[FFmpeg-devel] [PATCH] up VOFW in swscale?

Andreas Öman andreas
Sat Apr 4 10:01:54 CEST 2009

M?ns Rullg?rd wrote:
> Andreas ?man <andreas at lonelycoder.com> writes:
>> Michael Niedermayer wrote:
>>> On Wed, Apr 01, 2009 at 11:59:46PM +0200, Andreas ?man wrote:
>>>> Michael Niedermayer wrote:
>>>>> On Wed, Apr 01, 2009 at 09:28:46PM +0200, Andreas ?man wrote:
>>>>>> Hi
>>>>>> I use the scaler to rescale photos (>2048 pixels wide) in my
>>>>>> application.
>>>>>> With the old scaler this was not a problem but nowadays it
>>>>>> no longer works since the maximum width is limited to 2048 pix.
>>>>>> Therefore I propose we up this to 4096.
>>>>> can post some benchmarks with a CPU with small cache and a low resolution
>>>>> video?
>>>> Interesting exercise. Seems that increasing it to 4096 causes more
>>>> cache aliasing. However, increasing it to 5120 makes it faster than
>>>> the original code.
>>> looks  good so far but i still would like to see benchmarks from one
>>> or 2
>>> other cpus, at least one (non P4) intel
>> This is on a:
>> Intel(R) Core(TM)2 CPU          6600  @ 2.40GHz
>> I wouldn't say it's much of a difference on that one.
>> I don't have access to any non-x86 platforms of significance.
> You can have a login on my ppc if you like.

cpu             : 7455, altivec supported
clock           : 866.666664MHz
L2 cache        : 256K unified

Slightly more than a 1% slowdown.
I've tried various other offsets (also sub-pagesize) and it seems to
yield about the same result.

I guess this pretty much call it off, or?

user    11m46.620s
user    11m49.484s
user    11m47.932s
user    11m49.304s
user    11m49.680s

user    11m59.636s
user    11m56.500s
user    11m58.568s
user    11m56.580s
user    11m58.152s

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