modules/access/oss.c

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