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