[FFmpeg-devel] [PATCH] all: use predefined mathematics macros

[Clément Bœsch]

On Tue, Nov 10, 2015 at 10:35:23PM -0500, Ganesh Ajjanagadde wrote:
> This uses M_SQRT2, M_PI, and M_E instead of the actual literals.
> Benefits include:
> 1. Reduced scope for copy/paste errors and improved readability.
> 2. Consistency across the codebase.
> 3. Actually fixes an incorrect sqrt(2) in avcodec/ppc.
> 4. Greater precision in avcodec/ac3.
> 
> Patch tested with FATE on x86, ppc untested.
> 
> Signed-off-by: Ganesh Ajjanagadde <gajjanagadde at gmail.com>
> ---
>  libavcodec/ac3.h                   |  2 +-
>  libavcodec/cos_tablegen.c          |  4 +++-
>  libavcodec/mpegaudioenc_template.c |  4 ++--
>  libavcodec/mpegaudiotab.h          |  2 --
>  libavcodec/mpegvideo.c             |  4 ++--
>  libavcodec/ppc/fdctdsp.c           | 21 ++++++++++-----------
>  libavcodec/ratecontrol.c           |  4 ----
>  libavcodec/simple_idct.c           |  4 ++--
>  libavfilter/af_dynaudnorm.c        |  4 +---
>  9 files changed, 21 insertions(+), 28 deletions(-)
> 
> diff --git a/libavcodec/ac3.h b/libavcodec/ac3.h
> index 3f67e09..4dc7373 100644
> --- a/libavcodec/ac3.h
> +++ b/libavcodec/ac3.h
> @@ -100,7 +100,7 @@
>  #define AC3_LEVEL(x)            ROUND15((x) * FIXR15(0.7071067811865476))
>  
>  /* pre-defined gain values */
> -#define LEVEL_PLUS_3DB          1.4142135623730950
> +#define LEVEL_PLUS_3DB          M_SQRT2
>  #define LEVEL_PLUS_1POINT5DB    1.1892071150027209
>  #define LEVEL_MINUS_1POINT5DB   0.8408964152537145

>  #define LEVEL_MINUS_3DB         0.7071067811865476

M_SQRT1_2?

[...]

-- 
Clément B.
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