[MEncoder-users] x264 file playback is too slow!

Jeff Clagg snacky at ikaruga.co.uk
Thu Mar 23 02:27:25 CET 2006

On Wed, Mar 22, 2006 at 11:36:36AM -0800, some one wrote:
> Hi, I'm running debian sid @ P4 2,3 GHz CPU.
> I encoded a raw DV file to x264 using the following command:
> mencoder -ovc x264 -oac mp3lame -aspect 4/3 -x264encopts subq=6:4x4mv:8x8dct:me=3:frameref=5:bframes=3:b_pyramid:weight_b -lameopts q=0:preset=insane -vf pp=ci -o mencoder.mp4 dvgrab-001.dv
> Now when I try to play the file with mplayer, it's too slow and I get this message:
>            ************************************************
>            **** Your system is too SLOW to play this!  ****
>            ************************************************

This is sort of a FAQ. H.264 decoding is at least several times
slower than most other stuff you're used to.  You just have to deal
with it. Downscaling helps. So does reducing the bitrate, and either
don't set qcomp extremely high, or (probably worse quality) set some
vbv_maxrate that you can handle. Other than that, your best option is
to just use another codec.

The only option you're using that might have a significant impact on
speed is 4x4mv. But it will still have only a very small effect. You can
disable CABAC, but then I doubt x264 will be more efficient than xvid or
lavc's mpeg4, and it'll still be much slower than either of them.

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