely?

[foxyshadis]

What does that option do really, and how is it related to the h.264 deblocking options in the post-processing tab?
There's also the "skip deblocking when safe", could that help relieve some cpu without ruining the picture completely?
It means to not deblock regular b frames (not b-references), or more generally any frame that isn't referenced by another frame. For low-bitrate material you may notice pulsing blocking which might be very annoying. Using 'all' is bad, because the frames are encoded with the assumption that inloop is on, turning it off causes weird artifacts.

As for the PP tab, I keep meaning to provide a patch to make that confusing mess clearer. h.264 off means use regular ASP deblocking, which isn't quant scaled and looks horrible. You should always keep it on the 3rd option.