view src/audio/mint/SDL_mintaudio.h @ 4001:6831b8723a85 SDL-1.2

Don't initialize the audio buffer passed to the application's audio callback, since they are expected to entirely fill it with data or silence. For legacy apps that might expect the buffer to already have silence and thus may not fill the buffer in the callback, there's an environment variable to expose the old behaviour. Fixes Bugzilla #416.
author Ryan C. Gordon <icculus@icculus.org>
date Thu, 05 Jul 2007 02:24:36 +0000
parents e958a003b69b
children 2325dd996f73
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/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2004 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
*/
#include "SDL_config.h"

/*
	MiNT audio driver

	Patrice Mandin
*/

#ifndef _SDL_mintaudio_h
#define _SDL_mintaudio_h

#include "../SDL_sysaudio.h"
#include "SDL_mintaudio_stfa.h"

/* Hidden "this" pointer for the audio functions */
#define _THIS	SDL_AudioDevice *this

/* 16 predivisors with 3 clocks max. */
#define MINTAUDIO_maxfreqs		(16*3)		

typedef struct {
	Uint32	frequency;
	Uint32	masterclock;
	Uint32	predivisor;
	int	gpio_bits;	/* in case of external clock */
} mint_frequency_t;

struct SDL_PrivateAudioData {
	mint_frequency_t	frequencies[MINTAUDIO_maxfreqs];
	int 	freq_count;		/* Number of frequencies in the array */
	int		numfreq;		/* Number of selected frequency */
};

/* Old variable names */

#define MINTAUDIO_frequencies	(this->hidden->frequencies)
#define MINTAUDIO_freqcount		(this->hidden->freq_count)
#define MINTAUDIO_numfreq		(this->hidden->numfreq)

/* _MCH cookie (values>>16) */
enum {
	MCH_ST=0,
	MCH_STE,
	MCH_TT,
	MCH_F30,
	MCH_CLONE,
	MCH_ARANYM
};

/* Master clocks for replay frequencies */
#define MASTERCLOCK_STE		8010666		/* Not sure of this one */
#define MASTERCLOCK_TT		16107953	/* Not sure of this one */
#define MASTERCLOCK_FALCON1	25175000
#define MASTERCLOCK_FALCON2	32000000	/* Only usable for DSP56K */
#define MASTERCLOCK_FALCONEXT	-1		/* Clock on DSP56K port, unknown */
#define MASTERCLOCK_44K		22579200	/* Standard clock for 44.1 Khz */
#define MASTERCLOCK_48K		24576000	/* Standard clock for 48 Khz */

/* Master clock predivisors */
#define MASTERPREDIV_STE	160
#define MASTERPREDIV_TT		320
#define MASTERPREDIV_FALCON	256
#define MASTERPREDIV_MILAN	256

/* MFP 68901 interrupt sources */
enum {
	MFP_PARALLEL=0,
	MFP_DCD,
	MFP_CTS,
	MFP_BITBLT,
	MFP_TIMERD,
	MFP_BAUDRATE=MFP_TIMERD,
	MFP_TIMERC,
	MFP_200HZ=MFP_TIMERC,
	MFP_ACIA,
	MFP_DISK,
	MFP_TIMERB,
	MFP_HBLANK=MFP_TIMERB,
	MFP_TERR,
	MFP_TBE,
	MFP_RERR,
	MFP_RBF,
	MFP_TIMERA,
	MFP_DMASOUND=MFP_TIMERA,
	MFP_RING,
	MFP_MONODETECT
};

/* Xbtimer() timers */
enum {
	XB_TIMERA=0,
	XB_TIMERB,
	XB_TIMERC,
	XB_TIMERD
};

/* Variables */
extern SDL_AudioDevice *SDL_MintAudio_device;
extern Uint8 *SDL_MintAudio_audiobuf[2];	/* Pointers to buffers */
extern unsigned long SDL_MintAudio_audiosize;		/* Length of audio buffer=spec->size */
extern volatile unsigned short SDL_MintAudio_numbuf;		/* Buffer to play */
extern volatile unsigned short SDL_MintAudio_mutex;
extern cookie_stfa_t *SDL_MintAudio_stfa;
extern volatile unsigned long SDL_MintAudio_clocktics;
extern unsigned short SDL_MintAudio_hasfpu;	/* To preserve fpu registers if needed */

/* MiNT thread variables */
extern SDL_bool	SDL_MintAudio_mint_present;
extern SDL_bool SDL_MintAudio_quit_thread;
extern SDL_bool SDL_MintAudio_thread_finished;
extern long SDL_MintAudio_thread_pid;

/* Functions */
void SDL_MintAudio_Callback(void);
void SDL_MintAudio_AddFrequency(_THIS, Uint32 frequency, Uint32 clock,
	Uint32 prediv, int gpio_bits);
int SDL_MintAudio_SearchFrequency(_THIS, int desired_freq);
void SDL_MintAudio_CheckFpu(void);

/* MiNT thread functions */
int SDL_MintAudio_Thread(long param);
void SDL_MintAudio_WaitThread(void);

/* ASM interrupt functions */
void SDL_MintAudio_GsxbInterrupt(void);
void SDL_MintAudio_EmptyGsxbInterrupt(void);
void SDL_MintAudio_XbiosInterruptMeasureClock(void);
void SDL_MintAudio_XbiosInterrupt(void);
void SDL_MintAudio_Dma8Interrupt(void);
void SDL_MintAudio_StfaInterrupt(void);

#endif /* _SDL_mintaudio_h */