[FFmpeg-devel] [PATCH] avfilter: add firequalizer filter

[Paul B Mahol]

> +        center = s->fir_len / 2;
> +
> +        for (k = 0; k <= center; k++) {
> +            double u = k * (M_PI/center);
> +            double win;
> +            switch (s->wfunc) {
> +            case WFUNC_RECTANGULAR:
> +                win = 1.0;
> +                break;
> +            case WFUNC_HANN:
> +                win = 0.5 + 0.5 * cos(u);
> +                break;
> +            case WFUNC_HAMMING:
> +                win = 0.53836 + 0.46164 * cos(u);
> +                break;
> +            case WFUNC_BLACKMAN:
> +                win = 0.48 + 0.5 * cos(u) + 0.02 * cos(2*u);
> +                break;
> +            case WFUNC_NUTTALL3:
> +                win = 0.40897 + 0.5 * cos(u) + 0.09103 * cos(2*u);
> +                break;
> +            case WFUNC_MNUTTALL3:
> +                win = 0.4243801 + 0.4973406 * cos(u) + 0.0782793 * cos(2*u);
> +                break;
> +            case WFUNC_NUTTALL:
> +                win = 0.355768 + 0.487396 * cos(u) + 0.144232 * cos(2*u) + 0.012604 * cos(3*u);
> +                break;
> +            case WFUNC_BNUTTALL:
> +                win = 0.3635819 + 0.4891775 * cos(u) + 0.1365995 * cos(2*u) + 0.0106411 * cos(3*u);
> +                break;
> +            case WFUNC_BHARRIS:
> +                win = 0.35875 + 0.48829 * cos(u) + 0.14128 * cos(2*u) + 0.01168 * cos(3*u);
> +                break;

What about using libavfilter/window_func.c ?

Still LGTM.