Fixed bug #46 Date: Fri, 13 Jan 2006 18:09:45 -0500 From: mhall4400 vipmail kvcc edu Subject: Possible SDL bug Greetings I believe Ive come across a bug in your SDL product (1.2.9), in the CD-ROM control portion of the library. When calling the SDL_CDPlay() function to play the last track of a CD using the offset and length from an SDL_CD structure generated by SDL_CDOpen(), I get the following error from a call to SDL_Error(): mciSendCommand() error: The specified parameter is out of range for the specified command. The code returning the error is: SDL_CDPlay(g_playingDriveSDLCD, g_playingDriveSDLCD->track[trackNumberInt].offset, g_playingDriveSDLCD->track[trackNumberInt].length) Subtracting one from the length of the provided length seems to repair the problem: SDL_CDPlay(g_playingDriveSDLCD, g_playingDriveSDLCD->track[trackNumberInt].offset, (g_playingDriveSDLCD->track[trackNumberInt].length) - 1) Ive replicated this problem on Windows 98 SE (several months since last patch), fully-patched Window ME, seldom-patched Windows XP SP1, and fully-patched Windows XP SP2. While investigating the issue, I came across a line in your librarys win32 source code in file \src\cdrom\win32\SDL_syscdrom.c (source code zip archive from your download page), function: SDL_SYS_CDGetTOC(), line 226 where you add 1 to the value for length to fix MCI last track length bug. This may be the source of the issue (because subtracting 1 from the length seems to resolve the issue). Microsoft may have patched the referenced bug since you wrote that line. Mike Hall

.TH "SDL_CDPlayTracks" "3" "Tue 11 Sep 2001, 22:58" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_CDPlayTracks\- Play the given CD track(s)
.SH "SYNOPSIS"
.PP
\fB#include "SDL\&.h"
.sp
\fBint \fBSDL_CDPlayTracks\fP\fR(\fBSDL_CD *cdrom, int start_track, int start_frame, int ntracks, int nframes)\fR);
.SH "DESCRIPTION"
.PP
\fBSDL_CDPlayTracks\fP plays the given CD starting at track \fBstart_track\fR, for \fBntracks\fR tracks\&. 
.PP
\fBstart_frame\fR is the frame offset, from the beginning of the \fBstart_track\fR, at which to start\&. \fBnframes\fR is the frame offset, from the beginning of the last track (\fBstart_track\fR+\fBntracks\fR), at which to end playing\&.
.PP
\fBSDL_CDPlayTracks\fP should only be called after calling \fI\fBSDL_CDStatus\fP\fR to get track information about the CD\&.
.PP
.RS
\fBNote:  
.PP
Data tracks are ignored\&.
.RE
.SH "RETURN VALUE"
.PP
Returns \fB0\fR, or \fB-1\fR if there was an error\&.
.SH "EXAMPLES"
.PP
.PP
.nf
\f(CW/* assuming cdrom is a previously opened device */
/* Play the entire CD */
if(CD_INDRIVE(SDL_CDStatus(cdrom)))
  SDL_CDPlayTracks(cdrom, 0, 0, 0, 0);

/* Play the first track */
if(CD_INDRIVE(SDL_CDStatus(cdrom)))
  SDL_CDPlayTracks(cdrom, 0, 0, 1, 0);

/* Play first 15 seconds of the 2nd track */
if(CD_INDRIVE(SDL_CDStatus(cdrom)))
  SDL_CDPlayTracks(cdrom, 1, 0, 0, CD_FPS*15);\fR
.fi
.PP
 
.SH "SEE ALSO"
.PP
\fI\fBSDL_CDPlay\fP\fR, \fI\fBSDL_CDStatus\fP\fR, \fI\fBSDL_CD\fP\fR
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 22:58