/*

SDL - Simple DirectMedia Layer

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

/*

* Driver for native OpenBSD audio(4).

* vedge@vedge.com.ar.

*/

#include <errno.h>

#include <unistd.h>

#include <fcntl.h>

#include <sys/time.h>

#include <sys/ioctl.h>

#include <sys/stat.h>

#include <sys/types.h>

#include <sys/audioio.h>

#include "../SDL_audiomem.h"

#include "../SDL_audio_c.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)

{

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 */

}

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

SDL_OutOfMemory();

return(0);

}

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;

}

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)

{

/* 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;

}

}

}

#ifndef USE_BLOCKING_WRITES /* Not necessary when using blocking writes */

/* 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 {

/* Use select() for audio synchronization */

fd_set fdset;

struct timeval timeout;

FD_ZERO(&fdset);

FD_SET(audio_fd, &fdset);

timeout.tv_sec = 10;

timeout.tv_usec = 0;

#ifdef DEBUG_AUDIO

fprintf(stderr, "Waiting for audio to get ready\n");

#endif

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

const char *message =

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

/* In general we should never print to the screen,

but in this case we have no other way of letting

the user know what happened.

*/

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

this->enabled = 0;

/* Don't try to close - may hang */

audio_fd = -1;

#ifdef DEBUG_AUDIO

fprintf(stderr, "Done disabling audio\n");

#endif

}

#ifdef DEBUG_AUDIO

fprintf(stderr, "Ready!\n");

#endif

}

#endif /* !USE_BLOCKING_WRITES */

}

static void

OBSD_PlayAudio(_THIS)

{

int written, p=0;

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

do {

written = write(audio_fd, &mixbuf[p], mixlen-p);

if (written>0)

p += written;

if (written == -1 && errno != 0 && errno != EAGAIN && errno != EINTR)

{

/* Non recoverable error has occurred. It should be reported!!! */

perror("audio");

break;

}

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

SDL_Delay(1); /* Let a little CPU time go by */

}

} while ( p < written );

/* If timer synchronization is enabled, set the next write frame */

if ( frame_ticks ) {

next_frame += frame_ticks;

}

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

if ( written < 0 ) {

this->enabled = 0;

}

#ifdef DEBUG_AUDIO

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,"\n"

"[play/record info]\n"

"buffer size : %d bytes\n"

"sample rate : %i Hz\n"

"channels : %i\n"

"precision : %i-bit\n"

"encoding : 0x%x\n"

"seek : %i\n"

"sample count : %i\n"

"EOF count : %i\n"

"paused : %s\n"

"error occured : %s\n"

"waiting : %s\n"

"active : %s\n"

"",

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,"\n"

"[audio info]\n"

"monitor_gain : %i\n"

"hw block size : %d bytes\n"

"hi watermark : %i\n"

"lo watermark : %i\n"

"audio mode : %s\n"

"",

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];

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;

AUDIO_INITINFO(&info);

for (format = SDL_FirstAudioFormat(spec->format);

format; format = SDL_NextAudioFormat())

switch(format) {

case AUDIO_U8:

info.play.encoding = AUDIO_ENCODING_ULINEAR;

info.play.precision = 8;

break;

case AUDIO_S8:

info.play.encoding = AUDIO_ENCODING_SLINEAR;

info.play.precision = 8;

break;

case AUDIO_S16LSB:

info.play.encoding = AUDIO_ENCODING_SLINEAR_LE;

info.play.precision = 16;

break;

case AUDIO_S16MSB:

info.play.encoding = AUDIO_ENCODING_SLINEAR_BE;

info.play.precision = 16;

break;

case AUDIO_U16LSB:

info.play.encoding = AUDIO_ENCODING_ULINEAR_LE;

info.play.precision = 16;

break;

case AUDIO_U16MSB:

info.play.encoding = AUDIO_ENCODING_ULINEAR_BE;

info.play.precision = 16;

break;

default:

continue;

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

break;

}

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

return(-1);

}

if (ioctl(audio_fd, AUDIO_SETINFO, &info) == -1)

spec->channels = 1;

AUDIO_INITINFO(&info);

(void)ioctl(audio_fd, AUDIO_SETINFO, &info);

(void)ioctl(audio_fd, AUDIO_GETINFO, &info);

spec->freq = info.play.sample_rate;

/* Allocate mixing buffer */

mixlen = spec->size;

mixbuf = (Uint8*)SDL_AllocAudioMem(mixlen);

if(mixbuf == NULL) {

return(-1);

}

/* 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);

}