[FFmpeg-devel] [RFC][PATCHv2] swscale: NEON optimized unscaled rgba to nv12 conversion

Michael Niedermayer michaelni at gmx.at
Mon Dec 9 03:38:35 CET 2013


On Sat, Dec 07, 2013 at 02:42:55PM +0800, Yu Xiaolei wrote:
> On Wed, Dec 4, 2013 at 7:54 PM, Michael Niedermayer <michaelni at gmx.at> wrote:
> > On Wed, Dec 04, 2013 at 02:57:30PM +0800, Yu Xiaolei wrote:
> >> Added copyright headers.
> >>
> >> RGB2YUV coeffs are loaded from SwsContext, but signs are still hardcoded.
> >> If this is not acceptable, I will rewrite it using multiply by scalar
> >> at the cost of several more instructions (widening operations) per
> >> 16x2 block.
> >>
> >
> >> Conversion is done in unsigned 16bit math. There will be rounding
> >> errors compared to c implementation.
> >
> > then SWS_ACCURATE_RND should be checked before using the neon code
> >
> 
> Added 32-bit code path.
> 16-bit code path is rewritten using multiply-by-scalar to allow code
> sharing with 32-bit path.
> As a result signs are no longer hardcoded.
> 
> get_unscaled_swscale_neon will select 16-bit or 32-bit routine based
> on SWS_ACCURATE_RND

i wanted to test it but it seems there are some stray newlines in
the patch

Applying: swscale: NEON optimized unscaled rgba to nv12 conversion
fatal: corrupt patch at line 573


[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Dictatorship naturally arises out of democracy, and the most aggravated
form of tyranny and slavery out of the most extreme liberty. -- Plato
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