Mercurial > sdl-ios-xcode
view docs/html/audio.html @ 4106:12bb6311fd5d SDL-1.2
Hans de Goede fixed bug #495
When running boswars: http://www.boswars.org/ on a machine with intel
integrathed graphics it crashes when it tries to play the initial theora
splashscreen video:
X Error of failed request: BadAlloc (insufficient resources for operation)
Major opcode of failed request: 140 (XVideo)
Minor opcode of failed request: 19 ()
Serial number of failed request: 25
Current serial number in output stream: 26
boswars: xcb_xlib.c:41: xcb_xlib_lock: Assertion `!c->xlib.lock' failed.
Aborted
I recognized this problem from a few years back, when I encountered it while
working on the Xv blitter for xmame. The problem is that for some reason
creation the Xvport and XvImage succeeds, and failure (lack of resources / hw
capability?) is only indicated during the first XvPut[Shm]Image. I've written a
patch for SDL using the work around for this I developed for xmame (and which
is still used successfully in xmame after many years of usage).
I'll admit it isn't very pretty, but after investigating several possibilities
this was the best option, any other fixes would need changes to the SDL api and
abi.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Sat, 29 Dec 2007 02:23:48 +0000 |
parents | 355632dca928 |
children |
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<HTML ><HEAD ><TITLE >Audio</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+ "><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 SUMMARY="Header navigation 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" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlaudiospec.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="CHAPTER" ><H1 ><A NAME="AUDIO" ></A >Chapter 10. Audio</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 SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="sdljoystickclose.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="sdlaudiospec.html" ACCESSKEY="N" >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" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >SDL_AudioSpec</TD ></TR ></TABLE ></DIV ></BODY ></HTML >