out_oss.c

   1 /*
   2
   3     PROGRAM_NAME PROGRAM_VERSION - PROGRAM_DESCRIPTION
   4
   5     Copyright (C) 2003 Angel Ortega <angel@triptico.com>
   6
   7     This program is free software; you can redistribute it and/or
   8     modify it under the terms of the GNU General Public License
   9     as published by the Free Software Foundation; either version 2
  10     of the License, or (at your option) any later version.
  11
  12     This program is distributed in the hope that it will be useful,
  13     but WITHOUT ANY WARRANTY; without even the implied warranty of
  14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15     GNU General Public License for more details.
  16
  17     You should have received a copy of the GNU General Public License
  18     along with this program; if not, write to the Free Software
  19     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  20
  21     http://www.triptico.com
  22
  23 */
  24
  25 #include "config.h"
  26
  27 #ifdef LINUX_OSS
  28
  29 #include <stdio.h>
  30 #include <string.h>
  31 #include <stdlib.h>
  32 #include <fcntl.h>
  33 #include <sys/ioctl.h>
  34 #include <sys/types.h>
  35 #include <unistd.h>
  36 #include <errno.h>
  37 #include <signal.h>
  38
  39 #include <linux/soundcard.h>
  40 #include <linux/cdrom.h>
  41
  42 #include "core.h"
  43 #include "output.h"
  44
  45 /*******************
  46         Data
  47 ********************/
  48
  49 static int _audio_fd=-1;
  50
  51 #define SOUND_BUFFER_BITS 10
  52 #define SOUND_BUFFER_SIZE (1<<SOUND_BUFFER_BITS)
  53
  54 /*******************
  55         Code
  56 ********************/
  57
  58 static int detect_endianess(void)
  59 /* is this machine big or little endian? */
  60 {
  61         short s;
  62         unsigned char * c;
  63
  64         s=1;
  65         c=(unsigned char *) &s;
  66
  67         if(*c==1) return(AFMT_S16_LE);
  68         return(AFMT_S16_BE);
  69 }
  70
  71
  72 int _out_open_oss(char * devfile)
  73 {
  74         int n;
  75
  76         if((_audio_fd=open(devfile, O_WRONLY))==-1)
  77                 return(-100);
  78
  79         n=(2<<16)|SOUND_BUFFER_BITS;
  80         if(ioctl(_audio_fd, SNDCTL_DSP_SETFRAGMENT, &n)==-1)
  81                 return(-101);
  82
  83         if(ioctl(_audio_fd, SNDCTL_DSP_RESET, 0)==-1)
  84                 return(-102);
  85
  86         if(ioctl(_audio_fd, SNDCTL_DSP_SPEED, &_frequency)==-1)
  87                 return(-103);
  88
  89         n=1;
  90         if(ioctl(_audio_fd, SNDCTL_DSP_STEREO, &n)==-1)
  91                 return(-104);
  92
  93         n=detect_endianess();
  94         if(ioctl(_audio_fd, SNDCTL_DSP_SETFMT, &n)==-1)
  95         {
  96                 /* do I really want 8 bit output? */
  97                 n=AFMT_U8;
  98                 if(ioctl(_audio_fd, SNDCTL_DSP_SETFMT, &n)==-1)
  99                         return(-105);
 100         }
 101
 102         return(0);
 103 }
 104
 105
 106 int _out_write_oss(float lsample, float rsample)
 107 {
 108 /*      char c;
 109
 110         c=lsample & 0xff; write(_audio_fd, &c, 1);
 111         c=(lsample & 0xff00) >> 8; write(_audio_fd, &c, 1);
 112         c=rsample & 0xff; write(_audio_fd, &c, 1);
 113         c=(rsample & 0xff00) >> 8; write(_audio_fd, &c, 1); */
 114         short int i;
 115
 116         i=(short int) lsample & 0xffff;
 117         write(_audio_fd, &i, sizeof(short int));
 118
 119         i=(short int) rsample & 0xffff;
 120         write(_audio_fd, &i, sizeof(short int));
 121
 122         return(0);
 123 }
 124
 125
 126 int _out_close_oss(void)
 127 {
 128         close(_audio_fd);
 129         return(0);
 130 }
 131
 132 #endif /* #ifdef LINUX_OSS */