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 #ifdef LINUX_OSS
  26
  27 #include <stdio.h>
  28 #include <string.h>
  29 #include <stdlib.h>
  30 #include <fcntl.h>
  31 #include <sys/ioctl.h>
  32 #include <sys/types.h>
  33 #include <unistd.h>
  34 #include <errno.h>
  35 #include <signal.h>
  36
  37 #include <linux/soundcard.h>
  38 #include <linux/cdrom.h>
  39
  40 #include "output.h"
  41
  42 /*******************
  43         Data
  44 ********************/
  45
  46 extern int _frequency;
  47
  48 static int _audio_fd=-1;
  49
  50 #define SOUND_BUFFER_BITS 10
  51 #define SOUND_BUFFER_SIZE (1<<SOUND_BUFFER_BITS)
  52
  53 /*******************
  54         Code
  55 ********************/
  56
  57 static int detect_endianess(void)
  58 /* is this machine big or little endian? */
  59 {
  60         short s;
  61         unsigned char * c;
  62
  63         s=1;
  64         c=(unsigned char *) &s;
  65
  66         if(*c==1) return(AFMT_S16_LE);
  67         return(AFMT_S16_BE);
  68 }
  69
  70
  71 int _out_open_oss(char * devfile)
  72 {
  73         int n;
  74
  75         if((_audio_fd=open(devfile, O_WRONLY))==-1)
  76                 return(0);
  77
  78         n=(2<<16)|SOUND_BUFFER_BITS;
  79         if(ioctl(_audio_fd, SNDCTL_DSP_SETFRAGMENT, &n)==-1)
  80                 return(0);
  81
  82         if(ioctl(_audio_fd, SNDCTL_DSP_RESET, 0)==-1)
  83                 return(0);
  84
  85         if(ioctl(_audio_fd, SNDCTL_DSP_SPEED, &_frequency)==-1)
  86                 return(0);
  87
  88         n=1;
  89         if(ioctl(_audio_fd, SNDCTL_DSP_STEREO, &n)==-1)
  90                 return(0);
  91
  92         n=detect_endianess();
  93         if(ioctl(_audio_fd, SNDCTL_DSP_SETFMT, &n)==-1)
  94         {
  95                 /* do I really want 8 bit output? */
  96                 n=AFMT_U8;
  97                 if(ioctl(_audio_fd, SNDCTL_DSP_SETFMT, &n)==-1)
  98                         return(0);
  99         }
 100
 101         return(1);
 102 }
 103
 104
 105 int _out_write_oss(int lsample, int rsample)
 106 {
 107 /*      char c;
 108
 109         c=lsample & 0xff; write(_audio_fd, &c, 1);
 110         c=(lsample & 0xff00) >> 8; write(_audio_fd, &c, 1);
 111         c=rsample & 0xff; write(_audio_fd, &c, 1);
 112         c=(rsample & 0xff00) >> 8; write(_audio_fd, &c, 1); */
 113         short int i;
 114
 115         i=lsample & 0xffff; write(_audio_fd, &i, sizeof(short int));
 116         i=rsample & 0xffff; write(_audio_fd, &i, sizeof(short int));
 117
 118         return(0);
 119 }
 120
 121
 122 int _out_close_oss(void)
 123 {
 124         close(_audio_fd);
 125         return(0);
 126 }
 127
 128 #endif /* #ifdef LINUX_OSS */