Mercurial > sdl-ios-xcode
annotate docs/html/guideaudioexamples.html @ 3096:ae4e80dbe330
Date: Tue, 17 Feb 2009 14:00:25 +0100
From: Stefan Klug
Subject: [SDL] Possible bug, paused audio playing garbage
On my WinCE device a paused audio device plays random garbage.
This might also be the issue in the thread "sound cracks with SDL_mixer
and AUDIO_S16LSB"
I don't have that much knowledge of the SDL audio part, but the attached
patch fixes it for me, and collapses two redundant ifs.
I'm not sure if this is the correct way to fix this.
Shouldn't the complete stream conversion part of the RunAudio loop be
dependent on the paused property of the device? (not only the call to
(*fill)(udata, istream, istream_len).
Anyways. Would be great if the patch or a fix could find its way to SVN ;-)
Cheers
Stefan
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Mon, 23 Mar 2009 05:21:40 +0000 |
| parents | 355632dca928 |
| children |
| rev | line source |
|---|---|
| 0 | 1 <HTML |
| 2 ><HEAD | |
| 3 ><TITLE | |
| 4 >Audio Examples</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="Examples" | |
| 14 HREF="guideexamples.html"><LINK | |
| 15 REL="PREVIOUS" | |
| 16 TITLE="Event Examples" | |
| 17 HREF="guideeventexamples.html"><LINK | |
| 18 REL="NEXT" | |
| 19 TITLE="CDROM Examples" | |
| 20 HREF="guidecdromexamples.html"></HEAD | |
| 21 ><BODY | |
| 22 CLASS="SECT1" | |
| 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="guideeventexamples.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 >Chapter 4. Examples</TD | |
| 57 ><TD | |
| 58 WIDTH="10%" | |
| 59 ALIGN="right" | |
| 60 VALIGN="bottom" | |
| 61 ><A | |
| 62 HREF="guidecdromexamples.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 ><DIV | |
| 72 CLASS="SECT1" | |
| 73 ><H1 | |
| 74 CLASS="SECT1" | |
| 75 ><A | |
| 76 NAME="GUIDEAUDIOEXAMPLES" | |
|
803
355632dca928
Updated SDL HTML documentation
Sam Lantinga <slouken@libsdl.org>
parents:
181
diff
changeset
|
77 ></A |
|
355632dca928
Updated SDL HTML documentation
Sam Lantinga <slouken@libsdl.org>
parents:
181
diff
changeset
|
78 >Audio Examples</H1 |
| 0 | 79 ><P |
| 80 ></P | |
| 81 ><DIV | |
| 82 CLASS="SECT2" | |
| 83 ><H2 | |
| 84 CLASS="SECT2" | |
| 85 ><A | |
|
55
55f1f1b3e27d
Added new docs for SDL 1.2.1
Sam Lantinga <slouken@lokigames.com>
parents:
0
diff
changeset
|
86 NAME="AEN382" |
|
803
355632dca928
Updated SDL HTML documentation
Sam Lantinga <slouken@libsdl.org>
parents:
181
diff
changeset
|
87 ></A |
|
355632dca928
Updated SDL HTML documentation
Sam Lantinga <slouken@libsdl.org>
parents:
181
diff
changeset
|
88 >Opening the audio device</H2 |
| 0 | 89 ><P |
| 90 ><PRE | |
| 91 CLASS="PROGRAMLISTING" | |
| 92 > SDL_AudioSpec wanted; | |
| 93 extern void fill_audio(void *udata, Uint8 *stream, int len); | |
| 94 | |
| 95 /* Set the audio format */ | |
| 96 wanted.freq = 22050; | |
| 97 wanted.format = AUDIO_S16; | |
| 98 wanted.channels = 2; /* 1 = mono, 2 = stereo */ | |
| 99 wanted.samples = 1024; /* Good low-latency value for callback */ | |
| 100 wanted.callback = fill_audio; | |
| 101 wanted.userdata = NULL; | |
| 102 | |
| 103 /* Open the audio device, forcing the desired format */ | |
| 104 if ( SDL_OpenAudio(&wanted, NULL) < 0 ) { | |
| 105 fprintf(stderr, "Couldn't open audio: %s\n", SDL_GetError()); | |
| 106 return(-1); | |
| 107 } | |
| 108 return(0);</PRE | |
| 109 ></P | |
| 110 ></DIV | |
| 111 ><DIV | |
| 112 CLASS="SECT2" | |
| 113 ><H2 | |
| 114 CLASS="SECT2" | |
| 115 ><A | |
|
55
55f1f1b3e27d
Added new docs for SDL 1.2.1
Sam Lantinga <slouken@lokigames.com>
parents:
0
diff
changeset
|
116 NAME="AEN386" |
|
803
355632dca928
Updated SDL HTML documentation
Sam Lantinga <slouken@libsdl.org>
parents:
181
diff
changeset
|
117 ></A |
|
355632dca928
Updated SDL HTML documentation
Sam Lantinga <slouken@libsdl.org>
parents:
181
diff
changeset
|
118 >Playing audio</H2 |
| 0 | 119 ><P |
| 120 ><PRE | |
| 121 CLASS="PROGRAMLISTING" | |
| 122 > static Uint8 *audio_chunk; | |
| 123 static Uint32 audio_len; | |
| 124 static Uint8 *audio_pos; | |
| 125 | |
| 126 /* The audio function callback takes the following parameters: | |
| 127 stream: A pointer to the audio buffer to be filled | |
| 128 len: The length (in bytes) of the audio buffer | |
| 129 */ | |
| 130 void fill_audio(void *udata, Uint8 *stream, int len) | |
| 131 { | |
| 132 /* Only play if we have data left */ | |
| 133 if ( audio_len == 0 ) | |
| 134 return; | |
| 135 | |
| 136 /* Mix as much data as possible */ | |
| 137 len = ( len > audio_len ? audio_len : len ); | |
|
181
e5bc29de3f0a
Updated from the SDL Documentation Project
Sam Lantinga <slouken@libsdl.org>
parents:
55
diff
changeset
|
138 SDL_MixAudio(stream, audio_pos, len, SDL_MIX_MAXVOLUME); |
| 0 | 139 audio_pos += len; |
| 140 audio_len -= len; | |
| 141 } | |
| 142 | |
| 143 /* Load the audio data ... */ | |
| 144 | |
| 145 ;;;;; | |
| 146 | |
| 147 audio_pos = audio_chunk; | |
| 148 | |
| 149 /* Let the callback function play the audio chunk */ | |
| 150 SDL_PauseAudio(0); | |
| 151 | |
| 152 /* Do some processing */ | |
| 153 | |
| 154 ;;;;; | |
| 155 | |
| 156 /* Wait for sound to complete */ | |
| 157 while ( audio_len > 0 ) { | |
| 158 SDL_Delay(100); /* Sleep 1/10 second */ | |
| 159 } | |
| 160 SDL_CloseAudio();</PRE | |
| 161 ></P | |
| 162 ></DIV | |
| 163 ></DIV | |
| 164 ><DIV | |
| 165 CLASS="NAVFOOTER" | |
| 166 ><HR | |
| 167 ALIGN="LEFT" | |
| 168 WIDTH="100%"><TABLE | |
|
803
355632dca928
Updated SDL HTML documentation
Sam Lantinga <slouken@libsdl.org>
parents:
181
diff
changeset
|
169 SUMMARY="Footer navigation table" |
| 0 | 170 WIDTH="100%" |
| 171 BORDER="0" | |
| 172 CELLPADDING="0" | |
| 173 CELLSPACING="0" | |
| 174 ><TR | |
| 175 ><TD | |
| 176 WIDTH="33%" | |
| 177 ALIGN="left" | |
| 178 VALIGN="top" | |
| 179 ><A | |
| 180 HREF="guideeventexamples.html" | |
|
803
355632dca928
Updated SDL HTML documentation
Sam Lantinga <slouken@libsdl.org>
parents:
181
diff
changeset
|
181 ACCESSKEY="P" |
| 0 | 182 >Prev</A |
| 183 ></TD | |
| 184 ><TD | |
| 185 WIDTH="34%" | |
| 186 ALIGN="center" | |
| 187 VALIGN="top" | |
| 188 ><A | |
| 189 HREF="index.html" | |
|
803
355632dca928
Updated SDL HTML documentation
Sam Lantinga <slouken@libsdl.org>
parents:
181
diff
changeset
|
190 ACCESSKEY="H" |
| 0 | 191 >Home</A |
| 192 ></TD | |
| 193 ><TD | |
| 194 WIDTH="33%" | |
| 195 ALIGN="right" | |
| 196 VALIGN="top" | |
| 197 ><A | |
| 198 HREF="guidecdromexamples.html" | |
|
803
355632dca928
Updated SDL HTML documentation
Sam Lantinga <slouken@libsdl.org>
parents:
181
diff
changeset
|
199 ACCESSKEY="N" |
| 0 | 200 >Next</A |
| 201 ></TD | |
| 202 ></TR | |
| 203 ><TR | |
| 204 ><TD | |
| 205 WIDTH="33%" | |
| 206 ALIGN="left" | |
| 207 VALIGN="top" | |
| 208 >Event Examples</TD | |
| 209 ><TD | |
| 210 WIDTH="34%" | |
| 211 ALIGN="center" | |
| 212 VALIGN="top" | |
| 213 ><A | |
| 214 HREF="guideexamples.html" | |
|
803
355632dca928
Updated SDL HTML documentation
Sam Lantinga <slouken@libsdl.org>
parents:
181
diff
changeset
|
215 ACCESSKEY="U" |
| 0 | 216 >Up</A |
| 217 ></TD | |
| 218 ><TD | |
| 219 WIDTH="33%" | |
| 220 ALIGN="right" | |
| 221 VALIGN="top" | |
| 222 >CDROM Examples</TD | |
| 223 ></TR | |
| 224 ></TABLE | |
| 225 ></DIV | |
| 226 ></BODY | |
| 227 ></HTML | |
| 228 > |