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/*
* madplay - MPEG audio decoder and player
* Copyright (C) 2000-2004 Robert Leslie
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* $Id: audio_empeg.c,v 1.16 2004/01/23 09:41:31 rob Exp $
*/
# ifdef HAVE_CONFIG_H
# include "config.h"
# endif
# include "global.h"
# include <unistd.h>
# include <fcntl.h>
# include <sys/ioctl.h>
# include <sys/soundcard.h>
# include <errno.h>
# include <string.h>
# include <mad.h>
# include "audio.h"
# define AUDIO_DEVICE "/dev/dsp"
# define AUDIO_FILLSZ 4608
static int sfd;
static
int init(struct audio_init *init)
{
if (init->path == 0)
init->path = AUDIO_DEVICE;
sfd = open(init->path, O_WRONLY);
if (sfd == -1) {
audio_error = ":";
return -1;
}
return 0;
}
static
int config(struct audio_config *config)
{
/*
* The empeg-car's audio device is locked at 44100 Hz stereo 16-bit
* signed little-endian; no configuration is necessary or possible,
* but we may need to resample the output and/or convert to stereo.
*/
config->channels = 2;
config->speed = 44100;
config->precision = 16;
return 0;
}
static
int output(unsigned char const *ptr, unsigned int len)
{
while (len) {
int wrote;
wrote = write(sfd, ptr, len);
if (wrote == -1) {
if (errno == EINTR)
continue;
else {
audio_error = ":write";
return -1;
}
}
ptr += wrote;
len -= wrote;
}
return 0;
}
static
int buffer(unsigned char const *ptr, unsigned int len)
{
static unsigned char hold[AUDIO_FILLSZ];
static unsigned int held;
unsigned int left, grab;
if (len == 0) {
if (held) {
memset(&hold[held], 0, sizeof(hold) - held);
held = 0;
return output(hold, sizeof(hold));
}
return 0;
}
if (held == 0 && len == sizeof(hold))
return output(ptr, len);
left = sizeof(hold) - held;
while (len) {
grab = len < left ? len : left;
memcpy(&hold[held], ptr, grab);
held += grab;
left -= grab;
ptr += grab;
len -= grab;
if (left == 0) {
if (output(hold, sizeof(hold)) == -1)
return -1;
held = 0;
left = sizeof(hold);
}
}
return 0;
}
# define drain() buffer(0, 0)
static
int play(struct audio_play *play)
{
unsigned char data[MAX_NSAMPLES * 2 * 2];
unsigned int len;
len = audio_pcm_s16le(data, play->nsamples,
play->samples[0], play->samples[1],
play->mode, play->stats);
return buffer(data, len);
}
static
int stop(struct audio_stop *stop)
{
return 0;
}
static
int finish(struct audio_finish *finish)
{
int result = 0;
if (drain() == -1)
result = -1;
if (close(sfd) == -1 && result == 0) {
audio_error = ":close";
result = -1;
}
return result;
}
int audio_empeg(union audio_control *control)
{
audio_error = 0;
switch (control->command) {
case AUDIO_COMMAND_INIT:
return init(&control->init);
case AUDIO_COMMAND_CONFIG:
return config(&control->config);
case AUDIO_COMMAND_PLAY:
return play(&control->play);
case AUDIO_COMMAND_STOP:
return stop(&control->stop);
case AUDIO_COMMAND_FINISH:
return finish(&control->finish);
}
return 0;
}
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