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view docs/html/guidecdromexamples.html @ 968:4675910b0b7b
Date: Mon, 11 Oct 2004 15:17:27 +0300 (EEST)
From: Hannu Savolainen
Subject: Re: SDL uses obsolete OSS features
I did some work on getting OSS to work better with SDL. There have been
some problems with select which should be fixed now.
I'm having some problems in understanding what is the purpose of the
DSP_WaitAudio() routine. I added a return to the very beginning of this
routine and commendted out the define for USE_BLOCKING_WRITES. At least
lbreakout2 seems to work as well as earlier. The latencies are the same.
An ordinary blocking write does exactly the same thing than DSP_WaitAudio
does. So I would recommend using the USE_BLOCKING_WRITES approach and
removing everything from the DSP_WaitAudio routine. Also enabling
USE_BLOCKING_WRITES makes it possible to simplify DSP_PlayAudio() because
you don't need to handle the partial writes (the do-while loop).
Attached is a patch against SDL-1.2.7. After these changes SDL will use
OSS as it's designed to be used (make it as simple as possible). This code
should work with all OSS implementations because it uses only the very
fundamental features that have been there since the jurassic times.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Fri, 12 Nov 2004 21:39:04 +0000 |
parents | 355632dca928 |
children |
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<HTML ><HEAD ><TITLE >CDROM Examples</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="Examples" HREF="guideexamples.html"><LINK REL="PREVIOUS" TITLE="Audio Examples" HREF="guideaudioexamples.html"><LINK REL="NEXT" TITLE="Time Examples" HREF="guidetimeexamples.html"></HEAD ><BODY CLASS="SECT1" 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="guideaudioexamples.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" >Chapter 4. Examples</TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="guidetimeexamples.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="SECT1" ><H1 CLASS="SECT1" ><A NAME="GUIDECDROMEXAMPLES" ></A >CDROM Examples</H1 ><P ></P ><DIV CLASS="SECT2" ><H2 CLASS="SECT2" ><A NAME="AEN393" ></A >Listing CD-ROM drives</H2 ><P ><PRE CLASS="PROGRAMLISTING" > #include "SDL.h" /* Initialize SDL first */ if ( SDL_Init(SDL_INIT_CDROM) < 0 ) { fprintf(stderr, "Couldn't initialize SDL: %s\n",SDL_GetError()); exit(1); } atexit(SDL_Quit); /* Find out how many CD-ROM drives are connected to the system */ printf("Drives available: %d\n", SDL_CDNumDrives()); for ( i=0; i<SDL_CDNumDrives(); ++i ) { printf("Drive %d: \"%s\"\n", i, SDL_CDName(i)); }</PRE ></P ></DIV ><DIV CLASS="SECT2" ><H2 CLASS="SECT2" ><A NAME="AEN397" ></A >Opening the default drive</H2 ><P ><PRE CLASS="PROGRAMLISTING" > SDL_CD *cdrom; CDstatus status; char *status_str; cdrom = SDL_CDOpen(0); if ( cdrom == NULL ) { fprintf(stderr, "Couldn't open default CD-ROM drive: %s\n", SDL_GetError()); exit(2); } status = SDL_CDStatus(cdrom); switch (status) { case CD_TRAYEMPTY: status_str = "tray empty"; break; case CD_STOPPED: status_str = "stopped"; break; case CD_PLAYING: status_str = "playing"; break; case CD_PAUSED: status_str = "paused"; break; case CD_ERROR: status_str = "error state"; break; } printf("Drive status: %s\n", status_str); if ( status >= CD_PLAYING ) { int m, s, f; FRAMES_TO_MSF(cdrom->cur_frame, &m, &s, &f); printf("Currently playing track %d, %d:%2.2d\n", cdrom->track[cdrom->cur_track].id, m, s); }</PRE ></P ></DIV ><DIV CLASS="SECT2" ><H2 CLASS="SECT2" ><A NAME="AEN401" ></A >Listing the tracks on a CD</H2 ><P ><PRE CLASS="PROGRAMLISTING" > SDL_CD *cdrom; /* Assuming this has already been set.. */ int i; int m, s, f; SDL_CDStatus(cdrom); printf("Drive tracks: %d\n", cdrom->numtracks); for ( i=0; i<cdrom->numtracks; ++i ) { FRAMES_TO_MSF(cdrom->track[i].length, &m, &s, &f); if ( f > 0 ) ++s; printf("\tTrack (index %d) %d: %d:%2.2d\n", i, cdrom->track[i].id, m, s); }</PRE ></P ></DIV ><DIV CLASS="SECT2" ><H2 CLASS="SECT2" ><A NAME="AEN405" ></A >Play an entire CD</H2 ><P ><PRE CLASS="PROGRAMLISTING" > SDL_CD *cdrom; /* Assuming this has already been set.. */ // Play entire CD: if ( CD_INDRIVE(SDL_CDStatus(cdrom)) ) SDL_CDPlayTracks(cdrom, 0, 0, 0, 0); // Play last track: if ( CD_INDRIVE(SDL_CDStatus(cdrom)) ) { SDL_CDPlayTracks(cdrom, cdrom->numtracks-1, 0, 0, 0); } // Play first and second track and 10 seconds of third track: if ( CD_INDRIVE(SDL_CDStatus(cdrom)) ) SDL_CDPlayTracks(cdrom, 0, 0, 2, CD_FPS * 10);</PRE ></P ></DIV ></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="guideaudioexamples.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="guidetimeexamples.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >Audio Examples</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="guideexamples.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >Time Examples</TD ></TR ></TABLE ></DIV ></BODY ></HTML >