mdw@git.distorted.org.uk Git - 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 <fcntl.h>
  29 #include <unistd.h>
  30 #include <errno.h>
  31 #include <time.h>
  32
  33 #include "mem.h"
  34 #include "log.h"
  35 #include "uaudio.h"
  36 #include "configuration.h"
  37
  38 #ifndef AFMT_U16_NE
  39 # if BYTE_ORDER == BIG_ENDIAN
  40 #  define AFMT_U16_NE AFMT_U16_BE
  41 # else
  42 #  define AFMT_U16_NE AFMT_U16_LE
  43 # endif
  44 #endif
  45
  46 /* documentation does not match implementation! */
  47 #ifndef SOUND_MIXER_READ
  48 # define SOUND_MIXER_READ(x) MIXER_READ(x)
  49 #endif
  50 #ifndef SOUND_MIXER_WRITE
  51 # define SOUND_MIXER_WRITE(x) MIXER_WRITE(x)
  52 #endif
  53
  54 static int oss_fd = -1;
  55 static int oss_mixer_fd = -1;
  56 static int oss_mixer_channel;
  57
  58 static const char *const oss_options[] = {
  59   "device",
  60   "mixer-device",
  61   "mixer-channel",
  62   NULL
  63 };
  64
  65 /** @brief Open the OSS sound device */
  66 static void oss_open(void) {
  67   const char *device = uaudio_get("device", NULL);
  68
  69 #if EMPEG_HOST
  70   if(!device || !*device || !strcmp(device, "default"))
  71     device = "/dev/audio";
  72 #else
  73   if(!device || !*device || !strcmp(device, "default")) {
  74     if(access("/dev/dsp", W_OK) == 0)
  75       device = "/dev/dsp";
  76     else
  77       device = "/dev/audio";
  78   }
  79 #endif
  80   if((oss_fd = open(device, O_WRONLY, 0)) < 0)
  81     disorder_fatal(errno, "error opening %s", device);
  82 #if !EMPEG_HOST
  83   int stereo = (uaudio_channels == 2), format;
  84   if(ioctl(oss_fd, SNDCTL_DSP_STEREO, &stereo) < 0)
  85     disorder_fatal(errno, "error calling ioctl SNDCTL_DSP_STEREO %d", stereo);
  86   if(uaudio_bits == 16)
  87     format = uaudio_signed ? AFMT_S16_NE : AFMT_U16_NE;
  88   else
  89     format = uaudio_signed ? AFMT_S8 : AFMT_U8;
  90   if(ioctl(oss_fd, SNDCTL_DSP_SETFMT, &format) < 0)
  91     disorder_fatal(errno, "error calling ioctl SNDCTL_DSP_SETFMT %#x", format);
  92   int rate = uaudio_rate;
  93   if(ioctl(oss_fd, SNDCTL_DSP_SPEED, &rate) < 0)
  94     disorder_fatal(errno, "error calling ioctl SNDCTL_DSP_SPEED %d", rate);
  95   if(rate != uaudio_rate)
  96     disorder_error(0, "asked for %dHz, got %dHz", uaudio_rate, rate);
  97 #endif
  98 }
  99
 100 /** @brief Close the OSS sound device */
 101 static void oss_close(void) {
 102   if(oss_fd != -1) {
 103     close(oss_fd);
 104     oss_fd = -1;
 105   }
 106 }
 107
 108 /** @brief Actually play sound via OSS */
 109 static size_t oss_play(void *buffer, size_t samples, unsigned flags) {
 110   /* cf uaudio-alsa.c:alsa-play() */
 111   if(flags & UAUDIO_PAUSED) {
 112     if(flags & UAUDIO_PAUSE)
 113       oss_close();
 114     if(samples > 64)
 115       samples /= 2;
 116     const uint64_t ns = ((uint64_t)samples * 1000000000
 117                          / (uaudio_rate * uaudio_channels));
 118     struct timespec ts[1];
 119     ts->tv_sec = ns / 1000000000;
 120     ts->tv_nsec = ns % 1000000000;
 121     while(nanosleep(ts, ts) < 0 && errno == EINTR)
 122       ;
 123     return samples;
 124   }
 125   if(flags & UAUDIO_RESUME)
 126     oss_open();
 127   const size_t bytes = samples * uaudio_sample_size;
 128   int rc = write(oss_fd, buffer, bytes);
 129   if(rc < 0)
 130     disorder_fatal(errno, "error writing to sound device");
 131   return rc / uaudio_sample_size;
 132 }
 133
 134 static void oss_start(uaudio_callback *callback,
 135                       void *userdata) {
 136   if(uaudio_channels != 1 && uaudio_channels != 2)
 137     disorder_fatal(0, "asked for %d channels but only support 1 or 2",
 138           uaudio_channels);
 139   if(uaudio_bits != 8 && uaudio_bits != 16)
 140     disorder_fatal(0, "asked for %d bits/channel but only support 8 or 16",
 141           uaudio_bits);
 142 #if EMPEG_HOST
 143   /* Very specific buffer size requirements here apparently */
 144   uaudio_thread_start(callback, userdata, oss_play,
 145                       4608 / uaudio_sample_size,
 146                       4608 / uaudio_sample_size,
 147                       0);
 148 #else
 149   /* We could SNDCTL_DSP_GETBLKSIZE but only when the device is already open,
 150    * which is kind of inconvenient.  We go with 1-4Kbyte for now. */
 151   uaudio_thread_start(callback, userdata, oss_play,
 152                       32 / uaudio_sample_size,
 153                       4096 / uaudio_sample_size,
 154                       0);
 155 #endif
 156 }
 157
 158 static void oss_stop(void) {
 159   uaudio_thread_stop();
 160   oss_close();                          /* might not have been paused */
 161 }
 162
 163 /** @brief Channel names */
 164 static const char *oss_channels[] = SOUND_DEVICE_NAMES;
 165
 166 static int oss_mixer_find_channel(const char *channel) {
 167   if(!channel[strspn(channel, "0123456789")])
 168     return atoi(channel);
 169   else {
 170     for(unsigned n = 0; n < sizeof oss_channels / sizeof *oss_channels; ++n)
 171       if(!strcmp(oss_channels[n], channel))
 172         return n;
 173     return -1;
 174   }
 175 }
 176
 177 static void oss_open_mixer(void) {
 178   const char *mixer = uaudio_get("mixer-device", "/dev/mixer");
 179   /* TODO infer mixer-device from device */
 180   if((oss_mixer_fd = open(mixer, O_RDWR, 0)) < 0)
 181     disorder_fatal(errno, "error opening %s", mixer);
 182   const char *channel = uaudio_get("mixer-channel", "pcm");
 183   oss_mixer_channel = oss_mixer_find_channel(channel);
 184   if(oss_mixer_channel < 0)
 185     disorder_fatal(0, "no such channel as '%s'", channel);
 186 }
 187
 188 static void oss_close_mixer(void) {
 189   close(oss_mixer_fd);
 190   oss_mixer_fd = -1;
 191 }
 192
 193 static void oss_get_volume(int *left, int *right) {
 194   int r;
 195
 196   *left = *right = 0;
 197   if(ioctl(oss_mixer_fd, SOUND_MIXER_READ(oss_mixer_channel), &r) < 0)
 198     disorder_error(errno, "error getting volume");
 199   else {
 200     *left = r & 0xff;
 201     *right = (r >> 8) & 0xff;
 202   }
 203 }
 204
 205 static void oss_set_volume(int *left, int *right) {
 206   int r =  (*left & 0xff) + (*right & 0xff) * 256;
 207   if(ioctl(oss_mixer_fd, SOUND_MIXER_WRITE(oss_mixer_channel), &r) == -1)
 208     disorder_error(errno, "error setting volume");
 209   else if(ioctl(oss_mixer_fd, SOUND_MIXER_READ(oss_mixer_channel), &r) < 0)
 210     disorder_error(errno, "error getting volume");
 211   else {
 212     *left = r & 0xff;
 213     *right = (r >> 8) & 0xff;
 214   }
 215 }
 216
 217 static void oss_configure(void) {
 218   uaudio_set("device", config->device);
 219   uaudio_set("mixer-device", config->mixer);
 220   uaudio_set("mixer-channel", config->channel);
 221 }
 222
 223 const struct uaudio uaudio_oss = {
 224   .name = "oss",
 225   .options = oss_options,
 226   .start = oss_start,
 227   .stop = oss_stop,
 228   .activate = uaudio_thread_activate,
 229   .deactivate = uaudio_thread_deactivate,
 230   .open_mixer = oss_open_mixer,
 231   .close_mixer = oss_close_mixer,
 232   .get_volume = oss_get_volume,
 233   .set_volume = oss_set_volume,
 234   .configure = oss_configure,
 235   .flags = UAUDIO_API_CLIENT | UAUDIO_API_SERVER,
 236 };
 237
 238 #endif
 239
 240 /*
 241 Local Variables:
 242 c-basic-offset:2
 243 comment-column:40
 244 fill-column:79
 245 indent-tabs-mode:nil
 246 End:
 247 */