view src/cdrom/win32/SDL_syscdrom.c @ 765:4c2ba6161939

Editors Note: The original patch was modified to use SDL_Delay() instead of nanosleep because nanosleep may not be portable to all systems using SDL with the ALSA backend. This may be a moot point with the switch to blocking writes anyway... Date: Sat, 27 Dec 2003 21:47:36 +0100 From: Michel Daenzer To: Debian Bug Tracking System Subject: [SDL] Bug#225252: [PATCH] ALSA fixes Package: libsdl1.2debian-all Version: 1.2.6-2 Severity: normal Tags: patch For SDL 1.2.6, the ALSA backend was changed to call snd_pcm_open() with SND_PCM_NONBLOCK. That's a good idea per se, however, it causes high CPU usage, interrupted sound and stuttering in some games here. Taking a nanosleep whenever snd_pcm_writei() returns -EAGAIN fixes this, but I think it's more efficient to use blocking mode for the actual sound playback. Feedback from the SDL and ALSA lists appreciated. The patch also fixes the default ALSA device to be used.
author Sam Lantinga <slouken@libsdl.org>
date Sun, 04 Jan 2004 15:40:50 +0000
parents f6ffac90895c
children b8d311d90021
line wrap: on
line source

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002  Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 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
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public
    License along with this library; if not, write to the Free
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    Sam Lantinga
    slouken@libsdl.org
*/

#ifdef SAVE_RCSID
static char rcsid =
 "@(#) $Id$";
#endif

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

#include <stdlib.h>
#include <stdio.h>
#include <windows.h>
#include <mmsystem.h>

#include "SDL_error.h"
#include "SDL_cdrom.h"
#include "SDL_syscdrom.h"

/* This really broken?? */
#define BROKEN_MCI_PAUSE	/* Pausing actually stops play -- Doh! */

/* The maximum number of CD-ROM drives we'll detect (Don't change!) */
#define MAX_DRIVES	26	

/* A list of available CD-ROM drives */
static char *SDL_cdlist[MAX_DRIVES];
static MCIDEVICEID SDL_mciID[MAX_DRIVES];
#ifdef BROKEN_MCI_PAUSE
static int SDL_paused[MAX_DRIVES];
#endif

/* 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);


/* Add a CD-ROM drive to our list of valid drives */
static void AddDrive(char *drive)
{
	int i;

	if ( SDL_numcds < MAX_DRIVES ) {
		/* Add this drive to our list */
		i = SDL_numcds;
		SDL_cdlist[i] = (char *)malloc(strlen(drive)+1);
		if ( SDL_cdlist[i] == NULL ) {
			SDL_OutOfMemory();
			return;
		}
		strcpy(SDL_cdlist[i], drive);
		++SDL_numcds;
#ifdef CDROM_DEBUG
  fprintf(stderr, "Added CD-ROM drive: %s\n", drive);
#endif
	}
}

int  SDL_SYS_CDInit(void)
{
	/* checklist: Drive 'A' - 'Z' */
	int i;
	char drive[4];

	/* 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;

	/* Scan the system for CD-ROM drives */
	for ( i='A'; i<='Z'; ++i ) {
		sprintf(drive, "%c:\\", i);
		if ( GetDriveType(drive) == DRIVE_CDROM ) {
			AddDrive(drive);
		}
	}
	memset(SDL_mciID, 0, sizeof(SDL_mciID));
	return(0);
}

/* General ioctl() CD-ROM command function */
static int SDL_SYS_CDioctl(int id, UINT msg, DWORD flags, void *arg)
{
	MCIERROR mci_error;

	mci_error = mciSendCommand(SDL_mciID[id], msg, flags, (DWORD)arg);
	if ( mci_error ) {
		char error[256];

		mciGetErrorString(mci_error, error, 256);
		SDL_SetError("mciSendCommand() error: %s", error);
	}
	return(!mci_error ? 0 : -1);
}

static const char *SDL_SYS_CDName(int drive)
{
	return(SDL_cdlist[drive]);
}

static int SDL_SYS_CDOpen(int drive)
{
	MCI_OPEN_PARMS mci_open;
	MCI_SET_PARMS mci_set;
	char device[3];
	DWORD flags;

	/* Open the requested device */
	mci_open.lpstrDeviceType = (LPCSTR) MCI_DEVTYPE_CD_AUDIO;
	device[0] = *SDL_cdlist[drive];
	device[1] = ':';
	device[2] = '\0';
	mci_open.lpstrElementName = device;
	flags =
	  (MCI_OPEN_TYPE|MCI_OPEN_SHAREABLE|MCI_OPEN_TYPE_ID|MCI_OPEN_ELEMENT);
	if ( SDL_SYS_CDioctl(0, MCI_OPEN, flags, &mci_open) < 0 ) {
		flags &= ~MCI_OPEN_SHAREABLE;
		if ( SDL_SYS_CDioctl(0, MCI_OPEN, flags, &mci_open) < 0 ) {
			return(-1);
		}
	}
	SDL_mciID[drive] = mci_open.wDeviceID;

	/* Set the minute-second-frame time format */
	mci_set.dwTimeFormat = MCI_FORMAT_MSF;
	SDL_SYS_CDioctl(drive, MCI_SET, MCI_SET_TIME_FORMAT, &mci_set);

#ifdef BROKEN_MCI_PAUSE
	SDL_paused[drive] = 0;
#endif
	return(drive);
}

static int SDL_SYS_CDGetTOC(SDL_CD *cdrom)
{
	MCI_STATUS_PARMS mci_status;
	int i, okay;
	DWORD flags;

	okay = 0;
	mci_status.dwItem = MCI_STATUS_NUMBER_OF_TRACKS;
	flags = MCI_STATUS_ITEM | MCI_WAIT;
	if ( SDL_SYS_CDioctl(cdrom->id, MCI_STATUS, flags, &mci_status) == 0 ) {
		cdrom->numtracks = mci_status.dwReturn;
		if ( cdrom->numtracks > SDL_MAX_TRACKS ) {
			cdrom->numtracks = SDL_MAX_TRACKS;
		}
		/* Read all the track TOC entries */
		flags = MCI_STATUS_ITEM | MCI_TRACK | MCI_WAIT;
		for ( i=0; i<cdrom->numtracks; ++i ) {
			cdrom->track[i].id = i+1;
			mci_status.dwTrack = cdrom->track[i].id;
#ifdef MCI_CDA_STATUS_TYPE_TRACK
			mci_status.dwItem = MCI_CDA_STATUS_TYPE_TRACK;
			if ( SDL_SYS_CDioctl(cdrom->id, MCI_STATUS, flags,
							&mci_status) < 0 ) {
				break;
			}
			if ( mci_status.dwReturn == MCI_CDA_TRACK_AUDIO ) {
				cdrom->track[i].type = SDL_AUDIO_TRACK;
			} else {
				cdrom->track[i].type = SDL_DATA_TRACK;
			}
#else
			cdrom->track[i].type = SDL_AUDIO_TRACK;
#endif
			mci_status.dwItem = MCI_STATUS_POSITION;
			if ( SDL_SYS_CDioctl(cdrom->id, MCI_STATUS, flags,
							&mci_status) < 0 ) {
				break;
			}
			cdrom->track[i].offset = MSF_TO_FRAMES(
					MCI_MSF_MINUTE(mci_status.dwReturn),
					MCI_MSF_SECOND(mci_status.dwReturn),
					MCI_MSF_FRAME(mci_status.dwReturn));
			cdrom->track[i].length = 0;
			if ( i > 0 ) {
				cdrom->track[i-1].length =
						cdrom->track[i].offset-
						cdrom->track[i-1].offset;
			}
		}
		if ( i == cdrom->numtracks ) {
			mci_status.dwTrack = cdrom->track[i - 1].id;
			mci_status.dwItem = MCI_STATUS_LENGTH;
			if ( SDL_SYS_CDioctl(cdrom->id, MCI_STATUS, flags,
							&mci_status) == 0 ) {
				cdrom->track[i - 1].length = MSF_TO_FRAMES(
					MCI_MSF_MINUTE(mci_status.dwReturn),
					MCI_MSF_SECOND(mci_status.dwReturn),
					MCI_MSF_FRAME(mci_status.dwReturn)) + 1; /* +1 to fix */
											/* MCI last track length bug */
				/* compute lead-out offset */
				cdrom->track[i].offset = cdrom->track[i - 1].offset +
					cdrom->track[i - 1].length;
				cdrom->track[i].length = 0;
				okay = 1;
			}
		}
	}
	return(okay ? 0 : -1);
}

/* Get CD-ROM status */
static CDstatus SDL_SYS_CDStatus(SDL_CD *cdrom, int *position)
{
	CDstatus status;
	MCI_STATUS_PARMS mci_status;
	DWORD flags;

	flags = MCI_STATUS_ITEM | MCI_WAIT;
	mci_status.dwItem = MCI_STATUS_MODE;
	if ( SDL_SYS_CDioctl(cdrom->id, MCI_STATUS, flags, &mci_status) < 0 ) {
		status = CD_ERROR;
	} else {
		switch (mci_status.dwReturn) {
			case MCI_MODE_NOT_READY:
			case MCI_MODE_OPEN:
				status = CD_TRAYEMPTY;
				break;
			case MCI_MODE_STOP:
#ifdef BROKEN_MCI_PAUSE
				if ( SDL_paused[cdrom->id] ) {
					status = CD_PAUSED;
				} else {
					status = CD_STOPPED;
				}
#else
				status = CD_STOPPED;
#endif /* BROKEN_MCI_PAUSE */
				break;
			case MCI_MODE_PLAY:
#ifdef BROKEN_MCI_PAUSE
				if ( SDL_paused[cdrom->id] ) {
					status = CD_PAUSED;
				} else {
					status = CD_PLAYING;
				}
#else
				status = CD_PLAYING;
#endif /* BROKEN_MCI_PAUSE */
				break;
			case MCI_MODE_PAUSE:
				status = CD_PAUSED;
				break;
			default:
				status = CD_ERROR;
				break;
		}
	}
	if ( position ) {
		if ( status == CD_PLAYING || (status == CD_PAUSED) ) {
			mci_status.dwItem = MCI_STATUS_POSITION;
			if ( SDL_SYS_CDioctl(cdrom->id, MCI_STATUS, flags,
							&mci_status) == 0 ) {
				*position = MSF_TO_FRAMES(
					MCI_MSF_MINUTE(mci_status.dwReturn),
					MCI_MSF_SECOND(mci_status.dwReturn),
					MCI_MSF_FRAME(mci_status.dwReturn));
			} else {
				*position = 0;
			}
		} else {
			*position = 0;
		}
	}
	return(status);
}

/* Start play */
static int SDL_SYS_CDPlay(SDL_CD *cdrom, int start, int length)
{
	MCI_PLAY_PARMS mci_play;
	int m, s, f;
	DWORD flags;

	flags = MCI_FROM | MCI_TO | MCI_NOTIFY;
	mci_play.dwCallback = 0;
	FRAMES_TO_MSF(start, &m, &s, &f);
	mci_play.dwFrom = MCI_MAKE_MSF(m, s, f);
	FRAMES_TO_MSF(start+length, &m, &s, &f);
	mci_play.dwTo = MCI_MAKE_MSF(m, s, f);
	return(SDL_SYS_CDioctl(cdrom->id, MCI_PLAY, flags, &mci_play));
}

/* Pause play */
static int SDL_SYS_CDPause(SDL_CD *cdrom)
{
#ifdef BROKEN_MCI_PAUSE
	SDL_paused[cdrom->id] = 1;
#endif
	return(SDL_SYS_CDioctl(cdrom->id, MCI_PAUSE, MCI_WAIT, NULL));
}

/* Resume play */
static int SDL_SYS_CDResume(SDL_CD *cdrom)
{
#ifdef BROKEN_MCI_PAUSE
	MCI_STATUS_PARMS mci_status;
	int okay;
	int flags;

	okay = 0;
	/* Play from the current play position to end of CD */
	flags = MCI_STATUS_ITEM | MCI_WAIT;
	mci_status.dwItem = MCI_STATUS_POSITION;
	if ( SDL_SYS_CDioctl(cdrom->id, MCI_STATUS, flags, &mci_status) == 0 ) {
		MCI_PLAY_PARMS mci_play;

		flags = MCI_FROM | MCI_NOTIFY;
		mci_play.dwCallback = 0;
		mci_play.dwFrom = mci_status.dwReturn;
		if (SDL_SYS_CDioctl(cdrom->id,MCI_PLAY,flags,&mci_play) == 0) {
			okay = 1;
			SDL_paused[cdrom->id] = 0;
		}
	}
	return(okay ? 0 : -1);
#else
	return(SDL_SYS_CDioctl(cdrom->id, MCI_RESUME, MCI_WAIT, NULL));
#endif /* BROKEN_MCI_PAUSE */
}

/* Stop play */
static int SDL_SYS_CDStop(SDL_CD *cdrom)
{
	return(SDL_SYS_CDioctl(cdrom->id, MCI_STOP, MCI_WAIT, NULL));
}

/* Eject the CD-ROM */
static int SDL_SYS_CDEject(SDL_CD *cdrom)
{
	return(SDL_SYS_CDioctl(cdrom->id, MCI_SET, MCI_SET_DOOR_OPEN, NULL));
}

/* Close the CD-ROM handle */
static void SDL_SYS_CDClose(SDL_CD *cdrom)
{
	SDL_SYS_CDioctl(cdrom->id, MCI_CLOSE, MCI_WAIT, NULL);
}

void SDL_SYS_CDQuit(void)
{
	int i;

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