Mercurial > sdl-ios-xcode
view docs/html/sdlbuildaudiocvt.html @ 1157:baf35853ad54
Date: Mon, 10 Oct 2005 13:09:32 +0300
From: Tommi Kyntola <tommi.kyntola@ray.fi>
To: sdl@libsdl.org
Subject: [SDL] [RFC] get_ticks broken on linux
It uses gettimeofday to calculate the timedifference.
Gettimeofday returns current time which is seldom monotonous.
This breaks SDL timer subsystem. (time callbacks and all that
get borked when the time difference ms is suddenly ~ 2^32)
I posted a message about this earlier but got no response.
Some thoughts on this matter would be appreciated.
(Or even an explanation for the lack of interest.)
A patch below would use the posix timers that have been around
since posix 93 and do provide a good source of monotonous time
on linux boxes (and on few others too).
The following patch is also availabe at:
http://www.hut.fi/u/tkyntola/SDL-1.2.9-clockfix.patch
It's against 1.2.9, but I can easily rediffit against
the cvs branch is needed.
cheers,
Tommi Kyntola tommi.kyntola@ray.fi
author | Ryan C. Gordon <icculus@icculus.org> |
---|---|
date | Tue, 11 Oct 2005 18:16:12 +0000 |
parents | 355632dca928 |
children |
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<HTML ><HEAD ><TITLE >SDL_BuildAudioCVT</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="Audio" HREF="audio.html"><LINK REL="PREVIOUS" TITLE="SDL_AudioCVT" HREF="sdlaudiocvt.html"><LINK REL="NEXT" TITLE="SDL_ConvertAudio" HREF="sdlconvertaudio.html"></HEAD ><BODY CLASS="REFENTRY" 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="sdlaudiocvt.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlconvertaudio.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLBUILDAUDIOCVT" ></A >SDL_BuildAudioCVT</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN7002" ></A ><H2 >Name</H2 >SDL_BuildAudioCVT -- Initializes a SDL_AudioCVT structure for conversion</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN7005" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><A NAME="AEN7006" ></A ><P ></P ><PRE CLASS="FUNCSYNOPSISINFO" >#include "SDL.h"</PRE ><P ><CODE ><CODE CLASS="FUNCDEF" >int <B CLASS="FSFUNC" >SDL_BuildAudioCVT</B ></CODE >(SDL_AudioCVT *cvt, Uint16 src_format, Uint8 src_channels, int src_rate, Uint16 dst_format, Uint8 dst_channels, int dst_rate);</CODE ></P ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN7012" ></A ><H2 >Description</H2 ><P >Before an <A HREF="sdlaudiocvt.html" ><SPAN CLASS="STRUCTNAME" >SDL_AudioCVT</SPAN ></A > structure can be used to convert audio data it must be initialized with source and destination information. </P ><P ><TT CLASS="PARAMETER" ><I >src_format</I ></TT > and <TT CLASS="PARAMETER" ><I >dst_format</I ></TT > are the source and destination format of the conversion. (For information on audio formats see <A HREF="sdlaudiospec.html" ><SPAN CLASS="STRUCTNAME" > SDL_AudioSpec</SPAN ></A >). <TT CLASS="PARAMETER" ><I >src_channels</I ></TT > and <TT CLASS="PARAMETER" ><I >dst_channels</I ></TT > are the number of channels in the source and destination formats. Finally, <TT CLASS="PARAMETER" ><I >src_rate</I ></TT > and <TT CLASS="PARAMETER" ><I >dst_rate</I ></TT > are the frequency or samples-per-second of the source and destination formats. Once again, see <A HREF="sdlaudiospec.html" ><SPAN CLASS="STRUCTNAME" >SDL_AudioSpec</SPAN ></A >.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN7028" ></A ><H2 >Return Values</H2 ><P >Returns <SPAN CLASS="RETURNVALUE" >-1</SPAN > if the filter could not be built or 1 if it could.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN7032" ></A ><H2 >Examples</H2 ><P >See <A HREF="sdlconvertaudio.html" ><TT CLASS="FUNCTION" >SDL_ConvertAudio</TT ></A >.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN7037" ></A ><H2 >See Also</H2 ><P ><A HREF="sdlconvertaudio.html" ><TT CLASS="FUNCTION" >SDL_ConvertAudio</TT ></A >, <A HREF="sdlaudiocvt.html" ><TT CLASS="FUNCTION" >SDL_AudioCVT</TT ></A ></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="sdlaudiocvt.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="sdlconvertaudio.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_AudioCVT</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="audio.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >SDL_ConvertAudio</TD ></TR ></TABLE ></DIV ></BODY ></HTML >