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 "output.h"
  43
  44 /*******************
  45         Data
  46 ********************/
  47
  48 extern int _frequency;
  49
  50 static int _audio_fd=-1;
  51
  52 #define SOUND_BUFFER_BITS 10
  53 #define SOUND_BUFFER_SIZE (1<<SOUND_BUFFER_BITS)
  54
  55 /*******************
  56         Code
  57 ********************/
  58
  59 static int detect_endianess(void)
  60 /* is this machine big or little endian? */
  61 {
  62         short s;
  63         unsigned char * c;
  64
  65         s=1;
  66         c=(unsigned char *) &s;
  67
  68         if(*c==1) return(AFMT_S16_LE);
  69         return(AFMT_S16_BE);
  70 }
  71
  72
  73 int _out_open_oss(char * devfile)
  74 {
  75         int n;
  76
  77         if((_audio_fd=open(devfile, O_WRONLY))==-1)
  78                 return(-100);
  79
  80         n=(2<<16)|SOUND_BUFFER_BITS;
  81         if(ioctl(_audio_fd, SNDCTL_DSP_SETFRAGMENT, &n)==-1)
  82                 return(-101);
  83
  84         if(ioctl(_audio_fd, SNDCTL_DSP_RESET, 0)==-1)
  85                 return(-102);
  86
  87         if(ioctl(_audio_fd, SNDCTL_DSP_SPEED, &_frequency)==-1)
  88                 return(-103);
  89
  90         n=1;
  91         if(ioctl(_audio_fd, SNDCTL_DSP_STEREO, &n)==-1)
  92                 return(-104);
  93
  94         n=detect_endianess();
  95         if(ioctl(_audio_fd, SNDCTL_DSP_SETFMT, &n)==-1)
  96         {
  97                 /* do I really want 8 bit output? */
  98                 n=AFMT_U8;
  99                 if(ioctl(_audio_fd, SNDCTL_DSP_SETFMT, &n)==-1)
 100                         return(-105);
 101         }
 102
 103         return(0);
 104 }
 105
 106
 107 int _out_write_oss(int lsample, int rsample)
 108 {
 109 /*      char c;
 110
 111         c=lsample & 0xff; write(_audio_fd, &c, 1);
 112         c=(lsample & 0xff00) >> 8; write(_audio_fd, &c, 1);
 113         c=rsample & 0xff; write(_audio_fd, &c, 1);
 114         c=(rsample & 0xff00) >> 8; write(_audio_fd, &c, 1); */
 115         short int i;
 116
 117         i=lsample & 0xffff; write(_audio_fd, &i, sizeof(short int));
 118         i=rsample & 0xffff; write(_audio_fd, &i, sizeof(short int));
 119
 120         return(0);
 121 }
 122
 123
 124 int _out_close_oss(void)
 125 {
 126         close(_audio_fd);
 127         return(0);
 128 }
 129
 130 #endif /* #ifdef LINUX_OSS */