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 <math.h>                                        /* sqrt */
  29
  30 #ifdef HAVE_CONFIG_H
  31 # include "config.h"
  32 #endif
  33
  34 #include <vlc/vlc.h>
  35 #include <vlc_plugin.h>
  36 #include <vlc_aout.h>
  37 #include <vlc_filter.h>
  38 #include <vlc_block.h>
  39
  40 /*****************************************************************************
  41  * Local prototypes
  42  *****************************************************************************/
  43 static int  Create    ( vlc_object_t * );
  44 static void Destroy   ( vlc_object_t * );
  45
  46 static void DoWork    ( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
  47                         aout_buffer_t * );
  48
  49 /* Audio filter2 */
  50 static int  OpenFilter ( vlc_object_t * );
  51 static void CloseFilter( vlc_object_t * );
  52 static block_t *Convert( filter_t *, block_t * );
  53
  54 /*****************************************************************************
  55  * Module descriptor
  56  *****************************************************************************/
  57 #define MODULE_DESCRIPTION N_ ( \
  58      "This effect gives you the feeling that you are standing in a room " \
  59      "with a complete 7.1 speaker set when using only a headphone, " \
  60      "providing a more realistic sound experience. It should also be " \
  61      "more comfortable and less tiring when listening to music for " \
  62      "long periods of time.\nIt works with any source format from mono " \
  63      "to 7.1.")
  64
  65 #define HEADPHONE_DIM_TEXT N_("Characteristic dimension")
  66 #define HEADPHONE_DIM_LONGTEXT N_( \
  67      "Distance between front left speaker and listener in meters.")
  68
  69 #define HEADPHONE_COMPENSATE_TEXT N_("Compensate delay")
  70 #define HEADPHONE_COMPENSATE_LONGTEXT N_( \
  71      "The delay which is introduced by the physical algorithm may "\
  72      "sometimes be disturbing for the synchronization between lips-movement "\
  73      "and speech. In case, turn this on to compensate.")
  74
  75 #define HEADPHONE_DOLBY_TEXT N_("No decoding of Dolby Surround")
  76 #define HEADPHONE_DOLBY_LONGTEXT N_( \
  77      "Dolby Surround encoded streams won't be decoded before being " \
  78      "processed by this filter. Enabling this setting is not recommended.")
  79
  80 vlc_module_begin();
  81     set_description( _("Headphone virtual spatialization effect") );
  82     set_shortname( _("Headphone effect") );
  83     set_help( MODULE_DESCRIPTION );
  84     set_category( CAT_AUDIO );
  85     set_subcategory( SUBCAT_AUDIO_AFILTER );
  86
  87     add_integer( "headphone-dim", 10, NULL, HEADPHONE_DIM_TEXT,
  88                  HEADPHONE_DIM_LONGTEXT, false );
  89     add_bool( "headphone-compensate", 0, NULL, HEADPHONE_COMPENSATE_TEXT,
  90               HEADPHONE_COMPENSATE_LONGTEXT, true );
  91     add_bool( "headphone-dolby", 0, NULL, HEADPHONE_DOLBY_TEXT,
  92               HEADPHONE_DOLBY_LONGTEXT, true );
  93
  94     set_capability( "audio filter", 0 );
  95     set_callbacks( Create, Destroy );
  96     add_shortcut( "headphone" );
  97
  98     /* Audio filter 2 */
  99     add_submodule();
 100     set_description( _("Headphone virtual spatialization effect") );
 101     set_capability( "audio filter2", 0 );
 102     set_callbacks( OpenFilter, CloseFilter );
 103 vlc_module_end();
 104
 105
 106 /*****************************************************************************
 107  * Internal data structures
 108  *****************************************************************************/
 109 struct atomic_operation_t
 110 {
 111     int i_source_channel_offset;
 112     int i_dest_channel_offset;
 113     unsigned int i_delay;/* in sample unit */
 114     double d_amplitude_factor;
 115 };
 116
 117 struct aout_filter_sys_t
 118 {
 119     size_t i_overflow_buffer_size;/* in bytes */
 120     uint8_t * p_overflow_buffer;
 121     unsigned int i_nb_atomic_operations;
 122     struct atomic_operation_t * p_atomic_operations;
 123 };
 124
 125 struct filter_sys_t
 126 {
 127     size_t i_overflow_buffer_size;/* in bytes */
 128     uint8_t * p_overflow_buffer;
 129     unsigned int i_nb_atomic_operations;
 130     struct atomic_operation_t * p_atomic_operations;
 131 };
 132
 133 /*****************************************************************************
 134  * Init: initialize internal data structures
 135  * and computes the needed atomic operations
 136  *****************************************************************************/
 137 /* x and z represent the coordinates of the virtual speaker
 138  *  relatively to the center of the listener's head, measured in meters :
 139  *
 140  *  left              right
 141  *Z
 142  *-
 143  *a          head
 144  *x
 145  *i
 146  *s
 147  *  rear left    rear right
 148  *
 149  *          x-axis
 150  *  */
 151 static void ComputeChannelOperations( struct aout_filter_sys_t * p_data
 152         , unsigned int i_rate, unsigned int i_next_atomic_operation
 153         , int i_source_channel_offset, double d_x, double d_z
 154         , double d_compensation_length, double d_channel_amplitude_factor )
 155 {
 156     double d_c = 340; /*sound celerity (unit: m/s)*/
 157     double d_compensation_delay = (d_compensation_length-0.1) / d_c * i_rate;
 158
 159     /* Left ear */
 160     p_data->p_atomic_operations[i_next_atomic_operation]
 161         .i_source_channel_offset = i_source_channel_offset;
 162     p_data->p_atomic_operations[i_next_atomic_operation]
 163         .i_dest_channel_offset = 0;/* left */
 164     p_data->p_atomic_operations[i_next_atomic_operation]
 165         .i_delay = (int)( sqrt( (-0.1-d_x)*(-0.1-d_x) + (0-d_z)*(0-d_z) )
 166                           / d_c * i_rate - d_compensation_delay );
 167     if( d_x < 0 )
 168     {
 169         p_data->p_atomic_operations[i_next_atomic_operation]
 170             .d_amplitude_factor = d_channel_amplitude_factor * 1.1 / 2;
 171     }
 172     else if( d_x > 0 )
 173     {
 174         p_data->p_atomic_operations[i_next_atomic_operation]
 175             .d_amplitude_factor = d_channel_amplitude_factor * 0.9 / 2;
 176     }
 177     else
 178     {
 179         p_data->p_atomic_operations[i_next_atomic_operation]
 180             .d_amplitude_factor = d_channel_amplitude_factor / 2;
 181     }
 182
 183     /* Right ear */
 184     p_data->p_atomic_operations[i_next_atomic_operation + 1]
 185         .i_source_channel_offset = i_source_channel_offset;
 186     p_data->p_atomic_operations[i_next_atomic_operation + 1]
 187         .i_dest_channel_offset = 1;/* right */
 188     p_data->p_atomic_operations[i_next_atomic_operation + 1]
 189         .i_delay = (int)( sqrt( (0.1-d_x)*(0.1-d_x) + (0-d_z)*(0-d_z) )
 190                           / d_c * i_rate - d_compensation_delay );
 191     if( d_x < 0 )
 192     {
 193         p_data->p_atomic_operations[i_next_atomic_operation + 1]
 194             .d_amplitude_factor = d_channel_amplitude_factor * 0.9 / 2;
 195     }
 196     else if( d_x > 0 )
 197     {
 198         p_data->p_atomic_operations[i_next_atomic_operation + 1]
 199             .d_amplitude_factor = d_channel_amplitude_factor * 1.1 / 2;
 200     }
 201     else
 202     {
 203         p_data->p_atomic_operations[i_next_atomic_operation + 1]
 204             .d_amplitude_factor = d_channel_amplitude_factor / 2;
 205     }
 206 }
 207
 208 static int Init( vlc_object_t *p_this, struct aout_filter_sys_t * p_data
 209         , unsigned int i_nb_channels, uint32_t i_physical_channels
 210         , unsigned int i_rate )
 211 {
 212     double d_x = config_GetInt( p_this, "headphone-dim" );
 213     double d_z = d_x;
 214     double d_z_rear = -d_x/3;
 215     double d_min = 0;
 216     unsigned int i_next_atomic_operation;
 217     int i_source_channel_offset;
 218     unsigned int i;
 219
 220     if( p_data == NULL )
 221     {
 222         msg_Dbg( p_this, "passing a null pointer as argument" );
 223         return 0;
 224     }
 225
 226     if( config_GetInt( p_this, "headphone-compensate" ) )
 227     {
 228         /* minimal distance to any speaker */
 229         if( i_physical_channels & AOUT_CHAN_REARCENTER )
 230         {
 231             d_min = d_z_rear;
 232         }
 233         else
 234         {
 235             d_min = d_z;
 236         }
 237     }
 238
 239     /* Number of elementary operations */
 240     p_data->i_nb_atomic_operations = i_nb_channels * 2;
 241     if( i_physical_channels & AOUT_CHAN_CENTER )
 242     {
 243         p_data->i_nb_atomic_operations += 2;
 244     }
 245     p_data->p_atomic_operations = malloc( sizeof(struct atomic_operation_t)
 246             * p_data->i_nb_atomic_operations );
 247     if( p_data->p_atomic_operations == NULL )
 248     {
 249         msg_Err( p_this, "out of memory" );
 250         return -1;
 251     }
 252
 253     /* For each virtual speaker, computes elementary wave propagation time
 254      * to each ear */
 255     i_next_atomic_operation = 0;
 256     i_source_channel_offset = 0;
 257     if( i_physical_channels & AOUT_CHAN_LEFT )
 258     {
 259         ComputeChannelOperations( p_data , i_rate
 260                 , i_next_atomic_operation , i_source_channel_offset
 261                 , -d_x , d_z , d_min , 2.0 / i_nb_channels );
 262         i_next_atomic_operation += 2;
 263         i_source_channel_offset++;
 264     }
 265     if( i_physical_channels & AOUT_CHAN_RIGHT )
 266     {
 267         ComputeChannelOperations( p_data , i_rate
 268                 , i_next_atomic_operation , i_source_channel_offset
 269                 , d_x , d_z , d_min , 2.0 / i_nb_channels );
 270         i_next_atomic_operation += 2;
 271         i_source_channel_offset++;
 272     }
 273     if( i_physical_channels & AOUT_CHAN_MIDDLELEFT )
 274     {
 275         ComputeChannelOperations( p_data , i_rate
 276                 , i_next_atomic_operation , i_source_channel_offset
 277                 , -d_x , 0 , d_min , 1.5 / i_nb_channels );
 278         i_next_atomic_operation += 2;
 279         i_source_channel_offset++;
 280     }
 281     if( i_physical_channels & AOUT_CHAN_MIDDLERIGHT )
 282     {
 283         ComputeChannelOperations( p_data , i_rate
 284                 , i_next_atomic_operation , i_source_channel_offset
 285                 , d_x , 0 , d_min , 1.5 / i_nb_channels );
 286         i_next_atomic_operation += 2;
 287         i_source_channel_offset++;
 288     }
 289     if( i_physical_channels & AOUT_CHAN_REARLEFT )
 290     {
 291         ComputeChannelOperations( p_data , i_rate
 292                 , i_next_atomic_operation , i_source_channel_offset
 293                 , -d_x , d_z_rear , d_min , 1.5 / i_nb_channels );
 294         i_next_atomic_operation += 2;
 295         i_source_channel_offset++;
 296     }
 297     if( i_physical_channels & AOUT_CHAN_REARRIGHT )
 298     {
 299         ComputeChannelOperations( p_data , i_rate
 300                 , i_next_atomic_operation , i_source_channel_offset
 301                 , d_x , d_z_rear , d_min , 1.5 / i_nb_channels );
 302         i_next_atomic_operation += 2;
 303         i_source_channel_offset++;
 304     }
 305     if( i_physical_channels & AOUT_CHAN_REARCENTER )
 306     {
 307         ComputeChannelOperations( p_data , i_rate
 308                 , i_next_atomic_operation , i_source_channel_offset
 309                 , 0 , -d_z , d_min , 1.5 / i_nb_channels );
 310         i_next_atomic_operation += 2;
 311         i_source_channel_offset++;
 312     }
 313     if( i_physical_channels & AOUT_CHAN_CENTER )
 314     {
 315         /* having two center channels increases the spatialization effect */
 316         ComputeChannelOperations( p_data , i_rate
 317                 , i_next_atomic_operation , i_source_channel_offset
 318                 , d_x / 5.0 , d_z , d_min , 0.75 / i_nb_channels );
 319         i_next_atomic_operation += 2;
 320         ComputeChannelOperations( p_data , i_rate
 321                 , i_next_atomic_operation , i_source_channel_offset
 322                 , -d_x / 5.0 , d_z , d_min , 0.75 / i_nb_channels );
 323         i_next_atomic_operation += 2;
 324         i_source_channel_offset++;
 325     }
 326     if( i_physical_channels & AOUT_CHAN_LFE )
 327     {
 328         ComputeChannelOperations( p_data , i_rate
 329                 , i_next_atomic_operation , i_source_channel_offset
 330                 , 0 , d_z_rear , d_min , 5.0 / i_nb_channels );
 331         i_next_atomic_operation += 2;
 332         i_source_channel_offset++;
 333     }
 334
 335     /* Initialize the overflow buffer
 336      * we need it because the process induce a delay in the samples */
 337     p_data->i_overflow_buffer_size = 0;
 338     for( i = 0 ; i < p_data->i_nb_atomic_operations ; i++ )
 339     {
 340         if( p_data->i_overflow_buffer_size
 341                 < p_data->p_atomic_operations[i].i_delay * 2 * sizeof (float) )
 342         {
 343             p_data->i_overflow_buffer_size
 344                 = p_data->p_atomic_operations[i].i_delay * 2 * sizeof (float);
 345         }
 346     }
 347     p_data->p_overflow_buffer = malloc( p_data->i_overflow_buffer_size );
 348     if( p_data->p_atomic_operations == NULL )
 349     {
 350         msg_Err( p_this, "out of memory" );
 351         return -1;
 352     }
 353     memset( p_data->p_overflow_buffer, 0 , p_data->i_overflow_buffer_size );
 354
 355     /* end */
 356     return 0;
 357 }
 358
 359 /*****************************************************************************
 360  * Create: allocate headphone downmixer
 361  *****************************************************************************/
 362 static int Create( vlc_object_t *p_this )
 363 {
 364     aout_filter_t * p_filter = (aout_filter_t *)p_this;
 365     bool b_fit = true;
 366
 367     /* Activate this filter only with stereo devices */
 368     if( p_filter->output.i_physical_channels
 369             != (AOUT_CHAN_LEFT|AOUT_CHAN_RIGHT) )
 370     {
 371         msg_Dbg( p_filter, "filter discarded (incompatible format)" );
 372         return VLC_EGENERIC;
 373     }
 374
 375     /* Request a specific format if not already compatible */
 376     if( p_filter->input.i_original_channels
 377             != p_filter->output.i_original_channels )
 378     {
 379         b_fit = false;
 380         p_filter->input.i_original_channels =
 381                                         p_filter->output.i_original_channels;
 382     }
 383     if( p_filter->input.i_format != VLC_FOURCC('f','l','3','2')
 384           || p_filter->output.i_format != VLC_FOURCC('f','l','3','2') )
 385     {
 386         b_fit = false;
 387         p_filter->input.i_format = VLC_FOURCC('f','l','3','2');
 388         p_filter->output.i_format = VLC_FOURCC('f','l','3','2');
 389     }
 390     if( p_filter->input.i_rate != p_filter->output.i_rate )
 391     {
 392         b_fit = false;
 393         p_filter->input.i_rate = p_filter->output.i_rate;
 394     }
 395     if( p_filter->input.i_physical_channels == (AOUT_CHAN_LEFT|AOUT_CHAN_RIGHT)
 396           && ( p_filter->input.i_original_channels & AOUT_CHAN_DOLBYSTEREO )
 397           && ! config_GetInt ( p_filter , "headphone-dolby" ) )
 398     {
 399         b_fit = false;
 400         p_filter->input.i_physical_channels = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT |
 401                                               AOUT_CHAN_CENTER |
 402                                               AOUT_CHAN_REARLEFT |
 403                                               AOUT_CHAN_REARRIGHT;
 404     }
 405     if( ! b_fit )
 406     {
 407         msg_Dbg( p_filter, "requesting specific format" );
 408         return VLC_EGENERIC;
 409     }
 410
 411     /* Allocate the memory needed to store the module's structure */
 412     p_filter->p_sys = malloc( sizeof(struct aout_filter_sys_t) );
 413     if( p_filter->p_sys == NULL )
 414     {
 415         msg_Err( p_filter, "out of memory" );
 416         return VLC_EGENERIC;
 417     }
 418     p_filter->p_sys->i_overflow_buffer_size = 0;
 419     p_filter->p_sys->p_overflow_buffer = NULL;
 420     p_filter->p_sys->i_nb_atomic_operations = 0;
 421     p_filter->p_sys->p_atomic_operations = NULL;
 422
 423     if( Init( VLC_OBJECT(p_filter), p_filter->p_sys
 424                 , aout_FormatNbChannels ( &p_filter->input )
 425                 , p_filter->input.i_physical_channels
 426                 , p_filter->input.i_rate ) < 0 )
 427     {
 428         return VLC_EGENERIC;
 429     }
 430
 431     p_filter->pf_do_work = DoWork;
 432     p_filter->b_in_place = 0;
 433
 434     return VLC_SUCCESS;
 435 }
 436
 437 /*****************************************************************************
 438  * Destroy: deallocate resources associated with headphone downmixer
 439  *****************************************************************************/
 440 static void Destroy( vlc_object_t *p_this )
 441 {
 442     aout_filter_t * p_filter = (aout_filter_t *)p_this;
 443
 444     if( p_filter->p_sys != NULL )
 445     {
 446         if( p_filter->p_sys->p_overflow_buffer != NULL )
 447         {
 448             free( p_filter->p_sys->p_overflow_buffer );
 449         }
 450         if( p_filter->p_sys->p_atomic_operations != NULL )
 451         {
 452             free( p_filter->p_sys->p_atomic_operations );
 453         }
 454         free( p_filter->p_sys );
 455         p_filter->p_sys = NULL;
 456     }
 457 }
 458
 459 /*****************************************************************************
 460  * DoWork: convert a buffer
 461  *****************************************************************************/
 462 static void DoWork( aout_instance_t * p_aout, aout_filter_t * p_filter,
 463                     aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
 464 {
 465     VLC_UNUSED(p_aout);
 466     int i_input_nb = aout_FormatNbChannels( &p_filter->input );
 467     int i_output_nb = aout_FormatNbChannels( &p_filter->output );
 468
 469     float * p_in = (float*) p_in_buf->p_buffer;
 470     uint8_t * p_out;
 471     uint8_t * p_overflow;
 472     uint8_t * p_slide;
 473
 474     size_t i_overflow_size;     /* in bytes */
 475     size_t i_out_size;          /* in bytes */
 476
 477     unsigned int i, j;
 478
 479     int i_source_channel_offset;
 480     int i_dest_channel_offset;
 481     unsigned int i_delay;
 482     double d_amplitude_factor;
 483
 484     /* out buffer characterisitcs */
 485     p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
 486     p_out_buf->i_nb_bytes = p_in_buf->i_nb_bytes * i_output_nb / i_input_nb;
 487     p_out = p_out_buf->p_buffer;
 488     i_out_size = p_out_buf->i_nb_bytes;
 489
 490     if( p_filter->p_sys != NULL )
 491     {
 492         /* Slide the overflow buffer */
 493         p_overflow = p_filter->p_sys->p_overflow_buffer;
 494         i_overflow_size = p_filter->p_sys->i_overflow_buffer_size;
 495
 496         memset( p_out, 0, i_out_size );
 497         if ( i_out_size > i_overflow_size )
 498             memcpy( p_out, p_overflow, i_overflow_size );
 499         else
 500             memcpy( p_out, p_overflow, i_out_size );
 501
 502         p_slide = p_filter->p_sys->p_overflow_buffer;
 503         while( p_slide < p_overflow + i_overflow_size )
 504         {
 505             if( p_slide + i_out_size < p_overflow + i_overflow_size )
 506             {
 507                 memset( p_slide, 0, i_out_size );
 508                 if( p_slide + 2 * i_out_size < p_overflow + i_overflow_size )
 509                     memcpy( p_slide, p_slide + i_out_size, i_out_size );
 510                 else
 511                     memcpy( p_slide, p_slide + i_out_size,
 512                             p_overflow + i_overflow_size - ( p_slide + i_out_size ) );
 513             }
 514             else
 515             {
 516                 memset( p_slide, 0, p_overflow + i_overflow_size - p_slide );
 517             }
 518             p_slide += i_out_size;
 519         }
 520
 521         /* apply the atomic operations */
 522         for( i = 0; i < p_filter->p_sys->i_nb_atomic_operations; i++ )
 523         {
 524             /* shorter variable names */
 525             i_source_channel_offset
 526                 = p_filter->p_sys->p_atomic_operations[i].i_source_channel_offset;
 527             i_dest_channel_offset
 528                 = p_filter->p_sys->p_atomic_operations[i].i_dest_channel_offset;
 529             i_delay = p_filter->p_sys->p_atomic_operations[i].i_delay;
 530             d_amplitude_factor
 531                 = p_filter->p_sys->p_atomic_operations[i].d_amplitude_factor;
 532
 533             if( p_out_buf->i_nb_samples > i_delay )
 534             {
 535                 /* current buffer coefficients */
 536                 for( j = 0; j < p_out_buf->i_nb_samples - i_delay; j++ )
 537                 {
 538                     ((float*)p_out)[ (i_delay+j)*i_output_nb + i_dest_channel_offset ]
 539                         += p_in[ j * i_input_nb + i_source_channel_offset ]
 540                            * d_amplitude_factor;
 541                 }
 542
 543                 /* overflow buffer coefficients */
 544                 for( j = 0; j < i_delay; j++ )
 545                 {
 546                     ((float*)p_overflow)[ j*i_output_nb + i_dest_channel_offset ]
 547                         += p_in[ (p_out_buf->i_nb_samples - i_delay + j)
 548                            * i_input_nb + i_source_channel_offset ]
 549                            * d_amplitude_factor;
 550                 }
 551             }
 552             else
 553             {
 554                 /* overflow buffer coefficients only */
 555                 for( j = 0; j < p_out_buf->i_nb_samples; j++ )
 556                 {
 557                     ((float*)p_overflow)[ (i_delay - p_out_buf->i_nb_samples + j)
 558                         * i_output_nb + i_dest_channel_offset ]
 559                         += p_in[ j * i_input_nb + i_source_channel_offset ]
 560                            * d_amplitude_factor;
 561                 }
 562             }
 563         }
 564     }
 565     else
 566     {
 567         memset( p_out, 0, i_out_size );
 568     }
 569 }
 570
 571 /*
 572  * Audio filter 2
 573  */
 574 /*****************************************************************************
 575  * OpenFilter:
 576  *****************************************************************************/
 577 static int OpenFilter( vlc_object_t *p_this )
 578 {
 579     filter_t *p_filter = (filter_t *)p_this;
 580     bool b_fit = true;
 581
 582     /* Activate this filter only with stereo devices */
 583     if( p_filter->fmt_out.audio.i_physical_channels
 584             != (AOUT_CHAN_LEFT|AOUT_CHAN_RIGHT) )
 585     {
 586         msg_Dbg( p_filter, "filter discarded (incompatible format)" );
 587         return VLC_EGENERIC;
 588     }
 589
 590     /* Request a specific format if not already compatible */
 591     if( p_filter->fmt_in.audio.i_original_channels
 592             != p_filter->fmt_out.audio.i_original_channels )
 593     {
 594         b_fit = false;
 595         p_filter->fmt_in.audio.i_original_channels =
 596                                         p_filter->fmt_out.audio.i_original_channels;
 597     }
 598     if( 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         b_fit = false;
 602         p_filter->fmt_in.audio.i_format = VLC_FOURCC('f','l','3','2');
 603         p_filter->fmt_out.audio.i_format = VLC_FOURCC('f','l','3','2');
 604     }
 605     if( p_filter->fmt_in.audio.i_rate != p_filter->fmt_out.audio.i_rate )
 606     {
 607         b_fit = false;
 608         p_filter->fmt_in.audio.i_rate = p_filter->fmt_out.audio.i_rate;
 609     }
 610     if( p_filter->fmt_in.audio.i_physical_channels == (AOUT_CHAN_LEFT|AOUT_CHAN_RIGHT)
 611           && ( p_filter->fmt_in.audio.i_original_channels & AOUT_CHAN_DOLBYSTEREO )
 612           && !config_GetInt( p_filter, "headphone-dolby" ) )
 613     {
 614         b_fit = false;
 615         p_filter->fmt_in.audio.i_physical_channels = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT |
 616                                               AOUT_CHAN_CENTER |
 617                                               AOUT_CHAN_REARLEFT |
 618                                               AOUT_CHAN_REARRIGHT;
 619     }
 620     if( !b_fit )
 621     {
 622         msg_Dbg( p_filter, "requesting specific format" );
 623         return VLC_EGENERIC;
 624     }
 625
 626     /* Allocate the memory needed to store the module's structure */
 627     p_filter->p_sys = malloc( sizeof(struct filter_sys_t) );
 628     if( p_filter->p_sys == NULL )
 629     {
 630         msg_Err( p_filter, "out of memory" );
 631         return VLC_EGENERIC;
 632     }
 633     p_filter->p_sys->i_overflow_buffer_size = 0;
 634     p_filter->p_sys->p_overflow_buffer = NULL;
 635     p_filter->p_sys->i_nb_atomic_operations = 0;
 636     p_filter->p_sys->p_atomic_operations = NULL;
 637
 638     if( Init( VLC_OBJECT(p_filter), (struct aout_filter_sys_t *)p_filter->p_sys
 639                 , aout_FormatNbChannels ( &(p_filter->fmt_in.audio) )
 640                 , p_filter->fmt_in.audio.i_physical_channels
 641                 , p_filter->fmt_in.audio.i_rate ) < 0 )
 642     {
 643         return VLC_EGENERIC;
 644     }
 645
 646     p_filter->pf_audio_filter = Convert;
 647     p_filter->fmt_out.audio.i_rate = p_filter->fmt_in.audio.i_rate;
 648
 649     return VLC_SUCCESS;
 650 }
 651
 652 /*****************************************************************************
 653  * CloseFilter : deallocate data structures
 654  *****************************************************************************/
 655 static void CloseFilter( vlc_object_t *p_this )
 656 {
 657     filter_t *p_filter = (filter_t *)p_this;
 658
 659     if( p_filter->p_sys != NULL )
 660     {
 661         if( p_filter->p_sys->p_overflow_buffer != NULL )
 662         {
 663             free ( p_filter->p_sys->p_overflow_buffer );
 664         }
 665         if( p_filter->p_sys->p_atomic_operations != NULL )
 666         {
 667             free ( p_filter->p_sys->p_atomic_operations );
 668         }
 669         free( p_filter->p_sys );
 670         p_filter->p_sys = NULL;
 671     }
 672 }
 673
 674 static block_t *Convert( filter_t *p_filter, block_t *p_block )
 675 {
 676     aout_filter_t aout_filter;
 677     aout_buffer_t in_buf, out_buf;
 678     block_t *p_out;
 679     int i_out_size;
 680
 681     if( !p_block || !p_block->i_samples )
 682     {
 683         if( p_block ) p_block->pf_release( p_block );
 684         return NULL;
 685     }
 686
 687     i_out_size = p_block->i_samples *
 688       p_filter->fmt_out.audio.i_bitspersample/8 *
 689         aout_FormatNbChannels( &(p_filter->fmt_out.audio) );
 690
 691     p_out = p_filter->pf_audio_buffer_new( p_filter, i_out_size );
 692     if( !p_out )
 693     {
 694         msg_Warn( p_filter, "can't get output buffer" );
 695         if( p_block ) p_block->pf_release( p_block );
 696         return NULL;
 697     }
 698
 699     p_out->i_samples = p_block->i_samples;
 700     p_out->i_dts = p_block->i_dts;
 701     p_out->i_pts = p_block->i_pts;
 702     p_out->i_length = p_block->i_length;
 703
 704     aout_filter.p_sys = (struct aout_filter_sys_t *)p_filter->p_sys;
 705     aout_filter.input = p_filter->fmt_in.audio;
 706     aout_filter.input.i_format = p_filter->fmt_in.i_codec;
 707     aout_filter.output = p_filter->fmt_out.audio;
 708     aout_filter.output.i_format = p_filter->fmt_out.i_codec;
 709     aout_filter.b_in_place = 0;
 710
 711     in_buf.p_buffer = p_block->p_buffer;
 712     in_buf.i_nb_bytes = p_block->i_buffer;
 713     in_buf.i_nb_samples = p_block->i_samples;
 714     out_buf.p_buffer = p_out->p_buffer;
 715     out_buf.i_nb_bytes = p_out->i_buffer;
 716     out_buf.i_nb_samples = p_out->i_samples;
 717
 718     DoWork( (aout_instance_t *)p_filter, &aout_filter, &in_buf, &out_buf );
 719
 720     p_out->i_buffer = out_buf.i_nb_bytes;
 721     p_out->i_samples = out_buf.i_nb_samples;
 722
 723     if( p_block ) p_block->pf_release( p_block );
 724     return p_out;
 725 }