[FFmpeg-devel] [PATCH] avfilter/vf_colorkey: Add colorkey video filter

[Michael Niedermayer]

On Sun, Apr 19, 2015 at 06:15:48PM +0200, Timo Rothenpieler wrote:
[...]
> +#define SATURATE(val) (FFMAX(FFMIN((val), 1.0), 0.0))
> +
> +static uint8_t do_colorkey_pixel(ColorkeyContext *ctx, uint8_t r, uint8_t g, uint8_t b)
> +{
> +    float diff_r = r / 255.0 - ctx->cf[0];
> +    float diff_g = g / 255.0 - ctx->cf[1];
> +    float diff_b = b / 255.0 - ctx->cf[2];
> +
> +    float diff = sqrt(diff_r * diff_r + diff_g * diff_g + diff_b * diff_b);
> +
> +    return SATURATE(FFMAX(diff - ctx->similarity, 0.0) / ctx->blend) * 255.0;


i suggest you factor the 255.0 out
like in

> +#define SATURATE(val) (FFMAX(FFMIN((val), 255.0), 0.0))
> +
> +static uint8_t do_colorkey_pixel(ColorkeyContext *ctx, uint8_t r, uint8_t g, uint8_t b)
> +{
> +    float diff_r = r - ctx->cf[0];
> +    float diff_g = g - ctx->cf[1];
> +    float diff_b = b - ctx->cf[2];
> +
> +    float diff = sqrt(diff_r * diff_r + diff_g * diff_g + diff_b * diff_b);
> +
> +    return SATURATE(FFMAX(diff - ctx->similarity, 0.0) / ctx->blend);

this changes the units of all the used "constants"

[...]
-- 
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