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", 0 )
  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 typedef struct
 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 } demux_sys_t;
 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     if (p_demux->out == NULL)
 156         return VLC_EGENERIC;
 157
 158     /* Set up p_demux */
 159     p_demux->pf_control = DemuxControl;
 160     p_demux->pf_demux = Demux;
 161
 162     p_demux->p_sys = p_sys = vlc_obj_calloc( p_this, 1, sizeof( demux_sys_t ) );
 163     if( p_sys == NULL ) return VLC_ENOMEM;
 164
 165     p_sys->i_sample_rate = var_InheritInteger( p_demux, CFG_PREFIX "samplerate" );
 166     p_sys->b_stereo = var_InheritBool( p_demux, CFG_PREFIX "stereo" );
 167     p_sys->i_fd = -1;
 168     p_sys->p_es = NULL;
 169     p_sys->p_block = NULL;
 170     p_sys->i_next_demux_date = -1;
 171
 172     if( p_demux->psz_location && *p_demux->psz_location )
 173         p_sys->psz_device = p_demux->psz_location;
 174     else
 175         p_sys->psz_device = OSS_DEFAULT;
 176
 177     if( FindMainDevice( p_demux ) != VLC_SUCCESS )
 178     {
 179         DemuxClose( p_this );
 180         return VLC_EGENERIC;
 181     }
 182
 183     return VLC_SUCCESS;
 184 }
 185
 186 /*****************************************************************************
 187  * Close: close device, free resources
 188  *****************************************************************************/
 189 static void DemuxClose( vlc_object_t *p_this )
 190 {
 191     demux_t     *p_demux = (demux_t *)p_this;
 192     demux_sys_t *p_sys   = p_demux->p_sys;
 193
 194     if( p_sys->i_fd >= 0 )
 195         vlc_close( p_sys->i_fd );
 196
 197     if( p_sys->p_block ) block_Release( p_sys->p_block );
 198 }
 199
 200 /*****************************************************************************
 201  * DemuxControl:
 202  *****************************************************************************/
 203 static int DemuxControl( demux_t *p_demux, int i_query, va_list args )
 204 {
 205     demux_sys_t *p_sys = p_demux->p_sys;
 206     bool *pb;
 207     int64_t    *pi64;
 208
 209     switch( i_query )
 210     {
 211         /* Special for access_demux */
 212         case DEMUX_CAN_PAUSE:
 213         case DEMUX_CAN_SEEK:
 214         case DEMUX_CAN_CONTROL_PACE:
 215             pb = va_arg( args, bool * );
 216             *pb = false;
 217             return VLC_SUCCESS;
 218
 219         case DEMUX_GET_PTS_DELAY:
 220             pi64 = va_arg( args, int64_t * );
 221             *pi64 = INT64_C(1000)
 222                   * var_InheritInteger( p_demux, "live-caching" );
 223             return VLC_SUCCESS;
 224
 225         case DEMUX_GET_TIME:
 226             pi64 = va_arg( args, int64_t * );
 227             *pi64 = mdate();
 228             return VLC_SUCCESS;
 229
 230         case DEMUX_SET_NEXT_DEMUX_TIME:
 231             p_sys->i_next_demux_date = va_arg( args, int64_t );
 232             return VLC_SUCCESS;
 233
 234         /* TODO implement others */
 235         default:
 236             return VLC_EGENERIC;
 237     }
 238
 239     return VLC_EGENERIC;
 240 }
 241
 242 /*****************************************************************************
 243  * Demux: Processes the audio frame
 244  *****************************************************************************/
 245 static int Demux( demux_t *p_demux )
 246 {
 247     demux_sys_t *p_sys = p_demux->p_sys;
 248
 249     struct pollfd fd;
 250     fd.fd = p_sys->i_fd;
 251     fd.events = POLLIN|POLLPRI;
 252     fd.revents = 0;
 253
 254     block_t *p_block = NULL;
 255
 256     do
 257     {
 258         if( p_block )
 259         {
 260             es_out_Send( p_demux->out, p_sys->p_es, p_block );
 261             p_block = NULL;
 262         }
 263
 264         /* Wait for data */
 265         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. */
 266         {
 267             if( errno == EINTR )
 268                 continue;
 269             if( fd.revents & (POLLIN|POLLPRI) )
 270             {
 271                 p_block = GrabAudio( p_demux );
 272                 if( p_block )
 273                     es_out_SetPCR( p_demux->out, p_block->i_pts );
 274             }
 275         }
 276     } while( p_block && p_sys->i_next_demux_date > 0 &&
 277              p_block->i_pts < p_sys->i_next_demux_date );
 278
 279     if( p_block )
 280         es_out_Send( p_demux->out, p_sys->p_es, p_block );
 281
 282     return 1;
 283 }
 284
 285 /*****************************************************************************
 286  * GrabAudio: Grab an audio frame
 287  *****************************************************************************/
 288 static block_t* GrabAudio( demux_t *p_demux )
 289 {
 290     demux_sys_t *p_sys = p_demux->p_sys;
 291     struct audio_buf_info buf_info;
 292     int i_read = 0, i_correct;
 293     block_t *p_block;
 294
 295     if( p_sys->p_block ) p_block = p_sys->p_block;
 296     else p_block = block_Alloc( p_sys->i_max_frame_size );
 297
 298     if( !p_block )
 299     {
 300         msg_Warn( p_demux, "cannot get block" );
 301         return NULL;
 302     }
 303
 304     p_sys->p_block = p_block;
 305
 306     i_read = read( p_sys->i_fd, p_block->p_buffer,
 307                 p_sys->i_max_frame_size );
 308
 309     if( i_read <= 0 ) return NULL;
 310
 311     p_block->i_buffer = i_read;
 312     p_sys->p_block = NULL;
 313
 314     /* Correct the date because of kernel buffering */
 315     i_correct = i_read;
 316     if( ioctl( p_sys->i_fd, SNDCTL_DSP_GETISPACE, &buf_info ) == 0 )
 317     {
 318         i_correct += buf_info.bytes;
 319     }
 320
 321     /* Timestamp */
 322     p_block->i_pts = p_block->i_dts =
 323         mdate() - CLOCK_FREQ * (mtime_t)i_correct /
 324         2 / ( p_sys->b_stereo ? 2 : 1) / p_sys->i_sample_rate;
 325
 326     return p_block;
 327 }
 328
 329 /*****************************************************************************
 330  * OpenAudioDev: open and set up the audio device and probe for capabilities
 331  *****************************************************************************/
 332 static int OpenAudioDevOss( demux_t *p_demux )
 333 {
 334     demux_sys_t *p_sys = (demux_sys_t *)p_demux->p_sys;
 335     int i_fd;
 336     int i_format;
 337
 338     i_fd = vlc_open( p_sys->psz_device, O_RDONLY | O_NONBLOCK );
 339
 340     if( i_fd < 0 )
 341     {
 342         msg_Err( p_demux, "cannot open OSS audio device (%s)",
 343                  vlc_strerror_c(errno) );
 344         goto adev_fail;
 345     }
 346
 347     i_format = AFMT_S16_LE;
 348     if( ioctl( i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0
 349         || i_format != AFMT_S16_LE )
 350     {
 351         msg_Err( p_demux,
 352                  "cannot set audio format (16b little endian) (%s)",
 353                  vlc_strerror_c(errno) );
 354         goto adev_fail;
 355     }
 356
 357     if( ioctl( i_fd, SNDCTL_DSP_STEREO, &p_sys->b_stereo ) < 0 )
 358     {
 359         msg_Err( p_demux, "cannot set audio channels count (%s)",
 360                  vlc_strerror_c(errno) );
 361         goto adev_fail;
 362     }
 363
 364     if( ioctl( i_fd, SNDCTL_DSP_SPEED, &p_sys->i_sample_rate ) < 0 )
 365     {
 366         msg_Err( p_demux, "cannot set audio sample rate (%s)",
 367                  vlc_strerror_c(errno) );
 368         goto adev_fail;
 369     }
 370
 371     p_sys->i_max_frame_size = 6 * 1024;
 372
 373     return i_fd;
 374
 375  adev_fail:
 376
 377     if( i_fd >= 0 )
 378         vlc_close( i_fd );
 379     return -1;
 380 }
 381
 382 static int OpenAudioDev( demux_t *p_demux )
 383 {
 384     demux_sys_t *p_sys = p_demux->p_sys;
 385     int i_fd = OpenAudioDevOss( p_demux );
 386
 387     if( i_fd < 0 )
 388         return i_fd;
 389
 390     msg_Dbg( p_demux, "opened adev=`%s' %s %dHz",
 391              p_sys->psz_device, p_sys->b_stereo ? "stereo" : "mono",
 392              p_sys->i_sample_rate );
 393
 394     es_format_t fmt;
 395     es_format_Init( &fmt, AUDIO_ES, VLC_CODEC_S16L );
 396
 397     fmt.audio.i_channels = p_sys->b_stereo ? 2 : 1;
 398     fmt.audio.i_rate = p_sys->i_sample_rate;
 399     fmt.audio.i_bitspersample = 16;
 400     fmt.audio.i_blockalign = fmt.audio.i_channels * fmt.audio.i_bitspersample / 8;
 401     fmt.i_bitrate = fmt.audio.i_channels * fmt.audio.i_rate * fmt.audio.i_bitspersample;
 402
 403     msg_Dbg( p_demux, "new audio es %d channels %dHz",
 404              fmt.audio.i_channels, fmt.audio.i_rate );
 405
 406     p_sys->p_es = es_out_Add( p_demux->out, &fmt );
 407
 408     return i_fd;
 409 }
 410
 411 /*****************************************************************************
 412  * ProbeAudioDev: probe audio for capabilities
 413  *****************************************************************************/
 414 static bool ProbeAudioDevOss( demux_t *p_demux, const char *psz_device )
 415 {
 416     int i_caps;
 417     int i_fd = vlc_open( psz_device, O_RDONLY | O_NONBLOCK );
 418
 419     if( i_fd < 0 )
 420     {
 421         msg_Err( p_demux, "cannot open device %s for OSS audio (%s)",
 422                  psz_device, vlc_strerror_c(errno) );
 423         goto open_failed;
 424     }
 425
 426     /* this will fail if the device is video */
 427     if( ioctl( i_fd, SNDCTL_DSP_GETCAPS, &i_caps ) < 0 )
 428     {
 429         msg_Err( p_demux, "cannot get audio caps (%s)",
 430                  vlc_strerror_c(errno) );
 431         goto open_failed;
 432     }
 433
 434     if( i_fd >= 0 )
 435         vlc_close( i_fd );
 436
 437     return true;
 438
 439 open_failed:
 440     if( i_fd >= 0 )
 441         vlc_close( i_fd );
 442     return false;
 443 }