src/audio/SDL_audiodev.c
author Sam Lantinga
Mon, 06 Feb 2006 08:28:51 +0000
changeset 1330 450721ad5436
parent 1312 c9b51268668f
child 1336 3692456e7b0f
permissions -rw-r--r--
It's now possible to build SDL without any C runtime at all on Windows,
using Visual C++ 2005
     1 /*
     2     SDL - Simple DirectMedia Layer
     3     Copyright (C) 1997-2006 Sam Lantinga
     4 
     5     This library is free software; you can redistribute it and/or
     6     modify it under the terms of the GNU Lesser General Public
     7     License as published by the Free Software Foundation; either
     8     version 2.1 of the License, or (at your option) any later version.
     9 
    10     This library is distributed in the hope that it will be useful,
    11     but WITHOUT ANY WARRANTY; without even the implied warranty of
    12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    13     Lesser General Public License for more details.
    14 
    15     You should have received a copy of the GNU Lesser General Public
    16     License along with this library; if not, write to the Free Software
    17     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
    18 
    19     Sam Lantinga
    20     slouken@libsdl.org
    21 */
    22 
    23 /* Get the name of the audio device we use for output */
    24 
    25 #if defined(unix) || defined(__unix__) || defined(__riscos__)
    26 
    27 #include <stdlib.h>
    28 #include <stdio.h>
    29 #include <fcntl.h>
    30 #include <sys/types.h>
    31 #include <sys/stat.h>
    32 #include <string.h>
    33 
    34 #include "SDL_audiodev_c.h"
    35 
    36 #ifndef _PATH_DEV_DSP
    37 #if defined(__NetBSD__) || defined(__OpenBSD__)
    38 #define _PATH_DEV_DSP  "/dev/audio"
    39 #else
    40 #define _PATH_DEV_DSP  "/dev/dsp"
    41 #endif
    42 #endif
    43 #ifndef _PATH_DEV_DSP24
    44 #define _PATH_DEV_DSP24	"/dev/sound/dsp"
    45 #endif
    46 #ifndef _PATH_DEV_AUDIO
    47 #define _PATH_DEV_AUDIO	"/dev/audio"
    48 #endif
    49 
    50 
    51 int SDL_OpenAudioPath(char *path, int maxlen, int flags, int classic)
    52 {
    53 	const char *audiodev;
    54 	int audio_fd;
    55 	char audiopath[1024];
    56 
    57 	/* Figure out what our audio device is */
    58 	if ( ((audiodev=getenv("SDL_PATH_DSP")) == NULL) &&
    59 	     ((audiodev=getenv("AUDIODEV")) == NULL) ) {
    60 		if ( classic ) {
    61 			audiodev = _PATH_DEV_AUDIO;
    62 		} else {
    63 			struct stat sb;
    64 
    65 			/* Added support for /dev/sound/\* in Linux 2.4 */
    66 			if ( ((stat("/dev/sound", &sb) == 0) && S_ISDIR(sb.st_mode)) &&
    67 				 ((stat(_PATH_DEV_DSP24, &sb) == 0) && S_ISCHR(sb.st_mode)) ) {
    68 				audiodev = _PATH_DEV_DSP24;
    69 			} else {
    70 				audiodev = _PATH_DEV_DSP;
    71 			}
    72 		}
    73 	}
    74 	audio_fd = open(audiodev, flags, 0);
    75 
    76 	/* If the first open fails, look for other devices */
    77 	if ( (audio_fd < 0) && (strlen(audiodev) < (sizeof(audiopath)-3)) ) {
    78 		int exists, instance;
    79 		struct stat sb;
    80 
    81 		instance = 1;
    82 		do { /* Don't use errno ENOENT - it may not be thread-safe */
    83 			sprintf(audiopath, "%s%d", audiodev, instance++);
    84 			exists = 0;
    85 			if ( stat(audiopath, &sb) == 0 ) {
    86 				exists = 1;
    87 				audio_fd = open(audiopath, flags, 0); 
    88 			}
    89 		} while ( exists && (audio_fd < 0) );
    90 		audiodev = audiopath;
    91 	}
    92 	if ( path != NULL ) {
    93 		strncpy(path, audiodev, maxlen);
    94 		path[maxlen-1] = '\0';
    95 	}
    96 	return(audio_fd);
    97 }
    98 
    99 #elif defined(_AIX)
   100 
   101 /* Get the name of the audio device we use for output */
   102 
   103 #include <stdlib.h>
   104 #include <sys/types.h>
   105 #include <sys/stat.h>
   106 #include <string.h>
   107 
   108 #include "SDL_audiodev_c.h"
   109 
   110 #ifndef _PATH_DEV_DSP
   111 #define _PATH_DEV_DSP	"/dev/%caud%c/%c"
   112 #endif
   113 
   114 char devsettings[][3] =
   115 {
   116     { 'p', '0', '1' }, { 'p', '0', '2' }, { 'p', '0', '3' }, { 'p', '0', '4' },
   117     { 'p', '1', '1' }, { 'p', '1', '2' }, { 'p', '1', '3' }, { 'p', '1', '4' },
   118     { 'p', '2', '1' }, { 'p', '2', '2' }, { 'p', '2', '3' }, { 'p', '2', '4' },
   119     { 'p', '3', '1' }, { 'p', '3', '2' }, { 'p', '3', '3' }, { 'p', '3', '4' },
   120     { 'b', '0', '1' }, { 'b', '0', '2' }, { 'b', '0', '3' }, { 'b', '0', '4' },
   121     { 'b', '1', '1' }, { 'b', '1', '2' }, { 'b', '1', '3' }, { 'b', '1', '4' },
   122     { 'b', '2', '1' }, { 'b', '2', '2' }, { 'b', '2', '3' }, { 'b', '2', '4' },
   123     { 'b', '3', '1' }, { 'b', '3', '2' }, { 'b', '3', '3' }, { 'b', '3', '4' },
   124     { '\0', '\0', '\0' }
   125 };
   126 
   127 static int OpenUserDefinedDevice(char *path, int maxlen, int flags)
   128 {
   129 	const char *audiodev;
   130 	int  audio_fd;
   131 
   132 	/* Figure out what our audio device is */
   133 	if ((audiodev=getenv("SDL_PATH_DSP")) == NULL) {
   134 	    audiodev=getenv("AUDIODEV");
   135 	}
   136 	if ( audiodev == NULL ) {
   137 	    return -1;
   138 	}
   139 	audio_fd = open(audiodev, flags, 0);
   140 	if ( path != NULL ) {
   141 		strncpy(path, audiodev, maxlen);
   142 		path[maxlen-1] = '\0';
   143 	}
   144 	return audio_fd;
   145 }
   146 
   147 int SDL_OpenAudioPath(char *path, int maxlen, int flags, int classic)
   148 {
   149     struct stat sb;
   150     int         audio_fd;
   151     char        audiopath[1024];
   152     int         cycle;
   153 
   154     audio_fd = OpenUserDefinedDevice(path,maxlen,flags);
   155     if ( audio_fd != -1 ) {
   156         return audio_fd;
   157     }
   158 
   159     cycle    = 0;
   160     while( devsettings[cycle][0] != '\0' ) {
   161         sprintf( audiopath,
   162                  _PATH_DEV_DSP,
   163                  devsettings[cycle][0],
   164                  devsettings[cycle][1],
   165                  devsettings[cycle][2]);
   166 
   167 	if ( stat(audiopath, &sb) == 0 ) {
   168 	    audio_fd = open(audiopath, flags, 0);
   169 	    if ( audio_fd > 0 ) {
   170 		if ( path != NULL ) {
   171 		    strncpy( path, audiopath, maxlen );
   172 		    path[maxlen-1] = '\0';
   173 		}
   174 	        return audio_fd;
   175 	    }
   176 	}
   177     }
   178     return -1;
   179 }
   180 
   181 #endif /* UNIX system */