Mercurial > sdl-ios-xcode
annotate docs/html/sdlpauseaudio.html @ 765:4c2ba6161939
Editors Note: The original patch was modified to use SDL_Delay() instead of
nanosleep because nanosleep may not be portable to all systems
using SDL with the ALSA backend. This may be a moot point with
the switch to blocking writes anyway...
Date: Sat, 27 Dec 2003 21:47:36 +0100
From: Michel Daenzer
To: Debian Bug Tracking System
Subject: [SDL] Bug#225252: [PATCH] ALSA fixes
Package: libsdl1.2debian-all
Version: 1.2.6-2
Severity: normal
Tags: patch
For SDL 1.2.6, the ALSA backend was changed to call snd_pcm_open() with
SND_PCM_NONBLOCK. That's a good idea per se, however, it causes high CPU
usage, interrupted sound and stuttering in some games here. Taking a nanosleep
whenever snd_pcm_writei() returns -EAGAIN fixes this, but I think it's more
efficient to use blocking mode for the actual sound playback. Feedback from the
SDL and ALSA lists appreciated.
The patch also fixes the default ALSA device to be used.
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Sun, 04 Jan 2004 15:40:50 +0000 |
| parents | e5bc29de3f0a |
| children | 355632dca928 |
| rev | line source |
|---|---|
| 0 | 1 <HTML |
| 2 ><HEAD | |
| 3 ><TITLE | |
| 4 >SDL_PauseAudio</TITLE | |
| 5 ><META | |
| 6 NAME="GENERATOR" | |
|
55
55f1f1b3e27d
Added new docs for SDL 1.2.1
Sam Lantinga <slouken@lokigames.com>
parents:
0
diff
changeset
|
7 CONTENT="Modular DocBook HTML Stylesheet Version 1.64 |
| 0 | 8 "><LINK |
| 9 REL="HOME" | |
| 10 TITLE="SDL Library Documentation" | |
| 11 HREF="index.html"><LINK | |
| 12 REL="UP" | |
| 13 TITLE="Audio" | |
| 14 HREF="audio.html"><LINK | |
| 15 REL="PREVIOUS" | |
| 16 TITLE="SDL_OpenAudio" | |
| 17 HREF="sdlopenaudio.html"><LINK | |
| 18 REL="NEXT" | |
| 19 TITLE="SDL_GetAudioStatus" | |
| 20 HREF="sdlgetaudiostatus.html"></HEAD | |
| 21 ><BODY | |
| 22 CLASS="REFENTRY" | |
| 23 BGCOLOR="#FFF8DC" | |
| 24 TEXT="#000000" | |
| 25 LINK="#0000ee" | |
| 26 VLINK="#551a8b" | |
| 27 ALINK="#ff0000" | |
| 28 ><DIV | |
| 29 CLASS="NAVHEADER" | |
| 30 ><TABLE | |
| 31 WIDTH="100%" | |
| 32 BORDER="0" | |
| 33 CELLPADDING="0" | |
| 34 CELLSPACING="0" | |
| 35 ><TR | |
| 36 ><TH | |
| 37 COLSPAN="3" | |
| 38 ALIGN="center" | |
| 39 >SDL Library Documentation</TH | |
| 40 ></TR | |
| 41 ><TR | |
| 42 ><TD | |
| 43 WIDTH="10%" | |
| 44 ALIGN="left" | |
| 45 VALIGN="bottom" | |
| 46 ><A | |
| 47 HREF="sdlopenaudio.html" | |
| 48 >Prev</A | |
| 49 ></TD | |
| 50 ><TD | |
| 51 WIDTH="80%" | |
| 52 ALIGN="center" | |
| 53 VALIGN="bottom" | |
| 54 ></TD | |
| 55 ><TD | |
| 56 WIDTH="10%" | |
| 57 ALIGN="right" | |
| 58 VALIGN="bottom" | |
| 59 ><A | |
| 60 HREF="sdlgetaudiostatus.html" | |
| 61 >Next</A | |
| 62 ></TD | |
| 63 ></TR | |
| 64 ></TABLE | |
| 65 ><HR | |
| 66 ALIGN="LEFT" | |
| 67 WIDTH="100%"></DIV | |
| 68 ><H1 | |
| 69 ><A | |
| 70 NAME="SDLPAUSEAUDIO" | |
| 71 >SDL_PauseAudio</A | |
| 72 ></H1 | |
| 73 ><DIV | |
| 74 CLASS="REFNAMEDIV" | |
| 75 ><A | |
|
181
e5bc29de3f0a
Updated from the SDL Documentation Project
Sam Lantinga <slouken@libsdl.org>
parents:
55
diff
changeset
|
76 NAME="AEN6377" |
| 0 | 77 ></A |
| 78 ><H2 | |
| 79 >Name</H2 | |
| 80 >SDL_PauseAudio -- Pauses and unpauses the audio callback processing</DIV | |
| 81 ><DIV | |
| 82 CLASS="REFSYNOPSISDIV" | |
| 83 ><A | |
|
181
e5bc29de3f0a
Updated from the SDL Documentation Project
Sam Lantinga <slouken@libsdl.org>
parents:
55
diff
changeset
|
84 NAME="AEN6380" |
| 0 | 85 ></A |
| 86 ><H2 | |
| 87 >Synopsis</H2 | |
| 88 ><DIV | |
| 89 CLASS="FUNCSYNOPSIS" | |
| 90 ><A | |
|
181
e5bc29de3f0a
Updated from the SDL Documentation Project
Sam Lantinga <slouken@libsdl.org>
parents:
55
diff
changeset
|
91 NAME="AEN6381" |
| 0 | 92 ></A |
| 93 ><P | |
| 94 ></P | |
| 95 ><PRE | |
| 96 CLASS="FUNCSYNOPSISINFO" | |
| 97 >#include "SDL.h"</PRE | |
| 98 ><P | |
| 99 ><CODE | |
| 100 ><CODE | |
| 101 CLASS="FUNCDEF" | |
| 102 >void <B | |
| 103 CLASS="FSFUNC" | |
| 104 >SDL_PauseAudio</B | |
| 105 ></CODE | |
| 106 >(int pause_on);</CODE | |
| 107 ></P | |
| 108 ><P | |
| 109 ></P | |
| 110 ></DIV | |
| 111 ></DIV | |
| 112 ><DIV | |
| 113 CLASS="REFSECT1" | |
| 114 ><A | |
|
181
e5bc29de3f0a
Updated from the SDL Documentation Project
Sam Lantinga <slouken@libsdl.org>
parents:
55
diff
changeset
|
115 NAME="AEN6387" |
| 0 | 116 ></A |
| 117 ><H2 | |
| 118 >Description</H2 | |
| 119 ><P | |
| 120 >This function pauses and unpauses the audio callback processing. | |
| 121 It should be called with <TT | |
| 122 CLASS="PARAMETER" | |
| 123 ><I | |
| 124 >pause_on</I | |
| 125 ></TT | |
| 126 >=0 after opening the audio | |
| 127 device to start playing sound. This is so you can safely initialize | |
| 128 data for your callback function after opening the audio device. | |
| 129 Silence will be written to the audio device during the pause.</P | |
| 130 ></DIV | |
| 131 ><DIV | |
| 132 CLASS="REFSECT1" | |
| 133 ><A | |
|
181
e5bc29de3f0a
Updated from the SDL Documentation Project
Sam Lantinga <slouken@libsdl.org>
parents:
55
diff
changeset
|
134 NAME="AEN6391" |
| 0 | 135 ></A |
| 136 ><H2 | |
| 137 >See Also</H2 | |
| 138 ><P | |
| 139 ><A | |
| 140 HREF="sdlgetaudiostatus.html" | |
| 141 ><TT | |
| 142 CLASS="FUNCTION" | |
| 143 >SDL_GetAudioStatus</TT | |
| 144 ></A | |
| 145 >, | |
| 146 <A | |
| 147 HREF="sdlopenaudio.html" | |
| 148 ><TT | |
| 149 CLASS="FUNCTION" | |
| 150 >SDL_OpenAudio</TT | |
| 151 ></A | |
| 152 ></P | |
| 153 ></DIV | |
| 154 ><DIV | |
| 155 CLASS="NAVFOOTER" | |
| 156 ><HR | |
| 157 ALIGN="LEFT" | |
| 158 WIDTH="100%"><TABLE | |
| 159 WIDTH="100%" | |
| 160 BORDER="0" | |
| 161 CELLPADDING="0" | |
| 162 CELLSPACING="0" | |
| 163 ><TR | |
| 164 ><TD | |
| 165 WIDTH="33%" | |
| 166 ALIGN="left" | |
| 167 VALIGN="top" | |
| 168 ><A | |
| 169 HREF="sdlopenaudio.html" | |
| 170 >Prev</A | |
| 171 ></TD | |
| 172 ><TD | |
| 173 WIDTH="34%" | |
| 174 ALIGN="center" | |
| 175 VALIGN="top" | |
| 176 ><A | |
| 177 HREF="index.html" | |
| 178 >Home</A | |
| 179 ></TD | |
| 180 ><TD | |
| 181 WIDTH="33%" | |
| 182 ALIGN="right" | |
| 183 VALIGN="top" | |
| 184 ><A | |
| 185 HREF="sdlgetaudiostatus.html" | |
| 186 >Next</A | |
| 187 ></TD | |
| 188 ></TR | |
| 189 ><TR | |
| 190 ><TD | |
| 191 WIDTH="33%" | |
| 192 ALIGN="left" | |
| 193 VALIGN="top" | |
| 194 >SDL_OpenAudio</TD | |
| 195 ><TD | |
| 196 WIDTH="34%" | |
| 197 ALIGN="center" | |
| 198 VALIGN="top" | |
| 199 ><A | |
| 200 HREF="audio.html" | |
| 201 >Up</A | |
| 202 ></TD | |
| 203 ><TD | |
| 204 WIDTH="33%" | |
| 205 ALIGN="right" | |
| 206 VALIGN="top" | |
| 207 >SDL_GetAudioStatus</TD | |
| 208 ></TR | |
| 209 ></TABLE | |
| 210 ></DIV | |
| 211 ></BODY | |
| 212 ></HTML | |
| 213 > |