Mercurial > sdl-ios-xcode
annotate docs/html/sdllockaudio.html @ 968:4675910b0b7b
Date: Mon, 11 Oct 2004 15:17:27 +0300 (EEST)
From: Hannu Savolainen
Subject: Re: SDL uses obsolete OSS features
I did some work on getting OSS to work better with SDL. There have been
some problems with select which should be fixed now.
I'm having some problems in understanding what is the purpose of the
DSP_WaitAudio() routine. I added a return to the very beginning of this
routine and commendted out the define for USE_BLOCKING_WRITES. At least
lbreakout2 seems to work as well as earlier. The latencies are the same.
An ordinary blocking write does exactly the same thing than DSP_WaitAudio
does. So I would recommend using the USE_BLOCKING_WRITES approach and
removing everything from the DSP_WaitAudio routine. Also enabling
USE_BLOCKING_WRITES makes it possible to simplify DSP_PlayAudio() because
you don't need to handle the partial writes (the do-while loop).
Attached is a patch against SDL-1.2.7. After these changes SDL will use
OSS as it's designed to be used (make it as simple as possible). This code
should work with all OSS implementations because it uses only the very
fundamental features that have been there since the jurassic times.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Fri, 12 Nov 2004 21:39:04 +0000 |
parents | 355632dca928 |
children |
rev | line source |
---|---|
0 | 1 <HTML |
2 ><HEAD | |
3 ><TITLE | |
4 >SDL_LockAudio</TITLE | |
5 ><META | |
6 NAME="GENERATOR" | |
803
355632dca928
Updated SDL HTML documentation
Sam Lantinga <slouken@libsdl.org>
parents:
181
diff
changeset
|
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="Audio" | |
14 HREF="audio.html"><LINK | |
15 REL="PREVIOUS" | |
16 TITLE="SDL_MixAudio" | |
17 HREF="sdlmixaudio.html"><LINK | |
18 REL="NEXT" | |
19 TITLE="SDL_UnlockAudio" | |
20 HREF="sdlunlockaudio.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 | |
803
355632dca928
Updated SDL HTML documentation
Sam Lantinga <slouken@libsdl.org>
parents:
181
diff
changeset
|
31 SUMMARY="Header navigation table" |
0 | 32 WIDTH="100%" |
33 BORDER="0" | |
34 CELLPADDING="0" | |
35 CELLSPACING="0" | |
36 ><TR | |
37 ><TH | |
38 COLSPAN="3" | |
39 ALIGN="center" | |
40 >SDL Library Documentation</TH | |
41 ></TR | |
42 ><TR | |
43 ><TD | |
44 WIDTH="10%" | |
45 ALIGN="left" | |
46 VALIGN="bottom" | |
47 ><A | |
48 HREF="sdlmixaudio.html" | |
803
355632dca928
Updated SDL HTML documentation
Sam Lantinga <slouken@libsdl.org>
parents:
181
diff
changeset
|
49 ACCESSKEY="P" |
0 | 50 >Prev</A |
51 ></TD | |
52 ><TD | |
53 WIDTH="80%" | |
54 ALIGN="center" | |
55 VALIGN="bottom" | |
56 ></TD | |
57 ><TD | |
58 WIDTH="10%" | |
59 ALIGN="right" | |
60 VALIGN="bottom" | |
61 ><A | |
62 HREF="sdlunlockaudio.html" | |
803
355632dca928
Updated SDL HTML documentation
Sam Lantinga <slouken@libsdl.org>
parents:
181
diff
changeset
|
63 ACCESSKEY="N" |
0 | 64 >Next</A |
65 ></TD | |
66 ></TR | |
67 ></TABLE | |
68 ><HR | |
69 ALIGN="LEFT" | |
70 WIDTH="100%"></DIV | |
71 ><H1 | |
72 ><A | |
73 NAME="SDLLOCKAUDIO" | |
803
355632dca928
Updated SDL HTML documentation
Sam Lantinga <slouken@libsdl.org>
parents:
181
diff
changeset
|
74 ></A |
355632dca928
Updated SDL HTML documentation
Sam Lantinga <slouken@libsdl.org>
parents:
181
diff
changeset
|
75 >SDL_LockAudio</H1 |
0 | 76 ><DIV |
77 CLASS="REFNAMEDIV" | |
78 ><A | |
803
355632dca928
Updated SDL HTML documentation
Sam Lantinga <slouken@libsdl.org>
parents:
181
diff
changeset
|
79 NAME="AEN7134" |
0 | 80 ></A |
81 ><H2 | |
82 >Name</H2 | |
83 >SDL_LockAudio -- Lock out the callback function</DIV | |
84 ><DIV | |
85 CLASS="REFSYNOPSISDIV" | |
86 ><A | |
803
355632dca928
Updated SDL HTML documentation
Sam Lantinga <slouken@libsdl.org>
parents:
181
diff
changeset
|
87 NAME="AEN7137" |
0 | 88 ></A |
89 ><H2 | |
90 >Synopsis</H2 | |
91 ><DIV | |
92 CLASS="FUNCSYNOPSIS" | |
93 ><A | |
803
355632dca928
Updated SDL HTML documentation
Sam Lantinga <slouken@libsdl.org>
parents:
181
diff
changeset
|
94 NAME="AEN7138" |
0 | 95 ></A |
96 ><P | |
97 ></P | |
98 ><PRE | |
99 CLASS="FUNCSYNOPSISINFO" | |
100 >#include "SDL.h"</PRE | |
101 ><P | |
102 ><CODE | |
103 ><CODE | |
104 CLASS="FUNCDEF" | |
105 >void <B | |
106 CLASS="FSFUNC" | |
107 >SDL_LockAudio</B | |
108 ></CODE | |
109 >(void);</CODE | |
110 ></P | |
111 ><P | |
112 ></P | |
113 ></DIV | |
114 ></DIV | |
115 ><DIV | |
116 CLASS="REFSECT1" | |
117 ><A | |
803
355632dca928
Updated SDL HTML documentation
Sam Lantinga <slouken@libsdl.org>
parents:
181
diff
changeset
|
118 NAME="AEN7144" |
0 | 119 ></A |
120 ><H2 | |
121 >Description</H2 | |
122 ><P | |
123 >The lock manipulated by these functions protects the callback function. | |
124 During a LockAudio period, you can be guaranteed that the | |
125 callback function is not running. Do not call these from the callback | |
126 function or you will cause deadlock.</P | |
127 ></DIV | |
128 ><DIV | |
129 CLASS="REFSECT1" | |
130 ><A | |
803
355632dca928
Updated SDL HTML documentation
Sam Lantinga <slouken@libsdl.org>
parents:
181
diff
changeset
|
131 NAME="AEN7147" |
0 | 132 ></A |
133 ><H2 | |
134 >See Also</H2 | |
135 ><P | |
136 ><A | |
137 HREF="sdlopenaudio.html" | |
138 ><TT | |
139 CLASS="FUNCTION" | |
140 >SDL_OpenAudio</TT | |
141 ></A | |
142 ></P | |
143 ></DIV | |
144 ><DIV | |
145 CLASS="NAVFOOTER" | |
146 ><HR | |
147 ALIGN="LEFT" | |
148 WIDTH="100%"><TABLE | |
803
355632dca928
Updated SDL HTML documentation
Sam Lantinga <slouken@libsdl.org>
parents:
181
diff
changeset
|
149 SUMMARY="Footer navigation table" |
0 | 150 WIDTH="100%" |
151 BORDER="0" | |
152 CELLPADDING="0" | |
153 CELLSPACING="0" | |
154 ><TR | |
155 ><TD | |
156 WIDTH="33%" | |
157 ALIGN="left" | |
158 VALIGN="top" | |
159 ><A | |
160 HREF="sdlmixaudio.html" | |
803
355632dca928
Updated SDL HTML documentation
Sam Lantinga <slouken@libsdl.org>
parents:
181
diff
changeset
|
161 ACCESSKEY="P" |
0 | 162 >Prev</A |
163 ></TD | |
164 ><TD | |
165 WIDTH="34%" | |
166 ALIGN="center" | |
167 VALIGN="top" | |
168 ><A | |
169 HREF="index.html" | |
803
355632dca928
Updated SDL HTML documentation
Sam Lantinga <slouken@libsdl.org>
parents:
181
diff
changeset
|
170 ACCESSKEY="H" |
0 | 171 >Home</A |
172 ></TD | |
173 ><TD | |
174 WIDTH="33%" | |
175 ALIGN="right" | |
176 VALIGN="top" | |
177 ><A | |
178 HREF="sdlunlockaudio.html" | |
803
355632dca928
Updated SDL HTML documentation
Sam Lantinga <slouken@libsdl.org>
parents:
181
diff
changeset
|
179 ACCESSKEY="N" |
0 | 180 >Next</A |
181 ></TD | |
182 ></TR | |
183 ><TR | |
184 ><TD | |
185 WIDTH="33%" | |
186 ALIGN="left" | |
187 VALIGN="top" | |
188 >SDL_MixAudio</TD | |
189 ><TD | |
190 WIDTH="34%" | |
191 ALIGN="center" | |
192 VALIGN="top" | |
193 ><A | |
194 HREF="audio.html" | |
803
355632dca928
Updated SDL HTML documentation
Sam Lantinga <slouken@libsdl.org>
parents:
181
diff
changeset
|
195 ACCESSKEY="U" |
0 | 196 >Up</A |
197 ></TD | |
198 ><TD | |
199 WIDTH="33%" | |
200 ALIGN="right" | |
201 VALIGN="top" | |
202 >SDL_UnlockAudio</TD | |
203 ></TR | |
204 ></TABLE | |
205 ></DIV | |
206 ></BODY | |
207 ></HTML | |
208 > |