chiark - git - mdw - disorder/blob - lib/uaudio-oss.c

   1 /*
   2  * This file is part of DisOrder.
   3  * Copyright (C) 2009 Richard Kettlewell
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, either version 3 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program 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
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18 /** @file lib/uaudio-oss.c
  19  * @brief Support for OSS backend */
  20 #include "common.h"
  21
  22 #if HAVE_SYS_SOUNDCARD_H || EMPEG_HOST
  23
  24 #if HAVE_SYS_SOUNDCARD_H
  25 # include <sys/soundcard.h>
  26 #endif
  27 #include <sys/ioctl.h>
  28 #include <pthread.h>
  29 #include <fcntl.h>
  30 #include <unistd.h>
  31 #include <errno.h>
  32 #include <arpa/inet.h>
  33
  34 #include "mem.h"
  35 #include "log.h"
  36 #include "syscalls.h"
  37
  38 static int oss_fd = -1;
  39 static pthread_t oss_thread;
  40 static uaudio_callback *oss_callback;
  41 static int oss_started;
  42 static int oss_activated;
  43 static int oss_going;
  44 static pthread_mutex_t oss_lock = PTHREAD_MUTEX_INITIALIZER;
  45 static pthread_cond_t oss_cond = PTHREAD_COND_INITIALIZER;
  46 static int oss_bufsize;
  47
  48 static const char *const oss_options[] = {
  49   "device",
  50   NULL
  51 };
  52
  53 static void *oss_thread(void *userdata) {
  54   int16_t *buffer;
  55   pthread_mutex_lock(&oss_lock);
  56   buffer = xmalloc(XXX);
  57   while(oss_started) {
  58     while(oss_started && !oss_activated)
  59       pthread_cond_wait(&oss_cond, &oss_lock);
  60     if(!oss_started)
  61       break;
  62     /* We are definitely active now */
  63     oss_going = 1;
  64     pthread_cond_signal(&oss_cond);
  65     while(oss_activated) {
  66       const int nsamples = oss_callback(buffer, oss_bufsizeXXX, userdata);;
  67       if(write(oss_fd, buffer, XXX) < 0)
  68         fatal(errno, "error playing audio");
  69       // TODO short writes!
  70     }
  71     oss_going = 0;
  72     pthread_cond_signal(&oss_cond);
  73   }
  74   pthread_mutex_unlock(&oss_lock);
  75   return NULL;
  76 }
  77
  78 static void oss_start(uaudio_callback *callback,
  79                       void *userdata) {
  80   int e;
  81   oss_callback = callback;
  82   if((e = pthread_create(&oss_thread,
  83                          NULL,
  84                          oss_thread_fn,
  85                          userdata)))
  86     fatal(e, "pthread_create");
  87 }
  88
  89 static void oss_stop(void) {
  90   void *result;
  91
  92   oss_deactivate();
  93   pthread_mutex_lock(&oss_lock);
  94   oss_started = 0;
  95   pthread_cond_signal(&oss_cond);
  96   pthread_mutex_unlock(&oss_lock);
  97   pthread_join(oss_thread, &result);
  98 }
  99
 100 static void oss_activate(void) {
 101   pthread_mutex_lock(&oss_lock);
 102   if(!oss_activated) {
 103     const char *device = uaudio_get(&uadiuo_oss, "device");
 104
 105 #if EMPEG_HOST
 106     if(!device || !*device || !strcmp(device, "default")) {
 107       device "/dev/audio";
 108 #else
 109     if(!device || !*device || !strcmp(device, "default")) {
 110       if(access("/dev/dsp", W_OK) == 0)
 111         device = "/dev/dsp";
 112       else
 113         device = "/dev/audio";
 114     }
 115 #endif
 116     if((oss_fd = open(device, O_WRONLY, 0)) < 0)
 117       fatal(errno, "error opening %s", device);
 118 #if EMPEG_HOST
 119     /* empeg audio driver only knows /dev/audio, only supports the equivalent
 120      * of AFMT_S16_NE, has a fixed buffer size, and does not support the
 121      * SNDCTL_ ioctls. */
 122     oss_bufsize = 4608;
 123 #else
 124     int stereo = (config->sample_format.channels == 2), format, rate;
 125     if(ioctl(ossfd, SNDCTL_DSP_STEREO, &stereo) < 0) {
 126       error(errno, "error calling ioctl SNDCTL_DSP_STEREO %d", stereo);
 127       goto failed;
 128     }
 129     /* TODO we need to think about where we decide this */
 130     if(config->sample_format.bits == 8)
 131       format = AFMT_U8;
 132     else if(config->sample_format.bits == 16)
 133       format = (config->sample_format.endian == ENDIAN_LITTLE
 134                 ? AFMT_S16_LE : AFMT_S16_BE);
 135     else
 136       fatal(0, "unsupported sample_format for oss backend");
 137     if(ioctl(oss_fd, SNDCTL_DSP_SETFMT, &format) < 0)
 138       fatal(errno, "error calling ioctl SNDCTL_DSP_SETFMT %#x", format);
 139     rate = config->sample_format.rate;
 140     if(ioctl(oss_fd, SNDCTL_DSP_SPEED, &rate) < 0)
 141       fatal(errno, "error calling ioctl SNDCTL_DSP_SPEED %d", rate);
 142     if((unsigned)rate != config->sample_format.rate)
 143       error(0, "asked for %luHz, got %dHz",
 144             (unsigned long)config->sample_format.rate, rate);
 145     if(ioctl(oss_fd, SNDCTL_DSP_GETBLKSIZE, &oss_bufsize) < 0) {
 146       error(errno, "ioctl SNDCTL_DSP_GETBLKSIZE");
 147       oss_bufsize = 2048;       /* guess */
 148     }
 149 #endif
 150     oss_activated = 1;
 151     pthread_cond_signal(&oss_cond);
 152     while(!oss_going)
 153       pthread_cond_wait(&oss_cond, &oss_lock);
 154   }
 155   pthread_mutex_unlock(&oss_lock);
 156 }
 157
 158 static void oss_deactivate(void) {
 159   pthread_mutex_lock(&oss_lock);
 160   if(oss_activated) {
 161     oss_activated = 0;
 162     pthread_cond_signal(&oss_cond);
 163     while(oss_going)
 164       pthread_cond_wait(&oss_cond, &oss_lock);
 165     close(oss_fd);
 166     oss_fd = -1;
 167   }
 168   pthread_mutex_unlock(&oss_lock);
 169 }
 170
 171 const struct uaudio uaudio_oss = {
 172   .name = "oss",
 173   .options = oss_options,
 174   .start = oss_start,
 175   .stop = oss_stop,
 176   .activate = oss_activate,
 177   .deactivate = oss_deactivate
 178 };
 179
 180 #endif
 181
 182 /*
 183 Local Variables:
 184 c-basic-offset:2
 185 comment-column:40
 186 fill-column:79
 187 indent-tabs-mode:nil
 188 End:
 189 */