mdw@git.distorted.org.uk Git - disorder/blob - server/speaker-oss.c

   1 /*
   2  * This file is part of DisOrder
   3  * Copyright (C) 2007 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 2 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, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * 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, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  18  * USA
  19  */
  20 /** @file server/speaker-oss.c
  21  * @brief Support for @ref BACKEND_OSS */
  22
  23 #include <config.h>
  24
  25 #if HAVE_SYS_SOUNDCARD_H
  26
  27 #include "types.h"
  28
  29 #include <unistd.h>
  30 #include <poll.h>
  31 #include <string.h>
  32 #include <fcntl.h>
  33 #include <unistd.h>
  34 #include <errno.h>
  35 #include <sys/ioctl.h>
  36 #include <sys/soundcard.h>
  37
  38 #include "configuration.h"
  39 #include "syscalls.h"
  40 #include "log.h"
  41 #include "speaker-protocol.h"
  42 #include "speaker.h"
  43
  44 /** @brief Current device */
  45 static int ossfd = -1;
  46
  47 /** @brief OSS backend initialization */
  48 static void oss_init(void) {
  49   info("selected OSS backend");
  50 }
  51
  52 /** @brief OSS deactivation */
  53 static void oss_deactivate(void) {
  54   if(ossfd != -1) {
  55     xclose(ossfd);
  56     ossfd = -1;
  57     device_state = device_closed;
  58     D(("released audio device"));
  59   }
  60 }
  61
  62 /** @brief OSS backend activation */
  63 static void oss_activate(void) {
  64   int stereo, format, rate;
  65   const char *device;
  66
  67   if(ossfd == -1) {
  68     /* Try to pick a device */
  69     if(!strcmp(config->device, "default")) {
  70       if(access("/dev/dsp", W_OK) == 0)
  71         device = "/dev/dsp";
  72       else if(access("/dev/audio", W_OK) == 0)
  73         device = "/dev/audio";
  74       else {
  75         error(0, "cannot determine default OSS device");
  76         goto failed;
  77       }
  78     } else
  79       device = config->device;  /* just believe the user */
  80     /* Open the device */
  81     if((ossfd = open(device, O_WRONLY, 0)) < 0) {
  82       error(errno, "error opening %s", device);
  83       goto failed;
  84     }
  85     /* Set the audio format */
  86     stereo = (config->sample_format.channels == 2);
  87     if(ioctl(ossfd, SNDCTL_DSP_STEREO, &stereo) < 0) {
  88       error(errno, "error calling ioctl SNDCTL_DSP_STEREO %d", stereo);
  89       goto failed;
  90     }
  91     if(config->sample_format.bits == 8)
  92       format = AFMT_U8;
  93     else if(config->sample_format.bits == 16)
  94       format = (config->sample_format.endian == ENDIAN_LITTLE
  95                 ? AFMT_S16_LE : AFMT_S16_BE);
  96     else {
  97       error(0, "unsupported sample_format for oss backend");
  98       goto failed;
  99     }
 100     if(ioctl(ossfd, SNDCTL_DSP_SETFMT, &format) < 0) {
 101       error(errno, "error calling ioctl SNDCTL_DSP_SETFMT %#x", format);
 102       goto failed;
 103     }
 104     rate = config->sample_format.rate;
 105     if(ioctl(ossfd, SNDCTL_DSP_SPEED, &rate) < 0) {
 106       error(errno, "error calling ioctl SNDCTL_DSP_SPEED %d", rate);
 107       goto failed;
 108     }
 109     if((unsigned)rate != config->sample_format.rate)
 110       error(0, "asked for %luHz, got %dHz",
 111             (unsigned long)config->sample_format.rate, rate);
 112     nonblock(ossfd);
 113     device_state = device_open;
 114   }
 115   return;
 116 failed:
 117   device_state = device_error;
 118   if(ossfd >= 0) {
 119     xclose(ossfd);
 120     ossfd = -1;
 121   }
 122 }
 123
 124 /** @brief Play via OSS */
 125 static size_t oss_play(size_t frames) {
 126   const size_t bytes_to_play = frames * bpf;
 127   ssize_t bytes_written;
 128
 129   bytes_written = write(ossfd, playing->buffer + playing->start,
 130                         bytes_to_play);
 131   if(bytes_written < 0)
 132     switch(errno) {
 133     case EINTR:                 /* interruped */
 134     case EAGAIN:                /* overrun */
 135       return 0;                 /* try again later */
 136     default:
 137       fatal(errno, "error writing to audio device");
 138     }
 139   return bytes_written / bpf;
 140 }
 141
 142 static int oss_slot;
 143
 144 /** @brief Fill in poll fd array for OSS */
 145 static void oss_beforepoll(int attribute((unused)) *timeoutp) {
 146   oss_slot = addfd(ossfd, POLLOUT|POLLERR);
 147 }
 148
 149 /** @brief Process poll() results for OSS */
 150 static int oss_ready(void) {
 151   return !!(fds[oss_slot].revents & (POLLOUT|POLLERR));
 152 }
 153
 154 const struct speaker_backend oss_backend = {
 155   BACKEND_OSS,
 156   0,
 157   oss_init,
 158   oss_activate,
 159   oss_play,
 160   oss_deactivate,
 161   oss_beforepoll,
 162   oss_ready
 163 };
 164
 165 #endif
 166
 167 /*
 168 Local Variables:
 169 c-basic-offset:2
 170 comment-column:40
 171 fill-column:79
 172 indent-tabs-mode:nil
 173 End:
 174 */