modules/audio_output/oss.c

   1 /*****************************************************************************
   2  * oss.c: Open Sound System audio output plugin for VLC
   3  *****************************************************************************
   4  * Copyright (C) 2000-2002 VLC authors and VideoLAN
   5  * Copyright (C) 2007-2012 Rémi Denis-Courmont
   6  *
   7  * Authors: Michel Kaempf <maxx@via.ecp.fr>
   8  *          Sam Hocevar <sam@zoy.org>
   9  *          Christophe Massiot <massiot@via.ecp.fr>
  10  *
  11  * This program is free software; you can redistribute it and/or modify it
  12  * under the terms of the GNU Lesser General Public License as published by
  13  * the Free Software Foundation; either version 2.1 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  19  * GNU Lesser General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU Lesser General Public License
  22  * along with this program; if not, write to the Free Software Foundation,
  23  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  24  *****************************************************************************/
  25
  26 #ifdef HAVE_CONFIG_H
  27 # include "config.h"
  28 #endif
  29
  30 #include <stdlib.h>
  31 #include <math.h>
  32 #include <errno.h>
  33 #include <sys/types.h>
  34 #include <fcntl.h>
  35 #include <sys/ioctl.h>
  36 #ifdef HAVE_SOUNDCARD_H
  37 # include <soundcard.h>
  38 #else
  39 # include <sys/soundcard.h>
  40 #endif
  41
  42 #ifndef SNDCTL_DSP_HALT
  43 # define SNDCTL_DSP_HALT SNDCTL_DSP_RESET
  44 #endif
  45
  46 #include <vlc_common.h>
  47 #include <vlc_plugin.h>
  48 #include <vlc_fs.h>
  49 #include <vlc_cpu.h>
  50 #include <vlc_aout.h>
  51
  52 #define A52_FRAME_NB 1536
  53
  54 typedef struct
  55 {
  56     int fd;
  57     audio_sample_format_t format;
  58     bool starting;
  59     bool soft_mute;
  60     float soft_gain;
  61     char *device;
  62 } aout_sys_t;
  63
  64 #include "volume.h"
  65
  66 static int Open (vlc_object_t *);
  67 static void Close (vlc_object_t *);
  68
  69 #define AUDIO_DEV_TEXT N_("Audio output device")
  70 #define AUDIO_DEV_LONGTEXT N_("OSS device node path.")
  71
  72 #define SPDIF_TEXT N_("Use S/PDIF when available")
  73 #define SPDIF_LONGTEXT N_( \
  74     "S/PDIF can be used by default when " \
  75     "your hardware supports it as well as the audio stream being played.")
  76
  77 vlc_module_begin ()
  78     set_shortname( "OSS" )
  79     set_description (N_("Open Sound System audio output"))
  80     set_category( CAT_AUDIO )
  81     set_subcategory( SUBCAT_AUDIO_AOUT )
  82     add_string ("oss-audio-device", "",
  83                 AUDIO_DEV_TEXT, AUDIO_DEV_LONGTEXT, false)
  84     add_bool("oss-spdif", false, SPDIF_TEXT, SPDIF_LONGTEXT, true)
  85     add_sw_gain ()
  86     set_capability( "audio output", 100 )
  87     set_callbacks (Open, Close)
  88 vlc_module_end ()
  89
  90 static int TimeGet (audio_output_t *, vlc_tick_t *);
  91 static void Play(audio_output_t *, block_t *, vlc_tick_t);
  92 static void Pause (audio_output_t *, bool, vlc_tick_t);
  93 static void Flush (audio_output_t *, bool);
  94
  95 static int Start (audio_output_t *aout, audio_sample_format_t *restrict fmt)
  96 {
  97     aout_sys_t* sys = aout->sys;
  98
  99     if (aout_FormatNbChannels(fmt) == 0)
 100         return VLC_EGENERIC;
 101
 102     /* Open the device */
 103     const char *device = sys->device;
 104     if (device == NULL)
 105         device = getenv ("OSS_AUDIODEV");
 106     if (device == NULL)
 107         device = "/dev/dsp";
 108
 109     int fd = vlc_open (device, O_WRONLY);
 110     if (fd == -1)
 111     {
 112         msg_Err (aout, "cannot open OSS device %s: %s", device,
 113                  vlc_strerror_c(errno));
 114         return VLC_EGENERIC;
 115     }
 116     msg_Dbg (aout, "using OSS device: %s", device);
 117
 118     /* Select audio format */
 119     int format;
 120     bool spdif = false;
 121
 122     switch (fmt->i_format)
 123     {
 124 #ifdef AFMT_FLOAT
 125         case VLC_CODEC_FL64:
 126         case VLC_CODEC_FL32:
 127             format = AFMT_FLOAT;
 128             break;
 129 #endif
 130         case VLC_CODEC_S32N:
 131             format = AFMT_S32_NE;
 132             break;
 133         case VLC_CODEC_S16N:
 134             format = AFMT_S16_NE;
 135             break;
 136         case VLC_CODEC_U8:
 137             format = AFMT_U8;
 138             break;
 139         default:
 140             if (AOUT_FMT_SPDIF(fmt))
 141                 spdif = var_InheritBool(aout, "oss-spdif");
 142             if (spdif)
 143                 format = AFMT_AC3;
 144 #ifdef AFMT_FLOAT
 145             else if (HAVE_FPU)
 146                 format = AFMT_FLOAT;
 147 #endif
 148             else
 149                 format = AFMT_S16_NE;
 150     }
 151
 152     if (ioctl (fd, SNDCTL_DSP_SETFMT, &format) < 0)
 153     {
 154         msg_Err (aout, "cannot set audio format 0x%X: %s", format,
 155                  vlc_strerror_c(errno));
 156         goto error;
 157     }
 158
 159     switch (format)
 160     {
 161         case AFMT_U8:     fmt->i_format = VLC_CODEC_U8;   break;
 162         case AFMT_S16_NE: fmt->i_format = VLC_CODEC_S16N; break;
 163         case AFMT_S32_NE: fmt->i_format = VLC_CODEC_S32N; break;
 164 #ifdef AFMT_FLOAT
 165         case AFMT_FLOAT:  fmt->i_format = VLC_CODEC_FL32; break;
 166 #endif
 167         case AFMT_AC3:
 168             if (spdif)
 169             {
 170                 fmt->i_format = VLC_CODEC_SPDIFL;
 171                 break;
 172             }
 173         default:
 174             msg_Err (aout, "unsupported audio format 0x%X", format);
 175             goto error;
 176     }
 177
 178     /* Select channels count */
 179     int channels = spdif ? 2 : aout_FormatNbChannels (fmt);
 180     if (ioctl (fd, SNDCTL_DSP_CHANNELS, &channels) < 0)
 181     {
 182         msg_Err (aout, "cannot set %d channels: %s", channels,
 183                  vlc_strerror_c(errno));
 184         goto error;
 185     }
 186
 187     switch (channels)
 188     {
 189         case 1: channels = AOUT_CHAN_CENTER;  break;
 190         case 2: channels = AOUT_CHANS_STEREO; break;
 191         case 4: channels = AOUT_CHANS_4_0;    break;
 192         case 6: channels = AOUT_CHANS_5_1;    break;
 193         case 8: channels = AOUT_CHANS_7_1;    break;
 194         default:
 195             msg_Err (aout, "unsupported channels count %d", channels);
 196             goto error;
 197     }
 198
 199     /* Select sample rate */
 200     int rate = spdif ? 48000 : fmt->i_rate;
 201     if (ioctl (fd, SNDCTL_DSP_SPEED, &rate) < 0)
 202     {
 203         msg_Err (aout, "cannot set %d Hz sample rate: %s", rate,
 204                  vlc_strerror_c(errno));
 205         goto error;
 206     }
 207
 208     /* Setup audio_output_t */
 209     aout->time_get = TimeGet;
 210     aout->play = Play;
 211     aout->pause = Pause;
 212     aout->flush = Flush;
 213
 214     if (spdif)
 215     {
 216         fmt->i_bytes_per_frame = AOUT_SPDIF_SIZE;
 217         fmt->i_frame_length = A52_FRAME_NB;
 218     }
 219     else
 220     {
 221         fmt->i_rate = rate;
 222         fmt->i_physical_channels = channels;
 223     }
 224     fmt->channel_type = AUDIO_CHANNEL_TYPE_BITMAP;
 225     aout_FormatPrepare (fmt);
 226
 227     /* Select timing */
 228     uint32_t bytes;
 229     if (spdif)
 230         bytes = AOUT_SPDIF_SIZE;
 231     else
 232         bytes = fmt->i_rate / (CLOCK_FREQ / AOUT_MIN_PREPARE_TIME)
 233                 * fmt->i_bytes_per_frame;
 234     if (unlikely(bytes < 16))
 235         bytes = 16;
 236
 237     int frag = (AOUT_MAX_ADVANCE_TIME / AOUT_MIN_PREPARE_TIME) << 16
 238              | (32 - clz(bytes - 1));
 239     if (ioctl (fd, SNDCTL_DSP_SETFRAGMENT, &frag) < 0)
 240         msg_Err (aout, "cannot set 0x%08x fragment: %s", frag,
 241                  vlc_strerror_c(errno));
 242
 243     sys->fd = fd;
 244     aout_SoftVolumeStart (aout);
 245     sys->starting = true;
 246     sys->format = *fmt;
 247     return VLC_SUCCESS;
 248 error:
 249     vlc_close (fd);
 250     return VLC_EGENERIC;
 251 }
 252
 253 static int TimeGet (audio_output_t *aout, vlc_tick_t *restrict pts)
 254 {
 255     aout_sys_t *sys = aout->sys;
 256     int delay;
 257
 258     if (ioctl (sys->fd, SNDCTL_DSP_GETODELAY, &delay) < 0)
 259     {
 260         msg_Warn (aout, "cannot get delay: %s", vlc_strerror_c(errno));
 261         return -1;
 262     }
 263
 264     *pts = (delay * CLOCK_FREQ * sys->format.i_frame_length)
 265                         / (sys->format.i_rate * sys->format.i_bytes_per_frame);
 266     return 0;
 267 }
 268
 269 /**
 270  * Queues one audio buffer to the hardware.
 271  */
 272 static void Play(audio_output_t *aout, block_t *block, vlc_tick_t date)
 273 {
 274     aout_sys_t *sys = aout->sys;
 275     int fd = sys->fd;
 276
 277     while (block->i_buffer > 0)
 278     {
 279         ssize_t bytes = write (fd, block->p_buffer, block->i_buffer);
 280         if (bytes >= 0)
 281         {
 282             block->p_buffer += bytes;
 283             block->i_buffer -= bytes;
 284         }
 285         else
 286             msg_Err (aout, "cannot write samples: %s", vlc_strerror_c(errno));
 287     }
 288     block_Release (block);
 289     (void) date;
 290 }
 291
 292 /**
 293  * Pauses/resumes the audio playback.
 294  */
 295 static void Pause (audio_output_t *aout, bool pause, vlc_tick_t date)
 296 {
 297     aout_sys_t *sys = aout->sys;
 298     int fd = sys->fd;
 299
 300     (void) date;
 301     ioctl (fd, pause ? SNDCTL_DSP_SILENCE : SNDCTL_DSP_SKIP, NULL);
 302 }
 303
 304 /**
 305  * Flushes/drains the audio playback buffer.
 306  */
 307 static void Flush (audio_output_t *aout, bool wait)
 308 {
 309     aout_sys_t *sys = aout->sys;
 310     int fd = sys->fd;
 311
 312     if (wait)
 313         return; /* drain is implicit with OSS */
 314     ioctl (fd, SNDCTL_DSP_HALT, NULL);
 315 }
 316
 317 /**
 318  * Releases the audio output device.
 319  */
 320 static void Stop (audio_output_t *aout)
 321 {
 322     aout_sys_t *sys = aout->sys;
 323     int fd = sys->fd;
 324
 325     ioctl (fd, SNDCTL_DSP_HALT, NULL);
 326     vlc_close (fd);
 327     sys->fd = -1;
 328 }
 329
 330 static int DevicesEnum (audio_output_t *aout)
 331 {
 332     int fd = vlc_open ("/dev/dsp", O_WRONLY);
 333     if (fd == -1)
 334         return -1;
 335
 336     oss_sysinfo si;
 337     int n = -1;
 338
 339     if (ioctl (fd, SNDCTL_SYSINFO, &si) < 0)
 340     {
 341         msg_Err (aout, "cannot get system infos: %s", vlc_strerror(errno));
 342         goto out;
 343     }
 344
 345     msg_Dbg (aout, "using %s version %s (0x%06X) under %s", si.product,
 346              si.version, si.versionnum, si.license);
 347
 348     for (int i = 0; i < si.numaudios; i++)
 349     {
 350         oss_audioinfo ai = { .dev = i };
 351
 352         if (ioctl (fd, SNDCTL_AUDIOINFO, &ai) < 0)
 353         {
 354             msg_Warn (aout, "cannot get device %d infos: %s", i,
 355                       vlc_strerror_c(errno));
 356             continue;
 357         }
 358         if (ai.caps & (PCM_CAP_HIDDEN|PCM_CAP_MODEM))
 359             continue;
 360         if (!(ai.caps & PCM_CAP_OUTPUT))
 361             continue;
 362         if (!ai.enabled)
 363             continue;
 364
 365         aout_HotplugReport (aout, ai.devnode, ai.name);
 366         n++;
 367     }
 368 out:
 369     vlc_close (fd);
 370     return n;
 371 }
 372
 373 static int DeviceSelect (audio_output_t *aout, const char *id)
 374 {
 375     aout_sys_t *sys = aout->sys;
 376     char *path = NULL;
 377
 378     if (id != NULL)
 379     {
 380         path = strdup (id);
 381         if (unlikely(path == NULL))
 382             return -1;
 383     }
 384
 385     free (sys->device);
 386     sys->device = path;
 387     aout_DeviceReport (aout, path);
 388     aout_RestartRequest (aout, AOUT_RESTART_OUTPUT);
 389     return 0;
 390 }
 391
 392 static int Open (vlc_object_t *obj)
 393 {
 394     audio_output_t *aout = (audio_output_t *)obj;
 395
 396     aout_sys_t *sys = malloc (sizeof (*sys));
 397     if(unlikely( sys == NULL ))
 398         return VLC_ENOMEM;
 399
 400     sys->fd = -1;
 401     sys->device = var_InheritString (aout, "oss-audio-device");
 402
 403     aout->sys = sys;
 404     aout->start = Start;
 405     aout->stop = Stop;
 406     aout->device_select = DeviceSelect;
 407     aout_DeviceReport (aout, sys->device);
 408     aout_SoftVolumeInit (aout);
 409
 410     DevicesEnum (aout);
 411     return VLC_SUCCESS;
 412 }
 413
 414 static void Close (vlc_object_t *obj)
 415 {
 416     audio_output_t *aout = (audio_output_t *)obj;
 417     aout_sys_t *sys = aout->sys;
 418
 419     free (sys->device);
 420     free (sys);
 421 }