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_common.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( N_("Headphone virtual spatialization effect") );
  82     set_shortname( N_("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( N_("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         return -1;
 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         return -1;
 347     memset( p_data->p_overflow_buffer, 0 , p_data->i_overflow_buffer_size );
 348
 349     /* end */
 350     return 0;
 351 }
 352
 353 /*****************************************************************************
 354  * Create: allocate headphone downmixer
 355  *****************************************************************************/
 356 static int Create( vlc_object_t *p_this )
 357 {
 358     aout_filter_t * p_filter = (aout_filter_t *)p_this;
 359     bool b_fit = true;
 360
 361     /* Activate this filter only with stereo devices */
 362     if( p_filter->output.i_physical_channels
 363             != (AOUT_CHAN_LEFT|AOUT_CHAN_RIGHT) )
 364     {
 365         msg_Dbg( p_filter, "filter discarded (incompatible format)" );
 366         return VLC_EGENERIC;
 367     }
 368
 369     /* Request a specific format if not already compatible */
 370     if( p_filter->input.i_original_channels
 371             != p_filter->output.i_original_channels )
 372     {
 373         b_fit = false;
 374         p_filter->input.i_original_channels =
 375                                         p_filter->output.i_original_channels;
 376     }
 377     if( p_filter->input.i_format != VLC_FOURCC('f','l','3','2')
 378           || p_filter->output.i_format != VLC_FOURCC('f','l','3','2') )
 379     {
 380         b_fit = false;
 381         p_filter->input.i_format = VLC_FOURCC('f','l','3','2');
 382         p_filter->output.i_format = VLC_FOURCC('f','l','3','2');
 383     }
 384     if( p_filter->input.i_rate != p_filter->output.i_rate )
 385     {
 386         b_fit = false;
 387         p_filter->input.i_rate = p_filter->output.i_rate;
 388     }
 389     if( p_filter->input.i_physical_channels == (AOUT_CHAN_LEFT|AOUT_CHAN_RIGHT)
 390           && ( p_filter->input.i_original_channels & AOUT_CHAN_DOLBYSTEREO )
 391           && ! config_GetInt ( p_filter , "headphone-dolby" ) )
 392     {
 393         b_fit = false;
 394         p_filter->input.i_physical_channels = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT |
 395                                               AOUT_CHAN_CENTER |
 396                                               AOUT_CHAN_REARLEFT |
 397                                               AOUT_CHAN_REARRIGHT;
 398     }
 399     if( ! b_fit )
 400     {
 401         msg_Dbg( p_filter, "requesting specific format" );
 402         return VLC_EGENERIC;
 403     }
 404
 405     /* Allocate the memory needed to store the module's structure */
 406     p_filter->p_sys = malloc( sizeof(struct aout_filter_sys_t) );
 407     if( p_filter->p_sys == NULL )
 408         return VLC_ENOMEM;
 409     p_filter->p_sys->i_overflow_buffer_size = 0;
 410     p_filter->p_sys->p_overflow_buffer = NULL;
 411     p_filter->p_sys->i_nb_atomic_operations = 0;
 412     p_filter->p_sys->p_atomic_operations = NULL;
 413
 414     if( Init( VLC_OBJECT(p_filter), p_filter->p_sys
 415                 , aout_FormatNbChannels ( &p_filter->input )
 416                 , p_filter->input.i_physical_channels
 417                 , p_filter->input.i_rate ) < 0 )
 418     {
 419         return VLC_EGENERIC;
 420     }
 421
 422     p_filter->pf_do_work = DoWork;
 423     p_filter->b_in_place = 0;
 424
 425     return VLC_SUCCESS;
 426 }
 427
 428 /*****************************************************************************
 429  * Destroy: deallocate resources associated with headphone downmixer
 430  *****************************************************************************/
 431 static void Destroy( vlc_object_t *p_this )
 432 {
 433     aout_filter_t * p_filter = (aout_filter_t *)p_this;
 434
 435     if( p_filter->p_sys != NULL )
 436     {
 437         if( p_filter->p_sys->p_overflow_buffer != NULL )
 438         {
 439             free( p_filter->p_sys->p_overflow_buffer );
 440         }
 441         if( p_filter->p_sys->p_atomic_operations != NULL )
 442         {
 443             free( p_filter->p_sys->p_atomic_operations );
 444         }
 445         free( p_filter->p_sys );
 446         p_filter->p_sys = NULL;
 447     }
 448 }
 449
 450 /*****************************************************************************
 451  * DoWork: convert a buffer
 452  *****************************************************************************/
 453 static void DoWork( aout_instance_t * p_aout, aout_filter_t * p_filter,
 454                     aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
 455 {
 456     VLC_UNUSED(p_aout);
 457     int i_input_nb = aout_FormatNbChannels( &p_filter->input );
 458     int i_output_nb = aout_FormatNbChannels( &p_filter->output );
 459
 460     float * p_in = (float*) p_in_buf->p_buffer;
 461     uint8_t * p_out;
 462     uint8_t * p_overflow;
 463     uint8_t * p_slide;
 464
 465     size_t i_overflow_size;     /* in bytes */
 466     size_t i_out_size;          /* in bytes */
 467
 468     unsigned int i, j;
 469
 470     int i_source_channel_offset;
 471     int i_dest_channel_offset;
 472     unsigned int i_delay;
 473     double d_amplitude_factor;
 474
 475     /* out buffer characterisitcs */
 476     p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
 477     p_out_buf->i_nb_bytes = p_in_buf->i_nb_bytes * i_output_nb / i_input_nb;
 478     p_out = p_out_buf->p_buffer;
 479     i_out_size = p_out_buf->i_nb_bytes;
 480
 481     if( p_filter->p_sys != NULL )
 482     {
 483         /* Slide the overflow buffer */
 484         p_overflow = p_filter->p_sys->p_overflow_buffer;
 485         i_overflow_size = p_filter->p_sys->i_overflow_buffer_size;
 486
 487         memset( p_out, 0, i_out_size );
 488         if ( i_out_size > i_overflow_size )
 489             memcpy( p_out, p_overflow, i_overflow_size );
 490         else
 491             memcpy( p_out, p_overflow, i_out_size );
 492
 493         p_slide = p_filter->p_sys->p_overflow_buffer;
 494         while( p_slide < p_overflow + i_overflow_size )
 495         {
 496             if( p_slide + i_out_size < p_overflow + i_overflow_size )
 497             {
 498                 memset( p_slide, 0, i_out_size );
 499                 if( p_slide + 2 * i_out_size < p_overflow + i_overflow_size )
 500                     memcpy( p_slide, p_slide + i_out_size, i_out_size );
 501                 else
 502                     memcpy( p_slide, p_slide + i_out_size,
 503                             p_overflow + i_overflow_size - ( p_slide + i_out_size ) );
 504             }
 505             else
 506             {
 507                 memset( p_slide, 0, p_overflow + i_overflow_size - p_slide );
 508             }
 509             p_slide += i_out_size;
 510         }
 511
 512         /* apply the atomic operations */
 513         for( i = 0; i < p_filter->p_sys->i_nb_atomic_operations; i++ )
 514         {
 515             /* shorter variable names */
 516             i_source_channel_offset
 517                 = p_filter->p_sys->p_atomic_operations[i].i_source_channel_offset;
 518             i_dest_channel_offset
 519                 = p_filter->p_sys->p_atomic_operations[i].i_dest_channel_offset;
 520             i_delay = p_filter->p_sys->p_atomic_operations[i].i_delay;
 521             d_amplitude_factor
 522                 = p_filter->p_sys->p_atomic_operations[i].d_amplitude_factor;
 523
 524             if( p_out_buf->i_nb_samples > i_delay )
 525             {
 526                 /* current buffer coefficients */
 527                 for( j = 0; j < p_out_buf->i_nb_samples - i_delay; j++ )
 528                 {
 529                     ((float*)p_out)[ (i_delay+j)*i_output_nb + i_dest_channel_offset ]
 530                         += p_in[ j * i_input_nb + i_source_channel_offset ]
 531                            * d_amplitude_factor;
 532                 }
 533
 534                 /* overflow buffer coefficients */
 535                 for( j = 0; j < i_delay; j++ )
 536                 {
 537                     ((float*)p_overflow)[ j*i_output_nb + i_dest_channel_offset ]
 538                         += p_in[ (p_out_buf->i_nb_samples - i_delay + j)
 539                            * i_input_nb + i_source_channel_offset ]
 540                            * d_amplitude_factor;
 541                 }
 542             }
 543             else
 544             {
 545                 /* overflow buffer coefficients only */
 546                 for( j = 0; j < p_out_buf->i_nb_samples; j++ )
 547                 {
 548                     ((float*)p_overflow)[ (i_delay - p_out_buf->i_nb_samples + j)
 549                         * i_output_nb + i_dest_channel_offset ]
 550                         += p_in[ j * i_input_nb + i_source_channel_offset ]
 551                            * d_amplitude_factor;
 552                 }
 553             }
 554         }
 555     }
 556     else
 557     {
 558         memset( p_out, 0, i_out_size );
 559     }
 560 }
 561
 562 /*
 563  * Audio filter 2
 564  */
 565 /*****************************************************************************
 566  * OpenFilter:
 567  *****************************************************************************/
 568 static int OpenFilter( vlc_object_t *p_this )
 569 {
 570     filter_t *p_filter = (filter_t *)p_this;
 571     bool b_fit = true;
 572
 573     /* Activate this filter only with stereo devices */
 574     if( p_filter->fmt_out.audio.i_physical_channels
 575             != (AOUT_CHAN_LEFT|AOUT_CHAN_RIGHT) )
 576     {
 577         msg_Dbg( p_filter, "filter discarded (incompatible format)" );
 578         return VLC_EGENERIC;
 579     }
 580
 581     /* Request a specific format if not already compatible */
 582     if( p_filter->fmt_in.audio.i_original_channels
 583             != p_filter->fmt_out.audio.i_original_channels )
 584     {
 585         b_fit = false;
 586         p_filter->fmt_in.audio.i_original_channels =
 587                                         p_filter->fmt_out.audio.i_original_channels;
 588     }
 589     if( p_filter->fmt_in.audio.i_format != VLC_FOURCC('f','l','3','2')
 590           || p_filter->fmt_out.audio.i_format != VLC_FOURCC('f','l','3','2') )
 591     {
 592         b_fit = false;
 593         p_filter->fmt_in.audio.i_format = VLC_FOURCC('f','l','3','2');
 594         p_filter->fmt_out.audio.i_format = VLC_FOURCC('f','l','3','2');
 595     }
 596     if( p_filter->fmt_in.audio.i_rate != p_filter->fmt_out.audio.i_rate )
 597     {
 598         b_fit = false;
 599         p_filter->fmt_in.audio.i_rate = p_filter->fmt_out.audio.i_rate;
 600     }
 601     if( p_filter->fmt_in.audio.i_physical_channels == (AOUT_CHAN_LEFT|AOUT_CHAN_RIGHT)
 602           && ( p_filter->fmt_in.audio.i_original_channels & AOUT_CHAN_DOLBYSTEREO )
 603           && !config_GetInt( p_filter, "headphone-dolby" ) )
 604     {
 605         b_fit = false;
 606         p_filter->fmt_in.audio.i_physical_channels = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT |
 607                                               AOUT_CHAN_CENTER |
 608                                               AOUT_CHAN_REARLEFT |
 609                                               AOUT_CHAN_REARRIGHT;
 610     }
 611     if( !b_fit )
 612     {
 613         msg_Dbg( p_filter, "requesting specific format" );
 614         return VLC_EGENERIC;
 615     }
 616
 617     /* Allocate the memory needed to store the module's structure */
 618     p_filter->p_sys = malloc( sizeof(struct filter_sys_t) );
 619     if( p_filter->p_sys == NULL )
 620         return VLC_ENOMEM;
 621     p_filter->p_sys->i_overflow_buffer_size = 0;
 622     p_filter->p_sys->p_overflow_buffer = NULL;
 623     p_filter->p_sys->i_nb_atomic_operations = 0;
 624     p_filter->p_sys->p_atomic_operations = NULL;
 625
 626     if( Init( VLC_OBJECT(p_filter), (struct aout_filter_sys_t *)p_filter->p_sys
 627                 , aout_FormatNbChannels ( &(p_filter->fmt_in.audio) )
 628                 , p_filter->fmt_in.audio.i_physical_channels
 629                 , p_filter->fmt_in.audio.i_rate ) < 0 )
 630     {
 631         return VLC_EGENERIC;
 632     }
 633
 634     p_filter->pf_audio_filter = Convert;
 635     p_filter->fmt_out.audio.i_rate = p_filter->fmt_in.audio.i_rate;
 636
 637     return VLC_SUCCESS;
 638 }
 639
 640 /*****************************************************************************
 641  * CloseFilter : deallocate data structures
 642  *****************************************************************************/
 643 static void CloseFilter( vlc_object_t *p_this )
 644 {
 645     filter_t *p_filter = (filter_t *)p_this;
 646
 647     if( p_filter->p_sys != NULL )
 648     {
 649         if( p_filter->p_sys->p_overflow_buffer != NULL )
 650         {
 651             free ( p_filter->p_sys->p_overflow_buffer );
 652         }
 653         if( p_filter->p_sys->p_atomic_operations != NULL )
 654         {
 655             free ( p_filter->p_sys->p_atomic_operations );
 656         }
 657         free( p_filter->p_sys );
 658         p_filter->p_sys = NULL;
 659     }
 660 }
 661
 662 static block_t *Convert( filter_t *p_filter, block_t *p_block )
 663 {
 664     aout_filter_t aout_filter;
 665     aout_buffer_t in_buf, out_buf;
 666     block_t *p_out;
 667     int i_out_size;
 668
 669     if( !p_block || !p_block->i_samples )
 670     {
 671         if( p_block ) p_block->pf_release( p_block );
 672         return NULL;
 673     }
 674
 675     i_out_size = p_block->i_samples *
 676       p_filter->fmt_out.audio.i_bitspersample/8 *
 677         aout_FormatNbChannels( &(p_filter->fmt_out.audio) );
 678
 679     p_out = p_filter->pf_audio_buffer_new( p_filter, i_out_size );
 680     if( !p_out )
 681     {
 682         msg_Warn( p_filter, "can't get output buffer" );
 683         if( p_block ) p_block->pf_release( p_block );
 684         return NULL;
 685     }
 686
 687     p_out->i_samples = p_block->i_samples;
 688     p_out->i_dts = p_block->i_dts;
 689     p_out->i_pts = p_block->i_pts;
 690     p_out->i_length = p_block->i_length;
 691
 692     aout_filter.p_sys = (struct aout_filter_sys_t *)p_filter->p_sys;
 693     aout_filter.input = p_filter->fmt_in.audio;
 694     aout_filter.input.i_format = p_filter->fmt_in.i_codec;
 695     aout_filter.output = p_filter->fmt_out.audio;
 696     aout_filter.output.i_format = p_filter->fmt_out.i_codec;
 697     aout_filter.b_in_place = 0;
 698
 699     in_buf.p_buffer = p_block->p_buffer;
 700     in_buf.i_nb_bytes = p_block->i_buffer;
 701     in_buf.i_nb_samples = p_block->i_samples;
 702     out_buf.p_buffer = p_out->p_buffer;
 703     out_buf.i_nb_bytes = p_out->i_buffer;
 704     out_buf.i_nb_samples = p_out->i_samples;
 705
 706     DoWork( (aout_instance_t *)p_filter, &aout_filter, &in_buf, &out_buf );
 707
 708     p_out->i_buffer = out_buf.i_nb_bytes;
 709     p_out->i_samples = out_buf.i_nb_samples;
 710
 711     if( p_block ) p_block->pf_release( p_block );
 712     return p_out;
 713 }