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

   Audio rate-conversion filter
   
   Written by Matti "ccr" Hamalainen <ccr@tnsp.org>

   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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include "xmms-sid.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)							\
	dataSize /= sizeof(g ## K ## int ## P); tmpo_ ## T = 0;			\
	sp_ ## T ## P = (g ## K ## int ## P *) srcBuf;				\
	dp_ ## T ## P = (g ## K ## int ## P *) destBuf;				\
	while (dataSize-- > 0) {						\
		for (tmp_ ## T = 0, i = 0; i < oversampleFactor; i++)		\
			tmp_ ## T += *(sp_ ## T ## P ++);			\
		tmpo_ ## T = (tmp_ ## T + tmpo_ ## T ) / (oversampleFactor * 2);	\
		*(dp_ ## T ## P ++) = tmpo_ ## T;				\
		}

gint xs_rateconv_filter(void *destBuf, void *srcBuf, AFormat audioFormat, gint oversampleFactor, gint dataSize)
{
 guint32 tmp_u, tmpo_u;
 gint32 tmp_s, tmpo_s;
 XS_FVAR(u, 8, u);
 XS_FVAR(s, 8,);
 XS_FVAR(u, 16, u);
 XS_FVAR(s, 16,);
 gint i;
 
 if (dataSize <= 0)
 	return dataSize;

 switch (audioFormat) {
 case FMT_U8:
 case FMT_S8:
 	XS_FILTER1(s, 8,);
 	break;
 	

 case FMT_U16_BE:
 case FMT_U16_LE:
 case FMT_U16_NE:
 	
 case FMT_S16_BE:
 case FMT_S16_LE:
 case FMT_S16_NE:
 	XS_FILTER1(s, 16,);
 	break;

 default:
 	return -1;
 }

 return 0;
}