view docs/html/cdrom.html @ 3846:66fb40445587 SDL-ryan-multiple-audio-device

Removed distinction between "available" and "init" in audio backends, since both had to be checked for success as a pair at the higher level and several of the Available methods were just always-succeed placeholders anyhow. Now the availability check is done in the init code, and the higher level tries all possible drivers until one manages to initialize successfully.
author Ryan C. Gordon <icculus@icculus.org>
date Tue, 17 Oct 2006 09:09:21 +0000
parents 355632dca928
children
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<HTML
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>CD-ROM</TITLE
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><H1
><A
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>Chapter 11. CD-ROM</H1
><DIV
CLASS="TOC"
><DL
><DT
><B
>Table of Contents</B
></DT
><DT
><A
HREF="sdlcdnumdrives.html"
>SDL_CDNumDrives</A
>&nbsp;--&nbsp;Returns the number of CD-ROM drives on the system.</DT
><DT
><A
HREF="sdlcdname.html"
>SDL_CDName</A
>&nbsp;--&nbsp;Returns a human-readable, system-dependent identifier for the CD-ROM.</DT
><DT
><A
HREF="sdlcdopen.html"
>SDL_CDOpen</A
>&nbsp;--&nbsp;Opens a CD-ROM drive for access.</DT
><DT
><A
HREF="sdlcdstatus.html"
>SDL_CDStatus</A
>&nbsp;--&nbsp;Returns the current status of the given drive.</DT
><DT
><A
HREF="sdlcdplay.html"
>SDL_CDPlay</A
>&nbsp;--&nbsp;Play a CD</DT
><DT
><A
HREF="sdlcdplaytracks.html"
>SDL_CDPlayTracks</A
>&nbsp;--&nbsp;Play the given CD track(s)</DT
><DT
><A
HREF="sdlcdpause.html"
>SDL_CDPause</A
>&nbsp;--&nbsp;Pauses a CDROM</DT
><DT
><A
HREF="sdlcdresume.html"
>SDL_CDResume</A
>&nbsp;--&nbsp;Resumes a CDROM</DT
><DT
><A
HREF="sdlcdstop.html"
>SDL_CDStop</A
>&nbsp;--&nbsp;Stops a CDROM</DT
><DT
><A
HREF="sdlcdeject.html"
>SDL_CDEject</A
>&nbsp;--&nbsp;Ejects a CDROM</DT
><DT
><A
HREF="sdlcdclose.html"
>SDL_CDClose</A
>&nbsp;--&nbsp;Closes a SDL_CD handle</DT
><DT
><A
HREF="sdlcd.html"
>SDL_CD</A
>&nbsp;--&nbsp;CDROM Drive Information</DT
><DT
><A
HREF="sdlcdtrack.html"
>SDL_CDtrack</A
>&nbsp;--&nbsp;CD Track Information Structure</DT
></DL
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><P
>SDL supports audio control of up to 32 local CD-ROM drives at once.</P
><P
>You use this API to perform all the basic functions of a CD player,
including listing the tracks, playing, stopping, and ejecting the CD-ROM.
(Currently, multi-changer CD drives are not supported.)</P
><P
>Before you call any of the SDL CD-ROM functions, you must first call
"<TT
CLASS="FUNCTION"
>SDL_Init(SDL_INIT_CDROM)</TT
>", which scans the system for
CD-ROM drives, and sets the program up for audio control.  Check the 
return code, which should be <SPAN
CLASS="RETURNVALUE"
>0</SPAN
>, to see if there 
were any errors in starting up.</P
><P
>After you have initialized the library, you can find out how many drives
are available using the <TT
CLASS="FUNCTION"
>SDL_CDNumDrives()</TT
> function.  
The first drive listed is the system default CD-ROM drive.  After you have 
chosen a drive, and have opened it with <TT
CLASS="FUNCTION"
>SDL_CDOpen()</TT
>, 
you can check the status and start playing if there's a CD in the drive.</P
><P
>A CD-ROM is organized into one or more tracks, each consisting of a certain
number of "frames".  Each frame is ~2K in size, and at normal playing speed,
a CD plays 75 frames per second.  SDL works with the number of frames on a
CD, but this can easily be converted to the more familiar minutes/seconds
format by using the <TT
CLASS="FUNCTION"
>FRAMES_TO_MSF()</TT
> macro.</P
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