modules/access/oss.c

   1 /*****************************************************************************
   2  * oss.c : OSS input module for vlc
   3  *****************************************************************************
   4  * Copyright (C) 2002-2009 VLC authors and VideoLAN
   5  * $Id$
   6  *
   7  * Authors: Benjamin Pracht <bigben at videolan dot org>
   8  *          Richard Hosking <richard at hovis dot net>
   9  *          Antoine Cellerier <dionoea at videolan d.t org>
  10  *          Dennis Lou <dlou99 at yahoo dot com>
  11  *
  12  * This program is free software; you can redistribute it and/or modify it
  13  * under the terms of the GNU Lesser General Public License as published by
  14  * the Free Software Foundation; either version 2.1 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  20  * GNU Lesser General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU Lesser General Public License
  23  * along with this program; if not, write to the Free Software Foundation,
  24  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  25  *****************************************************************************/
  26
  27 /*****************************************************************************
  28  * Preamble
  29  *****************************************************************************/
  30
  31 #ifdef HAVE_CONFIG_H
  32 # include "config.h"
  33 #endif
  34
  35 #include <vlc_common.h>
  36 #include <vlc_plugin.h>
  37 #include <vlc_access.h>
  38 #include <vlc_demux.h>
  39 #include <vlc_fs.h>
  40
  41 #include <errno.h>
  42 #include <fcntl.h>
  43 #include <unistd.h>
  44 #include <sys/ioctl.h>
  45 #include <sys/mman.h>
  46
  47 #ifdef HAVE_SYS_SOUNDCARD_H
  48 #  include <sys/soundcard.h>
  49 #endif
  50 #ifdef HAVE_SOUNDCARD_H
  51 #  include <soundcard.h>
  52 #endif
  53
  54 #include <poll.h>
  55
  56 /*****************************************************************************
  57  * Module descriptior
  58  *****************************************************************************/
  59
  60 static int  DemuxOpen ( vlc_object_t * );
  61 static void DemuxClose( vlc_object_t * );
  62
  63
  64 #define STEREO_TEXT N_( "Stereo" )
  65 #define STEREO_LONGTEXT N_( \
  66     "Capture the audio stream in stereo." )
  67 #define SAMPLERATE_TEXT N_( "Samplerate" )
  68 #define SAMPLERATE_LONGTEXT N_( \
  69     "Samplerate of the captured audio stream, in Hz (eg: 11025, 22050, 44100, 48000)" )
  70
  71 #define OSS_DEFAULT "/dev/dsp"
  72
  73 #define CFG_PREFIX "oss-"
  74
  75 vlc_module_begin ()
  76     set_shortname( N_("OSS") )
  77     set_description( N_("OSS input") )
  78     set_category( CAT_INPUT )
  79     set_subcategory( SUBCAT_INPUT_ACCESS )
  80
  81     add_shortcut( "oss" )
  82     set_capability( "access_demux", 10 )
  83     set_callbacks( DemuxOpen, DemuxClose )
  84
  85     add_bool( CFG_PREFIX "stereo", true, STEREO_TEXT, STEREO_LONGTEXT,
  86                 true )
  87     add_integer( CFG_PREFIX "samplerate", 48000, SAMPLERATE_TEXT,
  88                 SAMPLERATE_LONGTEXT, true )
  89 vlc_module_end ()
  90
  91 /*****************************************************************************
  92  * Access: local prototypes
  93  *****************************************************************************/
  94
  95 static int DemuxControl( demux_t *, int, va_list );
  96
  97 static int Demux( demux_t * );
  98
  99 static block_t* GrabAudio( demux_t *p_demux );
 100
 101 static int OpenAudioDev( demux_t * );
 102 static int OpenAudioDevOss( demux_t * );
 103 static bool ProbeAudioDevOss( demux_t *, const char *psz_device );
 104
 105 struct buffer_t
 106 {
 107     void *  start;
 108     size_t  length;
 109 };
 110
 111 struct demux_sys_t
 112 {
 113     const char *psz_device;  /* OSS device from MRL */
 114
 115     int  i_fd;
 116
 117     /* Audio */
 118     unsigned int i_sample_rate;
 119     bool b_stereo;
 120     size_t i_max_frame_size;
 121     block_t *p_block;
 122     es_out_id_t *p_es;
 123
 124     int64_t i_next_demux_date; /* Used to handle oss:// as input-slave properly */
 125 };
 126
 127 static int FindMainDevice( demux_t *p_demux )
 128 {
 129     demux_sys_t *p_sys = p_demux->p_sys;
 130
 131     msg_Dbg( p_demux, "opening device '%s'", p_sys->psz_device );
 132     if( ProbeAudioDevOss( p_demux, p_sys->psz_device ) )
 133     {
 134         msg_Dbg( p_demux, "'%s' is an audio device", p_sys->psz_device );
 135         p_sys->i_fd = OpenAudioDev( p_demux );
 136     }
 137
 138     if( p_sys->i_fd < 0 )
 139         return VLC_EGENERIC;
 140     return VLC_SUCCESS;
 141 }
 142
 143 /*****************************************************************************
 144  * DemuxOpen: opens oss device, access_demux callback
 145  *****************************************************************************
 146  *
 147  * url: <oss device>::::
 148  *
 149  *****************************************************************************/
 150 static int DemuxOpen( vlc_object_t *p_this )
 151 {
 152     demux_t     *p_demux = (demux_t*)p_this;
 153     demux_sys_t *p_sys;
 154
 155     /* Set up p_demux */
 156     p_demux->pf_control = DemuxControl;
 157     p_demux->pf_demux = Demux;
 158     p_demux->info.i_update = 0;
 159
 160     p_demux->p_sys = p_sys = vlc_obj_calloc( p_this, 1, sizeof( demux_sys_t ) );
 161     if( p_sys == NULL ) return VLC_ENOMEM;
 162
 163     p_sys->i_sample_rate = var_InheritInteger( p_demux, CFG_PREFIX "samplerate" );
 164     p_sys->b_stereo = var_InheritBool( p_demux, CFG_PREFIX "stereo" );
 165     p_sys->i_fd = -1;
 166     p_sys->p_es = NULL;
 167     p_sys->p_block = NULL;
 168     p_sys->i_next_demux_date = -1;
 169
 170     if( p_demux->psz_location && *p_demux->psz_location )
 171         p_sys->psz_device = p_demux->psz_location;
 172     else
 173         p_sys->psz_device = OSS_DEFAULT;
 174
 175     if( FindMainDevice( p_demux ) != VLC_SUCCESS )
 176     {
 177         DemuxClose( p_this );
 178         return VLC_EGENERIC;
 179     }
 180
 181     return VLC_SUCCESS;
 182 }
 183
 184 /*****************************************************************************
 185  * Close: close device, free resources
 186  *****************************************************************************/
 187 static void DemuxClose( vlc_object_t *p_this )
 188 {
 189     demux_t     *p_demux = (demux_t *)p_this;
 190     demux_sys_t *p_sys   = p_demux->p_sys;
 191
 192     if( p_sys->i_fd >= 0 )
 193         vlc_close( p_sys->i_fd );
 194
 195     if( p_sys->p_block ) block_Release( p_sys->p_block );
 196 }
 197
 198 /*****************************************************************************
 199  * DemuxControl:
 200  *****************************************************************************/
 201 static int DemuxControl( demux_t *p_demux, int i_query, va_list args )
 202 {
 203     demux_sys_t *p_sys = p_demux->p_sys;
 204     bool *pb;
 205     int64_t    *pi64;
 206
 207     switch( i_query )
 208     {
 209         /* Special for access_demux */
 210         case DEMUX_CAN_PAUSE:
 211         case DEMUX_CAN_SEEK:
 212         case DEMUX_CAN_CONTROL_PACE:
 213             pb = va_arg( args, bool * );
 214             *pb = false;
 215             return VLC_SUCCESS;
 216
 217         case DEMUX_GET_PTS_DELAY:
 218             pi64 = va_arg( args, int64_t * );
 219             *pi64 = INT64_C(1000)
 220                   * var_InheritInteger( p_demux, "live-caching" );
 221             return VLC_SUCCESS;
 222
 223         case DEMUX_GET_TIME:
 224             pi64 = va_arg( args, int64_t * );
 225             *pi64 = mdate();
 226             return VLC_SUCCESS;
 227
 228         case DEMUX_SET_NEXT_DEMUX_TIME:
 229             p_sys->i_next_demux_date = va_arg( args, int64_t );
 230             return VLC_SUCCESS;
 231
 232         /* TODO implement others */
 233         default:
 234             return VLC_EGENERIC;
 235     }
 236
 237     return VLC_EGENERIC;
 238 }
 239
 240 /*****************************************************************************
 241  * Demux: Processes the audio frame
 242  *****************************************************************************/
 243 static int Demux( demux_t *p_demux )
 244 {
 245     demux_sys_t *p_sys = p_demux->p_sys;
 246
 247     struct pollfd fd;
 248     fd.fd = p_sys->i_fd;
 249     fd.events = POLLIN|POLLPRI;
 250     fd.revents = 0;
 251
 252     block_t *p_block = NULL;
 253
 254     do
 255     {
 256         if( p_block )
 257         {
 258             es_out_Send( p_demux->out, p_sys->p_es, p_block );
 259             p_block = NULL;
 260         }
 261
 262         /* Wait for data */
 263         if( poll( &fd, 1, 10 ) ) /* Timeout after 0.01 seconds. Bigger delays are an issue when used with/as an input-slave since all the inputs run in the same thread. */
 264         {
 265             if( errno == EINTR )
 266                 continue;
 267             if( fd.revents & (POLLIN|POLLPRI) )
 268             {
 269                 p_block = GrabAudio( p_demux );
 270                 if( p_block )
 271                     es_out_SetPCR( p_demux->out, p_block->i_pts );
 272             }
 273         }
 274     } while( p_block && p_sys->i_next_demux_date > 0 &&
 275              p_block->i_pts < p_sys->i_next_demux_date );
 276
 277     if( p_block )
 278         es_out_Send( p_demux->out, p_sys->p_es, p_block );
 279
 280     return 1;
 281 }
 282
 283 /*****************************************************************************
 284  * GrabAudio: Grab an audio frame
 285  *****************************************************************************/
 286 static block_t* GrabAudio( demux_t *p_demux )
 287 {
 288     demux_sys_t *p_sys = p_demux->p_sys;
 289     struct audio_buf_info buf_info;
 290     int i_read = 0, i_correct;
 291     block_t *p_block;
 292
 293     if( p_sys->p_block ) p_block = p_sys->p_block;
 294     else p_block = block_Alloc( p_sys->i_max_frame_size );
 295
 296     if( !p_block )
 297     {
 298         msg_Warn( p_demux, "cannot get block" );
 299         return NULL;
 300     }
 301
 302     p_sys->p_block = p_block;
 303
 304     i_read = read( p_sys->i_fd, p_block->p_buffer,
 305                 p_sys->i_max_frame_size );
 306
 307     if( i_read <= 0 ) return NULL;
 308
 309     p_block->i_buffer = i_read;
 310     p_sys->p_block = NULL;
 311
 312     /* Correct the date because of kernel buffering */
 313     i_correct = i_read;
 314     if( ioctl( p_sys->i_fd, SNDCTL_DSP_GETISPACE, &buf_info ) == 0 )
 315     {
 316         i_correct += buf_info.bytes;
 317     }
 318
 319     /* Timestamp */
 320     p_block->i_pts = p_block->i_dts =
 321         mdate() - INT64_C(1000000) * (mtime_t)i_correct /
 322         2 / ( p_sys->b_stereo ? 2 : 1) / p_sys->i_sample_rate;
 323
 324     return p_block;
 325 }
 326
 327 /*****************************************************************************
 328  * OpenAudioDev: open and set up the audio device and probe for capabilities
 329  *****************************************************************************/
 330 static int OpenAudioDevOss( demux_t *p_demux )
 331 {
 332     demux_sys_t *p_sys = (demux_sys_t *)p_demux->p_sys;
 333     int i_fd;
 334     int i_format;
 335
 336     i_fd = vlc_open( p_sys->psz_device, O_RDONLY | O_NONBLOCK );
 337
 338     if( i_fd < 0 )
 339     {
 340         msg_Err( p_demux, "cannot open OSS audio device (%s)",
 341                  vlc_strerror_c(errno) );
 342         goto adev_fail;
 343     }
 344
 345     i_format = AFMT_S16_LE;
 346     if( ioctl( i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0
 347         || i_format != AFMT_S16_LE )
 348     {
 349         msg_Err( p_demux,
 350                  "cannot set audio format (16b little endian) (%s)",
 351                  vlc_strerror_c(errno) );
 352         goto adev_fail;
 353     }
 354
 355     if( ioctl( i_fd, SNDCTL_DSP_STEREO, &p_sys->b_stereo ) < 0 )
 356     {
 357         msg_Err( p_demux, "cannot set audio channels count (%s)",
 358                  vlc_strerror_c(errno) );
 359         goto adev_fail;
 360     }
 361
 362     if( ioctl( i_fd, SNDCTL_DSP_SPEED, &p_sys->i_sample_rate ) < 0 )
 363     {
 364         msg_Err( p_demux, "cannot set audio sample rate (%s)",
 365                  vlc_strerror_c(errno) );
 366         goto adev_fail;
 367     }
 368
 369     p_sys->i_max_frame_size = 6 * 1024;
 370
 371     return i_fd;
 372
 373  adev_fail:
 374
 375     if( i_fd >= 0 )
 376         vlc_close( i_fd );
 377     return -1;
 378 }
 379
 380 static int OpenAudioDev( demux_t *p_demux )
 381 {
 382     demux_sys_t *p_sys = p_demux->p_sys;
 383     int i_fd = OpenAudioDevOss( p_demux );
 384
 385     if( i_fd < 0 )
 386         return i_fd;
 387
 388     msg_Dbg( p_demux, "opened adev=`%s' %s %dHz",
 389              p_sys->psz_device, p_sys->b_stereo ? "stereo" : "mono",
 390              p_sys->i_sample_rate );
 391
 392     es_format_t fmt;
 393     es_format_Init( &fmt, AUDIO_ES, VLC_CODEC_S16L );
 394
 395     fmt.audio.i_channels = p_sys->b_stereo ? 2 : 1;
 396     fmt.audio.i_rate = p_sys->i_sample_rate;
 397     fmt.audio.i_bitspersample = 16;
 398     fmt.audio.i_blockalign = fmt.audio.i_channels * fmt.audio.i_bitspersample / 8;
 399     fmt.i_bitrate = fmt.audio.i_channels * fmt.audio.i_rate * fmt.audio.i_bitspersample;
 400
 401     msg_Dbg( p_demux, "new audio es %d channels %dHz",
 402              fmt.audio.i_channels, fmt.audio.i_rate );
 403
 404     p_sys->p_es = es_out_Add( p_demux->out, &fmt );
 405
 406     return i_fd;
 407 }
 408
 409 /*****************************************************************************
 410  * ProbeAudioDev: probe audio for capabilities
 411  *****************************************************************************/
 412 static bool ProbeAudioDevOss( demux_t *p_demux, const char *psz_device )
 413 {
 414     int i_caps;
 415     int i_fd = vlc_open( psz_device, O_RDONLY | O_NONBLOCK );
 416
 417     if( i_fd < 0 )
 418     {
 419         msg_Err( p_demux, "cannot open device %s for OSS audio (%s)",
 420                  psz_device, vlc_strerror_c(errno) );
 421         goto open_failed;
 422     }
 423
 424     /* this will fail if the device is video */
 425     if( ioctl( i_fd, SNDCTL_DSP_GETCAPS, &i_caps ) < 0 )
 426     {
 427         msg_Err( p_demux, "cannot get audio caps (%s)",
 428                  vlc_strerror_c(errno) );
 429         goto open_failed;
 430     }
 431
 432     if( i_fd >= 0 )
 433         vlc_close( i_fd );
 434
 435     return true;
 436
 437 open_failed:
 438     if( i_fd >= 0 )
 439         vlc_close( i_fd );
 440     return false;
 441 }