[FFmpeg-devel] [RFC] use ff_avc_find_startcode in ff_find_start_code

[Reimar Döffinger]

Hello,
On Tue, Feb 19, 2008 at 04:41:35PM +0100, Michael Niedermayer wrote:
> > 844 dezicycles in A2, 63644 runs, 1892 skips
>                                     ^^^^
> please do something about the skips!

That was because I ran it on the wrong file :-(


> [...]
> > And yes, I remembered to disable speedstep this time.
> 
> Thanks you
> Also please dont run anything else (like mp3 players) while testing
> and provide benchmark scores for 3 runs so we know how much randomnes
> is in there.

Ok, now something hopefully correct, all kinds of combinations tested.
For the matrix test file things are within measurement errors for
overall time.
The higher limit to skip values seems to have pushed it to an advantage
for my code, but I am quite suspicious about the values.
A clear difference for the GXF file, though I admit it is an extremely
stupidly encoded file, so the values there are not worht too much
either.

Greetings,
Reimar D?ffinger
-------------- next part --------------
matrix test file
===============================================
current code:
1207 dezicycles in A2, 32768 runs, 0 skips
1207 dezicycles in A2, 65535 runs, 1 skips
1215 dezicycles in A2, 131068 runs, 4 skips
real    0m34.449s
user    0m34.098s
sys     0m0.292s

1200 dezicycles in A2, 32766 runs, 2 skips
1199 dezicycles in A2, 65532 runs, 4 skips
1210 dezicycles in A2, 131066 runs, 6 skips
real    0m34.698s
user    0m34.010s
sys     0m0.660s

1200 dezicycles in A2, 32768 runs, 0 skips
1202 dezicycles in A2, 65536 runs, 0 skips
1210 dezicycles in A2, 131069 runs, 3 skips
real    0m34.473s
user    0m33.874s
sys     0m0.604s

my code:
1069 dezicycles in A2, 32766 runs, 2 skips
1069 dezicycles in A2, 65532 runs, 4 skips
1065 dezicycles in A2, 131064 runs, 8 skips
real    0m34.659s
user    0m33.974s
sys     0m0.660s

1066 dezicycles in A2, 32768 runs, 0 skips
1064 dezicycles in A2, 65535 runs, 1 skips
1065 dezicycles in A2, 131068 runs, 4 skips
real    0m34.783s
user    0m34.198s
sys     0m0.572s

1078 dezicycles in A2, 32768 runs, 0 skips
1082 dezicycles in A2, 65534 runs, 2 skips
1087 dezicycles in A2, 131067 runs, 5 skips
real    0m34.800s
user    0m34.086s
sys     0m0.676s


GXF file
==============================================
current code:
739 dezicycles in A2, 15912 runs, 472 skips
751 dezicycles in A2, 31825 runs, 943 skips
772 dezicycles in A2, 63646 runs, 1890 skips
real    0m7.271s
user    0m6.944s
sys     0m0.288s

741 dezicycles in A2, 15913 runs, 471 skips
767 dezicycles in A2, 31826 runs, 942 skips
803 dezicycles in A2, 63648 runs, 1888 skips
real    0m7.145s
user    0m6.932s
sys     0m0.212s

742 dezicycles in A2, 15912 runs, 472 skips
753 dezicycles in A2, 31825 runs, 943 skips
766 dezicycles in A2, 63648 runs, 1888 skips
real    0m7.230s
user    0m6.960s
sys     0m0.252s


my code:
855 dezicycles in A2, 15913 runs, 471 skips
843 dezicycles in A2, 31824 runs, 944 skips
842 dezicycles in A2, 63647 runs, 1889 skips
real    0m6.794s
user    0m6.536s
sys     0m0.236s

827 dezicycles in A2, 15913 runs, 471 skips
825 dezicycles in A2, 31825 runs, 943 skips
830 dezicycles in A2, 63648 runs, 1888 skips
real    0m6.788s
user    0m6.560s
sys     0m0.228s

842 dezicycles in A2, 15913 runs, 471 skips
837 dezicycles in A2, 31825 runs, 943 skips
838 dezicycles in A2, 63647 runs, 1889 skips
real    0m6.804s
user    0m6.568s
sys     0m0.216s

GXF with skip detection completely disabled:
==============================================
current:
110465 dezicycles in A2, 16384 runs, 0 skips
109356 dezicycles in A2, 32768 runs, 0 skips
106168 dezicycles in A2, 65536 runs, 0 skips
real    0m7.238s
user    0m6.980s
sys     0m0.252s

110301 dezicycles in A2, 16384 runs, 0 skips
108860 dezicycles in A2, 32768 runs, 0 skips
105526 dezicycles in A2, 65536 runs, 0 skips
real    0m7.164s
user    0m6.960s
sys     0m0.204s

110998 dezicycles in A2, 16384 runs, 0 skips
109815 dezicycles in A2, 32768 runs, 0 skips
106457 dezicycles in A2, 65536 runs, 0 skips
real    0m7.236s
user    0m6.952s
sys     0m0.284s


mine:
44358 dezicycles in A2, 16384 runs, 0 skips
43757 dezicycles in A2, 32768 runs, 0 skips
42462 dezicycles in A2, 65536 runs, 0 skips
real    0m6.804s
user    0m6.492s
sys     0m0.268s

44288 dezicycles in A2, 16384 runs, 0 skips
43672 dezicycles in A2, 32768 runs, 0 skips
42584 dezicycles in A2, 65536 runs, 0 skipsi
real    0m6.817s
user    0m6.524s
sys     0m0.268s

44230 dezicycles in A2, 16384 runs, 0 skips
43777 dezicycles in A2, 32768 runs, 0 skips
42441 dezicycles in A2, 65536 runs, 0 skips
real    0m6.783s
user    0m6.496s
sys     0m0.268s