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annotate src/audio/SDL_mixer_m68k.h @ 2042:3908e1f808e1

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Fixed bug #292 I might be on crack here. It looks like SDL_ConvertMono() in src/audio/SDL_audiocvt.c adds the left and right channels of a stereo stream together, and clamps the new mono channel if it would overflow. Shouldn't it be dividing by 2 to average the two sample points instead of clamping? Otherwise the mono sample point's volume doubles in the conversion. This would also make the conversion faster, as it replaces two branches per sample frame with a bitwise shift. --ryan.
author Sam Lantinga <slouken@libsdl.org>
date Sun, 24 Sep 2006 15:56:36 +0000
parents c121d94672cb
children 99210400e8b9
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1 /*
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2 SDL - Simple DirectMedia Layer
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3 Copyright (C) 1997-2004 Sam Lantinga
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4
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5 This library is free software; you can redistribute it and/or
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6 modify it under the terms of the GNU Library General Public
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7 License as published by the Free Software Foundation; either
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8 version 2 of the License, or (at your option) any later version.
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9
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10 This library is distributed in the hope that it will be useful,
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11 but WITHOUT ANY WARRANTY; without even the implied warranty of
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12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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13 Library General Public License for more details.
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14
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15 You should have received a copy of the GNU Library General Public
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16 License along with this library; if not, write to the Free
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17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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18
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19 Sam Lantinga
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20 slouken@libsdl.org
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21 */
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22 #include "SDL_config.h"
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23
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24 /*
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25 m68k assembly mix routines
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26
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27 Patrice Mandin
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28 */
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29
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30 #if defined(__M68000__) && defined(__GNUC__)
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31 void SDL_MixAudio_m68k_U8(char *dst, char *src, long len, long volume,
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32 char *mix8);
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33 void SDL_MixAudio_m68k_S8(char *dst, char *src, long len, long volume);
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34
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35 void SDL_MixAudio_m68k_S16MSB(short *dst, short *src, long len, long volume);
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36 void SDL_MixAudio_m68k_S16LSB(short *dst, short *src, long len, long volume);
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37 #endif
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38 /* vi: set ts=4 sw=4 expandtab: */