distrib/sdl-1.2.15/src/audio/dsp/SDL_dspaudio.c - emulator-unstable-refactoring - Git at Google

 /*
     SDL - Simple DirectMedia Layer
     Copyright (C) 1997-2012 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

     Modified in Oct 2004 by Hannu Savolainen
     hannu@opensound.com
 */
 #include "SDL_config.h"

 /* Allow access to a raw mixing buffer */

 #include <stdio.h>	/* For perror() */
 #include <string.h>	/* For strerror() */
 #include <errno.h>
 #include <unistd.h>
 #include <fcntl.h>
 #include <signal.h>
 #include <sys/time.h>
 #include <sys/ioctl.h>
 #include <sys/stat.h>

 #if SDL_AUDIO_DRIVER_OSS_SOUNDCARD_H
 /* This is installed on some systems */
 #include <soundcard.h>
 #else
 /* This is recommended by OSS */
 #include <sys/soundcard.h>
 #endif

 #include "SDL_timer.h"
 #include "SDL_audio.h"
 #include "../SDL_audiomem.h"
 #include "../SDL_audio_c.h"
 #include "../SDL_audiodev_c.h"
 #include "SDL_dspaudio.h"

 /* The tag name used by DSP audio */
 #define DSP_DRIVER_NAME         "dsp"

 /* Open the audio device for playback, and don't block if busy */
 #define OPEN_FLAGS	(O_WRONLY|O_NONBLOCK)

 /* Audio driver functions */
 static int DSP_OpenAudio(_THIS, SDL_AudioSpec *spec);
 static void DSP_WaitAudio(_THIS);
 static void DSP_PlayAudio(_THIS);
 static Uint8 *DSP_GetAudioBuf(_THIS);
 static void DSP_CloseAudio(_THIS);

 /* Audio driver bootstrap functions */

 static int Audio_Available(void)
 {
 	int fd;
 	int available;

 	available = 0;
 	fd = SDL_OpenAudioPath(NULL, 0, OPEN_FLAGS, 0);
 	if ( fd >= 0 ) {
 		available = 1;
 		close(fd);
 	}
 	return(available);
 }

 static void Audio_DeleteDevice(SDL_AudioDevice *device)
 {
 	SDL_free(device->hidden);
 	SDL_free(device);
 }

 static SDL_AudioDevice *Audio_CreateDevice(int devindex)
 {
 	SDL_AudioDevice *this;

 	/* Initialize all variables that we clean on shutdown */
 	this = (SDL_AudioDevice *)SDL_malloc(sizeof(SDL_AudioDevice));
 	if ( this ) {
 		SDL_memset(this, 0, (sizeof *this));
 		this->hidden = (struct SDL_PrivateAudioData *)
 				SDL_malloc((sizeof *this->hidden));
 	}
 	if ( (this == NULL) || (this->hidden == NULL) ) {
 		SDL_OutOfMemory();
 		if ( this ) {
 			SDL_free(this);
 		}
 		return(0);
 	}
 	SDL_memset(this->hidden, 0, (sizeof *this->hidden));
 	audio_fd = -1;

 	/* Set the function pointers */
 	this->OpenAudio = DSP_OpenAudio;
 	this->WaitAudio = DSP_WaitAudio;
 	this->PlayAudio = DSP_PlayAudio;
 	this->GetAudioBuf = DSP_GetAudioBuf;
 	this->CloseAudio = DSP_CloseAudio;

 	this->free = Audio_DeleteDevice;

 	return this;
 }

 AudioBootStrap DSP_bootstrap = {
 	DSP_DRIVER_NAME, "OSS /dev/dsp standard audio",
 	Audio_Available, Audio_CreateDevice
 };

 /* This function waits until it is possible to write a full sound buffer */
 static void DSP_WaitAudio(_THIS)
 {
 	/* Not needed at all since OSS handles waiting automagically */
 }

 static void DSP_PlayAudio(_THIS)
 {
 	if (write(audio_fd, mixbuf, mixlen)==-1)
 	{
 		perror("Audio write");
 		this->enabled = 0;
 	}

 #ifdef DEBUG_AUDIO
 	fprintf(stderr, "Wrote %d bytes of audio data\n", mixlen);
 #endif
 }

 static Uint8 *DSP_GetAudioBuf(_THIS)
 {
 	return(mixbuf);
 }

 static void DSP_CloseAudio(_THIS)
 {
 	if ( mixbuf != NULL ) {
 		SDL_FreeAudioMem(mixbuf);
 		mixbuf = NULL;
 	}
 	if ( audio_fd >= 0 ) {
 		close(audio_fd);
 		audio_fd = -1;
 	}
 }

 static int DSP_OpenAudio(_THIS, SDL_AudioSpec *spec)
 {
 	char audiodev[1024];
 	int format;
 	int value;
 	int frag_spec;
 	Uint16 test_format;

     /* Make sure fragment size stays a power of 2, or OSS fails. */
     /* I don't know which of these are actually legal values, though... */
     if (spec->channels > 8)
         spec->channels = 8;
     else if (spec->channels > 4)
         spec->channels = 4;
     else if (spec->channels > 2)
         spec->channels = 2;

 	/* Open the audio device */
 	audio_fd = SDL_OpenAudioPath(audiodev, sizeof(audiodev), OPEN_FLAGS, 0);
 	if ( audio_fd < 0 ) {
 		SDL_SetError("Couldn't open %s: %s", audiodev, strerror(errno));
 		return(-1);
 	}
 	mixbuf = NULL;

 	/* Make the file descriptor use blocking writes with fcntl() */
 	{ long flags;
 		flags = fcntl(audio_fd, F_GETFL);
 		flags &= ~O_NONBLOCK;
 		if ( fcntl(audio_fd, F_SETFL, flags) < 0 ) {
 			SDL_SetError("Couldn't set audio blocking mode");
 			DSP_CloseAudio(this);
 			return(-1);
 		}
 	}

 	/* Get a list of supported hardware formats */
 	if ( ioctl(audio_fd, SNDCTL_DSP_GETFMTS, &value) < 0 ) {
 		perror("SNDCTL_DSP_GETFMTS");
 		SDL_SetError("Couldn't get audio format list");
 		DSP_CloseAudio(this);
 		return(-1);
 	}

 	/* Try for a closest match on audio format */
 	format = 0;
 	for ( test_format = SDL_FirstAudioFormat(spec->format);
 						! format && test_format; ) {
 #ifdef DEBUG_AUDIO
 		fprintf(stderr, "Trying format 0x%4.4x\n", test_format);
 #endif
 		switch ( test_format ) {
 			case AUDIO_U8:
 				if ( value & AFMT_U8 ) {
 					format = AFMT_U8;
 				}
 				break;
 			case AUDIO_S16LSB:
 				if ( value & AFMT_S16_LE ) {
 					format = AFMT_S16_LE;
 				}
 				break;
 			case AUDIO_S16MSB:
 				if ( value & AFMT_S16_BE ) {
 					format = AFMT_S16_BE;
 				}
 				break;
 #if 0
 /*
  * These formats are not used by any real life systems so they are not
  * needed here.
  */
 			case AUDIO_S8:
 				if ( value & AFMT_S8 ) {
 					format = AFMT_S8;
 				}
 				break;
 			case AUDIO_U16LSB:
 				if ( value & AFMT_U16_LE ) {
 					format = AFMT_U16_LE;
 				}
 				break;
 			case AUDIO_U16MSB:
 				if ( value & AFMT_U16_BE ) {
 					format = AFMT_U16_BE;
 				}
 				break;
 #endif
 			default:
 				format = 0;
 				break;
 		}
 		if ( ! format ) {
 			test_format = SDL_NextAudioFormat();
 		}
 	}
 	if ( format == 0 ) {
 		SDL_SetError("Couldn't find any hardware audio formats");
 		DSP_CloseAudio(this);
 		return(-1);
 	}
 	spec->format = test_format;

 	/* Set the audio format */
 	value = format;
 	if ( (ioctl(audio_fd, SNDCTL_DSP_SETFMT, &value) < 0) ||
 						(value != format) ) {
 		perror("SNDCTL_DSP_SETFMT");
 		SDL_SetError("Couldn't set audio format");
 		DSP_CloseAudio(this);
 		return(-1);
 	}

 	/* Set the number of channels of output */
 	value = spec->channels;
 	if ( ioctl(audio_fd, SNDCTL_DSP_CHANNELS, &value) < 0 ) {
 		perror("SNDCTL_DSP_CHANNELS");
 		SDL_SetError("Cannot set the number of channels");
 		DSP_CloseAudio(this);
 		return(-1);
 	}
 	spec->channels = value;

 	/* Set the DSP frequency */
 	value = spec->freq;
 	if ( ioctl(audio_fd, SNDCTL_DSP_SPEED, &value) < 0 ) {
 		perror("SNDCTL_DSP_SPEED");
 		SDL_SetError("Couldn't set audio frequency");
 		DSP_CloseAudio(this);
 		return(-1);
 	}
 	spec->freq = value;

 	/* Calculate the final parameters for this audio specification */
 	SDL_CalculateAudioSpec(spec);

 	/* Determine the power of two of the fragment size */
 	for ( frag_spec = 0; (0x01U<<frag_spec) < spec->size; ++frag_spec );
 	if ( (0x01U<<frag_spec) != spec->size ) {
 		SDL_SetError("Fragment size must be a power of two");
 		DSP_CloseAudio(this);
 		return(-1);
 	}
 	frag_spec |= 0x00020000;	/* two fragments, for low latency */

 	/* Set the audio buffering parameters */
 #ifdef DEBUG_AUDIO
 	fprintf(stderr, "Requesting %d fragments of size %d\n",
 		(frag_spec >> 16), 1<<(frag_spec&0xFFFF));
 #endif
 	if ( ioctl(audio_fd, SNDCTL_DSP_SETFRAGMENT, &frag_spec) < 0 ) {
 		perror("SNDCTL_DSP_SETFRAGMENT");
 	}
 #ifdef DEBUG_AUDIO
 	{ audio_buf_info info;
 	  ioctl(audio_fd, SNDCTL_DSP_GETOSPACE, &info);
 	  fprintf(stderr, "fragments = %d\n", info.fragments);
 	  fprintf(stderr, "fragstotal = %d\n", info.fragstotal);
 	  fprintf(stderr, "fragsize = %d\n", info.fragsize);
 	  fprintf(stderr, "bytes = %d\n", info.bytes);
 	}
 #endif

 	/* Allocate mixing buffer */
 	mixlen = spec->size;
 	mixbuf = (Uint8 *)SDL_AllocAudioMem(mixlen);
 	if ( mixbuf == NULL ) {
 		DSP_CloseAudio(this);
 		return(-1);
 	}
 	SDL_memset(mixbuf, spec->silence, spec->size);

 	/* Get the parent process id (we're the parent of the audio thread) */
 	parent = getpid();

 	/* We're ready to rock and roll. :-) */
 	return(0);
 }
	/*
	SDL - Simple DirectMedia Layer
	Copyright (C) 1997-2012 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

	Modified in Oct 2004 by Hannu Savolainen
	hannu@opensound.com
	*/
	#include "SDL_config.h"

	/* Allow access to a raw mixing buffer */

	#include <stdio.h> /* For perror() */
	#include <string.h> /* For strerror() */
	#include <errno.h>
	#include <unistd.h>
	#include <fcntl.h>
	#include <signal.h>
	#include <sys/time.h>
	#include <sys/ioctl.h>
	#include <sys/stat.h>

	#if SDL_AUDIO_DRIVER_OSS_SOUNDCARD_H
	/* This is installed on some systems */
	#include <soundcard.h>
	#else
	/* This is recommended by OSS */
	#include <sys/soundcard.h>
	#endif

	#include "SDL_timer.h"
	#include "SDL_audio.h"
	#include "../SDL_audiomem.h"
	#include "../SDL_audio_c.h"
	#include "../SDL_audiodev_c.h"
	#include "SDL_dspaudio.h"

	/* The tag name used by DSP audio */
	#define DSP_DRIVER_NAME "dsp"

	/* Open the audio device for playback, and don't block if busy */
	#define OPEN_FLAGS (O_WRONLY\|O_NONBLOCK)

	/* Audio driver functions */
	static int DSP_OpenAudio(_THIS, SDL_AudioSpec *spec);
	static void DSP_WaitAudio(_THIS);
	static void DSP_PlayAudio(_THIS);
	static Uint8 *DSP_GetAudioBuf(_THIS);
	static void DSP_CloseAudio(_THIS);

	/* Audio driver bootstrap functions */

	static int Audio_Available(void)
	{
	int fd;
	int available;

	available = 0;
	fd = SDL_OpenAudioPath(NULL, 0, OPEN_FLAGS, 0);
	if ( fd >= 0 ) {
	available = 1;
	close(fd);
	}
	return(available);
	}

	static void Audio_DeleteDevice(SDL_AudioDevice *device)
	{
	SDL_free(device->hidden);
	SDL_free(device);
	}

	static SDL_AudioDevice *Audio_CreateDevice(int devindex)
	{
	SDL_AudioDevice *this;

	/* Initialize all variables that we clean on shutdown */
	this = (SDL_AudioDevice *)SDL_malloc(sizeof(SDL_AudioDevice));
	if ( this ) {
	SDL_memset(this, 0, (sizeof *this));
	this->hidden = (struct SDL_PrivateAudioData *)
	SDL_malloc((sizeof *this->hidden));
	}
	if ( (this == NULL) \|\| (this->hidden == NULL) ) {
	SDL_OutOfMemory();
	if ( this ) {
	SDL_free(this);
	}
	return(0);
	}
	SDL_memset(this->hidden, 0, (sizeof *this->hidden));
	audio_fd = -1;

	/* Set the function pointers */
	this->OpenAudio = DSP_OpenAudio;
	this->WaitAudio = DSP_WaitAudio;
	this->PlayAudio = DSP_PlayAudio;
	this->GetAudioBuf = DSP_GetAudioBuf;
	this->CloseAudio = DSP_CloseAudio;

	this->free = Audio_DeleteDevice;

	return this;
	}

	AudioBootStrap DSP_bootstrap = {
	DSP_DRIVER_NAME, "OSS /dev/dsp standard audio",
	Audio_Available, Audio_CreateDevice
	};

	/* This function waits until it is possible to write a full sound buffer */
	static void DSP_WaitAudio(_THIS)
	{
	/* Not needed at all since OSS handles waiting automagically */
	}

	static void DSP_PlayAudio(_THIS)
	{
	if (write(audio_fd, mixbuf, mixlen)==-1)
	{
	perror("Audio write");
	this->enabled = 0;
	}

	#ifdef DEBUG_AUDIO
	fprintf(stderr, "Wrote %d bytes of audio data\n", mixlen);
	#endif
	}

	static Uint8 *DSP_GetAudioBuf(_THIS)
	{
	return(mixbuf);
	}

	static void DSP_CloseAudio(_THIS)
	{
	if ( mixbuf != NULL ) {
	SDL_FreeAudioMem(mixbuf);
	mixbuf = NULL;
	}
	if ( audio_fd >= 0 ) {
	close(audio_fd);
	audio_fd = -1;
	}
	}

	static int DSP_OpenAudio(_THIS, SDL_AudioSpec *spec)
	{
	char audiodev[1024];
	int format;
	int value;
	int frag_spec;
	Uint16 test_format;

	/* Make sure fragment size stays a power of 2, or OSS fails. */
	/* I don't know which of these are actually legal values, though... */
	if (spec->channels > 8)
	spec->channels = 8;
	else if (spec->channels > 4)
	spec->channels = 4;
	else if (spec->channels > 2)
	spec->channels = 2;

	/* Open the audio device */
	audio_fd = SDL_OpenAudioPath(audiodev, sizeof(audiodev), OPEN_FLAGS, 0);
	if ( audio_fd < 0 ) {
	SDL_SetError("Couldn't open %s: %s", audiodev, strerror(errno));
	return(-1);
	}
	mixbuf = NULL;

	/* Make the file descriptor use blocking writes with fcntl() */
	{ long flags;
	flags = fcntl(audio_fd, F_GETFL);
	flags &= ~O_NONBLOCK;
	if ( fcntl(audio_fd, F_SETFL, flags) < 0 ) {
	SDL_SetError("Couldn't set audio blocking mode");
	DSP_CloseAudio(this);
	return(-1);
	}
	}

	/* Get a list of supported hardware formats */
	if ( ioctl(audio_fd, SNDCTL_DSP_GETFMTS, &value) < 0 ) {
	perror("SNDCTL_DSP_GETFMTS");
	SDL_SetError("Couldn't get audio format list");
	DSP_CloseAudio(this);
	return(-1);
	}

	/* Try for a closest match on audio format */
	format = 0;
	for ( test_format = SDL_FirstAudioFormat(spec->format);
	! format && test_format; ) {
	#ifdef DEBUG_AUDIO
	fprintf(stderr, "Trying format 0x%4.4x\n", test_format);
	#endif
	switch ( test_format ) {
	case AUDIO_U8:
	if ( value & AFMT_U8 ) {
	format = AFMT_U8;
	}
	break;
	case AUDIO_S16LSB:
	if ( value & AFMT_S16_LE ) {
	format = AFMT_S16_LE;
	}
	break;
	case AUDIO_S16MSB:
	if ( value & AFMT_S16_BE ) {
	format = AFMT_S16_BE;
	}
	break;
	#if 0
	/*
	* These formats are not used by any real life systems so they are not
	* needed here.
	*/
	case AUDIO_S8:
	if ( value & AFMT_S8 ) {
	format = AFMT_S8;
	}
	break;
	case AUDIO_U16LSB:
	if ( value & AFMT_U16_LE ) {
	format = AFMT_U16_LE;
	}
	break;
	case AUDIO_U16MSB:
	if ( value & AFMT_U16_BE ) {
	format = AFMT_U16_BE;
	}
	break;
	#endif
	default:
	format = 0;
	break;
	}
	if ( ! format ) {
	test_format = SDL_NextAudioFormat();
	}
	}
	if ( format == 0 ) {
	SDL_SetError("Couldn't find any hardware audio formats");
	DSP_CloseAudio(this);
	return(-1);
	}
	spec->format = test_format;

	/* Set the audio format */
	value = format;
	if ( (ioctl(audio_fd, SNDCTL_DSP_SETFMT, &value) < 0) \|\|
	(value != format) ) {
	perror("SNDCTL_DSP_SETFMT");
	SDL_SetError("Couldn't set audio format");
	DSP_CloseAudio(this);
	return(-1);
	}

	/* Set the number of channels of output */
	value = spec->channels;
	if ( ioctl(audio_fd, SNDCTL_DSP_CHANNELS, &value) < 0 ) {
	perror("SNDCTL_DSP_CHANNELS");
	SDL_SetError("Cannot set the number of channels");
	DSP_CloseAudio(this);
	return(-1);
	}
	spec->channels = value;

	/* Set the DSP frequency */
	value = spec->freq;
	if ( ioctl(audio_fd, SNDCTL_DSP_SPEED, &value) < 0 ) {
	perror("SNDCTL_DSP_SPEED");
	SDL_SetError("Couldn't set audio frequency");
	DSP_CloseAudio(this);
	return(-1);
	}
	spec->freq = value;

	/* Calculate the final parameters for this audio specification */
	SDL_CalculateAudioSpec(spec);

	/* Determine the power of two of the fragment size */
	for ( frag_spec = 0; (0x01U<<frag_spec) < spec->size; ++frag_spec );
	if ( (0x01U<<frag_spec) != spec->size ) {
	SDL_SetError("Fragment size must be a power of two");
	DSP_CloseAudio(this);
	return(-1);
	}
	frag_spec \|= 0x00020000; /* two fragments, for low latency */

	/* Set the audio buffering parameters */
	#ifdef DEBUG_AUDIO
	fprintf(stderr, "Requesting %d fragments of size %d\n",
	(frag_spec >> 16), 1<<(frag_spec&0xFFFF));
	#endif
	if ( ioctl(audio_fd, SNDCTL_DSP_SETFRAGMENT, &frag_spec) < 0 ) {
	perror("SNDCTL_DSP_SETFRAGMENT");
	}
	#ifdef DEBUG_AUDIO
	{ audio_buf_info info;
	ioctl(audio_fd, SNDCTL_DSP_GETOSPACE, &info);
	fprintf(stderr, "fragments = %d\n", info.fragments);
	fprintf(stderr, "fragstotal = %d\n", info.fragstotal);
	fprintf(stderr, "fragsize = %d\n", info.fragsize);
	fprintf(stderr, "bytes = %d\n", info.bytes);
	}
	#endif

	/* Allocate mixing buffer */
	mixlen = spec->size;
	mixbuf = (Uint8 *)SDL_AllocAudioMem(mixlen);
	if ( mixbuf == NULL ) {
	DSP_CloseAudio(this);
	return(-1);
	}
	SDL_memset(mixbuf, spec->silence, spec->size);

	/* Get the parent process id (we're the parent of the audio thread) */
	parent = getpid();

	/* We're ready to rock and roll. :-) */
	return(0);
	}