/*  
   XMMS-SID - SIDPlay input plugin for X MultiMedia System (XMMS)

   Audio rate-conversion filter
   
   Programmed and designed by Matti 'ccr' Hamalainen <ccr@tnsp.org>
   (C) Copyright 1999-2007 Tecnic Software productions (TNSP)

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program 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 General Public License along
   with this program; if not, write to the Free Software Foundation, Inc.,
   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "xs_filter.h"

/* Let's do some preprocessor magic :) */
#define XS_FVAR(T, P, K) g ## K ## int ## P *sp_ ## T ## P , *dp_ ## T ## P

#define XS_FILTER1(T, P, K, Q)                            \
    dataSize /= sizeof(g ## K ## int ## P);                 \
    sp_ ## T ## P = (g ## K ## int ## P *) srcBuf;                \
    dp_ ## T ## P = (g ## K ## int ## P *) destBuf;                \
    while (dataSize-- > 0) {                        \
        for (tmp = 0, i = 0; i < oversampleFactor; i++)            \
            tmp += (gint32) ((gint ## P) (*(sp_ ## T ## P ++) Q));    \
        xs_filter_mbn = (tmp + xs_filter_mbn) / (oversampleFactor + 1);    \
        *(dp_ ## T ## P ++) = ((g ## K ## int ## P) xs_filter_mbn) Q ;    \
        }


static gint32 xs_filter_mbn = 0;


gint xs_filter_rateconv(void *destBuf, void *srcBuf, const AFormat audioFormat,
            const gint oversampleFactor, const gint bufSize)
{
    static gint32 tmp;
    XS_FVAR(s, 8,);
    XS_FVAR(u, 8, u);
    XS_FVAR(s, 16,);
    XS_FVAR(u, 16, u);
    gint i;
    gint dataSize = bufSize;

    if (dataSize <= 0)
        return dataSize;

    switch (audioFormat) {
    case FMT_U8:
        XS_FILTER1(u, 8, u, ^0x80)
            break;

    case FMT_S8:
        XS_FILTER1(s, 8,,)
            break;


    case FMT_U16_BE:
    case FMT_U16_LE:
    case FMT_U16_NE:
        XS_FILTER1(u, 16, u, ^0x8000)
            break;

    case FMT_S16_BE:
    case FMT_S16_LE:
    case FMT_S16_NE:
        XS_FILTER1(s, 16,,)
            break;

    default:
        return -1;
    }

    return 0;
}