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view docs/html/audio.html @ 757:4f46fee887fe
Date: Sun, 14 Dec 2003 15:16:12 +0100
From: Stephane Marchesin
Subject: Re: [SDL] compile problem with sdl <-> alsa
The attathced patch does the trick (although there will have to be code
changes when the alsa 0.9 api get deprecated).
On a side-note, the good news is that using alsa 1.0.0rc1 solves the
previous issues I had with my ac97 via sound chipset.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Tue, 16 Dec 2003 13:16:50 +0000 |
parents | 55f1f1b3e27d |
children | 355632dca928 |
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<HTML ><HEAD ><TITLE >Audio</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="SDL Reference" HREF="reference.html"><LINK REL="PREVIOUS" TITLE="SDL_JoystickClose" HREF="sdljoystickclose.html"><LINK REL="NEXT" TITLE="SDL_AudioSpec" HREF="sdlaudiospec.html"><META NAME="KEYWORD" CONTENT="audio"><META NAME="KEYWORD" CONTENT="function"></HEAD ><BODY CLASS="CHAPTER" 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="sdljoystickclose.html" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlaudiospec.html" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="CHAPTER" ><H1 ><A NAME="AUDIO" >Chapter 10. Audio</A ></H1 ><DIV CLASS="TOC" ><DL ><DT ><B >Table of Contents</B ></DT ><DT ><A HREF="sdlaudiospec.html" >SDL_AudioSpec</A > — Audio Specification Structure</DT ><DT ><A HREF="sdlopenaudio.html" >SDL_OpenAudio</A > — Opens the audio device with the desired parameters.</DT ><DT ><A HREF="sdlpauseaudio.html" >SDL_PauseAudio</A > — Pauses and unpauses the audio callback processing</DT ><DT ><A HREF="sdlgetaudiostatus.html" >SDL_GetAudioStatus</A > — Get the current audio state</DT ><DT ><A HREF="sdlloadwav.html" >SDL_LoadWAV</A > — Load a WAVE file</DT ><DT ><A HREF="sdlfreewav.html" >SDL_FreeWAV</A > — Frees previously opened WAV data</DT ><DT ><A HREF="sdlaudiocvt.html" >SDL_AudioCVT</A > — Audio Conversion Structure</DT ><DT ><A HREF="sdlbuildaudiocvt.html" >SDL_BuildAudioCVT</A > — Initializes a SDL_AudioCVT structure for conversion</DT ><DT ><A HREF="sdlconvertaudio.html" >SDL_ConvertAudio</A > — Convert audio data to a desired audio format.</DT ><DT ><A HREF="sdlmixaudio.html" >SDL_MixAudio</A > — Mix audio data</DT ><DT ><A HREF="sdllockaudio.html" >SDL_LockAudio</A > — Lock out the callback function</DT ><DT ><A HREF="sdlunlockaudio.html" >SDL_UnlockAudio</A > — Unlock the callback function</DT ><DT ><A HREF="sdlcloseaudio.html" >SDL_CloseAudio</A > — Shuts down audio processing and closes the audio device.</DT ></DL ></DIV ><P >Sound on the computer is translated from waves that you hear into a series of values, or samples, each representing the amplitude of the wave. When these samples are sent in a stream to a sound card, an approximation of the original wave can be recreated. The more bits used to represent the amplitude, and the greater frequency these samples are gathered, the closer the approximated sound is to the original, and the better the quality of sound.</P ><P >This library supports both 8 and 16 bit signed and unsigned sound samples, at frequencies ranging from 11025 Hz to 44100 Hz, depending on the underlying hardware. If the hardware doesn't support the desired audio format or frequency, it can be emulated if desired (See <A HREF="sdlopenaudio.html" ><TT CLASS="FUNCTION" >SDL_OpenAudio()</TT ></A >)</P ><P >A commonly supported audio format is 16 bits per sample at 22050 Hz.</P ></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="sdljoystickclose.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="sdlaudiospec.html" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_JoystickClose</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="reference.html" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >SDL_AudioSpec</TD ></TR ></TABLE ></DIV ></BODY ></HTML >