[FFmpeg-devel] [PATCH] avfilter: add anoisesrc

[Kyle Swanson]

> +static double pink_filter(double white, double *buf) {
> +    double pink;
> +
> +    /* http://www.musicdsp.org/files/pink.txt */
> +    buf[0] = 0.99886 * buf[0] + white * 0.0555179;
> +    buf[1] = 0.99332 * buf[1] + white * 0.0750759;
> +    buf[2] = 0.96900 * buf[2] + white * 0.1538520;
> +    buf[3] = 0.86650 * buf[3] + white * 0.3104856;
> +    buf[4] = 0.55000 * buf[4] + white * 0.5329522;
> +    buf[5] = -0.7616 * buf[5] - white * 0.0168980;
> +    pink = buf[0] + buf[1] + buf[2] + buf[3] + buf[4] + buf[5] + buf[6] + white * 0.5362;
> +    buf[6] = white * 0.115926;
> +    return pink * 0.11;
> +}
> +
> +static double brown_filter(double white, double *buf) {
> +    double brown;
> +
> +    brown = ((0.02 * white) + buf[0]) / 1.02;
> +    buf[0] = brown;
> +    return brown * 3.5;
> +}

Using a fixed-point sample format also means these filters will need
to be re-done. Anyone know of a good fixed-point filter algorithms for
pink and brown noise?