Mercurial > sdl-ios-xcode

annotate src/audio/bsd/SDL_bsdaudio.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 5f6550e5184f
rev   line source
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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 #ifndef _SDL_openbsdaudio_h
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25 #define _SDL_openbsdaudio_h
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26
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27 #include "../SDL_sysaudio.h"
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28
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29 #define _THIS SDL_AudioDevice *this
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30
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31 struct SDL_PrivateAudioData
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32 {
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33 /* The file descriptor for the audio device */
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34 int audio_fd;
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35
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36 /* The parent process id, to detect when application quits */
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37 pid_t parent;
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38
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39 /* Raw mixing buffer */
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40 Uint8 *mixbuf;
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41 int mixlen;
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42
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43 /* Support for audio timing using a timer, in addition to select() */
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44 float frame_ticks;
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45 float next_frame;
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46 };
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47
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48 #define FUDGE_TICKS 10 /* The scheduler overhead ticks per frame */
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49
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50 /* Old variable names */
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51 #define audio_fd (this->hidden->audio_fd)
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52 #define parent (this->hidden->parent)
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53 #define mixbuf (this->hidden->mixbuf)
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54 #define mixlen (this->hidden->mixlen)
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55 #define frame_ticks (this->hidden->frame_ticks)
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56 #define next_frame (this->hidden->next_frame)
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57
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58 #endif /* _SDL_openbsdaudio_h */
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59 /* vi: set ts=4 sw=4 expandtab: */