Mercurial > sdl-ios-xcode
annotate docs/html/time.html @ 773:da0a2ad35bf4
Date: Sun, 4 Jan 2004 23:48:19 +0100
From: Max Horn
Subject: Re: Again Audio CD patch
Am 04.01.2004 um 22:38 schrieb Sam Lantinga:
>
> Okay, I fixed the buffering problems by simply using a 4 second buffer
> instead of a 1 second buffer. However, using your code I can't play an
> entire CD - the playback stops after the first song.
>
Found the problem: FSReadFork returns eofErr when the file is finished.
However, we check its return value for errors, and if anything but
noErr occurs, the reader thread aborts its current iteration. That is
bad, because it aborts before it can ever set the flag which tells that
the file is over (also, any remaining data which FSRead did return is
lost - so you'd not hear about to 4 seconds from the end of the file.
Furthermore, the computed data size was 8 bytes to high (I forgot to
account for the fact that the size of an (A)IFF chunk always contains
the chunk header & size fields, too). This is enough to make it work.
However, the end condition is rather fragile, so I tuned some other
things to be pessimistic (check for <= 0 instead of == 0, when eofErr
is encountered enforce mReadFilePosition == mFileLength). You never
know...
The attached patch fixes the issue for me.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Mon, 05 Jan 2004 00:57:51 +0000 |
parents | 55f1f1b3e27d |
children | 355632dca928 |
rev | line source |
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0 | 1 <HTML |
2 ><HEAD | |
3 ><TITLE | |
4 >Time</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="SDL Reference" | |
14 HREF="reference.html"><LINK | |
15 REL="PREVIOUS" | |
16 TITLE="SDL_CondWaitTimeout" | |
17 HREF="sdlcondwaittimeout.html"><LINK | |
18 REL="NEXT" | |
19 TITLE="SDL_GetTicks" | |
20 HREF="sdlgetticks.html"><META | |
21 NAME="KEYWORD" | |
22 CONTENT="time"><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 | |
35 WIDTH="100%" | |
36 BORDER="0" | |
37 CELLPADDING="0" | |
38 CELLSPACING="0" | |
39 ><TR | |
40 ><TH | |
41 COLSPAN="3" | |
42 ALIGN="center" | |
43 >SDL Library Documentation</TH | |
44 ></TR | |
45 ><TR | |
46 ><TD | |
47 WIDTH="10%" | |
48 ALIGN="left" | |
49 VALIGN="bottom" | |
50 ><A | |
51 HREF="sdlcondwaittimeout.html" | |
52 >Prev</A | |
53 ></TD | |
54 ><TD | |
55 WIDTH="80%" | |
56 ALIGN="center" | |
57 VALIGN="bottom" | |
58 ></TD | |
59 ><TD | |
60 WIDTH="10%" | |
61 ALIGN="right" | |
62 VALIGN="bottom" | |
63 ><A | |
64 HREF="sdlgetticks.html" | |
65 >Next</A | |
66 ></TD | |
67 ></TR | |
68 ></TABLE | |
69 ><HR | |
70 ALIGN="LEFT" | |
71 WIDTH="100%"></DIV | |
72 ><DIV | |
73 CLASS="CHAPTER" | |
74 ><H1 | |
75 ><A | |
76 NAME="TIME" | |
77 >Chapter 13. Time</A | |
78 ></H1 | |
79 ><DIV | |
80 CLASS="TOC" | |
81 ><DL | |
82 ><DT | |
83 ><B | |
84 >Table of Contents</B | |
85 ></DT | |
86 ><DT | |
87 ><A | |
88 HREF="sdlgetticks.html" | |
89 >SDL_GetTicks</A | |
90 > — Get the number of milliseconds since the SDL library initialization.</DT | |
91 ><DT | |
92 ><A | |
93 HREF="sdldelay.html" | |
94 >SDL_Delay</A | |
95 > — Wait a specified number of milliseconds before returning.</DT | |
96 ><DT | |
97 ><A | |
98 HREF="sdladdtimer.html" | |
99 >SDL_AddTimer</A | |
100 > — Add a timer which will call a callback after the specified number of milliseconds has | |
101 elapsed.</DT | |
102 ><DT | |
103 ><A | |
104 HREF="sdlremovetimer.html" | |
105 >SDL_RemoveTimer</A | |
106 > — Remove a timer which was added with | |
107 <A | |
108 HREF="sdladdtimer.html" | |
109 >SDL_AddTimer</A | |
110 >.</DT | |
111 ><DT | |
112 ><A | |
113 HREF="sdlsettimer.html" | |
114 >SDL_SetTimer</A | |
115 > — Set a callback to run after the specified number of milliseconds has | |
116 elapsed.</DT | |
117 ></DL | |
118 ></DIV | |
119 ><P | |
120 >SDL provides several cross-platform functions for dealing with time. | |
121 It provides a way to get the current time, a way to wait a little while, | |
122 and a simple timer mechanism. These functions give you two ways of moving an | |
123 object every x milliseconds: | |
124 | |
125 <P | |
126 ></P | |
127 ><UL | |
128 ><LI | |
129 ><P | |
130 >Use a timer callback function. This may have the bad effect that it runs in a seperate thread or uses alarm signals, but it's easier to implement.</P | |
131 ></LI | |
132 ><LI | |
133 ><P | |
134 >Or you can get the number of milliseconds passed, and move the object if, for example, 30 ms passed.</P | |
135 ></LI | |
136 ></UL | |
137 > </P | |
138 ></DIV | |
139 ><DIV | |
140 CLASS="NAVFOOTER" | |
141 ><HR | |
142 ALIGN="LEFT" | |
143 WIDTH="100%"><TABLE | |
144 WIDTH="100%" | |
145 BORDER="0" | |
146 CELLPADDING="0" | |
147 CELLSPACING="0" | |
148 ><TR | |
149 ><TD | |
150 WIDTH="33%" | |
151 ALIGN="left" | |
152 VALIGN="top" | |
153 ><A | |
154 HREF="sdlcondwaittimeout.html" | |
155 >Prev</A | |
156 ></TD | |
157 ><TD | |
158 WIDTH="34%" | |
159 ALIGN="center" | |
160 VALIGN="top" | |
161 ><A | |
162 HREF="index.html" | |
163 >Home</A | |
164 ></TD | |
165 ><TD | |
166 WIDTH="33%" | |
167 ALIGN="right" | |
168 VALIGN="top" | |
169 ><A | |
170 HREF="sdlgetticks.html" | |
171 >Next</A | |
172 ></TD | |
173 ></TR | |
174 ><TR | |
175 ><TD | |
176 WIDTH="33%" | |
177 ALIGN="left" | |
178 VALIGN="top" | |
179 >SDL_CondWaitTimeout</TD | |
180 ><TD | |
181 WIDTH="34%" | |
182 ALIGN="center" | |
183 VALIGN="top" | |
184 ><A | |
185 HREF="reference.html" | |
186 >Up</A | |
187 ></TD | |
188 ><TD | |
189 WIDTH="33%" | |
190 ALIGN="right" | |
191 VALIGN="top" | |
192 >SDL_GetTicks</TD | |
193 ></TR | |
194 ></TABLE | |
195 ></DIV | |
196 ></BODY | |
197 ></HTML | |
198 > |