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/***************************************************************************
oss.c - description
-------------------
begin : Wed May 15 2002
copyright : (C) 2002 by Pete Bernert
email : BlackDove@addcom.de
***************************************************************************/
/***************************************************************************
* *
* 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. See also the license.txt file for *
* additional informations. *
* *
***************************************************************************/
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <sys/soundcard.h>
#include "out.h"
////////////////////////////////////////////////////////////////////////
// oss globals
////////////////////////////////////////////////////////////////////////
#define OSS_MODE_STEREO 1
#define OSS_MODE_MONO 0
#define OSS_SPEED_44100 44100
#define FRAGMENT_SHIFT 12
#define FRAGMENT_SIZE (1 << FRAGMENT_SHIFT)
static int oss_audio_fd = -1;
extern int errno;
////////////////////////////////////////////////////////////////////////
// SETUP SOUND
////////////////////////////////////////////////////////////////////////
static int oss_init(void)
{
int pspeed=44100;
int pstereo;
int format;
int myfrag;
int oss_speed, oss_stereo;
pstereo = OSS_MODE_STEREO;
oss_speed = pspeed;
oss_stereo = pstereo;
if((oss_audio_fd=open("/dev/dsp",O_WRONLY,0))==-1)
{
printf("OSS device not available\n");
return -1;
}
if(ioctl(oss_audio_fd,SNDCTL_DSP_RESET,0)==-1)
{
printf("Sound reset failed\n");
return -1;
}
// we use 64 fragments with 1024 bytes each
// rearmed: now using 10*4096 for better latency
myfrag = (10<<16) | FRAGMENT_SHIFT;
if(ioctl(oss_audio_fd,SNDCTL_DSP_SETFRAGMENT,&myfrag)==-1)
{
printf("Sound set fragment failed!\n");
return -1;
}
format = AFMT_S16_NE;
if(ioctl(oss_audio_fd,SNDCTL_DSP_SETFMT,&format) == -1)
{
printf("Sound format not supported!\n");
return -1;
}
if(format!=AFMT_S16_NE)
{
printf("Sound format not supported!\n");
return -1;
}
if(ioctl(oss_audio_fd,SNDCTL_DSP_STEREO,&oss_stereo)==-1 || !oss_stereo)
{
printf("Stereo mode not supported!\n");
return -1;
}
if(ioctl(oss_audio_fd,SNDCTL_DSP_SPEED,&oss_speed)==-1)
{
printf("Sound frequency not supported\n");
return -1;
}
if(oss_speed!=pspeed)
{
printf("Sound frequency not supported\n");
return -1;
}
return 0;
}
////////////////////////////////////////////////////////////////////////
// REMOVE SOUND
////////////////////////////////////////////////////////////////////////
static void oss_finish(void)
{
if(oss_audio_fd != -1 )
{
close(oss_audio_fd);
oss_audio_fd = -1;
}
}
////////////////////////////////////////////////////////////////////////
// GET BUFFERED STATUS
////////////////////////////////////////////////////////////////////////
static int oss_busy(void)
{
audio_buf_info info;
unsigned long l;
if(oss_audio_fd == -1) return 1;
if(ioctl(oss_audio_fd,SNDCTL_DSP_GETOSPACE,&info)==-1)
l=0;
else
{
if(info.fragments<(info.fragstotal>>1)) // can we write in at least the half of fragments?
l=1; // -> no? wait
else l=0; // -> else go on
}
return l;
}
////////////////////////////////////////////////////////////////////////
// FEED SOUND DATA
////////////////////////////////////////////////////////////////////////
static void oss_feed(void *buf, int bytes)
{
audio_buf_info info;
char sbuf[4096];
if(oss_audio_fd == -1) return;
if(ioctl(oss_audio_fd,SNDCTL_DSP_GETOSPACE,&info)==0)
{
// for fast forward
if(bytes > info.fragments * FRAGMENT_SIZE)
bytes = info.fragments * FRAGMENT_SIZE;
if(bytes == 0)
return;
if(info.fragments==info.fragstotal)
{
memset(sbuf, 0, sizeof(sbuf));
write(oss_audio_fd, sbuf, sizeof(sbuf));
write(oss_audio_fd, sbuf, sizeof(sbuf));
write(oss_audio_fd, sbuf, sizeof(sbuf));
}
}
write(oss_audio_fd, buf, bytes);
}
void out_register_oss(struct out_driver *drv)
{
drv->name = "oss";
drv->init = oss_init;
drv->finish = oss_finish;
drv->busy = oss_busy;
drv->feed = oss_feed;
}
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