alsa-tools/ac3dec/output_linux.c
2001-04-17 19:31:03 +00:00

113 lines
2.2 KiB
C

/*
*
* output_linux.c
*
* Copyright (C) Aaron Holtzman - May 1999
*
* This file is part of ac3dec, a free Dolby AC-3 stream decoder.
*
* ac3dec 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, or (at your option)
* any later version.
*
* ac3dec 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 GNU Make; see the file COPYING. If not, write to
* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*
*
*/
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <math.h>
#if defined(__OpenBSD__)
#include <soundcard.h>
#elif defined(__FreeBSD__)
#include <machine/soundcard.h>
#else
#include <sys/soundcard.h>
#endif
#include <sys/ioctl.h>
//this sux...types should go in config.h methinks
typedef signed short sint_16;
typedef unsigned int uint_32;
#include "output.h"
static char dev[] = "/dev/dsp";
static int fd;
/*
* open the audio device for writing to
*/
int output_open(int bits, int rate, int channels)
{
int tmp;
/*
* Open the device driver
*/
fd=open(dev,O_WRONLY);
if(fd < 0)
{
fprintf(stderr,"%s: Opening audio device %s\n",
strerror(errno), dev);
goto ERR;
}
tmp = channels == 2 ? 1 : 0;
ioctl(fd,SNDCTL_DSP_STEREO,&tmp);
tmp = bits;
ioctl(fd,SNDCTL_DSP_SAMPLESIZE,&tmp);
tmp = rate;
ioctl(fd,SNDCTL_DSP_SPEED, &tmp);
//this is cheating
tmp = 256;
// ioctl(fd,SNDCTL_DSP_SETFRAGMENT,&tmp);
return 1;
ERR:
if(fd >= 0) { close(fd); }
return 0;
}
/*
* play the sample to the already opened file descriptor
*/
void output_play(sint_16* output_samples, uint_32 num_bytes)
{
// if(fd < 0)
// return;
write(fd,output_samples,1024 * 6);
}
void
output_close(void)
{
close(fd);
}