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Editors Note: The original patch was modified to use SDL_Delay() instead of
nanosleep because nanosleep may not be portable to all systems
using SDL with the ALSA backend. This may be a moot point with
the switch to blocking writes anyway...
Date: Sat, 27 Dec 2003 21:47:36 +0100
From: Michel Daenzer
To: Debian Bug Tracking System
Subject: [SDL] Bug#225252: [PATCH] ALSA fixes
Package: libsdl1.2debian-all
Version: 1.2.6-2
Severity: normal
Tags: patch
For SDL 1.2.6, the ALSA backend was changed to call snd_pcm_open() with
SND_PCM_NONBLOCK. That's a good idea per se, however, it causes high CPU
usage, interrupted sound and stuttering in some games here. Taking a nanosleep
whenever snd_pcm_writei() returns -EAGAIN fixes this, but I think it's more
efficient to use blocking mode for the actual sound playback. Feedback from the
SDL and ALSA lists appreciated.
The patch also fixes the default ALSA device to be used.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Sun, 04 Jan 2004 15:40:50 +0000 |
parents | e5bc29de3f0a |
children | 355632dca928 |
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<HTML ><HEAD ><TITLE >SDL_DisplayYUVOverlay</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="Video" HREF="video.html"><LINK REL="PREVIOUS" TITLE="SDL_UnlockYUVOverlay" HREF="sdlunlockyuvoverlay.html"><LINK REL="NEXT" TITLE="SDL_FreeYUVOverlay" HREF="sdlfreeyuvoverlay.html"></HEAD ><BODY CLASS="REFENTRY" 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="sdlunlockyuvoverlay.html" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlfreeyuvoverlay.html" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLDISPLAYYUVOVERLAY" >SDL_DisplayYUVOverlay</A ></H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN2524" ></A ><H2 >Name</H2 >SDL_DisplayYUVOverlay -- Blit the overlay to the display</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN2527" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><A NAME="AEN2528" ></A ><P ></P ><PRE CLASS="FUNCSYNOPSISINFO" >#include "SDL.h"</PRE ><P ><CODE ><CODE CLASS="FUNCDEF" >int <B CLASS="FSFUNC" >SDL_DisplayYUVOverlay</B ></CODE >(SDL_Overlay *overlay, SDL_Rect *dstrect);</CODE ></P ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN2534" ></A ><H2 >Description</H2 ><P >Blit the <TT CLASS="PARAMETER" ><I >overlay</I ></TT > to the surface specified when it was <A HREF="sdlcreateyuvoverlay.html" >created</A >. The <A HREF="sdlrect.html" ><SPAN CLASS="STRUCTNAME" >SDL_Rect</SPAN ></A > structure, <TT CLASS="PARAMETER" ><I >dstrect</I ></TT >, specifies the position and size of the destination. If the <TT CLASS="PARAMETER" ><I >dstrect</I ></TT > is a larger or smaller than the overlay then the overlay will be scaled, this is optimized for 2x scaling.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN2543" ></A ><H2 >Return Values</H2 ><P >Returns 0 on success</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN2546" ></A ><H2 >See Also</H2 ><P ><A HREF="sdloverlay.html" ><SPAN CLASS="STRUCTNAME" >SDL_Overlay</SPAN ></A >, <A HREF="sdlcreateyuvoverlay.html" ><TT CLASS="FUNCTION" >SDL_CreateYUVOverlay</TT ></A ></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="sdlunlockyuvoverlay.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="sdlfreeyuvoverlay.html" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_UnlockYUVOverlay</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="video.html" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >SDL_FreeYUVOverlay</TD ></TR ></TABLE ></DIV ></BODY ></HTML >