git.sesse.net Git - vlc/blob - modules/audio_filter/channel_mixer/headphone.c

   1 /*****************************************************************************
   2  * headphone.c : headphone virtual spatialization channel mixer module
   3  *               -> gives the feeling of a real room with a simple headphone
   4  *****************************************************************************
   5  * Copyright (C) 2002-2006 the VideoLAN team
   6  * $Id$
   7  *
   8  * Authors: Boris Dorès <babal@via.ecp.fr>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  23  *****************************************************************************/
  24
  25 /*****************************************************************************
  26  * Preamble
  27  *****************************************************************************/
  28 #include <stdlib.h>                                      /* malloc(), free() */
  29 #include <string.h>
  30 #include <math.h>                                        /* sqrt */
  31
  32 #include <vlc/vlc.h>
  33 #include <vlc_aout.h>
  34 #include <vlc_filter.h>
  35 #include <vlc_block.h>
  36
  37 /*****************************************************************************
  38  * Local prototypes
  39  *****************************************************************************/
  40 static int  Create    ( vlc_object_t * );
  41 static void Destroy   ( vlc_object_t * );
  42
  43 static void DoWork    ( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
  44                         aout_buffer_t * );
  45
  46 /* Audio filter2 */
  47 static int  OpenFilter ( vlc_object_t * );
  48 static void CloseFilter( vlc_object_t * );
  49 static block_t *Convert( filter_t *, block_t * );
  50
  51 /*****************************************************************************
  52  * Module descriptor
  53  *****************************************************************************/
  54 #define MODULE_DESCRIPTION N_ ( \
  55      "This effect gives you the feeling that you are standing in a room " \
  56      "with a complete 7.1 speaker set when using only a headphone, " \
  57      "providing a more realistic sound experience. It should also be " \
  58      "more comfortable and less tiring when listening to music for " \
  59      "long periods of time.\nIt works with any source format from mono " \
  60      "to 7.1.")
  61
  62 #define HEADPHONE_DIM_TEXT N_("Characteristic dimension")
  63 #define HEADPHONE_DIM_LONGTEXT N_( \
  64      "Distance between front left speaker and listener in meters.")
  65
  66 #define HEADPHONE_COMPENSATE_TEXT N_("Compensate delay")
  67 #define HEADPHONE_COMPENSATE_LONGTEXT N_( \
  68      "The delay which is introduced by the physical algorithm may "\
  69      "sometimes be disturbing for the synchronization between lips-movement "\
  70      "and speech. In case, turn this on to compensate.")
  71
  72 #define HEADPHONE_DOLBY_TEXT N_("No decoding of Dolby Surround")
  73 #define HEADPHONE_DOLBY_LONGTEXT N_( \
  74      "Dolby Surround encoded streams won't be decoded before being " \
  75      "processed by this filter. Enabling this setting is not recommended.")
  76
  77 vlc_module_begin();
  78     set_description( _("Headphone virtual spatialization effect") );
  79     set_shortname( _("Headphone effect") );
  80     set_help( MODULE_DESCRIPTION );
  81     set_category( CAT_AUDIO );
  82     set_subcategory( SUBCAT_AUDIO_AFILTER );
  83
  84     add_integer( "headphone-dim", 10, NULL, HEADPHONE_DIM_TEXT,
  85                  HEADPHONE_DIM_LONGTEXT, VLC_FALSE );
  86     add_bool( "headphone-compensate", 0, NULL, HEADPHONE_COMPENSATE_TEXT,
  87               HEADPHONE_COMPENSATE_LONGTEXT, VLC_TRUE );
  88     add_bool( "headphone-dolby", 0, NULL, HEADPHONE_DOLBY_TEXT,
  89               HEADPHONE_DOLBY_LONGTEXT, VLC_TRUE );
  90
  91     set_capability( "audio filter", 0 );
  92     set_callbacks( Create, Destroy );
  93     add_shortcut( "headphone" );
  94
  95     /* Audio filter 2 */
  96     add_submodule();
  97     set_description( _("Headphone virtual spatialization effect") );
  98     set_capability( "audio filter2", 0 );
  99     set_callbacks( OpenFilter, CloseFilter );
 100 vlc_module_end();
 101
 102
 103 /*****************************************************************************
 104  * Internal data structures
 105  *****************************************************************************/
 106 struct atomic_operation_t
 107 {
 108     int i_source_channel_offset;
 109     int i_dest_channel_offset;
 110     unsigned int i_delay;/* in sample unit */
 111     double d_amplitude_factor;
 112 };
 113
 114 struct aout_filter_sys_t
 115 {
 116     size_t i_overflow_buffer_size;/* in bytes */
 117     byte_t * p_overflow_buffer;
 118     unsigned int i_nb_atomic_operations;
 119     struct atomic_operation_t * p_atomic_operations;
 120 };
 121
 122 struct filter_sys_t
 123 {
 124     size_t i_overflow_buffer_size;/* in bytes */
 125     byte_t * p_overflow_buffer;
 126     unsigned int i_nb_atomic_operations;
 127     struct atomic_operation_t * p_atomic_operations;
 128 };
 129
 130 /*****************************************************************************
 131  * Init: initialize internal data structures
 132  * and computes the needed atomic operations
 133  *****************************************************************************/
 134 /* x and z represent the coordinates of the virtual speaker
 135  *  relatively to the center of the listener's head, measured in meters :
 136  *
 137  *  left              right
 138  *Z
 139  *-
 140  *a          head
 141  *x
 142  *i
 143  *s
 144  *  rear left    rear right
 145  *
 146  *          x-axis
 147  *  */
 148 static void ComputeChannelOperations( struct aout_filter_sys_t * p_data
 149         , unsigned int i_rate, unsigned int i_next_atomic_operation
 150         , int i_source_channel_offset, double d_x, double d_z
 151         , double d_compensation_length, double d_channel_amplitude_factor )
 152 {
 153     double d_c = 340; /*sound celerity (unit: m/s)*/
 154     double d_compensation_delay = (d_compensation_length-0.1) / d_c * i_rate;
 155
 156     /* Left ear */
 157     p_data->p_atomic_operations[i_next_atomic_operation]
 158         .i_source_channel_offset = i_source_channel_offset;
 159     p_data->p_atomic_operations[i_next_atomic_operation]
 160         .i_dest_channel_offset = 0;/* left */
 161     p_data->p_atomic_operations[i_next_atomic_operation]
 162         .i_delay = (int)( sqrt( (-0.1-d_x)*(-0.1-d_x) + (0-d_z)*(0-d_z) )
 163                           / d_c * i_rate - d_compensation_delay );
 164     if( d_x < 0 )
 165     {
 166         p_data->p_atomic_operations[i_next_atomic_operation]
 167             .d_amplitude_factor = d_channel_amplitude_factor * 1.1 / 2;
 168     }
 169     else if( d_x > 0 )
 170     {
 171         p_data->p_atomic_operations[i_next_atomic_operation]
 172             .d_amplitude_factor = d_channel_amplitude_factor * 0.9 / 2;
 173     }
 174     else
 175     {
 176         p_data->p_atomic_operations[i_next_atomic_operation]
 177             .d_amplitude_factor = d_channel_amplitude_factor / 2;
 178     }
 179
 180     /* Right ear */
 181     p_data->p_atomic_operations[i_next_atomic_operation + 1]
 182         .i_source_channel_offset = i_source_channel_offset;
 183     p_data->p_atomic_operations[i_next_atomic_operation + 1]
 184         .i_dest_channel_offset = 1;/* right */
 185     p_data->p_atomic_operations[i_next_atomic_operation + 1]
 186         .i_delay = (int)( sqrt( (0.1-d_x)*(0.1-d_x) + (0-d_z)*(0-d_z) )
 187                           / d_c * i_rate - d_compensation_delay );
 188     if( d_x < 0 )
 189     {
 190         p_data->p_atomic_operations[i_next_atomic_operation + 1]
 191             .d_amplitude_factor = d_channel_amplitude_factor * 0.9 / 2;
 192     }
 193     else if( d_x > 0 )
 194     {
 195         p_data->p_atomic_operations[i_next_atomic_operation + 1]
 196             .d_amplitude_factor = d_channel_amplitude_factor * 1.1 / 2;
 197     }
 198     else
 199     {
 200         p_data->p_atomic_operations[i_next_atomic_operation + 1]
 201             .d_amplitude_factor = d_channel_amplitude_factor / 2;
 202     }
 203 }
 204
 205 static int Init( vlc_object_t *p_this, struct aout_filter_sys_t * p_data
 206         , unsigned int i_nb_channels, uint32_t i_physical_channels
 207         , unsigned int i_rate )
 208 {
 209     double d_x = config_GetInt( p_this, "headphone-dim" );
 210     double d_z = d_x;
 211     double d_z_rear = -d_x/3;
 212     double d_min = 0;
 213     unsigned int i_next_atomic_operation;
 214     int i_source_channel_offset;
 215     unsigned int i;
 216
 217     if( p_data == NULL )
 218     {
 219         msg_Dbg( p_this, "passing a null pointer as argument" );
 220         return 0;
 221     }
 222
 223     if( config_GetInt( p_this, "headphone-compensate" ) )
 224     {
 225         /* minimal distance to any speaker */
 226         if( i_physical_channels & AOUT_CHAN_REARCENTER )
 227         {
 228             d_min = d_z_rear;
 229         }
 230         else
 231         {
 232             d_min = d_z;
 233         }
 234     }
 235
 236     /* Number of elementary operations */
 237     p_data->i_nb_atomic_operations = i_nb_channels * 2;
 238     if( i_physical_channels & AOUT_CHAN_CENTER )
 239     {
 240         p_data->i_nb_atomic_operations += 2;
 241     }
 242     p_data->p_atomic_operations = malloc( sizeof(struct atomic_operation_t)
 243             * p_data->i_nb_atomic_operations );
 244     if( p_data->p_atomic_operations == NULL )
 245     {
 246         msg_Err( p_this, "out of memory" );
 247         return -1;
 248     }
 249
 250     /* For each virtual speaker, computes elementary wave propagation time
 251      * to each ear */
 252     i_next_atomic_operation = 0;
 253     i_source_channel_offset = 0;
 254     if( i_physical_channels & AOUT_CHAN_LEFT )
 255     {
 256         ComputeChannelOperations( p_data , i_rate
 257                 , i_next_atomic_operation , i_source_channel_offset
 258                 , -d_x , d_z , d_min , 2.0 / i_nb_channels );
 259         i_next_atomic_operation += 2;
 260         i_source_channel_offset++;
 261     }
 262     if( i_physical_channels & AOUT_CHAN_RIGHT )
 263     {
 264         ComputeChannelOperations( p_data , i_rate
 265                 , i_next_atomic_operation , i_source_channel_offset
 266                 , d_x , d_z , d_min , 2.0 / i_nb_channels );
 267         i_next_atomic_operation += 2;
 268         i_source_channel_offset++;
 269     }
 270     if( i_physical_channels & AOUT_CHAN_MIDDLELEFT )
 271     {
 272         ComputeChannelOperations( p_data , i_rate
 273                 , i_next_atomic_operation , i_source_channel_offset
 274                 , -d_x , 0 , d_min , 1.5 / i_nb_channels );
 275         i_next_atomic_operation += 2;
 276         i_source_channel_offset++;
 277     }
 278     if( i_physical_channels & AOUT_CHAN_MIDDLERIGHT )
 279     {
 280         ComputeChannelOperations( p_data , i_rate
 281                 , i_next_atomic_operation , i_source_channel_offset
 282                 , d_x , 0 , d_min , 1.5 / i_nb_channels );
 283         i_next_atomic_operation += 2;
 284         i_source_channel_offset++;
 285     }
 286     if( i_physical_channels & AOUT_CHAN_REARLEFT )
 287     {
 288         ComputeChannelOperations( p_data , i_rate
 289                 , i_next_atomic_operation , i_source_channel_offset
 290                 , -d_x , d_z_rear , d_min , 1.5 / i_nb_channels );
 291         i_next_atomic_operation += 2;
 292         i_source_channel_offset++;
 293     }
 294     if( i_physical_channels & AOUT_CHAN_REARRIGHT )
 295     {
 296         ComputeChannelOperations( p_data , i_rate
 297                 , i_next_atomic_operation , i_source_channel_offset
 298                 , d_x , d_z_rear , d_min , 1.5 / i_nb_channels );
 299         i_next_atomic_operation += 2;
 300         i_source_channel_offset++;
 301     }
 302     if( i_physical_channels & AOUT_CHAN_REARCENTER )
 303     {
 304         ComputeChannelOperations( p_data , i_rate
 305                 , i_next_atomic_operation , i_source_channel_offset
 306                 , 0 , -d_z , d_min , 1.5 / i_nb_channels );
 307         i_next_atomic_operation += 2;
 308         i_source_channel_offset++;
 309     }
 310     if( i_physical_channels & AOUT_CHAN_CENTER )
 311     {
 312         /* having two center channels increases the spatialization effect */
 313         ComputeChannelOperations( p_data , i_rate
 314                 , i_next_atomic_operation , i_source_channel_offset
 315                 , d_x / 5.0 , d_z , d_min , 0.75 / i_nb_channels );
 316         i_next_atomic_operation += 2;
 317         ComputeChannelOperations( p_data , i_rate
 318                 , i_next_atomic_operation , i_source_channel_offset
 319                 , -d_x / 5.0 , d_z , d_min , 0.75 / i_nb_channels );
 320         i_next_atomic_operation += 2;
 321         i_source_channel_offset++;
 322     }
 323     if( i_physical_channels & AOUT_CHAN_LFE )
 324     {
 325         ComputeChannelOperations( p_data , i_rate
 326                 , i_next_atomic_operation , i_source_channel_offset
 327                 , 0 , d_z_rear , d_min , 5.0 / i_nb_channels );
 328         i_next_atomic_operation += 2;
 329         i_source_channel_offset++;
 330     }
 331
 332     /* Initialize the overflow buffer
 333      * we need it because the process induce a delay in the samples */
 334     p_data->i_overflow_buffer_size = 0;
 335     for( i = 0 ; i < p_data->i_nb_atomic_operations ; i++ )
 336     {
 337         if( p_data->i_overflow_buffer_size
 338                 < p_data->p_atomic_operations[i].i_delay * 2 * sizeof (float) )
 339         {
 340             p_data->i_overflow_buffer_size
 341                 = p_data->p_atomic_operations[i].i_delay * 2 * sizeof (float);
 342         }
 343     }
 344     p_data->p_overflow_buffer = malloc( p_data->i_overflow_buffer_size );
 345     if( p_data->p_atomic_operations == NULL )
 346     {
 347         msg_Err( p_this, "out of memory" );
 348         return -1;
 349     }
 350     memset( p_data->p_overflow_buffer, 0 , p_data->i_overflow_buffer_size );
 351
 352     /* end */
 353     return 0;
 354 }
 355
 356 /*****************************************************************************
 357  * Create: allocate headphone downmixer
 358  *****************************************************************************/
 359 static int Create( vlc_object_t *p_this )
 360 {
 361     aout_filter_t * p_filter = (aout_filter_t *)p_this;
 362     vlc_bool_t b_fit = VLC_TRUE;
 363
 364     /* Activate this filter only with stereo devices */
 365     if( p_filter->output.i_physical_channels
 366             != (AOUT_CHAN_LEFT|AOUT_CHAN_RIGHT) )
 367     {
 368         msg_Dbg( p_filter, "filter discarded (incompatible format)" );
 369         return VLC_EGENERIC;
 370     }
 371
 372     /* Request a specific format if not already compatible */
 373     if( p_filter->input.i_original_channels
 374             != p_filter->output.i_original_channels )
 375     {
 376         b_fit = VLC_FALSE;
 377         p_filter->input.i_original_channels =
 378                                         p_filter->output.i_original_channels;
 379     }
 380     if( p_filter->input.i_format != VLC_FOURCC('f','l','3','2')
 381           || p_filter->output.i_format != VLC_FOURCC('f','l','3','2') )
 382     {
 383         b_fit = VLC_FALSE;
 384         p_filter->input.i_format = VLC_FOURCC('f','l','3','2');
 385         p_filter->output.i_format = VLC_FOURCC('f','l','3','2');
 386     }
 387     if( p_filter->input.i_rate != p_filter->output.i_rate )
 388     {
 389         b_fit = VLC_FALSE;
 390         p_filter->input.i_rate = p_filter->output.i_rate;
 391     }
 392     if( p_filter->input.i_physical_channels == (AOUT_CHAN_LEFT|AOUT_CHAN_RIGHT)
 393           && ( p_filter->input.i_original_channels & AOUT_CHAN_DOLBYSTEREO )
 394           && ! config_GetInt ( p_filter , "headphone-dolby" ) )
 395     {
 396         b_fit = VLC_FALSE;
 397         p_filter->input.i_physical_channels = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT |
 398                                               AOUT_CHAN_CENTER |
 399                                               AOUT_CHAN_REARLEFT |
 400                                               AOUT_CHAN_REARRIGHT;
 401     }
 402     if( ! b_fit )
 403     {
 404         msg_Dbg( p_filter, "requesting specific format" );
 405         return VLC_EGENERIC;
 406     }
 407
 408     /* Allocate the memory needed to store the module's structure */
 409     p_filter->p_sys = malloc( sizeof(struct aout_filter_sys_t) );
 410     if( p_filter->p_sys == NULL )
 411     {
 412         msg_Err( p_filter, "out of memory" );
 413         return VLC_EGENERIC;
 414     }
 415     p_filter->p_sys->i_overflow_buffer_size = 0;
 416     p_filter->p_sys->p_overflow_buffer = NULL;
 417     p_filter->p_sys->i_nb_atomic_operations = 0;
 418     p_filter->p_sys->p_atomic_operations = NULL;
 419
 420     if( Init( VLC_OBJECT(p_filter), p_filter->p_sys
 421                 , aout_FormatNbChannels ( &p_filter->input )
 422                 , p_filter->input.i_physical_channels
 423                 , p_filter->input.i_rate ) < 0 )
 424     {
 425         return VLC_EGENERIC;
 426     }
 427
 428     p_filter->pf_do_work = DoWork;
 429     p_filter->b_in_place = 0;
 430
 431     return VLC_SUCCESS;
 432 }
 433
 434 /*****************************************************************************
 435  * Destroy: deallocate resources associated with headphone downmixer
 436  *****************************************************************************/
 437 static void Destroy( vlc_object_t *p_this )
 438 {
 439     aout_filter_t * p_filter = (aout_filter_t *)p_this;
 440
 441     if( p_filter->p_sys != NULL )
 442     {
 443         if( p_filter->p_sys->p_overflow_buffer != NULL )
 444         {
 445             free( p_filter->p_sys->p_overflow_buffer );
 446         }
 447         if( p_filter->p_sys->p_atomic_operations != NULL )
 448         {
 449             free( p_filter->p_sys->p_atomic_operations );
 450         }
 451         free( p_filter->p_sys );
 452         p_filter->p_sys = NULL;
 453     }
 454 }
 455
 456 /*****************************************************************************
 457  * DoWork: convert a buffer
 458  *****************************************************************************/
 459 static void DoWork( aout_instance_t * p_aout, aout_filter_t * p_filter,
 460                     aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
 461 {
 462     int i_input_nb = aout_FormatNbChannels( &p_filter->input );
 463     int i_output_nb = aout_FormatNbChannels( &p_filter->output );
 464
 465     float * p_in = (float*) p_in_buf->p_buffer;
 466     byte_t * p_out;
 467     byte_t * p_overflow;
 468     byte_t * p_slide;
 469
 470     size_t i_overflow_size;     /* in bytes */
 471     size_t i_out_size;          /* in bytes */
 472
 473     unsigned int i, j;
 474
 475     int i_source_channel_offset;
 476     int i_dest_channel_offset;
 477     unsigned int i_delay;
 478     double d_amplitude_factor;
 479
 480     /* out buffer characterisitcs */
 481     p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
 482     p_out_buf->i_nb_bytes = p_in_buf->i_nb_bytes * i_output_nb / i_input_nb;
 483     p_out = p_out_buf->p_buffer;
 484     i_out_size = p_out_buf->i_nb_bytes;
 485
 486     if( p_filter->p_sys != NULL )
 487     {
 488         /* Slide the overflow buffer */
 489         p_overflow = p_filter->p_sys->p_overflow_buffer;
 490         i_overflow_size = p_filter->p_sys->i_overflow_buffer_size;
 491
 492         memset( p_out, 0, i_out_size );
 493         if ( i_out_size > i_overflow_size )
 494             memcpy( p_out, p_overflow, i_overflow_size );
 495         else
 496             memcpy( p_out, p_overflow, i_out_size );
 497
 498         p_slide = p_filter->p_sys->p_overflow_buffer;
 499         while( p_slide < p_overflow + i_overflow_size )
 500         {
 501             if( p_slide + i_out_size < p_overflow + i_overflow_size )
 502             {
 503                 memset( p_slide, 0, i_out_size );
 504                 if( p_slide + 2 * i_out_size < p_overflow + i_overflow_size )
 505                     memcpy( p_slide, p_slide + i_out_size, i_out_size );
 506                 else
 507                     memcpy( p_slide, p_slide + i_out_size,
 508                             p_overflow + i_overflow_size - ( p_slide + i_out_size ) );
 509             }
 510             else
 511             {
 512                 memset( p_slide, 0, p_overflow + i_overflow_size - p_slide );
 513             }
 514             p_slide += i_out_size;
 515         }
 516
 517         /* apply the atomic operations */
 518         for( i = 0; i < p_filter->p_sys->i_nb_atomic_operations; i++ )
 519         {
 520             /* shorter variable names */
 521             i_source_channel_offset
 522                 = p_filter->p_sys->p_atomic_operations[i].i_source_channel_offset;
 523             i_dest_channel_offset
 524                 = p_filter->p_sys->p_atomic_operations[i].i_dest_channel_offset;
 525             i_delay = p_filter->p_sys->p_atomic_operations[i].i_delay;
 526             d_amplitude_factor
 527                 = p_filter->p_sys->p_atomic_operations[i].d_amplitude_factor;
 528
 529             if( p_out_buf->i_nb_samples > i_delay )
 530             {
 531                 /* current buffer coefficients */
 532                 for( j = 0; j < p_out_buf->i_nb_samples - i_delay; j++ )
 533                 {
 534                     ((float*)p_out)[ (i_delay+j)*i_output_nb + i_dest_channel_offset ]
 535                         += p_in[ j * i_input_nb + i_source_channel_offset ]
 536                            * d_amplitude_factor;
 537                 }
 538
 539                 /* overflow buffer coefficients */
 540                 for( j = 0; j < i_delay; j++ )
 541                 {
 542                     ((float*)p_overflow)[ j*i_output_nb + i_dest_channel_offset ]
 543                         += p_in[ (p_out_buf->i_nb_samples - i_delay + j)
 544                            * i_input_nb + i_source_channel_offset ]
 545                            * d_amplitude_factor;
 546                 }
 547             }
 548             else
 549             {
 550                 /* overflow buffer coefficients only */
 551                 for( j = 0; j < p_out_buf->i_nb_samples; j++ )
 552                 {
 553                     ((float*)p_overflow)[ (i_delay - p_out_buf->i_nb_samples + j)
 554                         * i_output_nb + i_dest_channel_offset ]
 555                         += p_in[ j * i_input_nb + i_source_channel_offset ]
 556                            * d_amplitude_factor;
 557                 }
 558             }
 559         }
 560     }
 561     else
 562     {
 563         memset( p_out, 0, i_out_size );
 564     }
 565 }
 566
 567 /*
 568  * Audio filter 2
 569  */
 570 /*****************************************************************************
 571  * OpenFilter:
 572  *****************************************************************************/
 573 static int OpenFilter( vlc_object_t *p_this )
 574 {
 575     filter_t *p_filter = (filter_t *)p_this;
 576     vlc_bool_t b_fit = VLC_TRUE;
 577
 578     /* Activate this filter only with stereo devices */
 579     if( p_filter->fmt_out.audio.i_physical_channels
 580             != (AOUT_CHAN_LEFT|AOUT_CHAN_RIGHT) )
 581     {
 582         msg_Dbg( p_filter, "filter discarded (incompatible format)" );
 583         return VLC_EGENERIC;
 584     }
 585
 586     /* Request a specific format if not already compatible */
 587     if( p_filter->fmt_in.audio.i_original_channels
 588             != p_filter->fmt_out.audio.i_original_channels )
 589     {
 590         b_fit = VLC_FALSE;
 591         p_filter->fmt_in.audio.i_original_channels =
 592                                         p_filter->fmt_out.audio.i_original_channels;
 593     }
 594     if( p_filter->fmt_in.audio.i_format != VLC_FOURCC('f','l','3','2')
 595           || p_filter->fmt_out.audio.i_format != VLC_FOURCC('f','l','3','2') )
 596     {
 597         b_fit = VLC_FALSE;
 598         p_filter->fmt_in.audio.i_format = VLC_FOURCC('f','l','3','2');
 599         p_filter->fmt_out.audio.i_format = VLC_FOURCC('f','l','3','2');
 600     }
 601     if( p_filter->fmt_in.audio.i_rate != p_filter->fmt_out.audio.i_rate )
 602     {
 603         b_fit = VLC_FALSE;
 604         p_filter->fmt_in.audio.i_rate = p_filter->fmt_out.audio.i_rate;
 605     }
 606     if( p_filter->fmt_in.audio.i_physical_channels == (AOUT_CHAN_LEFT|AOUT_CHAN_RIGHT)
 607           && ( p_filter->fmt_in.audio.i_original_channels & AOUT_CHAN_DOLBYSTEREO )
 608           && !config_GetInt( p_filter, "headphone-dolby" ) )
 609     {
 610         b_fit = VLC_FALSE;
 611         p_filter->fmt_in.audio.i_physical_channels = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT |
 612                                               AOUT_CHAN_CENTER |
 613                                               AOUT_CHAN_REARLEFT |
 614                                               AOUT_CHAN_REARRIGHT;
 615     }
 616     if( !b_fit )
 617     {
 618         msg_Dbg( p_filter, "requesting specific format" );
 619         return VLC_EGENERIC;
 620     }
 621
 622     /* Allocate the memory needed to store the module's structure */
 623     p_filter->p_sys = malloc( sizeof(struct filter_sys_t) );
 624     if( p_filter->p_sys == NULL )
 625     {
 626         msg_Err( p_filter, "out of memory" );
 627         return VLC_EGENERIC;
 628     }
 629     p_filter->p_sys->i_overflow_buffer_size = 0;
 630     p_filter->p_sys->p_overflow_buffer = NULL;
 631     p_filter->p_sys->i_nb_atomic_operations = 0;
 632     p_filter->p_sys->p_atomic_operations = NULL;
 633
 634     if( Init( VLC_OBJECT(p_filter), (struct aout_filter_sys_t *)p_filter->p_sys
 635                 , aout_FormatNbChannels ( &(p_filter->fmt_in.audio) )
 636                 , p_filter->fmt_in.audio.i_physical_channels
 637                 , p_filter->fmt_in.audio.i_rate ) < 0 )
 638     {
 639         return VLC_EGENERIC;
 640     }
 641
 642     p_filter->pf_audio_filter = Convert;
 643     p_filter->fmt_out.audio.i_rate = p_filter->fmt_in.audio.i_rate;
 644
 645     return VLC_SUCCESS;
 646 }
 647
 648 /*****************************************************************************
 649  * CloseFilter : deallocate data structures
 650  *****************************************************************************/
 651 static void CloseFilter( vlc_object_t *p_this )
 652 {
 653     filter_t *p_filter = (filter_t *)p_this;
 654
 655     if( p_filter->p_sys != NULL )
 656     {
 657         if( p_filter->p_sys->p_overflow_buffer != NULL )
 658         {
 659             free ( p_filter->p_sys->p_overflow_buffer );
 660         }
 661         if( p_filter->p_sys->p_atomic_operations != NULL )
 662         {
 663             free ( p_filter->p_sys->p_atomic_operations );
 664         }
 665         free( p_filter->p_sys );
 666         p_filter->p_sys = NULL;
 667     }
 668 }
 669
 670 static block_t *Convert( filter_t *p_filter, block_t *p_block )
 671 {
 672     aout_filter_t aout_filter;
 673     aout_buffer_t in_buf, out_buf;
 674     block_t *p_out;
 675     int i_out_size;
 676
 677     if( !p_block || !p_block->i_samples )
 678     {
 679         if( p_block ) p_block->pf_release( p_block );
 680         return NULL;
 681     }
 682
 683     i_out_size = p_block->i_samples *
 684       p_filter->fmt_out.audio.i_bitspersample/8 *
 685         aout_FormatNbChannels( &(p_filter->fmt_out.audio) );
 686
 687     p_out = p_filter->pf_audio_buffer_new( p_filter, i_out_size );
 688     if( !p_out )
 689     {
 690         msg_Warn( p_filter, "can't get output buffer" );
 691         if( p_block ) p_block->pf_release( p_block );
 692         return NULL;
 693     }
 694
 695     p_out->i_samples = p_block->i_samples;
 696     p_out->i_dts = p_block->i_dts;
 697     p_out->i_pts = p_block->i_pts;
 698     p_out->i_length = p_block->i_length;
 699
 700     aout_filter.p_sys = (struct aout_filter_sys_t *)p_filter->p_sys;
 701     aout_filter.input = p_filter->fmt_in.audio;
 702     aout_filter.input.i_format = p_filter->fmt_in.i_codec;
 703     aout_filter.output = p_filter->fmt_out.audio;
 704     aout_filter.output.i_format = p_filter->fmt_out.i_codec;
 705     aout_filter.b_in_place = 0;
 706
 707     in_buf.p_buffer = p_block->p_buffer;
 708     in_buf.i_nb_bytes = p_block->i_buffer;
 709     in_buf.i_nb_samples = p_block->i_samples;
 710     out_buf.p_buffer = p_out->p_buffer;
 711     out_buf.i_nb_bytes = p_out->i_buffer;
 712     out_buf.i_nb_samples = p_out->i_samples;
 713
 714     DoWork( (aout_instance_t *)p_filter, &aout_filter, &in_buf, &out_buf );
 715
 716     p_out->i_buffer = out_buf.i_nb_bytes;
 717     p_out->i_samples = out_buf.i_nb_samples;
 718
 719     if( p_block ) p_block->pf_release( p_block );
 720     return p_out;
 721 }