Mercurial > sdl-ios-xcode
annotate docs/html/audio.html @ 4333:55717a755897 SDL-1.2
Switched from setting the period size and count to setting the buffer size directly, based on feedback from the ALSA development list:
http://mailman.alsa-project.org/pipermail/alsa-devel/2009-October/022267.html
This has the nice side effect of reducing latency on my SBLive! card.
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Tue, 13 Oct 2009 09:56:15 +0000 |
| parents | 355632dca928 |
| children |
| rev | line source |
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| 0 | 1 <HTML |
| 2 ><HEAD | |
| 3 ><TITLE | |
| 4 >Audio</TITLE | |
| 5 ><META | |
| 6 NAME="GENERATOR" | |
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7 CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+ |
| 0 | 8 "><LINK |
| 9 REL="HOME" | |
| 10 TITLE="SDL Library Documentation" | |
| 11 HREF="index.html"><LINK | |
| 12 REL="UP" | |
| 13 TITLE="SDL Reference" | |
| 14 HREF="reference.html"><LINK | |
| 15 REL="PREVIOUS" | |
| 16 TITLE="SDL_JoystickClose" | |
| 17 HREF="sdljoystickclose.html"><LINK | |
| 18 REL="NEXT" | |
| 19 TITLE="SDL_AudioSpec" | |
| 20 HREF="sdlaudiospec.html"><META | |
| 21 NAME="KEYWORD" | |
| 22 CONTENT="audio"><META | |
| 23 NAME="KEYWORD" | |
| 24 CONTENT="function"></HEAD | |
| 25 ><BODY | |
| 26 CLASS="CHAPTER" | |
| 27 BGCOLOR="#FFF8DC" | |
| 28 TEXT="#000000" | |
| 29 LINK="#0000ee" | |
| 30 VLINK="#551a8b" | |
| 31 ALINK="#ff0000" | |
| 32 ><DIV | |
| 33 CLASS="NAVHEADER" | |
| 34 ><TABLE | |
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35 SUMMARY="Header navigation table" |
| 0 | 36 WIDTH="100%" |
| 37 BORDER="0" | |
| 38 CELLPADDING="0" | |
| 39 CELLSPACING="0" | |
| 40 ><TR | |
| 41 ><TH | |
| 42 COLSPAN="3" | |
| 43 ALIGN="center" | |
| 44 >SDL Library Documentation</TH | |
| 45 ></TR | |
| 46 ><TR | |
| 47 ><TD | |
| 48 WIDTH="10%" | |
| 49 ALIGN="left" | |
| 50 VALIGN="bottom" | |
| 51 ><A | |
| 52 HREF="sdljoystickclose.html" | |
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53 ACCESSKEY="P" |
| 0 | 54 >Prev</A |
| 55 ></TD | |
| 56 ><TD | |
| 57 WIDTH="80%" | |
| 58 ALIGN="center" | |
| 59 VALIGN="bottom" | |
| 60 ></TD | |
| 61 ><TD | |
| 62 WIDTH="10%" | |
| 63 ALIGN="right" | |
| 64 VALIGN="bottom" | |
| 65 ><A | |
| 66 HREF="sdlaudiospec.html" | |
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67 ACCESSKEY="N" |
| 0 | 68 >Next</A |
| 69 ></TD | |
| 70 ></TR | |
| 71 ></TABLE | |
| 72 ><HR | |
| 73 ALIGN="LEFT" | |
| 74 WIDTH="100%"></DIV | |
| 75 ><DIV | |
| 76 CLASS="CHAPTER" | |
| 77 ><H1 | |
| 78 ><A | |
| 79 NAME="AUDIO" | |
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80 ></A |
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81 >Chapter 10. Audio</H1 |
| 0 | 82 ><DIV |
| 83 CLASS="TOC" | |
| 84 ><DL | |
| 85 ><DT | |
| 86 ><B | |
| 87 >Table of Contents</B | |
| 88 ></DT | |
| 89 ><DT | |
| 90 ><A | |
| 91 HREF="sdlaudiospec.html" | |
| 92 >SDL_AudioSpec</A | |
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93 > -- Audio Specification Structure</DT |
| 0 | 94 ><DT |
| 95 ><A | |
| 96 HREF="sdlopenaudio.html" | |
| 97 >SDL_OpenAudio</A | |
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98 > -- Opens the audio device with the desired parameters.</DT |
| 0 | 99 ><DT |
| 100 ><A | |
| 101 HREF="sdlpauseaudio.html" | |
| 102 >SDL_PauseAudio</A | |
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103 > -- Pauses and unpauses the audio callback processing</DT |
| 0 | 104 ><DT |
| 105 ><A | |
| 106 HREF="sdlgetaudiostatus.html" | |
| 107 >SDL_GetAudioStatus</A | |
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108 > -- Get the current audio state</DT |
| 0 | 109 ><DT |
| 110 ><A | |
| 111 HREF="sdlloadwav.html" | |
| 112 >SDL_LoadWAV</A | |
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113 > -- Load a WAVE file</DT |
| 0 | 114 ><DT |
| 115 ><A | |
| 116 HREF="sdlfreewav.html" | |
| 117 >SDL_FreeWAV</A | |
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118 > -- Frees previously opened WAV data</DT |
| 0 | 119 ><DT |
| 120 ><A | |
| 121 HREF="sdlaudiocvt.html" | |
| 122 >SDL_AudioCVT</A | |
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123 > -- Audio Conversion Structure</DT |
| 0 | 124 ><DT |
| 125 ><A | |
| 126 HREF="sdlbuildaudiocvt.html" | |
| 127 >SDL_BuildAudioCVT</A | |
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128 > -- Initializes a SDL_AudioCVT structure for conversion</DT |
| 0 | 129 ><DT |
| 130 ><A | |
| 131 HREF="sdlconvertaudio.html" | |
| 132 >SDL_ConvertAudio</A | |
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133 > -- Convert audio data to a desired audio format.</DT |
| 0 | 134 ><DT |
| 135 ><A | |
| 136 HREF="sdlmixaudio.html" | |
| 137 >SDL_MixAudio</A | |
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138 > -- Mix audio data</DT |
| 0 | 139 ><DT |
| 140 ><A | |
| 141 HREF="sdllockaudio.html" | |
| 142 >SDL_LockAudio</A | |
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143 > -- Lock out the callback function</DT |
| 0 | 144 ><DT |
| 145 ><A | |
| 146 HREF="sdlunlockaudio.html" | |
| 147 >SDL_UnlockAudio</A | |
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148 > -- Unlock the callback function</DT |
| 0 | 149 ><DT |
| 150 ><A | |
| 151 HREF="sdlcloseaudio.html" | |
| 152 >SDL_CloseAudio</A | |
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153 > -- Shuts down audio processing and closes the audio device.</DT |
| 0 | 154 ></DL |
| 155 ></DIV | |
| 156 ><P | |
| 157 >Sound on the computer is translated from waves that you hear into a series of | |
| 158 values, or samples, each representing the amplitude of the wave. When these | |
| 159 samples are sent in a stream to a sound card, an approximation of the original | |
| 160 wave can be recreated. The more bits used to represent the amplitude, and the | |
| 161 greater frequency these samples are gathered, the closer the approximated | |
| 162 sound is to the original, and the better the quality of sound.</P | |
| 163 ><P | |
| 164 >This library supports both 8 and 16 bit signed and unsigned sound samples, | |
| 165 at frequencies ranging from 11025 Hz to 44100 Hz, depending on the | |
| 166 underlying hardware. If the hardware doesn't support the desired audio | |
| 167 format or frequency, it can be emulated if desired (See | |
| 168 <A | |
| 169 HREF="sdlopenaudio.html" | |
| 170 ><TT | |
| 171 CLASS="FUNCTION" | |
| 172 >SDL_OpenAudio()</TT | |
| 173 ></A | |
| 174 >)</P | |
| 175 ><P | |
| 176 >A commonly supported audio format is 16 bits per sample at 22050 Hz.</P | |
| 177 ></DIV | |
| 178 ><DIV | |
| 179 CLASS="NAVFOOTER" | |
| 180 ><HR | |
| 181 ALIGN="LEFT" | |
| 182 WIDTH="100%"><TABLE | |
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183 SUMMARY="Footer navigation table" |
| 0 | 184 WIDTH="100%" |
| 185 BORDER="0" | |
| 186 CELLPADDING="0" | |
| 187 CELLSPACING="0" | |
| 188 ><TR | |
| 189 ><TD | |
| 190 WIDTH="33%" | |
| 191 ALIGN="left" | |
| 192 VALIGN="top" | |
| 193 ><A | |
| 194 HREF="sdljoystickclose.html" | |
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195 ACCESSKEY="P" |
| 0 | 196 >Prev</A |
| 197 ></TD | |
| 198 ><TD | |
| 199 WIDTH="34%" | |
| 200 ALIGN="center" | |
| 201 VALIGN="top" | |
| 202 ><A | |
| 203 HREF="index.html" | |
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204 ACCESSKEY="H" |
| 0 | 205 >Home</A |
| 206 ></TD | |
| 207 ><TD | |
| 208 WIDTH="33%" | |
| 209 ALIGN="right" | |
| 210 VALIGN="top" | |
| 211 ><A | |
| 212 HREF="sdlaudiospec.html" | |
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213 ACCESSKEY="N" |
| 0 | 214 >Next</A |
| 215 ></TD | |
| 216 ></TR | |
| 217 ><TR | |
| 218 ><TD | |
| 219 WIDTH="33%" | |
| 220 ALIGN="left" | |
| 221 VALIGN="top" | |
| 222 >SDL_JoystickClose</TD | |
| 223 ><TD | |
| 224 WIDTH="34%" | |
| 225 ALIGN="center" | |
| 226 VALIGN="top" | |
| 227 ><A | |
| 228 HREF="reference.html" | |
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229 ACCESSKEY="U" |
| 0 | 230 >Up</A |
| 231 ></TD | |
| 232 ><TD | |
| 233 WIDTH="33%" | |
| 234 ALIGN="right" | |
| 235 VALIGN="top" | |
| 236 >SDL_AudioSpec</TD | |
| 237 ></TR | |
| 238 ></TABLE | |
| 239 ></DIV | |
| 240 ></BODY | |
| 241 ></HTML | |
| 242 > |