/*

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

*/

/* Allow access to a raw mixing buffer */

#include <fcntl.h>

#include <errno.h>

#ifdef __NetBSD__

#include <sys/ioctl.h>

#include <sys/audioio.h>

#endif

#ifdef __SVR4

#include <sys/audioio.h>

#else

#include <sys/time.h>

#include <sys/types.h>

#endif

#include <unistd.h>

#include "SDL_stdlib.h"

#include "SDL_string.h"

#include "SDL_endian.h"

#include "SDL_audio.h"

#include "SDL_audiomem.h"

#include "SDL_audiodev_c.h"

#include "SDL_sunaudio.h"

#include "SDL_audio_c.h"

#include "SDL_timer.h"

/* 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, 1);

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 SUNAUDIO_bootstrap = {

"audio", "UNIX /dev/audio interface",

Audio_Available, Audio_CreateDevice

};

#ifdef DEBUG_AUDIO

void CheckUnderflow(_THIS)

{

#ifdef AUDIO_GETINFO

audio_info_t info;

int left;

ioctl(audio_fd, AUDIO_GETINFO, &info);

left = (written - info.play.samples);

if ( written && (left == 0) ) {

fprintf(stderr, "audio underflow!\n");

}

#endif

}

#endif

void DSP_WaitAudio(_THIS)

{

#ifdef AUDIO_GETINFO

#define SLEEP_FUDGE 10 /* 10 ms scheduling fudge factor */

audio_info_t info;

Sint32 left;

ioctl(audio_fd, AUDIO_GETINFO, &info);

left = (written - info.play.samples);

if ( left > fragsize ) {

Sint32 sleepy;

sleepy = ((left - fragsize)/frequency);

sleepy -= SLEEP_FUDGE;

if ( sleepy > 0 ) {

SDL_Delay(sleepy);

}

}

#else

fd_set fdset;

FD_ZERO(&fdset);

FD_SET(audio_fd, &fdset);

select(audio_fd+1, NULL, &fdset, NULL, NULL);

#endif

}

static Uint8 snd2au(int sample);

void DSP_PlayAudio(_THIS)

{

/* Write the audio data */

if ( ulaw_only ) {

/* Assuming that this->spec.freq >= 8000 Hz */

int accum, incr, pos;

Uint8 *aubuf;

accum = 0;

incr = this->spec.freq/8;

aubuf = ulaw_buf;

switch (audio_fmt & 0xFF) {

case 8: {

Uint8 *sndbuf;

sndbuf = mixbuf;

for ( pos=0; pos < fragsize; ++pos ) {

*aubuf = snd2au((0x80-*sndbuf)*64);

accum += incr;

while ( accum > 0 ) {

accum -= 1000;

sndbuf += 1;

}

aubuf += 1;

}

}

break;

case 16: {

Sint16 *sndbuf;

sndbuf = (Sint16 *)mixbuf;

for ( pos=0; pos < fragsize; ++pos ) {

*aubuf = snd2au(*sndbuf/4);

accum += incr;

while ( accum > 0 ) {

accum -= 1000;

sndbuf += 1;

}

aubuf += 1;

}

}

break;

}

#ifdef DEBUG_AUDIO

CheckUnderflow(this);

#endif

if ( write(audio_fd, ulaw_buf, fragsize) < 0 ) {

/* Assume fatal error, for now */

this->enabled = 0;

}

written += fragsize;

} else {

#ifdef DEBUG_AUDIO

CheckUnderflow(this);

#endif

if ( write(audio_fd, mixbuf, this->spec.size) < 0 ) {

/* Assume fatal error, for now */

this->enabled = 0;

}

written += fragsize;

}

}

Uint8 *DSP_GetAudioBuf(_THIS)

{

return(mixbuf);

}

void DSP_CloseAudio(_THIS)

{

if ( mixbuf != NULL ) {

SDL_FreeAudioMem(mixbuf);

mixbuf = NULL;

}

if ( ulaw_buf != NULL ) {

SDL_free(ulaw_buf);

ulaw_buf = NULL;

}

close(audio_fd);

}

int DSP_OpenAudio(_THIS, SDL_AudioSpec *spec)

{

char audiodev[1024];

#ifdef AUDIO_SETINFO

int enc;

#endif

int desired_freq = spec->freq;

/* Initialize our freeable variables, in case we fail*/

audio_fd = -1;

mixbuf = NULL;

ulaw_buf = NULL;

/* Determine the audio parameters from the AudioSpec */

switch ( spec->format & 0xFF ) {

case 8: { /* Unsigned 8 bit audio data */

spec->format = AUDIO_U8;

#ifdef AUDIO_SETINFO

enc = AUDIO_ENCODING_LINEAR8;

#endif

}

break;

case 16: { /* Signed 16 bit audio data */

spec->format = AUDIO_S16SYS;

#ifdef AUDIO_SETINFO

enc = AUDIO_ENCODING_LINEAR;

#endif

}

break;

default: {

SDL_SetError("Unsupported audio format");

return(-1);

}

}

audio_fmt = spec->format;

/* Open the audio device */

audio_fd = SDL_OpenAudioPath(audiodev, sizeof(audiodev), OPEN_FLAGS, 1);

if ( audio_fd < 0 ) {

SDL_SetError("Couldn't open %s: %s", audiodev,

strerror(errno));

return(-1);

}

ulaw_only = 0; /* modern Suns do support linear audio */

#ifdef AUDIO_SETINFO

for(;;) {

audio_info_t info;

AUDIO_INITINFO(&info); /* init all fields to "no change" */

/* Try to set the requested settings */

info.play.sample_rate = spec->freq;

info.play.channels = spec->channels;

info.play.precision = (enc == AUDIO_ENCODING_ULAW)

? 8 : spec->format & 0xff;

info.play.encoding = enc;

if( ioctl(audio_fd, AUDIO_SETINFO, &info) == 0 ) {

/* Check to be sure we got what we wanted */

if(ioctl(audio_fd, AUDIO_GETINFO, &info) < 0) {

SDL_SetError("Error getting audio parameters: %s",

strerror(errno));

return -1;

}

if(info.play.encoding == enc

&& info.play.precision == (spec->format & 0xff)

&& info.play.channels == spec->channels) {

/* Yow! All seems to be well! */

spec->freq = info.play.sample_rate;

break;

}

}

switch(enc) {

case AUDIO_ENCODING_LINEAR8:

/* unsigned 8bit apparently not supported here */

enc = AUDIO_ENCODING_LINEAR;

spec->format = AUDIO_S16SYS;

break; /* try again */

case AUDIO_ENCODING_LINEAR:

/* linear 16bit didn't work either, resort to µ-law */

enc = AUDIO_ENCODING_ULAW;

spec->channels = 1;

spec->freq = 8000;

spec->format = AUDIO_U8;

ulaw_only = 1;

break;

default:

/* oh well... */

SDL_SetError("Error setting audio parameters: %s",

strerror(errno));

return -1;

}

}

#endif /* AUDIO_SETINFO */

written = 0;

/* We can actually convert on-the-fly to U-Law */

if ( ulaw_only ) {

spec->freq = desired_freq;

fragsize = (spec->samples*1000)/(spec->freq/8);

frequency = 8;

ulaw_buf = (Uint8 *)SDL_malloc(fragsize);

if ( ulaw_buf == NULL ) {

SDL_OutOfMemory();

return(-1);

}

spec->channels = 1;

} else {

fragsize = spec->samples;

frequency = spec->freq/1000;

}

#ifdef DEBUG_AUDIO

fprintf(stderr, "Audio device %s U-Law only\n",

ulaw_only ? "is" : "is not");

fprintf(stderr, "format=0x%x chan=%d freq=%d\n",

spec->format, spec->channels, spec->freq);

#endif

/* Update the fragment size as size in bytes */

SDL_CalculateAudioSpec(spec);

/* Allocate mixing buffer */

mixbuf = (Uint8 *)SDL_AllocAudioMem(spec->size);

if ( mixbuf == NULL ) {

SDL_OutOfMemory();

return(-1);

}

SDL_memset(mixbuf, spec->silence, spec->size);

/* We're ready to rock and roll. :-) */

return(0);

}

/************************************************************************/

/* This function (snd2au()) copyrighted: */

/************************************************************************/

/* Copyright 1989 by Rich Gopstein and Harris Corporation */

/* */

/* Permission to use, copy, modify, and distribute this software */

/* and its documentation for any purpose and without fee is */

/* hereby granted, provided that the above copyright notice */

/* appears in all copies and that both that copyright notice and */

/* this permission notice appear in supporting documentation, and */

/* that the name of Rich Gopstein and Harris Corporation not be */

/* used in advertising or publicity pertaining to distribution */

/* of the software without specific, written prior permission. */

/* Rich Gopstein and Harris Corporation make no representations */

/* about the suitability of this software for any purpose. It */

/* provided "as is" without express or implied warranty. */

/************************************************************************/

static Uint8 snd2au(int sample)

{

int mask;

if (sample < 0) {

sample = -sample;

mask = 0x7f;

} else {

mask = 0xff;

}

if (sample < 32) {

sample = 0xF0 | (15 - sample / 2);

} else if (sample < 96) {

sample = 0xE0 | (15 - (sample - 32) / 4);

} else if (sample < 224) {

sample = 0xD0 | (15 - (sample - 96) / 8);

} else if (sample < 480) {

sample = 0xC0 | (15 - (sample - 224) / 16);

} else if (sample < 992) {

sample = 0xB0 | (15 - (sample - 480) / 32);

} else if (sample < 2016) {

sample = 0xA0 | (15 - (sample - 992) / 64);

} else if (sample < 4064) {

sample = 0x90 | (15 - (sample - 2016) / 128);

} else if (sample < 8160) {

sample = 0x80 | (15 - (sample - 4064) / 256);

} else {

sample = 0x80;

}

return (mask & sample);

}