[x264-devel] Re: Speed Issue

[Xiaojie Huang]

--- Loren Merritt <lorenm at u.washington.edu> wrote:

> On Thu, 14 Oct 2004, Xiaojie Huang wrote:
> My benchmark: 1.5% faster. ymmv.
> 
> $> time ./mencoder-r50 -ovc x264 -x264encopts
> qp_constant=20:subq=1:frameref=1:cabac in.avi
> x264 [info]: analyse=64(44362ms) encode=16(11600ms)
> write=9(6812ms) filter=8(5900ms)
> x264 [info]: slice I:25   Avg size:19203
> x264 [info]: slice P:1405 Avg size:5874
> x264 [info]: slice I      Avg I4x4:521   I16x16:444 
> x264 [info]: slice P      Avg I4x4:72    I16x16:104 
>  P:275   P8x8:31    PSKIP:481 
> x264 [info]: kb/s:1171.5 fps:19.880
> 86.770u 1.780s 1:29.84 98.5%    0+0k 0+0io 2669pf+0w
> 
> $> time ./mencoder-xia -ovc x264 -x264encopts
> qp_constant=20:subq=1:frameref=1:cabac in.avi
> x264 [info]: analyse=65(44144ms) encode=15(10708ms)
> write=9(6711ms) filter=8(5878ms)
> x264 [info]: slice I:25   Avg size:19203
> x264 [info]: slice P:1405 Avg size:5874
> x264 [info]: slice I      Avg I4x4:521   I16x16:444 
> x264 [info]: slice P      Avg I4x4:72    I16x16:104 
>  P:275   P8x8:31    PSKIP:481 
> x264 [info]: kb/s:1171.5 fps:20.204
> 85.670u 1.830s 1:28.19 99.2%    0+0k 0+0io 2662pf+0w
Encoding speed denpends on many parameters including
the test sequence, QP, GOP structure, etc.
Just for Intra coding, the following is the test
result.
For example: on P4 2.3G CPU, 256M
parameter: x264 -i 1 -o mobile-x264.264 mobile.cif
352x288
The original: 26.33 fps
The modification: 29.50 fps
The gain is 12%
 
> I think a better / more general way would be to
> combine the analyse and 
> encode functions. This would also be required for a
> rate/distortion MB 
> type decision (which I am trying to implement).
Yes, there are many operations which can be merged to
avoid extra computations.

Xiaojie Huang
 


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