Mercurial > sdl-ios-xcode
view docs/html/sdlcdtrack.html @ 3880:74e828c64315 SDL-1.2
Fixed bug #292
I might be on crack here.
It looks like SDL_ConvertMono() in src/audio/SDL_audiocvt.c adds the left and
right channels of a stereo stream together, and clamps the new mono channel if
it would overflow.
Shouldn't it be dividing by 2 to average the two sample points instead of
clamping? Otherwise the mono sample point's volume doubles in the conversion.
This would also make the conversion faster, as it replaces two branches per
sample frame with a bitwise shift.
--ryan.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Sun, 24 Sep 2006 15:45:37 +0000 |
parents | 355632dca928 |
children |
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<HTML ><HEAD ><TITLE >SDL_CDtrack</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="CD-ROM" HREF="cdrom.html"><LINK REL="PREVIOUS" TITLE="SDL_CD" HREF="sdlcd.html"><LINK REL="NEXT" TITLE="Multi-threaded Programming" HREF="thread.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="sdlcd.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="thread.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLCDTRACK" ></A >SDL_CDtrack</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN7628" ></A ><H2 >Name</H2 >SDL_CDtrack -- CD Track Information Structure</DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN7631" ></A ><H2 >Structure Definition</H2 ><PRE CLASS="PROGRAMLISTING" >typedef struct{ Uint8 id; Uint8 type; Uint32 length; Uint32 offset; } SDL_CDtrack;</PRE ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN7634" ></A ><H2 >Structure Data</H2 ><DIV CLASS="INFORMALTABLE" ><A NAME="AEN7636" ></A ><P ></P ><TABLE BORDER="0" CLASS="CALSTABLE" ><TBODY ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >id</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Track number (0-99)</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >type</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_AUDIO_TRACK</TT > or <TT CLASS="LITERAL" >SDL_DATA_TRACK</TT ></TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >length</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Length, in frames, of this track</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >offset</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Frame offset to the beginning of this track</TD ></TR ></TBODY ></TABLE ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN7657" ></A ><H2 >Description</H2 ><P ><SPAN CLASS="STRUCTNAME" >SDL_CDtrack</SPAN > stores data on each track on a CD, its fields should be pretty self explainatory. It is a member a the <A HREF="sdlcd.html" ><SPAN CLASS="STRUCTNAME" >SDL_CD</SPAN ></A > structure.</P ><DIV CLASS="NOTE" ><BLOCKQUOTE CLASS="NOTE" ><P ><B >Note: </B >Frames can be converted to standard timings. There are <TT CLASS="LITERAL" >CD_FPS</TT > frames per second, so <SPAN CLASS="STRUCTNAME" >SDL_CDtrack</SPAN >.<TT CLASS="STRUCTFIELD" ><I >length</I ></TT >/<TT CLASS="LITERAL" >CD_FPS</TT >=length_in_seconds.</P ></BLOCKQUOTE ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN7669" ></A ><H2 >See Also</H2 ><P ><A HREF="sdlcd.html" ><SPAN CLASS="STRUCTNAME" >SDL_CD</SPAN ></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="sdlcd.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="thread.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_CD</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="cdrom.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >Multi-threaded Programming</TD ></TR ></TABLE ></DIV ></BODY ></HTML >