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     msg_Dbg( p_demux, "opening device '%s'", p_demux->p_sys->psz_device );
 130     if( ProbeAudioDevOss( p_demux, p_demux->p_sys->psz_device ) )
 131     {
 132         msg_Dbg( p_demux, "'%s' is an audio device", p_demux->p_sys->psz_device );
 133         p_demux->p_sys->i_fd = OpenAudioDev( p_demux );
 134     }
 135
 136     if( p_demux->p_sys->i_fd < 0 )
 137         return VLC_EGENERIC;
 138     return VLC_SUCCESS;
 139 }
 140
 141 /*****************************************************************************
 142  * DemuxOpen: opens oss device, access_demux callback
 143  *****************************************************************************
 144  *
 145  * url: <oss device>::::
 146  *
 147  *****************************************************************************/
 148 static int DemuxOpen( vlc_object_t *p_this )
 149 {
 150     demux_t     *p_demux = (demux_t*)p_this;
 151     demux_sys_t *p_sys;
 152
 153     /* Only when selected */
 154     if( *p_demux->psz_access == '\0' ) return VLC_EGENERIC;
 155
 156     /* Set up p_demux */
 157     p_demux->pf_control = DemuxControl;
 158     p_demux->pf_demux = Demux;
 159     p_demux->info.i_update = 0;
 160     p_demux->info.i_title = 0;
 161     p_demux->info.i_seekpoint = 0;
 162
 163     p_demux->p_sys = p_sys = vlc_obj_calloc( p_this, 1, sizeof( demux_sys_t ) );
 164     if( p_sys == NULL ) return VLC_ENOMEM;
 165
 166     p_sys->i_sample_rate = var_InheritInteger( p_demux, CFG_PREFIX "samplerate" );
 167     p_sys->b_stereo = var_InheritBool( p_demux, CFG_PREFIX "stereo" );
 168     p_sys->i_fd = -1;
 169     p_sys->p_es = NULL;
 170     p_sys->p_block = NULL;
 171     p_sys->i_next_demux_date = -1;
 172
 173     if( p_demux->psz_location && *p_demux->psz_location )
 174         p_sys->psz_device = p_demux->psz_location;
 175     else
 176         p_sys->psz_device = OSS_DEFAULT;
 177
 178     if( FindMainDevice( p_demux ) != VLC_SUCCESS )
 179     {
 180         DemuxClose( p_this );
 181         return VLC_EGENERIC;
 182     }
 183
 184     return VLC_SUCCESS;
 185 }
 186
 187 /*****************************************************************************
 188  * Close: close device, free resources
 189  *****************************************************************************/
 190 static void DemuxClose( vlc_object_t *p_this )
 191 {
 192     demux_t     *p_demux = (demux_t *)p_this;
 193     demux_sys_t *p_sys   = p_demux->p_sys;
 194
 195     if( p_sys->i_fd >= 0 )
 196         vlc_close( p_sys->i_fd );
 197
 198     if( p_sys->p_block ) block_Release( p_sys->p_block );
 199 }
 200
 201 /*****************************************************************************
 202  * DemuxControl:
 203  *****************************************************************************/
 204 static int DemuxControl( demux_t *p_demux, int i_query, va_list args )
 205 {
 206     demux_sys_t *p_sys = p_demux->p_sys;
 207     bool *pb;
 208     int64_t    *pi64;
 209
 210     switch( i_query )
 211     {
 212         /* Special for access_demux */
 213         case DEMUX_CAN_PAUSE:
 214         case DEMUX_CAN_SEEK:
 215         case DEMUX_CAN_CONTROL_PACE:
 216             pb = va_arg( args, bool * );
 217             *pb = false;
 218             return VLC_SUCCESS;
 219
 220         case DEMUX_GET_PTS_DELAY:
 221             pi64 = va_arg( args, int64_t * );
 222             *pi64 = INT64_C(1000)
 223                   * var_InheritInteger( p_demux, "live-caching" );
 224             return VLC_SUCCESS;
 225
 226         case DEMUX_GET_TIME:
 227             pi64 = va_arg( args, int64_t * );
 228             *pi64 = mdate();
 229             return VLC_SUCCESS;
 230
 231         case DEMUX_SET_NEXT_DEMUX_TIME:
 232             p_sys->i_next_demux_date = va_arg( args, int64_t );
 233             return VLC_SUCCESS;
 234
 235         /* TODO implement others */
 236         default:
 237             return VLC_EGENERIC;
 238     }
 239
 240     return VLC_EGENERIC;
 241 }
 242
 243 /*****************************************************************************
 244  * Demux: Processes the audio frame
 245  *****************************************************************************/
 246 static int Demux( demux_t *p_demux )
 247 {
 248     demux_sys_t *p_sys = p_demux->p_sys;
 249
 250     struct pollfd fd;
 251     fd.fd = p_sys->i_fd;
 252     fd.events = POLLIN|POLLPRI;
 253     fd.revents = 0;
 254
 255     block_t *p_block = NULL;
 256
 257     do
 258     {
 259         if( p_block )
 260         {
 261             es_out_Send( p_demux->out, p_sys->p_es, p_block );
 262             p_block = NULL;
 263         }
 264
 265         /* Wait for data */
 266         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. */
 267         {
 268             if( errno == EINTR )
 269                 continue;
 270             if( fd.revents & (POLLIN|POLLPRI) )
 271             {
 272                 p_block = GrabAudio( p_demux );
 273                 if( p_block )
 274                     es_out_SetPCR( p_demux->out, p_block->i_pts );
 275             }
 276         }
 277     } while( p_block && p_sys->i_next_demux_date > 0 &&
 278              p_block->i_pts < p_sys->i_next_demux_date );
 279
 280     if( p_block )
 281         es_out_Send( p_demux->out, p_sys->p_es, p_block );
 282
 283     return 1;
 284 }
 285
 286 /*****************************************************************************
 287  * GrabAudio: Grab an audio frame
 288  *****************************************************************************/
 289 static block_t* GrabAudio( demux_t *p_demux )
 290 {
 291     demux_sys_t *p_sys = p_demux->p_sys;
 292     struct audio_buf_info buf_info;
 293     int i_read = 0, i_correct;
 294     block_t *p_block;
 295
 296     if( p_sys->p_block ) p_block = p_sys->p_block;
 297     else p_block = block_Alloc( p_sys->i_max_frame_size );
 298
 299     if( !p_block )
 300     {
 301         msg_Warn( p_demux, "cannot get block" );
 302         return NULL;
 303     }
 304
 305     p_sys->p_block = p_block;
 306
 307     i_read = read( p_sys->i_fd, p_block->p_buffer,
 308                 p_sys->i_max_frame_size );
 309
 310     if( i_read <= 0 ) return NULL;
 311
 312     p_block->i_buffer = i_read;
 313     p_sys->p_block = NULL;
 314
 315     /* Correct the date because of kernel buffering */
 316     i_correct = i_read;
 317     if( ioctl( p_sys->i_fd, SNDCTL_DSP_GETISPACE, &buf_info ) == 0 )
 318     {
 319         i_correct += buf_info.bytes;
 320     }
 321
 322     /* Timestamp */
 323     p_block->i_pts = p_block->i_dts =
 324         mdate() - INT64_C(1000000) * (mtime_t)i_correct /
 325         2 / ( p_sys->b_stereo ? 2 : 1) / p_sys->i_sample_rate;
 326
 327     return p_block;
 328 }
 329
 330 /*****************************************************************************
 331  * OpenAudioDev: open and set up the audio device and probe for capabilities
 332  *****************************************************************************/
 333 static int OpenAudioDevOss( demux_t *p_demux )
 334 {
 335     int i_fd;
 336     int i_format;
 337
 338     i_fd = vlc_open( p_demux->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,
 358                &p_demux->p_sys->b_stereo ) < 0 )
 359     {
 360         msg_Err( p_demux, "cannot set audio channels count (%s)",
 361                  vlc_strerror_c(errno) );
 362         goto adev_fail;
 363     }
 364
 365     if( ioctl( i_fd, SNDCTL_DSP_SPEED,
 366                &p_demux->p_sys->i_sample_rate ) < 0 )
 367     {
 368         msg_Err( p_demux, "cannot set audio sample rate (%s)",
 369                  vlc_strerror_c(errno) );
 370         goto adev_fail;
 371     }
 372
 373     p_demux->p_sys->i_max_frame_size = 6 * 1024;
 374
 375     return i_fd;
 376
 377  adev_fail:
 378
 379     if( i_fd >= 0 )
 380         vlc_close( i_fd );
 381     return -1;
 382 }
 383
 384 static int OpenAudioDev( demux_t *p_demux )
 385 {
 386     demux_sys_t *p_sys = p_demux->p_sys;
 387     int i_fd = OpenAudioDevOss( p_demux );
 388
 389     if( i_fd < 0 )
 390         return i_fd;
 391
 392     msg_Dbg( p_demux, "opened adev=`%s' %s %dHz",
 393              p_sys->psz_device, p_sys->b_stereo ? "stereo" : "mono",
 394              p_sys->i_sample_rate );
 395
 396     es_format_t fmt;
 397     es_format_Init( &fmt, AUDIO_ES, VLC_CODEC_S16L );
 398
 399     fmt.audio.i_channels = p_sys->b_stereo ? 2 : 1;
 400     fmt.audio.i_rate = p_sys->i_sample_rate;
 401     fmt.audio.i_bitspersample = 16;
 402     fmt.audio.i_blockalign = fmt.audio.i_channels * fmt.audio.i_bitspersample / 8;
 403     fmt.i_bitrate = fmt.audio.i_channels * fmt.audio.i_rate * fmt.audio.i_bitspersample;
 404
 405     msg_Dbg( p_demux, "new audio es %d channels %dHz",
 406              fmt.audio.i_channels, fmt.audio.i_rate );
 407
 408     p_sys->p_es = es_out_Add( p_demux->out, &fmt );
 409
 410     return i_fd;
 411 }
 412
 413 /*****************************************************************************
 414  * ProbeAudioDev: probe audio for capabilities
 415  *****************************************************************************/
 416 static bool ProbeAudioDevOss( demux_t *p_demux, const char *psz_device )
 417 {
 418     int i_caps;
 419     int i_fd = vlc_open( psz_device, O_RDONLY | O_NONBLOCK );
 420
 421     if( i_fd < 0 )
 422     {
 423         msg_Err( p_demux, "cannot open device %s for OSS audio (%s)",
 424                  psz_device, vlc_strerror_c(errno) );
 425         goto open_failed;
 426     }
 427
 428     /* this will fail if the device is video */
 429     if( ioctl( i_fd, SNDCTL_DSP_GETCAPS, &i_caps ) < 0 )
 430     {
 431         msg_Err( p_demux, "cannot get audio caps (%s)",
 432                  vlc_strerror_c(errno) );
 433         goto open_failed;
 434     }
 435
 436     if( i_fd >= 0 )
 437         vlc_close( i_fd );
 438
 439     return true;
 440
 441 open_failed:
 442     if( i_fd >= 0 )
 443         vlc_close( i_fd );
 444     return false;
 445 }