annotate src/audio/dsp/SDL_dspaudio.h @ 4001:6831b8723a85 SDL-1.2

Don't initialize the audio buffer passed to the application's audio callback, since they are expected to entirely fill it with data or silence. For legacy apps that might expect the buffer to already have silence and thus may not fill the buffer in the callback, there's an environment variable to expose the old behaviour. Fixes Bugzilla #416.
author Ryan C. Gordon <icculus@icculus.org>
date Thu, 05 Jul 2007 02:24:36 +0000
parents d910939febfa
children 782fd950bd46 a1b03ba2fcd0
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1 /*
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2 SDL - Simple DirectMedia Layer
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3 Copyright (C) 1997-2006 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 Lesser General Public
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7 License as published by the Free Software Foundation; either
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8 version 2.1 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 Lesser 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 Lesser General Public
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16 License along with this library; if not, write to the Free Software
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17 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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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_dspaudio_h
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25 #define _SDL_dspaudio_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 /* Hidden "this" pointer for the video functions */
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30 #define _THIS SDL_AudioDevice *this
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31
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32 struct SDL_PrivateAudioData {
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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 #define FUDGE_TICKS 10 /* The scheduler overhead ticks per frame */
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44
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45 /* Old variable names */
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46 #define audio_fd (this->hidden->audio_fd)
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47 #define parent (this->hidden->parent)
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48 #define mixbuf (this->hidden->mixbuf)
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49 #define mixlen (this->hidden->mixlen)
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50 #define frame_ticks (this->hidden->frame_ticks)
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51 #define next_frame (this->hidden->next_frame)
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52
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53 #endif /* _SDL_dspaudio_h */