PeerStreamer

/*

 * Generate a header file for hardcoded ff_cos_* tables

 *

 * Copyright (c) 2009 Reimar Döffinger <Reimar.Doeffinger@gmx.de>

 *

 * This file is part of Libav.

 *

 * Libav is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * Libav is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with Libav; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

#include <stdio.h>

#include <string.h>

#include <math.h>

#ifndef M_PI

#define M_PI 3.14159265358979323846

#endif

#define BITS 16

#define FLOATFMT "%.18e"

#define FIXEDFMT "%6d"

static int clip_f15(int v)

{

    return v < -32767 ? -32767 :

           v >  32767 ?  32767 :

           v;

}

static void printval(double val, int fixed)

{

    if (fixed)

        printf(" "FIXEDFMT",", clip_f15(lrint(val * (double)(1<<15))));

    else

        printf(" "FLOATFMT",", val);

}

int main(int argc, char *argv[])

{

    int i, j;

    int do_sin = argc > 1 && !strcmp(argv[1], "sin");

    int fixed  = argc > 2 && !strcmp(argv[2], "fixed");

    double (*func)(double) = do_sin ? sin : cos;

    printf("/* This file was generated by libavcodec/costablegen */\n");

    printf("#define CONFIG_FFT_FLOAT %d\n", !fixed);

    printf("#include \"libavcodec/%s\"\n", do_sin ? "rdft.h" : "fft.h");

    for (i = 4; i <= BITS; i++) {

        int m = 1 << i;

        double freq = 2*M_PI/m;

        printf("%s(%i) = {\n   ", do_sin ? "SINTABLE" : "COSTABLE", m);

        for (j = 0; j < m/2 - 1; j++) {

            int idx = j > m/4 ? m/2 - j : j;

            if (do_sin && j >= m/4)

                idx = m/4 - j;

            printval(func(idx*freq), fixed);

            if ((j & 3) == 3)

                printf("\n   ");

        }

        printval(func(do_sin ? -(m/4 - 1)*freq : freq), fixed);

        printf("\n};\n");

    }

    return 0;

}