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/*
* Copyright (C) 2000 the xine project
*
* This file is part of xine, a unix video player.
*
* xine 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.
*
* xine 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
*
* $Id: resample.c,v 1.1 2001/04/24 20:53:00 f1rmb Exp $
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <inttypes.h>
/* contributed by paul flinders */
void audio_out_resample_stereo(int16_t* input_samples, uint32_t in_samples,
int16_t* output_samples, uint32_t out_samples)
{
int osample;
/* 16+16 fixed point math */
uint32_t isample = 0;
uint32_t istep = (in_samples << 16)/out_samples;
#ifdef VERBOSE
printf ("Audio : resample %d samples to %d\n",
in_samples, out_samples);
#endif
for (osample = 0; osample < out_samples - 1; osample++) {
int s1;
int s2;
int16_t os;
uint32_t t = isample&0xffff;
/* don't "optimize" the (isample >> 16)*2 to (isample >> 15) */
s1 = input_samples[(isample >> 16)*2];
s2 = input_samples[(isample >> 16)*2+2];
os = (s1 * (0x10000-t)+ s2 * t) >> 16;
output_samples[osample * 2] = os;
s1 = input_samples[(isample >> 16)*2+1];
s2 = input_samples[(isample >> 16)*2+3];
os = (s1 * (0x10000-t)+ s2 * t) >> 16;
output_samples[(osample * 2 )+1] = os;
isample += istep;
}
output_samples[out_samples*2-2] = input_samples[in_samples*2-2];
output_samples[out_samples*2-1] = input_samples[in_samples*2-1];
}
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