view src/cdrom/os2/SDL_syscdrom.c @ 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 92947e3a18db
children 782fd950bd46 c121d94672cb a1b03ba2fcd0
line wrap: on
line source

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2006 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

#ifdef SDL_CDROM_OS2

/* Functions for system-level CD-ROM audio control */

#define INCL_MCIOS2
#include <os2.h>
#include <os2me.h>

#include "SDL_cdrom.h"
#include "../SDL_syscdrom.h"

/* Size of MCI result buffer (in bytes) */
#define MCI_CMDRETBUFSIZE	128

/* The maximum number of CD-ROM drives we'll detect */
#define MAX_DRIVES	16	

/* A list of available CD-ROM drives */
static char *SDL_cdlist[MAX_DRIVES];
//static dev_t SDL_cdmode[MAX_DRIVES];

/* The system-dependent CD control functions */
static const char *SDL_SYS_CDName(int drive);
static int SDL_SYS_CDOpen(int drive);
static int SDL_SYS_CDGetTOC(SDL_CD *cdrom);
static CDstatus SDL_SYS_CDStatus(SDL_CD *cdrom, int *position);
static int SDL_SYS_CDPlay(SDL_CD *cdrom, int start, int length);
static int SDL_SYS_CDPause(SDL_CD *cdrom);
static int SDL_SYS_CDResume(SDL_CD *cdrom);
static int SDL_SYS_CDStop(SDL_CD *cdrom);
static int SDL_SYS_CDEject(SDL_CD *cdrom);
static void SDL_SYS_CDClose(SDL_CD *cdrom);

/* MCI Timing Functions */
#define	MCI_MMTIMEPERSECOND		3000
#define	FRAMESFROMMM(mmtime)		(((mmtime)*CD_FPS)/MCI_MMTIMEPERSECOND)


/* Ready for MCI CDAudio Devices */
int  SDL_SYS_CDInit(void)
{
int i; /* generig counter */
MCI_SYSINFO_PARMS		msp;	/* Structure to MCI SysInfo parameters */
CHAR 						SysInfoRet[MCI_CMDRETBUFSIZE];	/* Buffer for MCI Command result */

/* Fill in our driver capabilities */
SDL_CDcaps.Name = SDL_SYS_CDName;
SDL_CDcaps.Open = SDL_SYS_CDOpen;
SDL_CDcaps.GetTOC = SDL_SYS_CDGetTOC;
SDL_CDcaps.Status = SDL_SYS_CDStatus;
SDL_CDcaps.Play = SDL_SYS_CDPlay;
SDL_CDcaps.Pause = SDL_SYS_CDPause;
SDL_CDcaps.Resume = SDL_SYS_CDResume;
SDL_CDcaps.Stop = SDL_SYS_CDStop;
SDL_CDcaps.Eject = SDL_SYS_CDEject;
SDL_CDcaps.Close = SDL_SYS_CDClose;

/* Get the number of CD ROMs in the System */
/* Clean SysInfo structure */
SDL_memset(&msp, 0x00, sizeof(MCI_SYSINFO_PARMS));
/* Prepare structure to Ask Numer of Audio CDs */
msp.usDeviceType = MCI_DEVTYPE_CD_AUDIO;	/* CD Audio Type */
msp.pszReturn = (PSZ)&SysInfoRet; 	/* Return Structure */
msp.ulRetSize = MCI_CMDRETBUFSIZE; 	/* Size of ret struct */
if (LOUSHORT(mciSendCommand(0,MCI_SYSINFO, MCI_SYSINFO_QUANTITY | MCI_WAIT, (PVOID)&msp, 0)) != MCIERR_SUCCESS) return(CD_ERROR);
SDL_numcds = atoi(SysInfoRet);
if (SDL_numcds > MAX_DRIVES) SDL_numcds = MAX_DRIVES; /* Limit maximum CD number */

/* Get and Add their system name to the SDL_cdlist */
msp.pszReturn = (PSZ)&SysInfoRet; 				/* Return Structure */
msp.ulRetSize = MCI_CMDRETBUFSIZE; 			/* Size of ret struct */
msp.usDeviceType = MCI_DEVTYPE_CD_AUDIO;		/* CD Audio Type */
for (i=0; i<SDL_numcds; i++)
	{
	msp.ulNumber = i+1;
	mciSendCommand(0,MCI_SYSINFO, MCI_SYSINFO_NAME | MCI_WAIT,&msp, 0);
	SDL_cdlist[i] = SDL_strdup(SysInfoRet);
	if ( SDL_cdlist[i] == NULL )
		{
		SDL_OutOfMemory();
		return(-1);
		}
	}
return(0);
}

/* Return CDAudio System Dependent Device Name - Ready for MCI*/
static const char *SDL_SYS_CDName(int drive)
{
return(SDL_cdlist[drive]);
}

/* Open CDAudio Device - Ready for MCI */
static int SDL_SYS_CDOpen(int drive)
{
MCI_OPEN_PARMS	mop;
MCI_SET_PARMS msp;
MCI_GENERIC_PARMS mgp;

/* Open the device */
mop.hwndCallback = (HWND)NULL;		// None
mop.usDeviceID = (USHORT)NULL;		// Will be returned.
mop.pszDeviceType = (PSZ)SDL_cdlist[drive];		// CDAudio Device
if (LOUSHORT(mciSendCommand(0,MCI_OPEN,MCI_WAIT,&mop, 0)) != MCIERR_SUCCESS) return(CD_ERROR);
/* Set time format */
msp.hwndCallback = (HWND)NULL;		// None
msp.ulTimeFormat = MCI_FORMAT_MSF;	// Minute : Second : Frame structure
msp.ulSpeedFormat = (ULONG)NULL;		// No change
msp.ulAudio = (ULONG)NULL;				// No Channel
msp.ulLevel = (ULONG)NULL;				// No Volume
msp.ulOver = (ULONG)NULL;				// No Delay
msp.ulItem = (ULONG)NULL;				// No item
msp.ulValue = (ULONG)NULL;				// No value for item flag
if (LOUSHORT(mciSendCommand(mop.usDeviceID,MCI_SET,MCI_WAIT | MCI_SET_TIME_FORMAT,&msp, 0)) == MCIERR_SUCCESS) return (mop.usDeviceID);
/* Error setting time format? - Close opened device */
mgp.hwndCallback = (HWND)NULL;		// None
mciSendCommand(mop.usDeviceID,MCI_CLOSE,MCI_WAIT,&mgp, 0);
return(CD_ERROR);
}

/* Get CD Table Of Contents - Ready for MCI */
static int SDL_SYS_CDGetTOC(SDL_CD *cdrom)
{
MCI_TOC_PARMS mtp;
MCI_STATUS_PARMS msp;
MCI_TOC_REC * mtr;
INT i;

/* Correction because MCI cannot read TOC while CD is playing (it'll stop!) */
if (cdrom->status == CD_PLAYING || cdrom->status == CD_PAUSED) return 0;

/* Get Number of Tracks */
msp.hwndCallback = (HWND)NULL; /* None */
msp.ulReturn = (ULONG)NULL; /* We want this information */
msp.ulItem = MCI_STATUS_NUMBER_OF_TRACKS;
msp.ulValue = (ULONG)NULL; /* No additional information */
if (LOUSHORT(mciSendCommand(cdrom->id,MCI_STATUS,MCI_WAIT | MCI_STATUS_ITEM,&msp, 0)) != MCIERR_SUCCESS) return(CD_ERROR);
cdrom->numtracks = msp.ulReturn;
if ( cdrom->numtracks > SDL_MAX_TRACKS )
	{
	cdrom->numtracks = SDL_MAX_TRACKS;
	}
/* Alocate space for TOC data */
mtr = (MCI_TOC_REC *)SDL_malloc(cdrom->numtracks*sizeof(MCI_TOC_REC));
if ( mtr == NULL )
	{
	SDL_OutOfMemory();
	return(-1);
	}
/* Get TOC from CD */
mtp.pBuf = mtr;
mtp.ulBufSize = cdrom->numtracks*sizeof(MCI_TOC_REC);
if (LOUSHORT(mciSendCommand(cdrom->id,MCI_GETTOC,MCI_WAIT,&mtp, 0)) != MCIERR_SUCCESS)
	{
	SDL_OutOfMemory();
	SDL_free(mtr);
	return(CD_ERROR);
	}
/* Fill SDL Tracks Structure */
for (i=0; i<cdrom->numtracks; i++)
	{
	/* Set Track ID */
	cdrom->track[i].id = (mtr+i)->TrackNum;
	/* Set Track Type */
	msp.hwndCallback = (HWND)NULL; /* None */
	msp.ulReturn = (ULONG)NULL; /* We want this information */
	msp.ulItem = MCI_CD_STATUS_TRACK_TYPE;
	msp.ulValue = (ULONG)((mtr+i)->TrackNum); /* Track Number? */
	if (LOUSHORT(mciSendCommand(cdrom->id,MCI_STATUS,MCI_WAIT | MCI_TRACK | MCI_STATUS_ITEM,&msp, 0)) != MCIERR_SUCCESS)
		{
		SDL_free(mtr);
		return (CD_ERROR);
		}
	if (msp.ulReturn==MCI_CD_TRACK_AUDIO) cdrom->track[i].type = SDL_AUDIO_TRACK;
	else cdrom->track[i].type = SDL_DATA_TRACK;
	/* Set Track Length - values from MCI are in MMTIMEs - 3000 MMTIME = 1 second */
	cdrom->track[i].length = FRAMESFROMMM((mtr+i)->ulEndAddr - (mtr+i)->ulStartAddr);
	/* Set Track Offset */
	cdrom->track[i].offset = FRAMESFROMMM((mtr+i)->ulStartAddr);
	}
SDL_free(mtr);
return(0);
}


/* Get CD-ROM status - Ready for MCI */
static CDstatus SDL_SYS_CDStatus(SDL_CD *cdrom, int *position)
{
CDstatus status;
MCI_STATUS_PARMS msp;

/* Get Status from MCI */
msp.hwndCallback = (HWND)NULL; /* None */
msp.ulReturn = (ULONG)NULL; /* We want this information */
msp.ulItem = MCI_STATUS_MODE;
msp.ulValue = (ULONG)NULL; /* No additional information */
if (LOUSHORT(mciSendCommand(cdrom->id,MCI_STATUS,MCI_WAIT | MCI_STATUS_ITEM,&msp, 0)) != MCIERR_SUCCESS) status = CD_ERROR;
else
	{
	switch(msp.ulReturn)
		{
		case	MCI_MODE_NOT_READY:
			status = CD_TRAYEMPTY;
			break;
		case	MCI_MODE_PAUSE:
			status = CD_PAUSED;
			break;
		case	MCI_MODE_PLAY:
			status = CD_PLAYING;
			break;
		case	MCI_MODE_STOP:
			status = CD_STOPPED;
			break;
		/* These cases should not occour */
		case	MCI_MODE_RECORD:
		case	MCI_MODE_SEEK:
		default:
			status = CD_ERROR;
			break;
		}
	}

/* Determine position */
if (position != NULL) /* The SDL $&$&%# CDROM call sends NULL pointer here! */
	{
		if ((status == CD_PLAYING) || (status == CD_PAUSED))
		{
		/* Get Position */
		msp.hwndCallback = (HWND)NULL; /* None */
		msp.ulReturn = (ULONG)NULL; /* We want this information */
		msp.ulItem = MCI_STATUS_POSITION;
		msp.ulValue = (ULONG)NULL; /* No additiona info */
		if (LOUSHORT(mciSendCommand(cdrom->id,MCI_STATUS,MCI_WAIT | MCI_STATUS_ITEM,&msp, 0)) != MCIERR_SUCCESS) return (CD_ERROR);
		/* Convert from MSF (format selected in the Open process) to Frames (format that will be returned) */
		*position = MSF_TO_FRAMES(MSF_MINUTE(msp.ulReturn),MSF_SECOND(msp.ulReturn),MSF_FRAME(msp.ulReturn));
		}
	else *position = 0;
	}
return(status);
}

/* Start play - Ready for MCI */
static int SDL_SYS_CDPlay(SDL_CD *cdrom, int start, int length)
{
MCI_GENERIC_PARMS mgp;
MCI_STATUS_PARMS msp;
MCI_PLAY_PARMS	mpp;
ULONG min,sec,frm;

/* Start MSF */
FRAMES_TO_MSF(start, &min, &sec, &frm);
MSF_MINUTE(mpp.ulFrom) = min;
MSF_SECOND(mpp.ulFrom) = sec;
MSF_FRAME(mpp.ulFrom) = frm;
/* End MSF */
FRAMES_TO_MSF(start+length, &min, &sec, &frm);
MSF_MINUTE(mpp.ulTo) = min;
MSF_SECOND(mpp.ulTo) = sec;
MSF_FRAME(mpp.ulTo) = frm;
#ifdef DEBUG_CDROM
	fprintf(stderr, "Trying to play from %d:%d:%d to %d:%d:%d\n",
	playtime.cdmsf_min0, playtime.cdmsf_sec0, playtime.cdmsf_frame0,
	playtime.cdmsf_min1, playtime.cdmsf_sec1, playtime.cdmsf_frame1);
#endif
/* Verifies if it is paused first... and if it is, unpause before stopping it. */
msp.hwndCallback = (HWND)NULL; /* None */
msp.ulReturn = (ULONG)NULL; /* We want this information */
msp.ulItem = MCI_STATUS_MODE;
msp.ulValue = (ULONG)NULL; /* No additional information */
if (LOUSHORT(mciSendCommand(cdrom->id,MCI_STATUS,MCI_WAIT | MCI_STATUS_ITEM,&msp, 0)) == MCIERR_SUCCESS)
	{
	if (msp.ulReturn == MCI_MODE_PAUSE)
		{
		mgp.hwndCallback = (HWND)NULL;		// None
		mciSendCommand(cdrom->id,MCI_RESUME,0,&mgp, 0);
		}
	}
/* Now play it. */
mpp.hwndCallback = (HWND)NULL;		// We do not want the info. temp
if (LOUSHORT(mciSendCommand(cdrom->id,MCI_PLAY,MCI_FROM | MCI_TO,&mpp, 0)) == MCIERR_SUCCESS) return 0;
return (CD_ERROR);
}

/* Pause play - Ready for MCI */
static int SDL_SYS_CDPause(SDL_CD *cdrom)
{
MCI_GENERIC_PARMS mgp;

mgp.hwndCallback = (HWND)NULL;		// None
if (LOUSHORT(mciSendCommand(cdrom->id,MCI_PAUSE,MCI_WAIT,&mgp, 0)) == MCIERR_SUCCESS) return 0;
return(CD_ERROR);
}

/* Resume play - Ready for MCI */
static int SDL_SYS_CDResume(SDL_CD *cdrom)
{
MCI_GENERIC_PARMS mgp;

mgp.hwndCallback = (HWND)NULL;		// None
if (LOUSHORT(mciSendCommand(cdrom->id,MCI_RESUME,MCI_WAIT,&mgp, 0)) == MCIERR_SUCCESS) return 0;
return(CD_ERROR);
}

/* Stop play - Ready for MCI */
static int SDL_SYS_CDStop(SDL_CD *cdrom)
{
MCI_GENERIC_PARMS mgp;
MCI_STATUS_PARMS msp;

/* Verifies if it is paused first... and if it is, unpause before stopping it. */
msp.hwndCallback = (HWND)NULL; /* None */
msp.ulReturn = (ULONG)NULL; /* We want this information */
msp.ulItem = MCI_STATUS_MODE;
msp.ulValue = (ULONG)NULL; /* No additional information */
if (LOUSHORT(mciSendCommand(cdrom->id,MCI_STATUS,MCI_WAIT | MCI_STATUS_ITEM,&msp, 0)) == MCIERR_SUCCESS)
	{
	if (msp.ulReturn == MCI_MODE_PAUSE)
		{
		mgp.hwndCallback = (HWND)NULL;		// None
		mciSendCommand(cdrom->id,MCI_RESUME,0,&mgp, 0);
		}
	}
/* Now stops the media */
mgp.hwndCallback = (HWND)NULL;		// None
if (LOUSHORT(mciSendCommand(cdrom->id,MCI_STOP,MCI_WAIT,&mgp, 0)) == MCIERR_SUCCESS) return 0;
return(CD_ERROR);
}

/* Eject the CD-ROM - Ready for MCI */
static int SDL_SYS_CDEject(SDL_CD *cdrom)
{
MCI_SET_PARMS msp;

msp.hwndCallback = (HWND)NULL;		// None
msp.ulTimeFormat = (ULONG)NULL;		// No change
msp.ulSpeedFormat = (ULONG)NULL;		// No change
msp.ulAudio = (ULONG)NULL;				// No Channel
msp.ulLevel = (ULONG)NULL;				// No Volume
msp.ulOver = (ULONG)NULL;				// No Delay
msp.ulItem = (ULONG)NULL;					// No item
msp.ulValue = (ULONG)NULL;					// No value for item flag
if (LOUSHORT(mciSendCommand(cdrom->id,MCI_SET,MCI_WAIT | MCI_SET_DOOR_OPEN,&msp, 0)) == MCIERR_SUCCESS) return 0;
return(CD_ERROR);
}

/* Close the CD-ROM handle - Ready for MCI */
static void SDL_SYS_CDClose(SDL_CD *cdrom)
{
MCI_GENERIC_PARMS mgp;

mgp.hwndCallback = (HWND)NULL;		// None
mciSendCommand(cdrom->id,MCI_CLOSE,MCI_WAIT,&mgp, 0);
}

/* Finalize CDROM Subsystem - Ready for MCI */
void SDL_SYS_CDQuit(void)
{
int i;

if ( SDL_numcds > 0 )
	{
	for ( i=0; i<SDL_numcds; ++i )
		{
		SDL_free(SDL_cdlist[i]);
		}
	SDL_numcds = 0;
	}
}

#endif /* SDL_CDROM_OS2 */