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) 2002-2005 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 "audio_output.h"
  34 #include "aout_internal.h"
  35
  36 /*****************************************************************************
  37  * Local prototypes
  38  *****************************************************************************/
  39 static int  Create    ( vlc_object_t * );
  40 static void Destroy   ( vlc_object_t * );
  41
  42 static void DoWork    ( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
  43                         aout_buffer_t * );
  44
  45 /*****************************************************************************
  46  * Module descriptor
  47  *****************************************************************************/
  48 #define MODULE_DESCRIPTION N_ ( \
  49      "This effect gives you the feeling that you are standing in a room " \
  50      "with a complete 7.1 speaker set when using only a headphone, " \
  51      "providing a more realistic sound experience. It should also be " \
  52      "more comfortable and less tiring when listening to music for " \
  53      "long periods of time.\nIt works with any source format from mono " \
  54      "to 7.1.")
  55
  56 #define HEADPHONE_DIM_TEXT N_("Characteristic dimension")
  57 #define HEADPHONE_DIM_LONGTEXT N_( \
  58      "Distance between front left speaker and listener in meters.")
  59
  60 #define HEADPHONE_COMPENSATE_TEXT N_("Compensate delay")
  61 #define HEADPHONE_COMPENSATE_LONGTEXT N_( \
  62      "The delay which is introduced by the physical algorithm may "\
  63      "sometimes be disturbing for the lipsync. In that case, turn "\
  64      "this on to compensate.")
  65
  66 #define HEADPHONE_DOLBY_TEXT N_("No decoding of Dolby Surround")
  67 #define HEADPHONE_DOLBY_LONGTEXT N_( \
  68      "Dolby Surround encoded streams won't be decoded before being " \
  69      "processed by this filter. Enabling this setting is not recommended.")
  70
  71 vlc_module_begin();
  72     set_description( N_("Headphone virtual spatialization effect") );
  73     set_shortname( _("Headphone effect") );
  74     set_category( CAT_AUDIO );
  75     set_subcategory( SUBCAT_AUDIO_AFILTER );
  76
  77     add_integer( "headphone-dim", 10, NULL, HEADPHONE_DIM_TEXT,
  78                  HEADPHONE_DIM_LONGTEXT, VLC_FALSE );
  79     add_bool( "headphone-compensate", 0, NULL, HEADPHONE_COMPENSATE_TEXT,
  80               HEADPHONE_COMPENSATE_LONGTEXT, VLC_TRUE );
  81     add_bool( "headphone-dolby", 0, NULL, HEADPHONE_DOLBY_TEXT,
  82               HEADPHONE_DOLBY_LONGTEXT, VLC_TRUE );
  83
  84     set_capability( "audio filter", 0 );
  85     set_callbacks( Create, Destroy );
  86     add_shortcut( "headphone" );
  87 vlc_module_end();
  88
  89
  90 /*****************************************************************************
  91  * Internal data structures
  92  *****************************************************************************/
  93 struct atomic_operation_t
  94 {
  95     int i_source_channel_offset;
  96     int i_dest_channel_offset;
  97     unsigned int i_delay;/* in sample unit */
  98     double d_amplitude_factor;
  99 };
 100
 101 struct aout_filter_sys_t
 102 {
 103     size_t i_overflow_buffer_size;/* in bytes */
 104     byte_t * p_overflow_buffer;
 105     unsigned int i_nb_atomic_operations;
 106     struct atomic_operation_t * p_atomic_operations;
 107 };
 108
 109 /*****************************************************************************
 110  * Init: initialize internal data structures
 111  * and computes the needed atomic operations
 112  *****************************************************************************/
 113 /* x and z represent the coordinates of the virtual speaker
 114  *  relatively to the center of the listener's head, measured in meters :
 115  *
 116  *  left              right
 117  *Z
 118  *-
 119  *a          head
 120  *x
 121  *i
 122  *s
 123  *  rear left    rear right
 124  *
 125  *          x-axis
 126  *  */
 127 static void ComputeChannelOperations ( struct aout_filter_sys_t * p_data
 128         , unsigned int i_rate , unsigned int i_next_atomic_operation
 129         , int i_source_channel_offset , double d_x , double d_z
 130         , double d_compensation_length , double d_channel_amplitude_factor )
 131 {
 132     double d_c = 340; /*sound celerity (unit: m/s)*/
 133     double d_compensation_delay = (d_compensation_length-0.1) / d_c * i_rate;
 134
 135     /* Left ear */
 136     p_data->p_atomic_operations[i_next_atomic_operation]
 137         .i_source_channel_offset = i_source_channel_offset;
 138     p_data->p_atomic_operations[i_next_atomic_operation]
 139         .i_dest_channel_offset = 0;/* left */
 140     p_data->p_atomic_operations[i_next_atomic_operation]
 141         .i_delay = (int)( sqrt( (-0.1-d_x)*(-0.1-d_x) + (0-d_z)*(0-d_z) )
 142                           / d_c * i_rate - d_compensation_delay );
 143     if ( d_x < 0 )
 144     {
 145         p_data->p_atomic_operations[i_next_atomic_operation]
 146             .d_amplitude_factor = d_channel_amplitude_factor * 1.1 / 2;
 147     }
 148     else if ( d_x > 0 )
 149     {
 150         p_data->p_atomic_operations[i_next_atomic_operation]
 151             .d_amplitude_factor = d_channel_amplitude_factor * 0.9 / 2;
 152     }
 153     else
 154     {
 155         p_data->p_atomic_operations[i_next_atomic_operation]
 156             .d_amplitude_factor = d_channel_amplitude_factor / 2;
 157     }
 158
 159     /* Right ear */
 160     p_data->p_atomic_operations[i_next_atomic_operation + 1]
 161         .i_source_channel_offset = i_source_channel_offset;
 162     p_data->p_atomic_operations[i_next_atomic_operation + 1]
 163         .i_dest_channel_offset = 1;/* right */
 164     p_data->p_atomic_operations[i_next_atomic_operation + 1]
 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 + 1]
 170             .d_amplitude_factor = d_channel_amplitude_factor * 0.9 / 2;
 171     }
 172     else if ( d_x > 0 )
 173     {
 174         p_data->p_atomic_operations[i_next_atomic_operation + 1]
 175             .d_amplitude_factor = d_channel_amplitude_factor * 1.1 / 2;
 176     }
 177     else
 178     {
 179         p_data->p_atomic_operations[i_next_atomic_operation + 1]
 180             .d_amplitude_factor = d_channel_amplitude_factor / 2;
 181     }
 182 }
 183
 184 static int Init ( aout_filter_t * p_filter , struct aout_filter_sys_t * p_data
 185         , unsigned int i_nb_channels , uint32_t i_physical_channels
 186         , unsigned int i_rate )
 187 {
 188     double d_x = config_GetInt ( p_filter , "headphone-dim" );
 189     double d_z = d_x;
 190     double d_z_rear = -d_x/3;
 191     double d_min = 0;
 192     unsigned int i_next_atomic_operation;
 193     int i_source_channel_offset;
 194     unsigned int i;
 195
 196     if ( p_data == NULL )
 197     {
 198         msg_Dbg ( p_filter, "passing a null pointer as argument" );
 199         return 0;
 200     }
 201
 202     if ( config_GetInt ( p_filter , "headphone-compensate" ) )
 203     {
 204         /* minimal distance to any speaker */
 205         if ( i_physical_channels & AOUT_CHAN_REARCENTER )
 206         {
 207             d_min = d_z_rear;
 208         }
 209         else
 210         {
 211             d_min = d_z;
 212         }
 213     }
 214
 215     /* Number of elementary operations */
 216     p_data->i_nb_atomic_operations = i_nb_channels * 2;
 217     if ( i_physical_channels & AOUT_CHAN_CENTER )
 218     {
 219         p_data->i_nb_atomic_operations += 2;
 220     }
 221     p_data->p_atomic_operations = malloc ( sizeof(struct atomic_operation_t)
 222             * p_data->i_nb_atomic_operations );
 223     if ( p_data->p_atomic_operations == NULL )
 224     {
 225         msg_Err( p_filter, "out of memory" );
 226         return -1;
 227     }
 228
 229     /* For each virtual speaker, computes elementary wave propagation time
 230      * to each ear */
 231     i_next_atomic_operation = 0;
 232     i_source_channel_offset = 0;
 233     if ( i_physical_channels & AOUT_CHAN_LEFT )
 234     {
 235         ComputeChannelOperations ( p_data , i_rate
 236                 , i_next_atomic_operation , i_source_channel_offset
 237                 , -d_x , d_z , d_min , 2.0 / i_nb_channels );
 238         i_next_atomic_operation += 2;
 239         i_source_channel_offset++;
 240     }
 241     if ( i_physical_channels & AOUT_CHAN_RIGHT )
 242     {
 243         ComputeChannelOperations ( p_data , i_rate
 244                 , i_next_atomic_operation , i_source_channel_offset
 245                 , d_x , d_z , d_min , 2.0 / i_nb_channels );
 246         i_next_atomic_operation += 2;
 247         i_source_channel_offset++;
 248     }
 249     if ( i_physical_channels & AOUT_CHAN_MIDDLELEFT )
 250     {
 251         ComputeChannelOperations ( p_data , i_rate
 252                 , i_next_atomic_operation , i_source_channel_offset
 253                 , -d_x , 0 , d_min , 1.5 / i_nb_channels );
 254         i_next_atomic_operation += 2;
 255         i_source_channel_offset++;
 256     }
 257     if ( i_physical_channels & AOUT_CHAN_MIDDLERIGHT )
 258     {
 259         ComputeChannelOperations ( p_data , i_rate
 260                 , i_next_atomic_operation , i_source_channel_offset
 261                 , d_x , 0 , d_min , 1.5 / i_nb_channels );
 262         i_next_atomic_operation += 2;
 263         i_source_channel_offset++;
 264     }
 265     if ( i_physical_channels & AOUT_CHAN_REARLEFT )
 266     {
 267         ComputeChannelOperations ( p_data , i_rate
 268                 , i_next_atomic_operation , i_source_channel_offset
 269                 , -d_x , d_z_rear , d_min , 1.5 / i_nb_channels );
 270         i_next_atomic_operation += 2;
 271         i_source_channel_offset++;
 272     }
 273     if ( i_physical_channels & AOUT_CHAN_REARRIGHT )
 274     {
 275         ComputeChannelOperations ( p_data , i_rate
 276                 , i_next_atomic_operation , i_source_channel_offset
 277                 , d_x , d_z_rear , 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_REARCENTER )
 282     {
 283         ComputeChannelOperations ( p_data , i_rate
 284                 , i_next_atomic_operation , i_source_channel_offset
 285                 , 0 , -d_z , 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_CENTER )
 290     {
 291         /* having two center channels increases the spatialization effect */
 292         ComputeChannelOperations ( p_data , i_rate
 293                 , i_next_atomic_operation , i_source_channel_offset
 294                 , d_x / 5.0 , d_z , d_min , 0.75 / i_nb_channels );
 295         i_next_atomic_operation += 2;
 296         ComputeChannelOperations ( p_data , i_rate
 297                 , i_next_atomic_operation , i_source_channel_offset
 298                 , -d_x / 5.0 , d_z , d_min , 0.75 / i_nb_channels );
 299         i_next_atomic_operation += 2;
 300         i_source_channel_offset++;
 301     }
 302     if ( i_physical_channels & AOUT_CHAN_LFE )
 303     {
 304         ComputeChannelOperations ( p_data , i_rate
 305                 , i_next_atomic_operation , i_source_channel_offset
 306                 , 0 , d_z_rear , d_min , 5.0 / i_nb_channels );
 307         i_next_atomic_operation += 2;
 308         i_source_channel_offset++;
 309     }
 310
 311     /* Initialize the overflow buffer
 312      * we need it because the process induce a delay in the samples */
 313     p_data->i_overflow_buffer_size = 0;
 314     for ( i = 0 ; i < p_data->i_nb_atomic_operations ; i++ )
 315     {
 316         if ( p_data->i_overflow_buffer_size
 317                 < p_data->p_atomic_operations[i].i_delay * 2 * sizeof (float) )
 318         {
 319             p_data->i_overflow_buffer_size
 320                 = p_data->p_atomic_operations[i].i_delay * 2 * sizeof (float);
 321         }
 322     }
 323     p_data->p_overflow_buffer = malloc ( p_data->i_overflow_buffer_size );
 324     if ( p_data->p_atomic_operations == NULL )
 325     {
 326         msg_Err( p_filter, "out of memory" );
 327         return -1;
 328     }
 329     memset ( p_data->p_overflow_buffer , 0 , p_data->i_overflow_buffer_size );
 330
 331     /* end */
 332     return 0;
 333 }
 334
 335 /*****************************************************************************
 336  * Create: allocate headphone downmixer
 337  *****************************************************************************/
 338 static int Create( vlc_object_t *p_this )
 339 {
 340     aout_filter_t * p_filter = (aout_filter_t *)p_this;
 341     vlc_bool_t b_fit = VLC_TRUE;
 342
 343     /* Activate this filter only with stereo devices */
 344     if ( p_filter->output.i_physical_channels
 345             != (AOUT_CHAN_LEFT|AOUT_CHAN_RIGHT) )
 346     {
 347         msg_Dbg( p_filter, "Filter discarded (incompatible format)" );
 348         return VLC_EGENERIC;
 349     }
 350
 351     /* Request a specific format if not already compatible */
 352     if ( p_filter->input.i_original_channels
 353             != p_filter->output.i_original_channels )
 354     {
 355         b_fit = VLC_FALSE;
 356         p_filter->input.i_original_channels =
 357                                         p_filter->output.i_original_channels;
 358     }
 359     if ( p_filter->input.i_format != VLC_FOURCC('f','l','3','2')
 360           || p_filter->output.i_format != VLC_FOURCC('f','l','3','2') )
 361     {
 362         b_fit = VLC_FALSE;
 363         p_filter->input.i_format = VLC_FOURCC('f','l','3','2');
 364         p_filter->output.i_format = VLC_FOURCC('f','l','3','2');
 365     }
 366     if ( p_filter->input.i_rate != p_filter->output.i_rate )
 367     {
 368         b_fit = VLC_FALSE;
 369         p_filter->input.i_rate = p_filter->output.i_rate;
 370     }
 371     if ( p_filter->input.i_physical_channels == (AOUT_CHAN_LEFT|AOUT_CHAN_RIGHT)
 372           && ( p_filter->input.i_original_channels & AOUT_CHAN_DOLBYSTEREO )
 373           && ! config_GetInt ( p_filter , "headphone-dolby" ) )
 374     {
 375         b_fit = VLC_FALSE;
 376         p_filter->input.i_physical_channels = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT |
 377                                               AOUT_CHAN_CENTER |
 378                                               AOUT_CHAN_REARLEFT |
 379                                               AOUT_CHAN_REARRIGHT;
 380     }
 381     if ( ! b_fit )
 382     {
 383         msg_Dbg( p_filter, "Requesting specific format" );
 384         return VLC_EGENERIC;
 385     }
 386
 387     /* Allocate the memory needed to store the module's structure */
 388     p_filter->p_sys = malloc( sizeof(struct aout_filter_sys_t) );
 389     if ( p_filter->p_sys == NULL )
 390     {
 391         msg_Err( p_filter, "Out of memory" );
 392         return VLC_EGENERIC;
 393     }
 394     p_filter->p_sys->i_overflow_buffer_size = 0;
 395     p_filter->p_sys->p_overflow_buffer = NULL;
 396     p_filter->p_sys->i_nb_atomic_operations = 0;
 397     p_filter->p_sys->p_atomic_operations = NULL;
 398
 399     if ( Init( p_filter , p_filter->p_sys
 400                 , aout_FormatNbChannels ( &p_filter->input )
 401                 , p_filter->input.i_physical_channels
 402                 , p_filter->input.i_rate ) < 0 )
 403     {
 404         return VLC_EGENERIC;
 405     }
 406
 407     p_filter->pf_do_work = DoWork;
 408     p_filter->b_in_place = 0;
 409
 410     return VLC_SUCCESS;
 411 }
 412
 413 /*****************************************************************************
 414  * Destroy: deallocate resources associated with headphone downmixer
 415  *****************************************************************************/
 416 static void Destroy( vlc_object_t *p_this )
 417 {
 418     aout_filter_t * p_filter = (aout_filter_t *)p_this;
 419
 420     if ( p_filter->p_sys != NULL )
 421     {
 422         if ( p_filter->p_sys->p_overflow_buffer != NULL )
 423         {
 424             free ( p_filter->p_sys->p_overflow_buffer );
 425         }
 426         if ( p_filter->p_sys->p_atomic_operations != NULL )
 427         {
 428             free ( p_filter->p_sys->p_atomic_operations );
 429         }
 430         free ( p_filter->p_sys );
 431         p_filter->p_sys = NULL;
 432     }
 433 }
 434
 435 /*****************************************************************************
 436  * DoWork: convert a buffer
 437  *****************************************************************************/
 438 static void DoWork( aout_instance_t * p_aout, aout_filter_t * p_filter,
 439                     aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
 440 {
 441     int i_input_nb = aout_FormatNbChannels( &p_filter->input );
 442     int i_output_nb = aout_FormatNbChannels( &p_filter->output );
 443
 444     float * p_in = (float*) p_in_buf->p_buffer;
 445     byte_t * p_out;
 446     byte_t * p_overflow;
 447     byte_t * p_slide;
 448
 449     size_t i_overflow_size;/* in bytes */
 450     size_t i_out_size;/* in bytes */
 451
 452     unsigned int i, j;
 453
 454     int i_source_channel_offset;
 455     int i_dest_channel_offset;
 456     unsigned int i_delay;
 457     double d_amplitude_factor;
 458
 459
 460     /* out buffer characterisitcs */
 461     p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
 462     p_out_buf->i_nb_bytes = p_in_buf->i_nb_bytes * i_output_nb / i_input_nb;
 463     p_out = p_out_buf->p_buffer;
 464     i_out_size = p_out_buf->i_nb_bytes;
 465
 466     if ( p_filter->p_sys != NULL )
 467     {
 468         /* Slide the overflow buffer */
 469         p_overflow = p_filter->p_sys->p_overflow_buffer;
 470         i_overflow_size = p_filter->p_sys->i_overflow_buffer_size;
 471
 472         memset ( p_out , 0 , i_out_size );
 473         if ( i_out_size > i_overflow_size )
 474             memcpy ( p_out , p_overflow , i_overflow_size );
 475         else
 476             memcpy ( p_out , p_overflow , i_out_size );
 477
 478         p_slide = p_filter->p_sys->p_overflow_buffer;
 479         while ( p_slide < p_overflow + i_overflow_size )
 480         {
 481             if ( p_slide + i_out_size < p_overflow + i_overflow_size )
 482             {
 483                 memset ( p_slide , 0 , i_out_size );
 484                 if ( p_slide + 2 * i_out_size < p_overflow + i_overflow_size )
 485                     memcpy ( p_slide , p_slide + i_out_size , i_out_size );
 486                 else
 487                     memcpy ( p_slide , p_slide + i_out_size
 488                       , p_overflow + i_overflow_size - ( p_slide + i_out_size ) );
 489             }
 490             else
 491             {
 492                 memset ( p_slide , 0 , p_overflow + i_overflow_size - p_slide );
 493             }
 494             p_slide += i_out_size;
 495         }
 496
 497         /* apply the atomic operations */
 498         for ( i = 0 ; i < p_filter->p_sys->i_nb_atomic_operations ; i++ )
 499         {
 500             /* shorter variable names */
 501             i_source_channel_offset
 502                 = p_filter->p_sys->p_atomic_operations[i].i_source_channel_offset;
 503             i_dest_channel_offset
 504                 = p_filter->p_sys->p_atomic_operations[i].i_dest_channel_offset;
 505             i_delay = p_filter->p_sys->p_atomic_operations[i].i_delay;
 506             d_amplitude_factor
 507                 = p_filter->p_sys->p_atomic_operations[i].d_amplitude_factor;
 508
 509             if ( p_out_buf->i_nb_samples > i_delay )
 510             {
 511                 /* current buffer coefficients */
 512                 for ( j = 0 ; j < p_out_buf->i_nb_samples - i_delay ; j++ )
 513                 {
 514                     ((float*)p_out)[ (i_delay+j)*i_output_nb + i_dest_channel_offset ]
 515                         += p_in[ j * i_input_nb + i_source_channel_offset ]
 516                            * d_amplitude_factor;
 517                 }
 518
 519                 /* overflow buffer coefficients */
 520                 for ( j = 0 ; j < i_delay ; j++ )
 521                 {
 522                     ((float*)p_overflow)[ j*i_output_nb + i_dest_channel_offset ]
 523                         += p_in[ (p_out_buf->i_nb_samples - i_delay + j)
 524                            * i_input_nb + i_source_channel_offset ]
 525                            * d_amplitude_factor;
 526                 }
 527             }
 528             else
 529             {
 530                 /* overflow buffer coefficients only */
 531                 for ( j = 0 ; j < p_out_buf->i_nb_samples ; j++ )
 532                 {
 533                     ((float*)p_overflow)[ (i_delay - p_out_buf->i_nb_samples + j)
 534                         * 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         }
 540     }
 541     else
 542     {
 543         memset ( p_out , 0 , i_out_size );
 544     }
 545 }