/***
  This file is part of PulseAudio.

  Copyright 2004-2006 Lennart Poettering
  Copyright 2009 Wim Taymans <wim.taymans@collabora.co.uk.com>

  PulseAudio 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.

  PulseAudio 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
  General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with PulseAudio; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  USA.
***/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <string.h>

#include <pulse/sample.h>
#include <pulsecore/log.h>
#include <pulsecore/macro.h>

#include "remap.h"

static void remap_mono_to_stereo_c(pa_remap_t *m, void *dst, const void *src, unsigned n) {
    unsigned i;

    switch (*m->format) {
        case PA_SAMPLE_FLOAT32NE:
        {
            float *d, *s;

            d = (float *) dst;
            s = (float *) src;

            for (i = n >> 2; i; i--) {
                d[0] = d[1] = s[0];
                d[2] = d[3] = s[1];
                d[4] = d[5] = s[2];
                d[6] = d[7] = s[3];
                s += 4;
                d += 8;
            }
            for (i = n & 3; i; i--) {
                d[0] = d[1] = s[0];
                s++;
                d += 2;
            }
            break;
        }
        case PA_SAMPLE_S16NE:
        {
            int16_t *d, *s;

            d = (int16_t *) dst;
            s = (int16_t *) src;

            for (i = n >> 2; i; i--) {
                d[0] = d[1] = s[0];
                d[2] = d[3] = s[1];
                d[4] = d[5] = s[2];
                d[6] = d[7] = s[3];
                s += 4;
                d += 8;
            }
            for (i = n & 3; i; i--) {
                d[0] = d[1] = s[0];
                s++;
                d += 2;
            }
            break;
        }
        default:
            pa_assert_not_reached();
    }
}

static void remap_channels_matrix_c(pa_remap_t *m, void *dst, const void *src, unsigned n) {
    unsigned oc, ic, i;
    unsigned n_ic, n_oc;

    n_ic = m->i_ss->channels;
    n_oc = m->o_ss->channels;

    switch (*m->format) {
        case PA_SAMPLE_FLOAT32NE:
        {
            float *d, *s;

            memset(dst, 0, n * sizeof(float) * n_oc);

            for (oc = 0; oc < n_oc; oc++) {

                for (ic = 0; ic < n_ic; ic++) {
                    float vol;

                    vol = m->map_table_f[oc][ic];

                    if (vol <= 0.0)
                        continue;

                    d = (float *)dst + oc;
                    s = (float *)src + ic;

                    if (vol >= 1.0) {
                        for (i = n; i > 0; i--, s += n_ic, d += n_oc)
                            *d += *s;
                    } else {
                        for (i = n; i > 0; i--, s += n_ic, d += n_oc)
                            *d += *s * vol;
                    }
                }
            }

            break;
        }
        case PA_SAMPLE_S16NE:
        {
            int16_t *d, *s;

            memset(dst, 0, n * sizeof(int16_t) * n_oc);

            for (oc = 0; oc < n_oc; oc++) {

                for (ic = 0; ic < n_ic; ic++) {
                    int32_t vol;

                    vol = m->map_table_i[oc][ic];

                    if (vol <= 0)
                        continue;

                    d = (int16_t *)dst + oc;
                    s = (int16_t *)src + ic;

                    if (vol >= 0x10000) {
                        for (i = n; i > 0; i--, s += n_ic, d += n_oc)
                            *d += *s;
                    } else {
                        for (i = n; i > 0; i--, s += n_ic, d += n_oc)
                            *d += (int16_t) (((int32_t)*s * vol) >> 16);
                    }
                }
            }
            break;
        }
        default:
            pa_assert_not_reached();
    }
}

/* set the function that will execute the remapping based on the matrices */
static void init_remap_c(pa_remap_t *m) {
    unsigned n_oc, n_ic;

    n_oc = m->o_ss->channels;
    n_ic = m->i_ss->channels;

    /* find some common channel remappings, fall back to full matrix operation. */
    if (n_ic == 1 && n_oc == 2 &&
            m->map_table_f[0][0] >= 1.0 && m->map_table_f[1][0] >= 1.0) {
        m->do_remap = (pa_do_remap_func_t) remap_mono_to_stereo_c;
        pa_log_info("Using mono to stereo remapping");
    } else {
        m->do_remap = (pa_do_remap_func_t) remap_channels_matrix_c;
        pa_log_info("Using generic matrix remapping");
    }
}


/* default C implementation */
static pa_init_remap_func_t remap_func = init_remap_c;

void pa_init_remap(pa_remap_t *m) {
    pa_assert(remap_func);

    m->do_remap = NULL;

    /* call the installed remap init function */
    remap_func(m);

    if (m->do_remap == NULL) {
        /* nothing was installed, fallback to C version */
        init_remap_c(m);
    }
}

pa_init_remap_func_t pa_get_init_remap_func(void) {
    return remap_func;
}

void pa_set_init_remap_func(pa_init_remap_func_t func) {
    remap_func = func;
}