[Ffmpeg-devel] Re: [PATCH] h264 - loopify some get_cabac calls

Alexander Strange astrange
Fri Apr 20 04:30:55 CEST 2007


On Apr 19, 2007, at 10:05 PM, Trent Piepho wrote:

> On Thu, 19 Apr 2007, Alexander Strange wrote:
>> I finally found the time to look through the rest of the benchmarks I
>> did for this:
> [...]
>> faculty.vassar.edu/lowry/wilcoxon.html:
>> z = 2.78 / p = .0027 (95% significant)
>> z = 2.47 / p = .0068 (same)
>>
>> I don't think this is quite true, since the numbers are running
>> averages and not individual samples, but without std. deviations it's
>> the best I can do.
>
> Since you just have just one run, you can't do any kind of
> statistical analysis.  Using a running average at different
> points as if they were independent observations is completely
> invalid.

What did you do earlier in the thread?

> Why are there so many skips?

It skips once whenever it handles a skip macroblock. Probably it  
should skip START_TIMER as well, but I did it a while ago and the  
numbers should be the same.

I don't like benchmarking this way at all. I wonder if there are any  
x86 simulators as good as simg4/simg5 for PPC.





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