[x264-devel] Stuttering Of Panning Scenes

[Quentin Jackson]

Oh OK then, perhaps this is a great place to start.  When encoding a dvd
to 264 (I used the h264enc script) I ALWAYS get stuttering during
panning scenes (or some motion scenes) on playback.  It is not the kind
of stuttering that you would expect when your CPU is lagged (I've
checked that anyway I'm not even using 10% of one core of a quad cpu),
it's more of a tearing look, though it isn't that either, it's
definitely related to the encoding.  What I mean is if the camera is
flowing from left to right while recording a scenery shot, the 'pan'
will not be smooth and visually looks stutterish (a bit like a slow LCD
monitor watching sports).  I have researched this on the web and while
there are quite a few people experiencing it, there doesn't appear to be
a fix that I can see.  Suggestions have in forums been mostly centred
around hardware which I'm sure is not the problem for me.  It COULD be a
playback issue and not an encoding issue, but I don't believe so since
other encodings in xvid I have received do not experience this issue (or
if they do it is not noticeable).  It could be a mencoder issue and not
a 264 issue, though I'm not sure and am hoping for some guidance on that
from this list.

I am running OpenSuSE 11 (though have run various other flavours with
same result) and compile all the codecs and libraries, mplayer etc from
source.  I've tried different versions of 264 codec and mplayer with no
difference.  This is not a random application starting up and hogging
CPU or anything while watching).

Would someone be able to say absolutely that they have or haven't seen
this particular problem occur with x264?  Or that it will definately be
a mplayer problem because of x reason?  Or perhaps offer some
suggestions to help pin it down, it's the only thing making 264 not an
absolutely perfect encoder for me! :)

The command I'm currently using in mencoder is as below:

First pass options
~~~~~~~~~~~~~~~~~~
mencoder "dvd://1" -o /dev/null -dvd-device /home/quentinj/ISO/S.ISO -vf
crop=720:560:0:8,softskip,harddup -aid 128 -channels 6 -oac copy -ovc
x264 -x264encopts
pass=1:bitrate=1000:turbo=2:me=umh:me_range=24:me_prepass:nodct_decimate:nointerlaced:8x8dct:nofast_pskip:trellis=1:partitions=p8x8,b8x8,i8x8,i4x4:mixed_refs:bime:keyint=250:keyint_min=25:frameref=4:bframes=16:b_adapt:b_pyramid:weight_b:direct_pred=auto:subq=6:brdo:chroma_me:cabac:aq_strength=0.5:deblock=0,0:nossim:nopsnr:threads=auto -passlogfile /home/quentinj/.h264enc/h264enc.0rX1F0LW/h264.log

Second pass options
~~~~~~~~~~~~~~~~~~~
mencoder "dvd://1" -o "/home/quentinj/s.avi"
-dvd-device /home/quentinj/ISO/S.ISO -vf
crop=720:560:0:8,softskip,harddup -aid 128 -channels 6 -oac copy -ovc
x264 -x264encopts
pass=2:bitrate=1000:me=umh:me_range=24:me_prepass:nodct_decimate:nointerlaced:8x8dct:nofast_pskip:trellis=1:partitions=p8x8,b8x8,i8x8,i4x4:mixed_refs:keyint=250:keyint_min=25:frameref=4:bframes=16:bime:b_adapt:b_pyramid:weight_b:direct_pred=auto:subq=6:brdo:chroma_me:cabac:aq_strength=0.5:deblock=0,0:nossim:nopsnr:threads=auto -passlogfile /home/quentinj/.h264enc/h264enc.0rX1F0LW/h264.log

Thanks,

Q

-----Original Message-----
From: x264-devel-request at videolan.org
Reply-To: x264-devel at videolan.org
To: x264-devel at videolan.org
Subject: x264-devel Digest, Vol 14, Issue 6
Date: Sat, 05 Jul 2008 12:00:03 +0200


Message: 1
Date: Fri, 4 Jul 2008 11:31:25 -0600
From: "Jason Garrett-Glaser" <darkshikari at gmail.com>
Subject: Re: [x264-devel] Stuttering of panning scenes
To: "Mailing list for x264 developers" <x264-devel at videolan.org>
Message-ID:
        <28f2fcbc0807041031j345e4c6x439e0deb02399e3a at mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1

2008/7/4 Quentin Jackson <Quentin.Jackson at exclamation.co.nz>:
> I'm sure this must have been brought up before, but I can't find
anything so
> am trying here
>
> I'm sure you have all seen the stuttering of encodings during panning
> scenes, and seemingly a lot of motion scenes.

I have no idea what you're talking about, so you're wrongly sure ;)

Dark Shikari

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