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Old 5th October 2004, 18:20   #41  |  Link
netchris
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There must be something wrong with the compiler, since my built doesn't have these problems.
I would like to hear too what akupenguin's thinks about it.
Subq=5 does indeed offer better quality when working correctly. To my eyes the edges are more well defined (and the color gradients are better?)
Virus : since I started using quant 20 the problem with the second pass is gone. Lucky me
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Old 5th October 2004, 19:43   #42  |  Link
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is there some "reference" x264 encoding tool (commandline or so) which the x264 devs work on, for being able to differentiate between real x264 bugs and bugs introduced by "x264 wrappers", like ffdshow?
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Old 5th October 2004, 20:41   #43  |  Link
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in the lastest svn sources you have a vfw directory and i think you can built a vfw codec to play with
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Old 5th October 2004, 21:37   #44  |  Link
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Does anyone know of a vfw build available ?
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Old 6th October 2004, 06:12   #45  |  Link
akupenguin
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Quote:
Originally posted by bond
is there some "reference" x264 encoding tool (commandline or so) which the x264 devs work on?
There is a vfw frontend in the x264 subversion repository. However, it hasn't been updated since june and I have no idea if the author is still around. Enough has changed since then that it probably won't even compile as is.

There is also a simple commandline encoder program in svn, which could be considered the reference frontend. It is up to date, but still may contain unnoticed bugs, because (I think) no one uses it for real encodes.

And then there's mencoder, which I base all comparisons on.
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Old 6th October 2004, 06:34   #46  |  Link
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Quote:
Originally posted by virus
I'm glad to see that the in-loop filter has already been made adaptive. At what QP do you switch it off?
By default, it's completely off at QP<=15. (And of course it ramps up smoothly, so there's almost no filtering at QP=16, all the way up to something close to a plain blur at QP=51.)
The deblocking strength options control a QP offset. So a block/frame with QP=25 and deblock{alpha,beta}=-5, gets processed with the filter strengths from QP=20.
("alpha" affects how much change the filter is allowed to cause to any one pixel, "beta" affects the detail threshold. The unimaginative names are copied straight from the H.264 spec.)
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Old 6th October 2004, 20:29   #47  |  Link
bond
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Quote:
Originally posted by akupenguin
There is also a simple commandline encoder program in svn, which could be considered the reference frontend. It is up to date, but still may contain unnoticed bugs, because (I think) no one uses it for real encodes.

And then there's mencoder, which I base all comparisons on.
can anyone make a compile of this than plz?

or would you say that we should use mencoder for testing x264 itself?
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Old 6th October 2004, 23:10   #48  |  Link
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Making the little command line is pretty easy if you have MinGW, MSYS & binutils installed.

Run MSYS, then type

cd c:/x264/build/cygwin #or wherever you unzipped the directory

then type

make

and it should build x264.exe for you.

It only takes raw YUV files I think (though I briefly tested a HuffYUV file renamed *.yuv and it seemed to work).
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Old 7th October 2004, 03:35   #49  |  Link
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Quote:
Originally posted by Bogalvator
It only takes raw YUV files I think (though I briefly tested a HuffYUV file renamed *.yuv and it seemed to work).
Did you look at the output? It takes raw YUV. As in no headers or anything (hence why you have to specify resolution on the commandline). So there's absolutely no way for it to tell whether the input file is actually a YUV video. (Like most unix programs, it ignores the file extestion.) Anything you give it is a valid input, but it will look like random static if it's not in the right format.

And that is the main reason I recommend mencoder instead.

Last edited by akupenguin; 7th October 2004 at 04:05.
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Old 7th October 2004, 05:08   #50  |  Link
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@bond, I put up a build almost a month ago (2004.09.16). Also the last mplayer/mencoder build that I did has x264 enabled. Build is optimised for athlon-xp's though.
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Old 7th October 2004, 19:45   #51  |  Link
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cool stuff! thanks a lot
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Old 9th October 2004, 14:57   #52  |  Link
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So, after almost sinking into several assorted troubles, I've finally completed the PSNR test I started a while ago (look at the corresponding post on page 2 for further details about settings, source, bitrate, ...). I've added some x264 results as well as VP6.2 (sharpness 7, Best quality, "Best PSNR" postprocessing = deblocking only).

VP6.2: 43.76 dB
x264 (more iterations): 43.39 dB
x264 (Qpel on all): 43.35 dB
XviD (HPel): 43.03 dB
XviD (QPel): 42.91 dB
x264 (Hpel): 42.79 dB

finally we can see x264 among the masters
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Old 9th October 2004, 15:36   #53  |  Link
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Well done virus!

Quote:
finally we can see x264 among the masters
if you think how immature x264 is and still can achieve such results

I am curious if we will see an even higher psnr if you decrease the deblock beta to something like -5 or -4.
The image will be sharper (and vp6 has very high sharpness with the chosen options).
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Old 9th October 2004, 20:34   #54  |  Link
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Default deblocking settings were computed to give the best psnr, so I doubt playing with these settings will increase psnr.
Quote:
XviD (HPel): 43.03 dB
XviD (QPel): 42.91 dB
I'm curious, what was the clip you used ?
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Old 9th October 2004, 21:31   #55  |  Link
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I don't know what he used, but I've seen XviD's qpel give up to 0.5 dB worse than hpel, on anime.

And yes, deblock vars = 0 is the optimal setting for PSNR. (maybe +/- 1 for some sources, but you're not going to gain much.) The options are just in case you prefer sharpness or smoothness over mathematical accuracy. (I personally think 0 looks best, too.)
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Old 9th October 2004, 21:37   #56  |  Link
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Quote:
Originally posted by Manao
I'm curious, what was the clip you used ?
It's Ghost Ship DVD (PAL), chapter 3, 1000 frames.
Reasonably clean source. This is a very high motion clip featuring small, detailed sea waves, large near-uniform areas (sky+clouds), a wide range of difficult edges, some closeups on faces, a few underwater detailed frames and even some hardcoded text - all in 40 seconds. My reference clip for high-motion DVD content. The caps on page 2 of this thread can give you an idea.

As for the results with QPel/HPel, I don't know. Maybe with long MVs you have a better chance to have hpel vectors do the job well, without that extra 2 bits/MB. Instead, if you have a low-motion clip with many "static" MBs they may need some small MV like (0.25, 0.25) due to slight camera movements, and thus you may end up with more MBs (on average) which "need" QPel and overall, you can compensate better the MV overhead. But this is really just speculation... I failed to come up with a better explanation

IIRC gruel once said that re-encoding MPEG-2 material - which uses HPel only - can reduce QPel effeciency due to the way MPEG-2 handles subpel interpolation. So maybe on DVDs you simply have a better chance to find a clip where HPel works better than QPel.
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Old 10th October 2004, 01:25   #57  |  Link
akupenguin
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Quote:
Originally posted by virus
IIRC gruel once said that re-encoding MPEG-2 material - which uses HPel only - can reduce QPel effeciency due to the way MPEG-2 handles subpel interpolation. So maybe on DVDs you simply have a better chance to find a clip where HPel works better than QPel.
That too. When re-encoding from a lossy format, you gain PSNR (though not necessarily visual quality) by using a format/setting that reproduces the same artifacts as in the original. One such artifact is quantization of motion vectors.
This effect can be reduced by pp/crop/scale/denoising the video (which you should do anyway, unless you really need to know how well the codecs can accurately reproduce noise).
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Old 10th October 2004, 23:56   #58  |  Link
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It's so good to see that x264 is growing up!
I tried it in ffdshow and it looks nice.
Akupenguin, what do you think about interlaced encoding support?
Can we expect it any time soon? Or this feature have low development priority?
Quote:
Originally posted by celtic_druid
Also the last mplayer/mencoder build that I did has x264 enabled. Build is optimised for athlon-xp's though.
Should this build work for P4 under WinXP?
I am getting this error when I use '-ovc x264':



And other errors when I use another codecs.
It's the first time I am trying mencoder, so I may miss something important about it.
What can be wrong?
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Old 11th October 2004, 02:09   #59  |  Link
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where can i get this codec?
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Old 11th October 2004, 02:11   #60  |  Link
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It's part of FFDShow (VFW) and mplayer (win32/linux).
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