[FFmpeg-devel] [Updated PATCH 3/3] vc-1: Optimise parser (with special attention to ARM)

[Michael Niedermayer]

On Wed, Apr 23, 2014 at 02:59:19PM +0100, Ben Avison wrote:
> On Wed, 23 Apr 2014 03:26:22 +0100, Michael Niedermayer <michaelni at gmx.at> wrote:
> >is it faster to do all the steps intermingled ?
> >iam asking because the code should be simpler if it just uses
> >the optimized start code search and optimized header parsing
> >while maintaining the current structure
> >
> >for example the header parsing could be optmized like below:
> 
> OK, I've tried out your patch, and I also tried converting the start code
> searches in find_next_marker and vc1_find_frame_end to use the fast
> search function. The times (filtered to include only VC-1 functions) look
> like this:
> 
>       Before        MN version    MN + fast search  BA version
> M2TS  250.0 ± 11.2  160.9 ±  7.3  47.6 ± 9.0        27.2 ± 3.4
> MKV   149.0 ± 12.8   70.8 ± 11.2  17.6 ± 4.7         1.7 ± 0.8
> 
> In other words, yes there still seems to be a significant speed
> improvement from mixing the steps together. I suspect this comes down to
> the fact that the buffers that are used with real-world streams tend to
> bigger than even the L2 cache on the ARM11.

ok, then your solution is better

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

You can kill me, but you cannot change the truth.
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