Mercurial > sdl-ios-xcode
view docs/html/sdlcdopen.html @ 2042:3908e1f808e1
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 15:56:36 +0000 |
parents | 355632dca928 |
children |
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<HTML ><HEAD ><TITLE >SDL_CDOpen</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_CDName" HREF="sdlcdname.html"><LINK REL="NEXT" TITLE="SDL_CDStatus" HREF="sdlcdstatus.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="sdlcdname.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlcdstatus.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLCDOPEN" ></A >SDL_CDOpen</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN7274" ></A ><H2 >Name</H2 >SDL_CDOpen -- Opens a CD-ROM drive for access.</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN7277" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><A NAME="AEN7278" ></A ><P ></P ><PRE CLASS="FUNCSYNOPSISINFO" >#include "SDL.h"</PRE ><P ><CODE ><CODE CLASS="FUNCDEF" >SDL_CD *<B CLASS="FSFUNC" >SDL_CDOpen</B ></CODE >(int drive);</CODE ></P ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN7284" ></A ><H2 >Description</H2 ><P >Opens a CD-ROM drive for access. It returns a <A HREF="sdlcd.html" ><SPAN CLASS="STRUCTNAME" >SDL_CD</SPAN ></A > structure on success, or <TT CLASS="LITERAL" >NULL</TT > if the drive was invalid or busy. This newly opened CD-ROM becomes the default CD used when other CD functions are passed a <TT CLASS="LITERAL" >NULL</TT > CD-ROM handle. </P ><P >Drives are numbered starting with 0. Drive 0 is the system default CD-ROM.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN7292" ></A ><H2 >Examples</H2 ><PRE CLASS="PROGRAMLISTING" >SDL_CD *cdrom; int cur_track; int min, sec, frame; SDL_Init(SDL_INIT_CDROM); atexit(SDL_Quit); /* Check for CD drives */ if(!SDL_CDNumDrives()){ /* None found */ fprintf(stderr, "No CDROM devices available\n"); exit(-1); } /* Open the default drive */ cdrom=SDL_CDOpen(0); /* Did if open? Check if cdrom is NULL */ if(!cdrom){ fprintf(stderr, "Couldn't open drive: %s\n", SDL_GetError()); exit(-1); } /* Print Volume info */ printf("Name: %s\n", SDL_CDName(0)); printf("Tracks: %d\n", cdrom->numtracks); for(cur_track=0;cur_track < cdrom->numtracks; cur_track++){ FRAMES_TO_MSF(cdrom->track[cur_track].length, &min, &sec, &frame); printf("\tTrack %d: Length %d:%d\n", cur_track, min, sec); } SDL_CDClose(cdrom);</PRE ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN7295" ></A ><H2 >See Also</H2 ><P ><A HREF="sdlcd.html" ><SPAN CLASS="STRUCTNAME" >SDL_CD</SPAN ></A >, <A HREF="sdlcdtrack.html" ><SPAN CLASS="STRUCTNAME" >SDL_CDtrack</SPAN ></A >, <A HREF="sdlcdclose.html" ><TT CLASS="FUNCTION" >SDL_CDClose</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="sdlcdname.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="sdlcdstatus.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_CDName</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="cdrom.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >SDL_CDStatus</TD ></TR ></TABLE ></DIV ></BODY ></HTML >