src/audio/SDL_audiocvt.c
author Sam Lantinga <slouken@libsdl.org>
Mon, 13 Dec 2004 08:49:17 +0000
changeset 1011 4095d9ca23f2
parent 942 41a59de7f2ed
child 1312 c9b51268668f
permissions -rw-r--r--
*** empty log message ***
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/*
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    SDL - Simple DirectMedia Layer
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    Copyright (C) 1997-2004 Sam Lantinga
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    This library is free software; you can redistribute it and/or
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    modify it under the terms of the GNU Library General Public
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    License as published by the Free Software Foundation; either
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    version 2 of the License, or (at your option) any later version.
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    This library is distributed in the hope that it will be useful,
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    but WITHOUT ANY WARRANTY; without even the implied warranty of
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    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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    Library General Public License for more details.
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    You should have received a copy of the GNU Library General Public
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    License along with this library; if not, write to the Free
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    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
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    Sam Lantinga
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    slouken@libsdl.org
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*/
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#ifdef SAVE_RCSID
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static char rcsid =
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 "@(#) $Id$";
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#endif
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/* Functions for audio drivers to perform runtime conversion of audio format */
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#include <stdio.h>
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#include "SDL_error.h"
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#include "SDL_audio.h"
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/* Effectively mix right and left channels into a single channel */
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void SDL_ConvertMono(SDL_AudioCVT *cvt, Uint16 format)
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{
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	int i;
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	Sint32 sample;
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#ifdef DEBUG_CONVERT
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	fprintf(stderr, "Converting to mono\n");
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#endif
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	switch (format&0x8018) {
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		case AUDIO_U8: {
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			Uint8 *src, *dst;
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			src = cvt->buf;
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			dst = cvt->buf;
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			for ( i=cvt->len_cvt/2; i; --i ) {
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				sample = src[0] + src[1];
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				if ( sample > 255 ) {
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					*dst = 255;
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				} else {
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					*dst = sample;
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				}
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				src += 2;
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				dst += 1;
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			}
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		}
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		break;
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		case AUDIO_S8: {
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			Sint8 *src, *dst;
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			src = (Sint8 *)cvt->buf;
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			dst = (Sint8 *)cvt->buf;
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			for ( i=cvt->len_cvt/2; i; --i ) {
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				sample = src[0] + src[1];
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				if ( sample > 127 ) {
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					*dst = 127;
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				} else
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				if ( sample < -128 ) {
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					*dst = -128;
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				} else {
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					*dst = sample;
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				}
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				src += 2;
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				dst += 1;
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			}
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		}
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		break;
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		case AUDIO_U16: {
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			Uint8 *src, *dst;
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			src = cvt->buf;
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			dst = cvt->buf;
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			if ( (format & 0x1000) == 0x1000 ) {
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				for ( i=cvt->len_cvt/4; i; --i ) {
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					sample = (Uint16)((src[0]<<8)|src[1])+
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					         (Uint16)((src[2]<<8)|src[3]);
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					if ( sample > 65535 ) {
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						dst[0] = 0xFF;
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						dst[1] = 0xFF;
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					} else {
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						dst[1] = (sample&0xFF);
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						sample >>= 8;
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						dst[0] = (sample&0xFF);
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					}
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					src += 4;
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					dst += 2;
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				}
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			} else {
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				for ( i=cvt->len_cvt/4; i; --i ) {
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					sample = (Uint16)((src[1]<<8)|src[0])+
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					         (Uint16)((src[3]<<8)|src[2]);
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					if ( sample > 65535 ) {
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						dst[0] = 0xFF;
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						dst[1] = 0xFF;
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					} else {
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						dst[0] = (sample&0xFF);
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						sample >>= 8;
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						dst[1] = (sample&0xFF);
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					}
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					src += 4;
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					dst += 2;
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				}
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			}
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		}
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		break;
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		case AUDIO_S16: {
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			Uint8 *src, *dst;
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			src = cvt->buf;
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			dst = cvt->buf;
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			if ( (format & 0x1000) == 0x1000 ) {
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				for ( i=cvt->len_cvt/4; i; --i ) {
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					sample = (Sint16)((src[0]<<8)|src[1])+
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					         (Sint16)((src[2]<<8)|src[3]);
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					if ( sample > 32767 ) {
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						dst[0] = 0x7F;
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						dst[1] = 0xFF;
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					} else
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					if ( sample < -32768 ) {
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						dst[0] = 0x80;
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						dst[1] = 0x00;
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					} else {
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						dst[1] = (sample&0xFF);
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						sample >>= 8;
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						dst[0] = (sample&0xFF);
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					}
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					src += 4;
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					dst += 2;
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				}
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			} else {
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				for ( i=cvt->len_cvt/4; i; --i ) {
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					sample = (Sint16)((src[1]<<8)|src[0])+
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					         (Sint16)((src[3]<<8)|src[2]);
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					if ( sample > 32767 ) {
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						dst[1] = 0x7F;
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						dst[0] = 0xFF;
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					} else
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					if ( sample < -32768 ) {
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						dst[1] = 0x80;
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						dst[0] = 0x00;
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					} else {
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						dst[0] = (sample&0xFF);
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						sample >>= 8;
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						dst[1] = (sample&0xFF);
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					}
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					src += 4;
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					dst += 2;
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				}
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			}
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		}
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		break;
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	}
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	cvt->len_cvt /= 2;
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	if ( cvt->filters[++cvt->filter_index] ) {
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		cvt->filters[cvt->filter_index](cvt, format);
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	}
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}
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/* Discard top 4 channels */
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void SDL_ConvertStrip(SDL_AudioCVT *cvt, Uint16 format)
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{
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	int i;
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	Sint32 lsample, rsample;
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#ifdef DEBUG_CONVERT
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	fprintf(stderr, "Converting down to stereo\n");
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#endif
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	switch (format&0x8018) {
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		case AUDIO_U8: {
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			Uint8 *src, *dst;
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			src = cvt->buf;
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			dst = cvt->buf;
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			for ( i=cvt->len_cvt/6; i; --i ) {
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				lsample = src[0];
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				rsample = src[1];
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				dst[0] = lsample;
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				dst[1] = rsample;
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				src += 6;
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				dst += 2;
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			}
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		}
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		break;
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		case AUDIO_S8: {
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			Sint8 *src, *dst;
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			src = (Sint8 *)cvt->buf;
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			dst = (Sint8 *)cvt->buf;
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			for ( i=cvt->len_cvt/6; i; --i ) {
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				lsample = src[0];
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				rsample = src[1];
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				dst[0] = lsample;
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				dst[1] = rsample;
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				src += 6;
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				dst += 2;
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			}
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		}
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		break;
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		case AUDIO_U16: {
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			Uint8 *src, *dst;
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			src = cvt->buf;
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			dst = cvt->buf;
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			if ( (format & 0x1000) == 0x1000 ) {
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				for ( i=cvt->len_cvt/12; i; --i ) {
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					lsample = (Uint16)((src[0]<<8)|src[1]);
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					rsample = (Uint16)((src[2]<<8)|src[3]);
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						dst[1] = (lsample&0xFF);
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						lsample >>= 8;
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						dst[0] = (lsample&0xFF);
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						dst[3] = (rsample&0xFF);
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						rsample >>= 8;
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						dst[2] = (rsample&0xFF);
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					src += 12;
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					dst += 4;
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				}
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			} else {
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				for ( i=cvt->len_cvt/12; i; --i ) {
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					lsample = (Uint16)((src[1]<<8)|src[0]);
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					rsample = (Uint16)((src[3]<<8)|src[2]);
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						dst[0] = (lsample&0xFF);
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						lsample >>= 8;
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						dst[1] = (lsample&0xFF);
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						dst[2] = (rsample&0xFF);
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						rsample >>= 8;
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						dst[3] = (rsample&0xFF);
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					src += 12;
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					dst += 4;
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				}
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			}
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		}
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		break;
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		case AUDIO_S16: {
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			Uint8 *src, *dst;
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			src = cvt->buf;
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			dst = cvt->buf;
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			if ( (format & 0x1000) == 0x1000 ) {
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				for ( i=cvt->len_cvt/12; i; --i ) {
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					lsample = (Sint16)((src[0]<<8)|src[1]);
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					rsample = (Sint16)((src[2]<<8)|src[3]);
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						dst[1] = (lsample&0xFF);
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						lsample >>= 8;
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						dst[0] = (lsample&0xFF);
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						dst[3] = (rsample&0xFF);
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						rsample >>= 8;
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						dst[2] = (rsample&0xFF);
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					src += 12;
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					dst += 4;
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				}
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			} else {
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				for ( i=cvt->len_cvt/12; i; --i ) {
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					lsample = (Sint16)((src[1]<<8)|src[0]);
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					rsample = (Sint16)((src[3]<<8)|src[2]);
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						dst[0] = (lsample&0xFF);
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						lsample >>= 8;
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						dst[1] = (lsample&0xFF);
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						dst[2] = (rsample&0xFF);
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						rsample >>= 8;
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						dst[3] = (rsample&0xFF);
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					src += 12;
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					dst += 4;
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				}
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			}
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		}
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		break;
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	}
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	cvt->len_cvt /= 3;
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	if ( cvt->filters[++cvt->filter_index] ) {
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		cvt->filters[cvt->filter_index](cvt, format);
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	}
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}
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/* Discard top 2 channels of 6 */
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void SDL_ConvertStrip_2(SDL_AudioCVT *cvt, Uint16 format)
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{
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	int i;
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	Sint32 lsample, rsample;
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#ifdef DEBUG_CONVERT
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	fprintf(stderr, "Converting 6 down to quad\n");
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#endif
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	switch (format&0x8018) {
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		case AUDIO_U8: {
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			Uint8 *src, *dst;
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			src = cvt->buf;
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			dst = cvt->buf;
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			for ( i=cvt->len_cvt/4; i; --i ) {
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				lsample = src[0];
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				rsample = src[1];
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				dst[0] = lsample;
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				dst[1] = rsample;
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				src += 4;
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				dst += 2;
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			}
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		}
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		break;
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   324
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   325
		case AUDIO_S8: {
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			Sint8 *src, *dst;
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			src = (Sint8 *)cvt->buf;
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			dst = (Sint8 *)cvt->buf;
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			for ( i=cvt->len_cvt/4; i; --i ) {
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				lsample = src[0];
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				rsample = src[1];
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				dst[0] = lsample;
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				dst[1] = rsample;
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   335
				src += 4;
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   336
				dst += 2;
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   337
			}
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   338
		}
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   339
		break;
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   340
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   341
		case AUDIO_U16: {
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			Uint8 *src, *dst;
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   343
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			src = cvt->buf;
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   345
			dst = cvt->buf;
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   346
			if ( (format & 0x1000) == 0x1000 ) {
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				for ( i=cvt->len_cvt/8; i; --i ) {
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					lsample = (Uint16)((src[0]<<8)|src[1]);
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   349
					rsample = (Uint16)((src[2]<<8)|src[3]);
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   350
						dst[1] = (lsample&0xFF);
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   351
						lsample >>= 8;
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   352
						dst[0] = (lsample&0xFF);
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   353
						dst[3] = (rsample&0xFF);
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   354
						rsample >>= 8;
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   355
						dst[2] = (rsample&0xFF);
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   356
					src += 8;
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   357
					dst += 4;
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   358
				}
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   359
			} else {
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   360
				for ( i=cvt->len_cvt/8; i; --i ) {
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   361
					lsample = (Uint16)((src[1]<<8)|src[0]);
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   362
					rsample = (Uint16)((src[3]<<8)|src[2]);
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   363
						dst[0] = (lsample&0xFF);
slouken@942
   364
						lsample >>= 8;
slouken@942
   365
						dst[1] = (lsample&0xFF);
slouken@942
   366
						dst[2] = (rsample&0xFF);
slouken@942
   367
						rsample >>= 8;
slouken@942
   368
						dst[3] = (rsample&0xFF);
slouken@942
   369
					src += 8;
slouken@942
   370
					dst += 4;
slouken@942
   371
				}
slouken@942
   372
			}
slouken@942
   373
		}
slouken@942
   374
		break;
slouken@942
   375
slouken@942
   376
		case AUDIO_S16: {
slouken@942
   377
			Uint8 *src, *dst;
slouken@942
   378
slouken@942
   379
			src = cvt->buf;
slouken@942
   380
			dst = cvt->buf;
slouken@942
   381
			if ( (format & 0x1000) == 0x1000 ) {
slouken@942
   382
				for ( i=cvt->len_cvt/8; i; --i ) {
slouken@942
   383
					lsample = (Sint16)((src[0]<<8)|src[1]);
slouken@942
   384
					rsample = (Sint16)((src[2]<<8)|src[3]);
slouken@942
   385
						dst[1] = (lsample&0xFF);
slouken@942
   386
						lsample >>= 8;
slouken@942
   387
						dst[0] = (lsample&0xFF);
slouken@942
   388
						dst[3] = (rsample&0xFF);
slouken@942
   389
						rsample >>= 8;
slouken@942
   390
						dst[2] = (rsample&0xFF);
slouken@942
   391
					src += 8;
slouken@942
   392
					dst += 4;
slouken@942
   393
				}
slouken@942
   394
			} else {
slouken@942
   395
				for ( i=cvt->len_cvt/8; i; --i ) {
slouken@942
   396
					lsample = (Sint16)((src[1]<<8)|src[0]);
slouken@942
   397
					rsample = (Sint16)((src[3]<<8)|src[2]);
slouken@942
   398
						dst[0] = (lsample&0xFF);
slouken@942
   399
						lsample >>= 8;
slouken@942
   400
						dst[1] = (lsample&0xFF);
slouken@942
   401
						dst[2] = (rsample&0xFF);
slouken@942
   402
						rsample >>= 8;
slouken@942
   403
						dst[3] = (rsample&0xFF);
slouken@942
   404
					src += 8;
slouken@942
   405
					dst += 4;
slouken@942
   406
				}
slouken@942
   407
			}
slouken@942
   408
		}
slouken@942
   409
		break;
slouken@942
   410
	}
slouken@942
   411
	cvt->len_cvt /= 2;
slouken@942
   412
	if ( cvt->filters[++cvt->filter_index] ) {
slouken@942
   413
		cvt->filters[cvt->filter_index](cvt, format);
slouken@942
   414
	}
slouken@942
   415
}
slouken@0
   416
slouken@0
   417
/* Duplicate a mono channel to both stereo channels */
slouken@0
   418
void SDL_ConvertStereo(SDL_AudioCVT *cvt, Uint16 format)
slouken@0
   419
{
slouken@0
   420
	int i;
slouken@0
   421
slouken@0
   422
#ifdef DEBUG_CONVERT
slouken@0
   423
	fprintf(stderr, "Converting to stereo\n");
slouken@0
   424
#endif
slouken@0
   425
	if ( (format & 0xFF) == 16 ) {
slouken@0
   426
		Uint16 *src, *dst;
slouken@0
   427
slouken@0
   428
		src = (Uint16 *)(cvt->buf+cvt->len_cvt);
slouken@0
   429
		dst = (Uint16 *)(cvt->buf+cvt->len_cvt*2);
slouken@0
   430
		for ( i=cvt->len_cvt/2; i; --i ) {
slouken@0
   431
			dst -= 2;
slouken@0
   432
			src -= 1;
slouken@0
   433
			dst[0] = src[0];
slouken@0
   434
			dst[1] = src[0];
slouken@0
   435
		}
slouken@0
   436
	} else {
slouken@0
   437
		Uint8 *src, *dst;
slouken@0
   438
slouken@0
   439
		src = cvt->buf+cvt->len_cvt;
slouken@0
   440
		dst = cvt->buf+cvt->len_cvt*2;
slouken@0
   441
		for ( i=cvt->len_cvt; i; --i ) {
slouken@0
   442
			dst -= 2;
slouken@0
   443
			src -= 1;
slouken@0
   444
			dst[0] = src[0];
slouken@0
   445
			dst[1] = src[0];
slouken@0
   446
		}
slouken@0
   447
	}
slouken@0
   448
	cvt->len_cvt *= 2;
slouken@0
   449
	if ( cvt->filters[++cvt->filter_index] ) {
slouken@0
   450
		cvt->filters[cvt->filter_index](cvt, format);
slouken@0
   451
	}
slouken@0
   452
}
slouken@0
   453
slouken@942
   454
slouken@942
   455
/* Duplicate a stereo channel to a pseudo-5.1 stream */
slouken@942
   456
void SDL_ConvertSurround(SDL_AudioCVT *cvt, Uint16 format)
slouken@942
   457
{
slouken@942
   458
	int i;
slouken@942
   459
slouken@942
   460
#ifdef DEBUG_CONVERT
slouken@942
   461
	fprintf(stderr, "Converting stereo to surround\n");
slouken@942
   462
#endif
slouken@942
   463
	switch (format&0x8018) {
slouken@942
   464
slouken@942
   465
		case AUDIO_U8: {
slouken@942
   466
			Uint8 *src, *dst, lf, rf, ce;
slouken@942
   467
slouken@942
   468
			src = (Uint8 *)(cvt->buf+cvt->len_cvt);
slouken@942
   469
			dst = (Uint8 *)(cvt->buf+cvt->len_cvt*3);
slouken@942
   470
			for ( i=cvt->len_cvt; i; --i ) {
slouken@942
   471
				dst -= 6;
slouken@942
   472
				src -= 2;
slouken@942
   473
				lf = src[0];
slouken@942
   474
				rf = src[1];
slouken@942
   475
				ce = (lf/2) + (rf/2);
slouken@942
   476
				dst[0] = lf;
slouken@942
   477
				dst[1] = rf;
slouken@942
   478
				dst[2] = lf - ce;
slouken@942
   479
				dst[3] = rf - ce;
slouken@942
   480
				dst[4] = ce;
slouken@942
   481
				dst[5] = ce;
slouken@942
   482
			}
slouken@942
   483
		}
slouken@942
   484
		break;
slouken@942
   485
slouken@942
   486
		case AUDIO_S8: {
slouken@942
   487
			Sint8 *src, *dst, lf, rf, ce;
slouken@942
   488
slouken@1011
   489
			src = (Sint8 *)cvt->buf+cvt->len_cvt;
slouken@1011
   490
			dst = (Sint8 *)cvt->buf+cvt->len_cvt*3;
slouken@942
   491
			for ( i=cvt->len_cvt; i; --i ) {
slouken@942
   492
				dst -= 6;
slouken@942
   493
				src -= 2;
slouken@942
   494
				lf = src[0];
slouken@942
   495
				rf = src[1];
slouken@942
   496
				ce = (lf/2) + (rf/2);
slouken@942
   497
				dst[0] = lf;
slouken@942
   498
				dst[1] = rf;
slouken@942
   499
				dst[2] = lf - ce;
slouken@942
   500
				dst[3] = rf - ce;
slouken@942
   501
				dst[4] = ce;
slouken@942
   502
				dst[5] = ce;
slouken@942
   503
			}
slouken@942
   504
		}
slouken@942
   505
		break;
slouken@942
   506
slouken@942
   507
		case AUDIO_U16: {
slouken@942
   508
			Uint8 *src, *dst;
slouken@942
   509
			Uint16 lf, rf, ce, lr, rr;
slouken@942
   510
slouken@942
   511
			src = cvt->buf+cvt->len_cvt;
slouken@942
   512
			dst = cvt->buf+cvt->len_cvt*3;
slouken@942
   513
slouken@942
   514
			if ( (format & 0x1000) == 0x1000 ) {
slouken@942
   515
				for ( i=cvt->len_cvt/4; i; --i ) {
slouken@942
   516
					dst -= 12;
slouken@942
   517
					src -= 4;
slouken@942
   518
					lf = (Uint16)((src[0]<<8)|src[1]);
slouken@942
   519
					rf = (Uint16)((src[2]<<8)|src[3]);
slouken@942
   520
					ce = (lf/2) + (rf/2);
slouken@942
   521
					rr = lf - ce;
slouken@942
   522
					lr = rf - ce;
slouken@942
   523
						dst[1] = (lf&0xFF);
slouken@942
   524
						dst[0] = ((lf>>8)&0xFF);
slouken@942
   525
						dst[3] = (rf&0xFF);
slouken@942
   526
						dst[2] = ((rf>>8)&0xFF);
slouken@942
   527
slouken@942
   528
						dst[1+4] = (lr&0xFF);
slouken@942
   529
						dst[0+4] = ((lr>>8)&0xFF);
slouken@942
   530
						dst[3+4] = (rr&0xFF);
slouken@942
   531
						dst[2+4] = ((rr>>8)&0xFF);
slouken@942
   532
slouken@942
   533
						dst[1+8] = (ce&0xFF);
slouken@942
   534
						dst[0+8] = ((ce>>8)&0xFF);
slouken@942
   535
						dst[3+8] = (ce&0xFF);
slouken@942
   536
						dst[2+8] = ((ce>>8)&0xFF);
slouken@942
   537
				}
slouken@942
   538
			} else {
slouken@942
   539
				for ( i=cvt->len_cvt/4; i; --i ) {
slouken@942
   540
					dst -= 12;
slouken@942
   541
					src -= 4;
slouken@942
   542
					lf = (Uint16)((src[1]<<8)|src[0]);
slouken@942
   543
					rf = (Uint16)((src[3]<<8)|src[2]);
slouken@942
   544
					ce = (lf/2) + (rf/2);
slouken@942
   545
					rr = lf - ce;
slouken@942
   546
					lr = rf - ce;
slouken@942
   547
						dst[0] = (lf&0xFF);
slouken@942
   548
						dst[1] = ((lf>>8)&0xFF);
slouken@942
   549
						dst[2] = (rf&0xFF);
slouken@942
   550
						dst[3] = ((rf>>8)&0xFF);
slouken@942
   551
slouken@942
   552
						dst[0+4] = (lr&0xFF);
slouken@942
   553
						dst[1+4] = ((lr>>8)&0xFF);
slouken@942
   554
						dst[2+4] = (rr&0xFF);
slouken@942
   555
						dst[3+4] = ((rr>>8)&0xFF);
slouken@942
   556
slouken@942
   557
						dst[0+8] = (ce&0xFF);
slouken@942
   558
						dst[1+8] = ((ce>>8)&0xFF);
slouken@942
   559
						dst[2+8] = (ce&0xFF);
slouken@942
   560
						dst[3+8] = ((ce>>8)&0xFF);
slouken@942
   561
				}
slouken@942
   562
			}
slouken@942
   563
		}
slouken@942
   564
		break;
slouken@942
   565
slouken@942
   566
		case AUDIO_S16: {
slouken@942
   567
			Uint8 *src, *dst;
slouken@942
   568
			Sint16 lf, rf, ce, lr, rr;
slouken@942
   569
slouken@942
   570
			src = cvt->buf+cvt->len_cvt;
slouken@942
   571
			dst = cvt->buf+cvt->len_cvt*3;
slouken@942
   572
slouken@942
   573
			if ( (format & 0x1000) == 0x1000 ) {
slouken@942
   574
				for ( i=cvt->len_cvt/4; i; --i ) {
slouken@942
   575
					dst -= 12;
slouken@942
   576
					src -= 4;
slouken@942
   577
					lf = (Sint16)((src[0]<<8)|src[1]);
slouken@942
   578
					rf = (Sint16)((src[2]<<8)|src[3]);
slouken@942
   579
					ce = (lf/2) + (rf/2);
slouken@942
   580
					rr = lf - ce;
slouken@942
   581
					lr = rf - ce;
slouken@942
   582
						dst[1] = (lf&0xFF);
slouken@942
   583
						dst[0] = ((lf>>8)&0xFF);
slouken@942
   584
						dst[3] = (rf&0xFF);
slouken@942
   585
						dst[2] = ((rf>>8)&0xFF);
slouken@942
   586
slouken@942
   587
						dst[1+4] = (lr&0xFF);
slouken@942
   588
						dst[0+4] = ((lr>>8)&0xFF);
slouken@942
   589
						dst[3+4] = (rr&0xFF);
slouken@942
   590
						dst[2+4] = ((rr>>8)&0xFF);
slouken@942
   591
slouken@942
   592
						dst[1+8] = (ce&0xFF);
slouken@942
   593
						dst[0+8] = ((ce>>8)&0xFF);
slouken@942
   594
						dst[3+8] = (ce&0xFF);
slouken@942
   595
						dst[2+8] = ((ce>>8)&0xFF);
slouken@942
   596
				}
slouken@942
   597
			} else {
slouken@942
   598
				for ( i=cvt->len_cvt/4; i; --i ) {
slouken@942
   599
					dst -= 12;
slouken@942
   600
					src -= 4;
slouken@942
   601
					lf = (Sint16)((src[1]<<8)|src[0]);
slouken@942
   602
					rf = (Sint16)((src[3]<<8)|src[2]);
slouken@942
   603
					ce = (lf/2) + (rf/2);
slouken@942
   604
					rr = lf - ce;
slouken@942
   605
					lr = rf - ce;
slouken@942
   606
						dst[0] = (lf&0xFF);
slouken@942
   607
						dst[1] = ((lf>>8)&0xFF);
slouken@942
   608
						dst[2] = (rf&0xFF);
slouken@942
   609
						dst[3] = ((rf>>8)&0xFF);
slouken@942
   610
slouken@942
   611
						dst[0+4] = (lr&0xFF);
slouken@942
   612
						dst[1+4] = ((lr>>8)&0xFF);
slouken@942
   613
						dst[2+4] = (rr&0xFF);
slouken@942
   614
						dst[3+4] = ((rr>>8)&0xFF);
slouken@942
   615
slouken@942
   616
						dst[0+8] = (ce&0xFF);
slouken@942
   617
						dst[1+8] = ((ce>>8)&0xFF);
slouken@942
   618
						dst[2+8] = (ce&0xFF);
slouken@942
   619
						dst[3+8] = ((ce>>8)&0xFF);
slouken@942
   620
				}
slouken@942
   621
			}
slouken@942
   622
		}
slouken@942
   623
		break;
slouken@942
   624
	}
slouken@942
   625
	cvt->len_cvt *= 3;
slouken@942
   626
	if ( cvt->filters[++cvt->filter_index] ) {
slouken@942
   627
		cvt->filters[cvt->filter_index](cvt, format);
slouken@942
   628
	}
slouken@942
   629
}
slouken@942
   630
slouken@942
   631
slouken@942
   632
/* Duplicate a stereo channel to a pseudo-4.0 stream */
slouken@942
   633
void SDL_ConvertSurround_4(SDL_AudioCVT *cvt, Uint16 format)
slouken@942
   634
{
slouken@942
   635
	int i;
slouken@942
   636
slouken@942
   637
#ifdef DEBUG_CONVERT
slouken@942
   638
	fprintf(stderr, "Converting stereo to quad\n");
slouken@942
   639
#endif
slouken@942
   640
	switch (format&0x8018) {
slouken@942
   641
slouken@942
   642
		case AUDIO_U8: {
slouken@942
   643
			Uint8 *src, *dst, lf, rf, ce;
slouken@942
   644
slouken@942
   645
			src = (Uint8 *)(cvt->buf+cvt->len_cvt);
slouken@942
   646
			dst = (Uint8 *)(cvt->buf+cvt->len_cvt*2);
slouken@942
   647
			for ( i=cvt->len_cvt; i; --i ) {
slouken@942
   648
				dst -= 4;
slouken@942
   649
				src -= 2;
slouken@942
   650
				lf = src[0];
slouken@942
   651
				rf = src[1];
slouken@942
   652
				ce = (lf/2) + (rf/2);
slouken@942
   653
				dst[0] = lf;
slouken@942
   654
				dst[1] = rf;
slouken@942
   655
				dst[2] = lf - ce;
slouken@942
   656
				dst[3] = rf - ce;
slouken@942
   657
			}
slouken@942
   658
		}
slouken@942
   659
		break;
slouken@942
   660
slouken@942
   661
		case AUDIO_S8: {
slouken@942
   662
			Sint8 *src, *dst, lf, rf, ce;
slouken@942
   663
slouken@1011
   664
			src = (Sint8 *)cvt->buf+cvt->len_cvt;
slouken@1011
   665
			dst = (Sint8 *)cvt->buf+cvt->len_cvt*2;
slouken@942
   666
			for ( i=cvt->len_cvt; i; --i ) {
slouken@942
   667
				dst -= 4;
slouken@942
   668
				src -= 2;
slouken@942
   669
				lf = src[0];
slouken@942
   670
				rf = src[1];
slouken@942
   671
				ce = (lf/2) + (rf/2);
slouken@942
   672
				dst[0] = lf;
slouken@942
   673
				dst[1] = rf;
slouken@942
   674
				dst[2] = lf - ce;
slouken@942
   675
				dst[3] = rf - ce;
slouken@942
   676
			}
slouken@942
   677
		}
slouken@942
   678
		break;
slouken@942
   679
slouken@942
   680
		case AUDIO_U16: {
slouken@942
   681
			Uint8 *src, *dst;
slouken@942
   682
			Uint16 lf, rf, ce, lr, rr;
slouken@942
   683
slouken@942
   684
			src = cvt->buf+cvt->len_cvt;
slouken@942
   685
			dst = cvt->buf+cvt->len_cvt*2;
slouken@942
   686
slouken@942
   687
			if ( (format & 0x1000) == 0x1000 ) {
slouken@942
   688
				for ( i=cvt->len_cvt/4; i; --i ) {
slouken@942
   689
					dst -= 8;
slouken@942
   690
					src -= 4;
slouken@942
   691
					lf = (Uint16)((src[0]<<8)|src[1]);
slouken@942
   692
					rf = (Uint16)((src[2]<<8)|src[3]);
slouken@942
   693
					ce = (lf/2) + (rf/2);
slouken@942
   694
					rr = lf - ce;
slouken@942
   695
					lr = rf - ce;
slouken@942
   696
						dst[1] = (lf&0xFF);
slouken@942
   697
						dst[0] = ((lf>>8)&0xFF);
slouken@942
   698
						dst[3] = (rf&0xFF);
slouken@942
   699
						dst[2] = ((rf>>8)&0xFF);
slouken@942
   700
slouken@942
   701
						dst[1+4] = (lr&0xFF);
slouken@942
   702
						dst[0+4] = ((lr>>8)&0xFF);
slouken@942
   703
						dst[3+4] = (rr&0xFF);
slouken@942
   704
						dst[2+4] = ((rr>>8)&0xFF);
slouken@942
   705
				}
slouken@942
   706
			} else {
slouken@942
   707
				for ( i=cvt->len_cvt/4; i; --i ) {
slouken@942
   708
					dst -= 8;
slouken@942
   709
					src -= 4;
slouken@942
   710
					lf = (Uint16)((src[1]<<8)|src[0]);
slouken@942
   711
					rf = (Uint16)((src[3]<<8)|src[2]);
slouken@942
   712
					ce = (lf/2) + (rf/2);
slouken@942
   713
					rr = lf - ce;
slouken@942
   714
					lr = rf - ce;
slouken@942
   715
						dst[0] = (lf&0xFF);
slouken@942
   716
						dst[1] = ((lf>>8)&0xFF);
slouken@942
   717
						dst[2] = (rf&0xFF);
slouken@942
   718
						dst[3] = ((rf>>8)&0xFF);
slouken@942
   719
slouken@942
   720
						dst[0+4] = (lr&0xFF);
slouken@942
   721
						dst[1+4] = ((lr>>8)&0xFF);
slouken@942
   722
						dst[2+4] = (rr&0xFF);
slouken@942
   723
						dst[3+4] = ((rr>>8)&0xFF);
slouken@942
   724
				}
slouken@942
   725
			}
slouken@942
   726
		}
slouken@942
   727
		break;
slouken@942
   728
slouken@942
   729
		case AUDIO_S16: {
slouken@942
   730
			Uint8 *src, *dst;
slouken@942
   731
			Sint16 lf, rf, ce, lr, rr;
slouken@942
   732
slouken@942
   733
			src = cvt->buf+cvt->len_cvt;
slouken@942
   734
			dst = cvt->buf+cvt->len_cvt*2;
slouken@942
   735
slouken@942
   736
			if ( (format & 0x1000) == 0x1000 ) {
slouken@942
   737
				for ( i=cvt->len_cvt/4; i; --i ) {
slouken@942
   738
					dst -= 8;
slouken@942
   739
					src -= 4;
slouken@942
   740
					lf = (Sint16)((src[0]<<8)|src[1]);
slouken@942
   741
					rf = (Sint16)((src[2]<<8)|src[3]);
slouken@942
   742
					ce = (lf/2) + (rf/2);
slouken@942
   743
					rr = lf - ce;
slouken@942
   744
					lr = rf - ce;
slouken@942
   745
						dst[1] = (lf&0xFF);
slouken@942
   746
						dst[0] = ((lf>>8)&0xFF);
slouken@942
   747
						dst[3] = (rf&0xFF);
slouken@942
   748
						dst[2] = ((rf>>8)&0xFF);
slouken@942
   749
slouken@942
   750
						dst[1+4] = (lr&0xFF);
slouken@942
   751
						dst[0+4] = ((lr>>8)&0xFF);
slouken@942
   752
						dst[3+4] = (rr&0xFF);
slouken@942
   753
						dst[2+4] = ((rr>>8)&0xFF);
slouken@942
   754
				}
slouken@942
   755
			} else {
slouken@942
   756
				for ( i=cvt->len_cvt/4; i; --i ) {
slouken@942
   757
					dst -= 8;
slouken@942
   758
					src -= 4;
slouken@942
   759
					lf = (Sint16)((src[1]<<8)|src[0]);
slouken@942
   760
					rf = (Sint16)((src[3]<<8)|src[2]);
slouken@942
   761
					ce = (lf/2) + (rf/2);
slouken@942
   762
					rr = lf - ce;
slouken@942
   763
					lr = rf - ce;
slouken@942
   764
						dst[0] = (lf&0xFF);
slouken@942
   765
						dst[1] = ((lf>>8)&0xFF);
slouken@942
   766
						dst[2] = (rf&0xFF);
slouken@942
   767
						dst[3] = ((rf>>8)&0xFF);
slouken@942
   768
slouken@942
   769
						dst[0+4] = (lr&0xFF);
slouken@942
   770
						dst[1+4] = ((lr>>8)&0xFF);
slouken@942
   771
						dst[2+4] = (rr&0xFF);
slouken@942
   772
						dst[3+4] = ((rr>>8)&0xFF);
slouken@942
   773
				}
slouken@942
   774
			}
slouken@942
   775
		}
slouken@942
   776
		break;
slouken@942
   777
	}
slouken@942
   778
	cvt->len_cvt *= 2;
slouken@942
   779
	if ( cvt->filters[++cvt->filter_index] ) {
slouken@942
   780
		cvt->filters[cvt->filter_index](cvt, format);
slouken@942
   781
	}
slouken@942
   782
}
slouken@942
   783
slouken@942
   784
slouken@0
   785
/* Convert 8-bit to 16-bit - LSB */
slouken@0
   786
void SDL_Convert16LSB(SDL_AudioCVT *cvt, Uint16 format)
slouken@0
   787
{
slouken@0
   788
	int i;
slouken@0
   789
	Uint8 *src, *dst;
slouken@0
   790
slouken@0
   791
#ifdef DEBUG_CONVERT
slouken@0
   792
	fprintf(stderr, "Converting to 16-bit LSB\n");
slouken@0
   793
#endif
slouken@0
   794
	src = cvt->buf+cvt->len_cvt;
slouken@0
   795
	dst = cvt->buf+cvt->len_cvt*2;
slouken@0
   796
	for ( i=cvt->len_cvt; i; --i ) {
slouken@0
   797
		src -= 1;
slouken@0
   798
		dst -= 2;
slouken@0
   799
		dst[1] = *src;
slouken@0
   800
		dst[0] = 0;
slouken@0
   801
	}
slouken@0
   802
	format = ((format & ~0x0008) | AUDIO_U16LSB);
slouken@0
   803
	cvt->len_cvt *= 2;
slouken@0
   804
	if ( cvt->filters[++cvt->filter_index] ) {
slouken@0
   805
		cvt->filters[cvt->filter_index](cvt, format);
slouken@0
   806
	}
slouken@0
   807
}
slouken@0
   808
/* Convert 8-bit to 16-bit - MSB */
slouken@0
   809
void SDL_Convert16MSB(SDL_AudioCVT *cvt, Uint16 format)
slouken@0
   810
{
slouken@0
   811
	int i;
slouken@0
   812
	Uint8 *src, *dst;
slouken@0
   813
slouken@0
   814
#ifdef DEBUG_CONVERT
slouken@0
   815
	fprintf(stderr, "Converting to 16-bit MSB\n");
slouken@0
   816
#endif
slouken@0
   817
	src = cvt->buf+cvt->len_cvt;
slouken@0
   818
	dst = cvt->buf+cvt->len_cvt*2;
slouken@0
   819
	for ( i=cvt->len_cvt; i; --i ) {
slouken@0
   820
		src -= 1;
slouken@0
   821
		dst -= 2;
slouken@0
   822
		dst[0] = *src;
slouken@0
   823
		dst[1] = 0;
slouken@0
   824
	}
slouken@0
   825
	format = ((format & ~0x0008) | AUDIO_U16MSB);
slouken@0
   826
	cvt->len_cvt *= 2;
slouken@0
   827
	if ( cvt->filters[++cvt->filter_index] ) {
slouken@0
   828
		cvt->filters[cvt->filter_index](cvt, format);
slouken@0
   829
	}
slouken@0
   830
}
slouken@0
   831
slouken@0
   832
/* Convert 16-bit to 8-bit */
slouken@0
   833
void SDL_Convert8(SDL_AudioCVT *cvt, Uint16 format)
slouken@0
   834
{
slouken@0
   835
	int i;
slouken@0
   836
	Uint8 *src, *dst;
slouken@0
   837
slouken@0
   838
#ifdef DEBUG_CONVERT
slouken@0
   839
	fprintf(stderr, "Converting to 8-bit\n");
slouken@0
   840
#endif
slouken@0
   841
	src = cvt->buf;
slouken@0
   842
	dst = cvt->buf;
slouken@0
   843
	if ( (format & 0x1000) != 0x1000 ) { /* Little endian */
slouken@0
   844
		++src;
slouken@0
   845
	}
slouken@0
   846
	for ( i=cvt->len_cvt/2; i; --i ) {
slouken@0
   847
		*dst = *src;
slouken@0
   848
		src += 2;
slouken@0
   849
		dst += 1;
slouken@0
   850
	}
slouken@0
   851
	format = ((format & ~0x9010) | AUDIO_U8);
slouken@0
   852
	cvt->len_cvt /= 2;
slouken@0
   853
	if ( cvt->filters[++cvt->filter_index] ) {
slouken@0
   854
		cvt->filters[cvt->filter_index](cvt, format);
slouken@0
   855
	}
slouken@0
   856
}
slouken@0
   857
slouken@0
   858
/* Toggle signed/unsigned */
slouken@0
   859
void SDL_ConvertSign(SDL_AudioCVT *cvt, Uint16 format)
slouken@0
   860
{
slouken@0
   861
	int i;
slouken@0
   862
	Uint8 *data;
slouken@0
   863
slouken@0
   864
#ifdef DEBUG_CONVERT
slouken@0
   865
	fprintf(stderr, "Converting audio signedness\n");
slouken@0
   866
#endif
slouken@0
   867
	data = cvt->buf;
slouken@0
   868
	if ( (format & 0xFF) == 16 ) {
slouken@0
   869
		if ( (format & 0x1000) != 0x1000 ) { /* Little endian */
slouken@0
   870
			++data;
slouken@0
   871
		}
slouken@0
   872
		for ( i=cvt->len_cvt/2; i; --i ) {
slouken@0
   873
			*data ^= 0x80;
slouken@0
   874
			data += 2;
slouken@0
   875
		}
slouken@0
   876
	} else {
slouken@0
   877
		for ( i=cvt->len_cvt; i; --i ) {
slouken@0
   878
			*data++ ^= 0x80;
slouken@0
   879
		}
slouken@0
   880
	}
slouken@0
   881
	format = (format ^ 0x8000);
slouken@0
   882
	if ( cvt->filters[++cvt->filter_index] ) {
slouken@0
   883
		cvt->filters[cvt->filter_index](cvt, format);
slouken@0
   884
	}
slouken@0
   885
}
slouken@0
   886
slouken@0
   887
/* Toggle endianness */
slouken@0
   888
void SDL_ConvertEndian(SDL_AudioCVT *cvt, Uint16 format)
slouken@0
   889
{
slouken@0
   890
	int i;
slouken@0
   891
	Uint8 *data, tmp;
slouken@0
   892
slouken@0
   893
#ifdef DEBUG_CONVERT
slouken@0
   894
	fprintf(stderr, "Converting audio endianness\n");
slouken@0
   895
#endif
slouken@0
   896
	data = cvt->buf;
slouken@0
   897
	for ( i=cvt->len_cvt/2; i; --i ) {
slouken@0
   898
		tmp = data[0];
slouken@0
   899
		data[0] = data[1];
slouken@0
   900
		data[1] = tmp;
slouken@0
   901
		data += 2;
slouken@0
   902
	}
slouken@0
   903
	format = (format ^ 0x1000);
slouken@0
   904
	if ( cvt->filters[++cvt->filter_index] ) {
slouken@0
   905
		cvt->filters[cvt->filter_index](cvt, format);
slouken@0
   906
	}
slouken@0
   907
}
slouken@0
   908
slouken@0
   909
/* Convert rate up by multiple of 2 */
slouken@0
   910
void SDL_RateMUL2(SDL_AudioCVT *cvt, Uint16 format)
slouken@0
   911
{
slouken@0
   912
	int i;
slouken@0
   913
	Uint8 *src, *dst;
slouken@0
   914
slouken@0
   915
#ifdef DEBUG_CONVERT
slouken@0
   916
	fprintf(stderr, "Converting audio rate * 2\n");
slouken@0
   917
#endif
slouken@0
   918
	src = cvt->buf+cvt->len_cvt;
slouken@0
   919
	dst = cvt->buf+cvt->len_cvt*2;
slouken@0
   920
	switch (format & 0xFF) {
slouken@0
   921
		case 8:
slouken@0
   922
			for ( i=cvt->len_cvt; i; --i ) {
slouken@0
   923
				src -= 1;
slouken@0
   924
				dst -= 2;
slouken@0
   925
				dst[0] = src[0];
slouken@0
   926
				dst[1] = src[0];
slouken@0
   927
			}
slouken@0
   928
			break;
slouken@0
   929
		case 16:
slouken@0
   930
			for ( i=cvt->len_cvt/2; i; --i ) {
slouken@0
   931
				src -= 2;
slouken@0
   932
				dst -= 4;
slouken@0
   933
				dst[0] = src[0];
slouken@0
   934
				dst[1] = src[1];
slouken@0
   935
				dst[2] = src[0];
slouken@0
   936
				dst[3] = src[1];
slouken@0
   937
			}
slouken@0
   938
			break;
slouken@0
   939
	}
slouken@0
   940
	cvt->len_cvt *= 2;
slouken@0
   941
	if ( cvt->filters[++cvt->filter_index] ) {
slouken@0
   942
		cvt->filters[cvt->filter_index](cvt, format);
slouken@0
   943
	}
slouken@0
   944
}
slouken@0
   945
slouken@942
   946
slouken@942
   947
/* Convert rate up by multiple of 2, for stereo */
slouken@942
   948
void SDL_RateMUL2_c2(SDL_AudioCVT *cvt, Uint16 format)
slouken@942
   949
{
slouken@942
   950
	int i;
slouken@942
   951
	Uint8 *src, *dst;
slouken@942
   952
slouken@942
   953
#ifdef DEBUG_CONVERT
slouken@942
   954
	fprintf(stderr, "Converting audio rate * 2\n");
slouken@942
   955
#endif
slouken@942
   956
	src = cvt->buf+cvt->len_cvt;
slouken@942
   957
	dst = cvt->buf+cvt->len_cvt*2;
slouken@942
   958
	switch (format & 0xFF) {
slouken@942
   959
		case 8:
slouken@942
   960
			for ( i=cvt->len_cvt/2; i; --i ) {
slouken@942
   961
				src -= 2;
slouken@942
   962
				dst -= 4;
slouken@942
   963
				dst[0] = src[0];
slouken@942
   964
				dst[1] = src[1];
slouken@942
   965
				dst[2] = src[0];
slouken@942
   966
				dst[3] = src[1];
slouken@942
   967
			}
slouken@942
   968
			break;
slouken@942
   969
		case 16:
slouken@942
   970
			for ( i=cvt->len_cvt/4; i; --i ) {
slouken@942
   971
				src -= 4;
slouken@942
   972
				dst -= 8;
slouken@942
   973
				dst[0] = src[0];
slouken@942
   974
				dst[1] = src[1];
slouken@942
   975
				dst[2] = src[2];
slouken@942
   976
				dst[3] = src[3];
slouken@942
   977
				dst[4] = src[0];
slouken@942
   978
				dst[5] = src[1];
slouken@942
   979
				dst[6] = src[2];
slouken@942
   980
				dst[7] = src[3];
slouken@942
   981
			}
slouken@942
   982
			break;
slouken@942
   983
	}
slouken@942
   984
	cvt->len_cvt *= 2;
slouken@942
   985
	if ( cvt->filters[++cvt->filter_index] ) {
slouken@942
   986
		cvt->filters[cvt->filter_index](cvt, format);
slouken@942
   987
	}
slouken@942
   988
}
slouken@942
   989
slouken@942
   990
/* Convert rate up by multiple of 2, for quad */
slouken@942
   991
void SDL_RateMUL2_c4(SDL_AudioCVT *cvt, Uint16 format)
slouken@942
   992
{
slouken@942
   993
	int i;
slouken@942
   994
	Uint8 *src, *dst;
slouken@942
   995
slouken@942
   996
#ifdef DEBUG_CONVERT
slouken@942
   997
	fprintf(stderr, "Converting audio rate * 2\n");
slouken@942
   998
#endif
slouken@942
   999
	src = cvt->buf+cvt->len_cvt;
slouken@942
  1000
	dst = cvt->buf+cvt->len_cvt*2;
slouken@942
  1001
	switch (format & 0xFF) {
slouken@942
  1002
		case 8:
slouken@942
  1003
			for ( i=cvt->len_cvt/4; i; --i ) {
slouken@942
  1004
				src -= 4;
slouken@942
  1005
				dst -= 8;
slouken@942
  1006
				dst[0] = src[0];
slouken@942
  1007
				dst[1] = src[1];
slouken@942
  1008
				dst[2] = src[2];
slouken@942
  1009
				dst[3] = src[3];
slouken@942
  1010
				dst[4] = src[0];
slouken@942
  1011
				dst[5] = src[1];
slouken@942
  1012
				dst[6] = src[2];
slouken@942
  1013
				dst[7] = src[3];
slouken@942
  1014
			}
slouken@942
  1015
			break;
slouken@942
  1016
		case 16:
slouken@942
  1017
			for ( i=cvt->len_cvt/8; i; --i ) {
slouken@942
  1018
				src -= 8;
slouken@942
  1019
				dst -= 16;
slouken@942
  1020
				dst[0] = src[0];
slouken@942
  1021
				dst[1] = src[1];
slouken@942
  1022
				dst[2] = src[2];
slouken@942
  1023
				dst[3] = src[3];
slouken@942
  1024
				dst[4] = src[4];
slouken@942
  1025
				dst[5] = src[5];
slouken@942
  1026
				dst[6] = src[6];
slouken@942
  1027
				dst[7] = src[7];
slouken@942
  1028
				dst[8] = src[0];
slouken@942
  1029
				dst[9] = src[1];
slouken@942
  1030
				dst[10] = src[2];
slouken@942
  1031
				dst[11] = src[3];
slouken@942
  1032
				dst[12] = src[4];
slouken@942
  1033
				dst[13] = src[5];
slouken@942
  1034
				dst[14] = src[6];
slouken@942
  1035
				dst[15] = src[7];
slouken@942
  1036
			}
slouken@942
  1037
			break;
slouken@942
  1038
	}
slouken@942
  1039
	cvt->len_cvt *= 2;
slouken@942
  1040
	if ( cvt->filters[++cvt->filter_index] ) {
slouken@942
  1041
		cvt->filters[cvt->filter_index](cvt, format);
slouken@942
  1042
	}
slouken@942
  1043
}
slouken@942
  1044
slouken@942
  1045
slouken@942
  1046
/* Convert rate up by multiple of 2, for 5.1 */
slouken@942
  1047
void SDL_RateMUL2_c6(SDL_AudioCVT *cvt, Uint16 format)
slouken@942
  1048
{
slouken@942
  1049
	int i;
slouken@942
  1050
	Uint8 *src, *dst;
slouken@942
  1051
slouken@942
  1052
#ifdef DEBUG_CONVERT
slouken@942
  1053
	fprintf(stderr, "Converting audio rate * 2\n");
slouken@942
  1054
#endif
slouken@942
  1055
	src = cvt->buf+cvt->len_cvt;
slouken@942
  1056
	dst = cvt->buf+cvt->len_cvt*2;
slouken@942
  1057
	switch (format & 0xFF) {
slouken@942
  1058
		case 8:
slouken@942
  1059
			for ( i=cvt->len_cvt/6; i; --i ) {
slouken@942
  1060
				src -= 6;
slouken@942
  1061
				dst -= 12;
slouken@942
  1062
				dst[0] = src[0];
slouken@942
  1063
				dst[1] = src[1];
slouken@942
  1064
				dst[2] = src[2];
slouken@942
  1065
				dst[3] = src[3];
slouken@942
  1066
				dst[4] = src[4];
slouken@942
  1067
				dst[5] = src[5];
slouken@942
  1068
				dst[6] = src[0];
slouken@942
  1069
				dst[7] = src[1];
slouken@942
  1070
				dst[8] = src[2];
slouken@942
  1071
				dst[9] = src[3];
slouken@942
  1072
				dst[10] = src[4];
slouken@942
  1073
				dst[11] = src[5];
slouken@942
  1074
			}
slouken@942
  1075
			break;
slouken@942
  1076
		case 16:
slouken@942
  1077
			for ( i=cvt->len_cvt/12; i; --i ) {
slouken@942
  1078
				src -= 12;
slouken@942
  1079
				dst -= 24;
slouken@942
  1080
				dst[0] = src[0];
slouken@942
  1081
				dst[1] = src[1];
slouken@942
  1082
				dst[2] = src[2];
slouken@942
  1083
				dst[3] = src[3];
slouken@942
  1084
				dst[4] = src[4];
slouken@942
  1085
				dst[5] = src[5];
slouken@942
  1086
				dst[6] = src[6];
slouken@942
  1087
				dst[7] = src[7];
slouken@942
  1088
				dst[8] = src[8];
slouken@942
  1089
				dst[9] = src[9];
slouken@942
  1090
				dst[10] = src[10];
slouken@942
  1091
				dst[11] = src[11];
slouken@942
  1092
				dst[12] = src[0];
slouken@942
  1093
				dst[13] = src[1];
slouken@942
  1094
				dst[14] = src[2];
slouken@942
  1095
				dst[15] = src[3];
slouken@942
  1096
				dst[16] = src[4];
slouken@942
  1097
				dst[17] = src[5];
slouken@942
  1098
				dst[18] = src[6];
slouken@942
  1099
				dst[19] = src[7];
slouken@942
  1100
				dst[20] = src[8];
slouken@942
  1101
				dst[21] = src[9];
slouken@942
  1102
				dst[22] = src[10];
slouken@942
  1103
				dst[23] = src[11];
slouken@942
  1104
			}
slouken@942
  1105
			break;
slouken@942
  1106
	}
slouken@942
  1107
	cvt->len_cvt *= 2;
slouken@942
  1108
	if ( cvt->filters[++cvt->filter_index] ) {
slouken@942
  1109
		cvt->filters[cvt->filter_index](cvt, format);
slouken@942
  1110
	}
slouken@942
  1111
}
slouken@942
  1112
slouken@0
  1113
/* Convert rate down by multiple of 2 */
slouken@0
  1114
void SDL_RateDIV2(SDL_AudioCVT *cvt, Uint16 format)
slouken@0
  1115
{
slouken@0
  1116
	int i;
slouken@0
  1117
	Uint8 *src, *dst;
slouken@0
  1118
slouken@0
  1119
#ifdef DEBUG_CONVERT
slouken@0
  1120
	fprintf(stderr, "Converting audio rate / 2\n");
slouken@0
  1121
#endif
slouken@0
  1122
	src = cvt->buf;
slouken@0
  1123
	dst = cvt->buf;
slouken@0
  1124
	switch (format & 0xFF) {
slouken@0
  1125
		case 8:
slouken@0
  1126
			for ( i=cvt->len_cvt/2; i; --i ) {
slouken@0
  1127
				dst[0] = src[0];
slouken@0
  1128
				src += 2;
slouken@0
  1129
				dst += 1;
slouken@0
  1130
			}
slouken@0
  1131
			break;
slouken@0
  1132
		case 16:
slouken@0
  1133
			for ( i=cvt->len_cvt/4; i; --i ) {
slouken@0
  1134
				dst[0] = src[0];
slouken@0
  1135
				dst[1] = src[1];
slouken@0
  1136
				src += 4;
slouken@0
  1137
				dst += 2;
slouken@0
  1138
			}
slouken@0
  1139
			break;
slouken@0
  1140
	}
slouken@0
  1141
	cvt->len_cvt /= 2;
slouken@0
  1142
	if ( cvt->filters[++cvt->filter_index] ) {
slouken@0
  1143
		cvt->filters[cvt->filter_index](cvt, format);
slouken@0
  1144
	}
slouken@0
  1145
}
slouken@0
  1146
slouken@942
  1147
slouken@942
  1148
/* Convert rate down by multiple of 2, for stereo */
slouken@942
  1149
void SDL_RateDIV2_c2(SDL_AudioCVT *cvt, Uint16 format)
slouken@942
  1150
{
slouken@942
  1151
	int i;
slouken@942
  1152
	Uint8 *src, *dst;
slouken@942
  1153
slouken@942
  1154
#ifdef DEBUG_CONVERT
slouken@942
  1155
	fprintf(stderr, "Converting audio rate / 2\n");
slouken@942
  1156
#endif
slouken@942
  1157
	src = cvt->buf;
slouken@942
  1158
	dst = cvt->buf;
slouken@942
  1159
	switch (format & 0xFF) {
slouken@942
  1160
		case 8:
slouken@942
  1161
			for ( i=cvt->len_cvt/4; i; --i ) {
slouken@942
  1162
				dst[0] = src[0];
slouken@942
  1163
				dst[1] = src[1];
slouken@942
  1164
				src += 4;
slouken@942
  1165
				dst += 2;
slouken@942
  1166
			}
slouken@942
  1167
			break;
slouken@942
  1168
		case 16:
slouken@942
  1169
			for ( i=cvt->len_cvt/8; i; --i ) {
slouken@942
  1170
				dst[0] = src[0];
slouken@942
  1171
				dst[1] = src[1];
slouken@942
  1172
				dst[2] = src[2];
slouken@942
  1173
				dst[3] = src[3];
slouken@942
  1174
				src += 8;
slouken@942
  1175
				dst += 4;
slouken@942
  1176
			}
slouken@942
  1177
			break;
slouken@942
  1178
	}
slouken@942
  1179
	cvt->len_cvt /= 2;
slouken@942
  1180
	if ( cvt->filters[++cvt->filter_index] ) {
slouken@942
  1181
		cvt->filters[cvt->filter_index](cvt, format);
slouken@942
  1182
	}
slouken@942
  1183
}
slouken@942
  1184
slouken@942
  1185
slouken@942
  1186
/* Convert rate down by multiple of 2, for quad */
slouken@942
  1187
void SDL_RateDIV2_c4(SDL_AudioCVT *cvt, Uint16 format)
slouken@942
  1188
{
slouken@942
  1189
	int i;
slouken@942
  1190
	Uint8 *src, *dst;
slouken@942
  1191
slouken@942
  1192
#ifdef DEBUG_CONVERT
slouken@942
  1193
	fprintf(stderr, "Converting audio rate / 2\n");
slouken@942
  1194
#endif
slouken@942
  1195
	src = cvt->buf;
slouken@942
  1196
	dst = cvt->buf;
slouken@942
  1197
	switch (format & 0xFF) {
slouken@942
  1198
		case 8:
slouken@942
  1199
			for ( i=cvt->len_cvt/8; i; --i ) {
slouken@942
  1200
				dst[0] = src[0];
slouken@942
  1201
				dst[1] = src[1];
slouken@942
  1202
				dst[2] = src[2];
slouken@942
  1203
				dst[3] = src[3];
slouken@942
  1204
				src += 8;
slouken@942
  1205
				dst += 4;
slouken@942
  1206
			}
slouken@942
  1207
			break;
slouken@942
  1208
		case 16:
slouken@942
  1209
			for ( i=cvt->len_cvt/16; i; --i ) {
slouken@942
  1210
				dst[0] = src[0];
slouken@942
  1211
				dst[1] = src[1];
slouken@942
  1212
				dst[2] = src[2];
slouken@942
  1213
				dst[3] = src[3];
slouken@942
  1214
				dst[4] = src[4];
slouken@942
  1215
				dst[5] = src[5];
slouken@942
  1216
				dst[6] = src[6];
slouken@942
  1217
				dst[7] = src[7];
slouken@942
  1218
				src += 16;
slouken@942
  1219
				dst += 8;
slouken@942
  1220
			}
slouken@942
  1221
			break;
slouken@942
  1222
	}
slouken@942
  1223
	cvt->len_cvt /= 2;
slouken@942
  1224
	if ( cvt->filters[++cvt->filter_index] ) {
slouken@942
  1225
		cvt->filters[cvt->filter_index](cvt, format);
slouken@942
  1226
	}
slouken@942
  1227
}
slouken@942
  1228
slouken@942
  1229
/* Convert rate down by multiple of 2, for 5.1 */
slouken@942
  1230
void SDL_RateDIV2_c6(SDL_AudioCVT *cvt, Uint16 format)
slouken@942
  1231
{
slouken@942
  1232
	int i;
slouken@942
  1233
	Uint8 *src, *dst;
slouken@942
  1234
slouken@942
  1235
#ifdef DEBUG_CONVERT
slouken@942
  1236
	fprintf(stderr, "Converting audio rate / 2\n");
slouken@942
  1237
#endif
slouken@942
  1238
	src = cvt->buf;
slouken@942
  1239
	dst = cvt->buf;
slouken@942
  1240
	switch (format & 0xFF) {
slouken@942
  1241
		case 8:
slouken@942
  1242
			for ( i=cvt->len_cvt/12; i; --i ) {
slouken@942
  1243
				dst[0] = src[0];
slouken@942
  1244
				dst[1] = src[1];
slouken@942
  1245
				dst[2] = src[2];
slouken@942
  1246
				dst[3] = src[3];
slouken@942
  1247
				dst[4] = src[4];
slouken@942
  1248
				dst[5] = src[5];
slouken@942
  1249
				src += 12;
slouken@942
  1250
				dst += 6;
slouken@942
  1251
			}
slouken@942
  1252
			break;
slouken@942
  1253
		case 16:
slouken@942
  1254
			for ( i=cvt->len_cvt/24; i; --i ) {
slouken@942
  1255
				dst[0] = src[0];
slouken@942
  1256
				dst[1] = src[1];
slouken@942
  1257
				dst[2] = src[2];
slouken@942
  1258
				dst[3] = src[3];
slouken@942
  1259
				dst[4] = src[4];
slouken@942
  1260
				dst[5] = src[5];
slouken@942
  1261
				dst[6] = src[6];
slouken@942
  1262
				dst[7] = src[7];
slouken@942
  1263
				dst[8] = src[8];
slouken@942
  1264
				dst[9] = src[9];
slouken@942
  1265
				dst[10] = src[10];
slouken@942
  1266
				dst[11] = src[11];
slouken@942
  1267
				src += 24;
slouken@942
  1268
				dst += 12;
slouken@942
  1269
			}
slouken@942
  1270
			break;
slouken@942
  1271
	}
slouken@942
  1272
	cvt->len_cvt /= 2;
slouken@942
  1273
	if ( cvt->filters[++cvt->filter_index] ) {
slouken@942
  1274
		cvt->filters[cvt->filter_index](cvt, format);
slouken@942
  1275
	}
slouken@942
  1276
}
slouken@942
  1277
slouken@0
  1278
/* Very slow rate conversion routine */
slouken@0
  1279
void SDL_RateSLOW(SDL_AudioCVT *cvt, Uint16 format)
slouken@0
  1280
{
slouken@0
  1281
	double ipos;
slouken@0
  1282
	int i, clen;
slouken@0
  1283
slouken@0
  1284
#ifdef DEBUG_CONVERT
slouken@0
  1285
	fprintf(stderr, "Converting audio rate * %4.4f\n", 1.0/cvt->rate_incr);
slouken@0
  1286
#endif
slouken@0
  1287
	clen = (int)((double)cvt->len_cvt / cvt->rate_incr);
slouken@0
  1288
	if ( cvt->rate_incr > 1.0 ) {
slouken@0
  1289
		switch (format & 0xFF) {
slouken@0
  1290
			case 8: {
slouken@0
  1291
				Uint8 *output;
slouken@0
  1292
slouken@0
  1293
				output = cvt->buf;
slouken@0
  1294
				ipos = 0.0;
slouken@0
  1295
				for ( i=clen; i; --i ) {
slouken@0
  1296
					*output = cvt->buf[(int)ipos];
slouken@0
  1297
					ipos += cvt->rate_incr;
slouken@0
  1298
					output += 1;
slouken@0
  1299
				}
slouken@0
  1300
			}
slouken@0
  1301
			break;
slouken@0
  1302
slouken@0
  1303
			case 16: {
slouken@0
  1304
				Uint16 *output;
slouken@0
  1305
slouken@0
  1306
				clen &= ~1;
slouken@0
  1307
				output = (Uint16 *)cvt->buf;
slouken@0
  1308
				ipos = 0.0;
slouken@0
  1309
				for ( i=clen/2; i; --i ) {
slouken@0
  1310
					*output=((Uint16 *)cvt->buf)[(int)ipos];
slouken@0
  1311
					ipos += cvt->rate_incr;
slouken@0
  1312
					output += 1;
slouken@0
  1313
				}
slouken@0
  1314
			}
slouken@0
  1315
			break;
slouken@0
  1316
		}
slouken@0
  1317
	} else {
slouken@0
  1318
		switch (format & 0xFF) {
slouken@0
  1319
			case 8: {
slouken@0
  1320
				Uint8 *output;
slouken@0
  1321
slouken@0
  1322
				output = cvt->buf+clen;
slouken@0
  1323
				ipos = (double)cvt->len_cvt;
slouken@0
  1324
				for ( i=clen; i; --i ) {
slouken@0
  1325
					ipos -= cvt->rate_incr;
slouken@0
  1326
					output -= 1;
slouken@0
  1327
					*output = cvt->buf[(int)ipos];
slouken@0
  1328
				}
slouken@0
  1329
			}
slouken@0
  1330
			break;
slouken@0
  1331
slouken@0
  1332
			case 16: {
slouken@0
  1333
				Uint16 *output;
slouken@0
  1334
slouken@0
  1335
				clen &= ~1;
slouken@0
  1336
				output = (Uint16 *)(cvt->buf+clen);
slouken@0
  1337
				ipos = (double)cvt->len_cvt/2;
slouken@0
  1338
				for ( i=clen/2; i; --i ) {
slouken@0
  1339
					ipos -= cvt->rate_incr;
slouken@0
  1340
					output -= 1;
slouken@0
  1341
					*output=((Uint16 *)cvt->buf)[(int)ipos];
slouken@0
  1342
				}
slouken@0
  1343
			}
slouken@0
  1344
			break;
slouken@0
  1345
		}
slouken@0
  1346
	}
slouken@0
  1347
	cvt->len_cvt = clen;
slouken@0
  1348
	if ( cvt->filters[++cvt->filter_index] ) {
slouken@0
  1349
		cvt->filters[cvt->filter_index](cvt, format);
slouken@0
  1350
	}
slouken@0
  1351
}
slouken@0
  1352
slouken@0
  1353
int SDL_ConvertAudio(SDL_AudioCVT *cvt)
slouken@0
  1354
{
slouken@0
  1355
	/* Make sure there's data to convert */
slouken@0
  1356
	if ( cvt->buf == NULL ) {
slouken@0
  1357
		SDL_SetError("No buffer allocated for conversion");
slouken@0
  1358
		return(-1);
slouken@0
  1359
	}
slouken@0
  1360
	/* Return okay if no conversion is necessary */
slouken@0
  1361
	cvt->len_cvt = cvt->len;
slouken@0
  1362
	if ( cvt->filters[0] == NULL ) {
slouken@0
  1363
		return(0);
slouken@0
  1364
	}
slouken@0
  1365
slouken@0
  1366
	/* Set up the conversion and go! */
slouken@0
  1367
	cvt->filter_index = 0;
slouken@0
  1368
	cvt->filters[0](cvt, cvt->src_format);
slouken@0
  1369
	return(0);
slouken@0
  1370
}
slouken@0
  1371
slouken@0
  1372
/* Creates a set of audio filters to convert from one format to another. 
slouken@0
  1373
   Returns -1 if the format conversion is not supported, or 1 if the
slouken@0
  1374
   audio filter is set up.
slouken@0
  1375
*/
slouken@0
  1376
  
slouken@0
  1377
int SDL_BuildAudioCVT(SDL_AudioCVT *cvt,
slouken@0
  1378
	Uint16 src_format, Uint8 src_channels, int src_rate,
slouken@0
  1379
	Uint16 dst_format, Uint8 dst_channels, int dst_rate)
slouken@0
  1380
{
slouken@942
  1381
/*printf("Build format %04x->%04x, channels %u->%u, rate %d->%d\n",
slouken@942
  1382
		src_format, dst_format, src_channels, dst_channels, src_rate, dst_rate);*/
slouken@0
  1383
	/* Start off with no conversion necessary */
slouken@0
  1384
	cvt->needed = 0;
slouken@0
  1385
	cvt->filter_index = 0;
slouken@0
  1386
	cvt->filters[0] = NULL;
slouken@0
  1387
	cvt->len_mult = 1;
slouken@0
  1388
	cvt->len_ratio = 1.0;
slouken@0
  1389
slouken@0
  1390
	/* First filter:  Endian conversion from src to dst */
slouken@0
  1391
	if ( (src_format & 0x1000) != (dst_format & 0x1000)
slouken@0
  1392
	     && ((src_format & 0xff) != 8) ) {
slouken@0
  1393
		cvt->filters[cvt->filter_index++] = SDL_ConvertEndian;
slouken@0
  1394
	}
slouken@0
  1395
	
slouken@0
  1396
	/* Second filter: Sign conversion -- signed/unsigned */
slouken@0
  1397
	if ( (src_format & 0x8000) != (dst_format & 0x8000) ) {
slouken@0
  1398
		cvt->filters[cvt->filter_index++] = SDL_ConvertSign;
slouken@0
  1399
	}
slouken@0
  1400
slouken@0
  1401
	/* Next filter:  Convert 16 bit <--> 8 bit PCM */
slouken@0
  1402
	if ( (src_format & 0xFF) != (dst_format & 0xFF) ) {
slouken@0
  1403
		switch (dst_format&0x10FF) {
slouken@0
  1404
			case AUDIO_U8:
slouken@0
  1405
				cvt->filters[cvt->filter_index++] =
slouken@0
  1406
							 SDL_Convert8;
slouken@0
  1407
				cvt->len_ratio /= 2;
slouken@0
  1408
				break;
slouken@0
  1409
			case AUDIO_U16LSB:
slouken@0
  1410
				cvt->filters[cvt->filter_index++] =
slouken@0
  1411
							SDL_Convert16LSB;
slouken@0
  1412
				cvt->len_mult *= 2;
slouken@0
  1413
				cvt->len_ratio *= 2;
slouken@0
  1414
				break;
slouken@0
  1415
			case AUDIO_U16MSB:
slouken@0
  1416
				cvt->filters[cvt->filter_index++] =
slouken@0
  1417
							SDL_Convert16MSB;
slouken@0
  1418
				cvt->len_mult *= 2;
slouken@0
  1419
				cvt->len_ratio *= 2;
slouken@0
  1420
				break;
slouken@0
  1421
		}
slouken@0
  1422
	}
slouken@0
  1423
slouken@0
  1424
	/* Last filter:  Mono/Stereo conversion */
slouken@0
  1425
	if ( src_channels != dst_channels ) {
slouken@942
  1426
		if ( (src_channels == 1) && (dst_channels > 1) ) {
slouken@942
  1427
			cvt->filters[cvt->filter_index++] = 
slouken@942
  1428
						SDL_ConvertStereo;
slouken@942
  1429
			cvt->len_mult *= 2;
slouken@942
  1430
			src_channels = 2;
slouken@942
  1431
			cvt->len_ratio *= 2;
slouken@942
  1432
		}
slouken@942
  1433
		if ( (src_channels == 2) &&
slouken@942
  1434
				(dst_channels == 6) ) {
slouken@942
  1435
			cvt->filters[cvt->filter_index++] =
slouken@942
  1436
						 SDL_ConvertSurround;
slouken@942
  1437
			src_channels = 6;
slouken@942
  1438
			cvt->len_mult *= 3;
slouken@942
  1439
			cvt->len_ratio *= 3;
slouken@942
  1440
		}
slouken@942
  1441
		if ( (src_channels == 2) &&
slouken@942
  1442
				(dst_channels == 4) ) {
slouken@942
  1443
			cvt->filters[cvt->filter_index++] =
slouken@942
  1444
						 SDL_ConvertSurround_4;
slouken@942
  1445
			src_channels = 4;
slouken@942
  1446
			cvt->len_mult *= 2;
slouken@942
  1447
			cvt->len_ratio *= 2;
slouken@942
  1448
		}
slouken@0
  1449
		while ( (src_channels*2) <= dst_channels ) {
slouken@0
  1450
			cvt->filters[cvt->filter_index++] = 
slouken@0
  1451
						SDL_ConvertStereo;
slouken@0
  1452
			cvt->len_mult *= 2;
slouken@0
  1453
			src_channels *= 2;
slouken@0
  1454
			cvt->len_ratio *= 2;
slouken@0
  1455
		}
slouken@942
  1456
		if ( (src_channels == 6) &&
slouken@942
  1457
				(dst_channels <= 2) ) {
slouken@942
  1458
			cvt->filters[cvt->filter_index++] =
slouken@942
  1459
						 SDL_ConvertStrip;
slouken@942
  1460
			src_channels = 2;
slouken@942
  1461
			cvt->len_ratio /= 3;
slouken@942
  1462
		}
slouken@942
  1463
		if ( (src_channels == 6) &&
slouken@942
  1464
				(dst_channels == 4) ) {
slouken@942
  1465
			cvt->filters[cvt->filter_index++] =
slouken@942
  1466
						 SDL_ConvertStrip_2;
slouken@942
  1467
			src_channels = 4;
slouken@942
  1468
			cvt->len_ratio /= 2;
slouken@942
  1469
		}
slouken@0
  1470
		/* This assumes that 4 channel audio is in the format:
slouken@0
  1471
		     Left {front/back} + Right {front/back}
slouken@0
  1472
		   so converting to L/R stereo works properly.
slouken@0
  1473
		 */
slouken@0
  1474
		while ( ((src_channels%2) == 0) &&
slouken@0
  1475
				((src_channels/2) >= dst_channels) ) {
slouken@0
  1476
			cvt->filters[cvt->filter_index++] =
slouken@0
  1477
						 SDL_ConvertMono;
slouken@0
  1478
			src_channels /= 2;
slouken@0
  1479
			cvt->len_ratio /= 2;
slouken@0
  1480
		}
slouken@0
  1481
		if ( src_channels != dst_channels ) {
slouken@0
  1482
			/* Uh oh.. */;
slouken@0
  1483
		}
slouken@0
  1484
	}
slouken@0
  1485
slouken@0
  1486
	/* Do rate conversion */
slouken@0
  1487
	cvt->rate_incr = 0.0;
slouken@0
  1488
	if ( (src_rate/100) != (dst_rate/100) ) {
slouken@0
  1489
		Uint32 hi_rate, lo_rate;
slouken@0
  1490
		int len_mult;
slouken@0
  1491
		double len_ratio;
slouken@0
  1492
		void (*rate_cvt)(SDL_AudioCVT *cvt, Uint16 format);
slouken@0
  1493
slouken@0
  1494
		if ( src_rate > dst_rate ) {
slouken@0
  1495
			hi_rate = src_rate;
slouken@0
  1496
			lo_rate = dst_rate;
slouken@942
  1497
			switch (src_channels) {
slouken@942
  1498
				case 1: rate_cvt = SDL_RateDIV2; break;
slouken@942
  1499
				case 2: rate_cvt = SDL_RateDIV2_c2; break;
slouken@942
  1500
				case 4: rate_cvt = SDL_RateDIV2_c4; break;
slouken@942
  1501
				case 6: rate_cvt = SDL_RateDIV2_c6; break;
slouken@942
  1502
				default: return -1;
slouken@942
  1503
			}
slouken@0
  1504
			len_mult = 1;
slouken@0
  1505
			len_ratio = 0.5;
slouken@0
  1506
		} else {
slouken@0
  1507
			hi_rate = dst_rate;
slouken@0
  1508
			lo_rate = src_rate;
slouken@942
  1509
			switch (src_channels) {
slouken@942
  1510
				case 1: rate_cvt = SDL_RateMUL2; break;
slouken@942
  1511
				case 2: rate_cvt = SDL_RateMUL2_c2; break;
slouken@942
  1512
				case 4: rate_cvt = SDL_RateMUL2_c4; break;
slouken@942
  1513
				case 6: rate_cvt = SDL_RateMUL2_c6; break;
slouken@942
  1514
				default: return -1;
slouken@942
  1515
			}
slouken@0
  1516
			len_mult = 2;
slouken@0
  1517
			len_ratio = 2.0;
slouken@0
  1518
		}
slouken@0
  1519
		/* If hi_rate = lo_rate*2^x then conversion is easy */
slouken@0
  1520
		while ( ((lo_rate*2)/100) <= (hi_rate/100) ) {
slouken@0
  1521
			cvt->filters[cvt->filter_index++] = rate_cvt;
slouken@0
  1522
			cvt->len_mult *= len_mult;
slouken@0
  1523
			lo_rate *= 2;
slouken@0
  1524
			cvt->len_ratio *= len_ratio;
slouken@0
  1525
		}
slouken@0
  1526
		/* We may need a slow conversion here to finish up */
slouken@0
  1527
		if ( (lo_rate/100) != (hi_rate/100) ) {
slouken@0
  1528
#if 1
slouken@0
  1529
			/* The problem with this is that if the input buffer is
slouken@0
  1530
			   say 1K, and the conversion rate is say 1.1, then the
slouken@0
  1531
			   output buffer is 1.1K, which may not be an acceptable
slouken@0
  1532
			   buffer size for the audio driver (not a power of 2)
slouken@0
  1533
			*/
slouken@0
  1534
			/* For now, punt and hope the rate distortion isn't great.
slouken@0
  1535
			*/
slouken@0
  1536
#else
slouken@0
  1537
			if ( src_rate < dst_rate ) {
slouken@0
  1538
				cvt->rate_incr = (double)lo_rate/hi_rate;
slouken@0
  1539
				cvt->len_mult *= 2;
slouken@0
  1540
				cvt->len_ratio /= cvt->rate_incr;
slouken@0
  1541
			} else {
slouken@0
  1542
				cvt->rate_incr = (double)hi_rate/lo_rate;
slouken@0
  1543
				cvt->len_ratio *= cvt->rate_incr;
slouken@0
  1544
			}
slouken@0
  1545
			cvt->filters[cvt->filter_index++] = SDL_RateSLOW;
slouken@0
  1546
#endif
slouken@0
  1547
		}
slouken@0
  1548
	}
slouken@0
  1549
slouken@0
  1550
	/* Set up the filter information */
slouken@0
  1551
	if ( cvt->filter_index != 0 ) {
slouken@0
  1552
		cvt->needed = 1;
slouken@0
  1553
		cvt->src_format = src_format;
slouken@0
  1554
		cvt->dst_format = dst_format;
slouken@0
  1555
		cvt->len = 0;
slouken@0
  1556
		cvt->buf = NULL;
slouken@0
  1557
		cvt->filters[cvt->filter_index] = NULL;
slouken@0
  1558
	}
slouken@0
  1559
	return(cvt->needed);
slouken@0
  1560
}