/*

SDL - Simple DirectMedia Layer

Copyright (C) 1997, 1998, 1999, 2000, 2001 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@devolution.com

*/

/*

* Driver for native OpenBSD audio(4).

* vedge@vedge.com.ar.

*/

#include <stdlib.h>

#include <stdio.h>

#include <string.h>

#include <errno.h>

#include <unistd.h>

#include <fcntl.h>

#include <signal.h>

#include <sys/time.h>

#include <sys/ioctl.h>

#include <sys/stat.h>

#include <sys/types.h>

#include <sys/audioio.h>

#include "SDL_audio.h"

#include "SDL_error.h"

#include "SDL_audiomem.h"

#include "SDL_audio_c.h"

#include "SDL_timer.h"

#include "SDL_audiodev_c.h"

#include "SDL_openbsdaudio.h"

/* The tag name used by OpenBSD audio */

#define OBSD_DRIVER_NAME "openbsd"

/* Open the audio device for playback, and don't block if busy */

/* #define USE_BLOCKING_WRITES */

/* Use timer for synchronization */

/* #define USE_TIMER_SYNC */

/* #define DEBUG_AUDIO */

/* #define DEBUG_AUDIO_STREAM */

#ifdef USE_BLOCKING_WRITES

#define OPEN_FLAGS O_WRONLY

#else

#define OPEN_FLAGS (O_WRONLY|O_NONBLOCK)

#endif

/* Audio driver functions */

static void OBSD_WaitAudio(_THIS);

static int OBSD_OpenAudio(_THIS, SDL_AudioSpec *spec);

static void OBSD_PlayAudio(_THIS);

static Uint8 *OBSD_GetAudioBuf(_THIS);

static void OBSD_CloseAudio(_THIS);

#ifdef DEBUG_AUDIO

static void OBSD_Status(_THIS);

#endif

/* 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)

{

free(device->hidden);

free(device);

}

static SDL_AudioDevice

*Audio_CreateDevice(int devindex)

{

SDL_AudioDevice *this;

/* Initialize all variables that we clean on shutdown */

this = (SDL_AudioDevice*)malloc(sizeof(SDL_AudioDevice));

if(this) {

memset(this, 0, (sizeof *this));

this->hidden =

(struct SDL_PrivateAudioData*)malloc((sizeof *this->hidden));

}

if((this == NULL) || (this->hidden == NULL)) {

SDL_OutOfMemory();

if(this) free(this);

return(0);

}

memset(this->hidden, 0, (sizeof *this->hidden));

audio_fd = -1;

/* Set the function pointers */

this->OpenAudio = OBSD_OpenAudio;

this->WaitAudio = OBSD_WaitAudio;

this->PlayAudio = OBSD_PlayAudio;

this->GetAudioBuf = OBSD_GetAudioBuf;

this->CloseAudio = OBSD_CloseAudio;

this->free = Audio_DeleteDevice;

return this;

}

AudioBootStrap OBSD_bootstrap = {

OBSD_DRIVER_NAME, "Native OpenBSD audio",

Audio_Available, Audio_CreateDevice

};

/* This function waits until it is possible to write a full sound buffer */

static void

OBSD_WaitAudio(_THIS)

{

#ifndef USE_BLOCKING_WRITES

fd_set fdset;

/* Check to see if the thread-parent process is still alive */

{

static int cnt = 0;

/* Note that this only works with thread implementations

that use a different process id for each thread. */

if(parent && (((++cnt)%10) == 0)) { /* Check every 10 loops */

if(kill(parent, 0) < 0)

this->enabled = 0;

}

}

#ifdef USE_TIMER_SYNC

/* See if we need to use timed audio synchronization */

if(frame_ticks)

{

/* Use timer for general audio synchronization */

Sint32 ticks;

ticks = ((Sint32)(next_frame - SDL_GetTicks())) - FUDGE_TICKS;

if(ticks > 0)

SDL_Delay(ticks);

}

else

#endif /* USE_TIMER_SYNC */

{

/* Use select() for audio synchronization */

struct timeval timeout;

FD_ZERO(&fdset);

FD_SET(audio_fd, &fdset);

timeout.tv_sec = 10;

timeout.tv_usec = 0;

#if defined(DEBUG_AUDIO_STREAM) && defined(DEBUG_AUDIO_STREAM)

OBSD_Status(this);

#endif

if(select(audio_fd+1, NULL, &fdset, NULL, &timeout) <= 0)

{

const char *message =

"Audio timeout - buggy audio driver? (disabled)";

fprintf(stderr, "SDL: %s\n", message);

this->enabled = 0;

audio_fd = -1;

}

}

#endif /* !USE_BLOCKING_WRITES */

}

static void

OBSD_PlayAudio(_THIS)

{

int written;

/* Write the audio data, checking for EAGAIN on broken audio drivers */

do

{

written = write(audio_fd, mixbuf, mixlen);

if((written < 0) && ((errno == 0) || (errno == EAGAIN)))

SDL_Delay(1);

}

while((written < 0) &&

((errno == 0) || (errno == EAGAIN) || (errno == EINTR)));

#ifdef USE_TIMER_SYNC

if(frame_ticks)

next_frame += frame_ticks;

#endif

/* If we couldn't write, assume fatal error for now */

if(written < 0)

this->enabled = 0;

#ifdef DEBUG_AUDIO_STREAM

fprintf(stderr, "Wrote %d bytes of audio data\n", written);

#endif

}

static Uint8

*OBSD_GetAudioBuf(_THIS)

{

return(mixbuf);

}

static void

OBSD_CloseAudio(_THIS)

{

if(mixbuf != NULL) {

SDL_FreeAudioMem(mixbuf);

mixbuf = NULL;

}

if(audio_fd >= 0) {

close(audio_fd);

audio_fd = -1;

}

}

#ifdef DEBUG_AUDIO

void

OBSD_Status(_THIS)

{

audio_info_t info;

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

fprintf(stderr,"AUDIO_GETINFO failed.\n");

return;

}

fprintf(stderr,"

[play/record info]

buffer size : %d bytes

sample rate : %i Hz

channels : %i

precision : %i-bit

encoding : 0x%x

seek : %i

sample count : %i

EOF count : %i

paused : %s

error occured : %s

waiting : %s

active : %s

",

info.play.buffer_size,

info.play.sample_rate,

info.play.channels,

info.play.precision,

info.play.encoding,

info.play.seek,

info.play.samples,

info.play.eof,

info.play.pause ? "yes" : "no",

info.play.error ? "yes" : "no",

info.play.waiting ? "yes" : "no",

info.play.active ? "yes": "no");

fprintf(stderr,"

[audio info]

monitor_gain : %i

hw block size : %d bytes

hi watermark : %i

lo watermark : %i

audio mode : %s

",

info.monitor_gain,

info.blocksize,

info.hiwat, info.lowat,

(info.mode == AUMODE_PLAY) ? "PLAY"

: (info.mode = AUMODE_RECORD) ? "RECORD"

: (info.mode == AUMODE_PLAY_ALL ? "PLAY_ALL"

: "???"));

}

#endif /* DEBUG_AUDIO */

static int

OBSD_OpenAudio(_THIS, SDL_AudioSpec *spec)

{

char audiodev[64];

Uint16 setenc;

audio_encoding_t enc;

audio_info_t info;

AUDIO_INITINFO(&info);

/* Calculate the final parameters for this audio specification */

SDL_CalculateAudioSpec(spec);

#ifdef USE_TIMER_SYNC

frame_ticks = 0.0;

#endif

/* 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);

}

/* Set to play mode */

info.mode = AUMODE_PLAY;

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

SDL_SetError("Couldn't put device into play mode");

return(-1);

}

mixbuf = NULL;

setenc = 0;

for(enc.index = 0; (ioctl(audio_fd, AUDIO_GETENC, &enc)>=0)

&& (enc.encoding != setenc); enc.index++)

{

switch(spec->format)

{

case AUDIO_U8: /* 8-bit unsigned linear */

setenc = AUDIO_ENCODING_PCM8;

break;

case AUDIO_S8: /* 8-bit signed linear */

setenc = AUDIO_ENCODING_SLINEAR;

break;

case AUDIO_U16LSB: /* 16-bit unsigned linear, LSB */

setenc = AUDIO_ENCODING_ULINEAR_LE;

break;

case AUDIO_U16MSB: /* 16-bit unsigned linear, MSB */

setenc = AUDIO_ENCODING_ULINEAR_BE;

break;

case AUDIO_S16LSB: /* 16-bit signed linear, LSB */

setenc = AUDIO_ENCODING_SLINEAR_LE;

break;

case AUDIO_S16MSB: /* 16-bit signed linear, MSB */

setenc = AUDIO_ENCODING_SLINEAR_BE;

break;

}

#ifdef DEBUG_AUDIO

fprintf(stderr,"encoding #%i: \"%s\" %i-bit (0x%x) flags=%i...\n",

enc.index, enc.name, enc.precision, enc.encoding, enc.flags);

#endif

}

if(!setenc) {

SDL_SetError("No supported encoding for 0x%x", spec->format);

return(-1);

}

/* Set audio encoding */

info.play.encoding = enc.encoding;

info.play.precision = enc.precision;

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

SDL_SetError("Couldn't set encoding to 0x%x %i-bit",

enc.encoding, enc.precision);

return(-1);

}

/* Set audio channels */

info.play.channels = spec->channels;

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

info.play.channels = (spec->channels > 1);

ioctl(audio_fd, AUDIO_SETINFO, &info);

}

/* Set the sample rate */

info.play.sample_rate = spec->freq;

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

SDL_SetError("Couldn't set sample rate to %i Hz", spec->freq);

return(-1);

}

/* Allocate mixing buffer */

mixlen = spec->size;

mixbuf = (Uint8*)SDL_AllocAudioMem(mixlen);

if(mixbuf == NULL) {

return(-1);

}

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

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

parent = getpid();

#ifdef DEBUG_AUDIO

OBSD_Status(this);

#endif

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

return(0);

}