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Doh! Compile error if there was no X11 shared image support
author | Sam Lantinga <slouken@libsdl.org> |
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date | Mon, 02 Dec 2002 01:47:03 +0000 |
parents | e5bc29de3f0a |
children | 355632dca928 |
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<HTML ><HEAD ><TITLE >Audio Examples</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.64 "><LINK REL="HOME" TITLE="SDL Library Documentation" HREF="index.html"><LINK REL="UP" TITLE="Examples" HREF="guideexamples.html"><LINK REL="PREVIOUS" TITLE="Event Examples" HREF="guideeventexamples.html"><LINK REL="NEXT" TITLE="CDROM Examples" HREF="guidecdromexamples.html"></HEAD ><BODY CLASS="SECT1" BGCOLOR="#FFF8DC" TEXT="#000000" LINK="#0000ee" VLINK="#551a8b" ALINK="#ff0000" ><DIV CLASS="NAVHEADER" ><TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >SDL Library Documentation</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="guideeventexamples.html" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" >Chapter 4. Examples</TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="guidecdromexamples.html" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="SECT1" ><H1 CLASS="SECT1" ><A NAME="GUIDEAUDIOEXAMPLES" >Audio Examples</A ></H1 ><P ></P ><DIV CLASS="SECT2" ><H2 CLASS="SECT2" ><A NAME="AEN382" >Opening the audio device</A ></H2 ><P ><PRE CLASS="PROGRAMLISTING" > SDL_AudioSpec wanted; extern void fill_audio(void *udata, Uint8 *stream, int len); /* Set the audio format */ wanted.freq = 22050; wanted.format = AUDIO_S16; wanted.channels = 2; /* 1 = mono, 2 = stereo */ wanted.samples = 1024; /* Good low-latency value for callback */ wanted.callback = fill_audio; wanted.userdata = NULL; /* Open the audio device, forcing the desired format */ if ( SDL_OpenAudio(&wanted, NULL) < 0 ) { fprintf(stderr, "Couldn't open audio: %s\n", SDL_GetError()); return(-1); } return(0);</PRE ></P ></DIV ><DIV CLASS="SECT2" ><H2 CLASS="SECT2" ><A NAME="AEN386" >Playing audio</A ></H2 ><P ><PRE CLASS="PROGRAMLISTING" > static Uint8 *audio_chunk; static Uint32 audio_len; static Uint8 *audio_pos; /* The audio function callback takes the following parameters: stream: A pointer to the audio buffer to be filled len: The length (in bytes) of the audio buffer */ void fill_audio(void *udata, Uint8 *stream, int len) { /* Only play if we have data left */ if ( audio_len == 0 ) return; /* Mix as much data as possible */ len = ( len > audio_len ? audio_len : len ); SDL_MixAudio(stream, audio_pos, len, SDL_MIX_MAXVOLUME); audio_pos += len; audio_len -= len; } /* Load the audio data ... */ ;;;;; audio_pos = audio_chunk; /* Let the callback function play the audio chunk */ SDL_PauseAudio(0); /* Do some processing */ ;;;;; /* Wait for sound to complete */ while ( audio_len > 0 ) { SDL_Delay(100); /* Sleep 1/10 second */ } SDL_CloseAudio();</PRE ></P ></DIV ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="guideeventexamples.html" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="guidecdromexamples.html" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >Event Examples</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="guideexamples.html" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >CDROM Examples</TD ></TR ></TABLE ></DIV ></BODY ></HTML >