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., 59 Temple Place - Suite 330, Boston, MA  02111, 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 vlc_module_begin();
  61     set_description( N_("Headphone channel mixer with virtual spatialization effect") );
  62     set_shortname( _("Headphone effect") );
  63     set_category( CAT_AUDIO );
  64     set_subcategory( SUBCAT_AUDIO_AFILTER );
  65
  66     add_integer( "headphone-dim", 10, NULL, HEADPHONE_DIM_TEXT,
  67                  HEADPHONE_DIM_LONGTEXT, VLC_FALSE );
  68
  69     set_capability( "audio filter", 0 );
  70     set_callbacks( Create, Destroy );
  71     add_shortcut( "headphone" );
  72 vlc_module_end();
  73
  74
  75 /*****************************************************************************
  76  * Internal data structures
  77  *****************************************************************************/
  78 struct atomic_operation_t
  79 {
  80     int i_source_channel_offset;
  81     int i_dest_channel_offset;
  82     unsigned int i_delay;/* in sample unit */
  83     double d_amplitude_factor;
  84 };
  85
  86 struct aout_filter_sys_t
  87 {
  88     size_t i_overflow_buffer_size;/* in bytes */
  89     byte_t * p_overflow_buffer;
  90     unsigned int i_nb_atomic_operations;
  91     struct atomic_operation_t * p_atomic_operations;
  92 };
  93
  94 /*****************************************************************************
  95  * Init: initialize internal data structures
  96  * and computes the needed atomic operations
  97  *****************************************************************************/
  98 /* x and z represent the coordinates of the virtual speaker
  99  *  relatively to the center of the listener's head, measured in meters :
 100  *
 101  *  left              right
 102  *Z
 103  *-
 104  *a          head
 105  *x
 106  *i
 107  *s
 108  *  rear left    rear right
 109  *
 110  *          x-axis
 111  *  */
 112 static void ComputeChannelOperations ( struct aout_filter_sys_t * p_data
 113         , unsigned int i_rate , unsigned int i_next_atomic_operation
 114         , int i_source_channel_offset , double d_x , double d_z
 115         , double d_channel_amplitude_factor )
 116 {
 117     double d_c = 340; /*sound celerity (unit: m/s)*/
 118
 119     /* Left ear */
 120     p_data->p_atomic_operations[i_next_atomic_operation]
 121         .i_source_channel_offset = i_source_channel_offset;
 122     p_data->p_atomic_operations[i_next_atomic_operation]
 123         .i_dest_channel_offset = 0;/* left */
 124     p_data->p_atomic_operations[i_next_atomic_operation]
 125         .i_delay = (int)( sqrt( (-0.1-d_x)*(-0.1-d_x) + (0-d_z)*(0-d_z) )
 126                           / d_c * i_rate );
 127     if ( d_x < 0 )
 128     {
 129         p_data->p_atomic_operations[i_next_atomic_operation]
 130             .d_amplitude_factor = d_channel_amplitude_factor * 1.1 / 2;
 131     }
 132     else if ( d_x > 0 )
 133     {
 134         p_data->p_atomic_operations[i_next_atomic_operation]
 135             .d_amplitude_factor = d_channel_amplitude_factor * 0.9 / 2;
 136     }
 137     else
 138     {
 139         p_data->p_atomic_operations[i_next_atomic_operation]
 140             .d_amplitude_factor = d_channel_amplitude_factor / 2;
 141     }
 142
 143     /* Right ear */
 144     p_data->p_atomic_operations[i_next_atomic_operation + 1]
 145         .i_source_channel_offset = i_source_channel_offset;
 146     p_data->p_atomic_operations[i_next_atomic_operation + 1]
 147         .i_dest_channel_offset = 1;/* right */
 148     p_data->p_atomic_operations[i_next_atomic_operation + 1]
 149         .i_delay = (int)( sqrt( (0.1-d_x)*(0.1-d_x) + (0-d_z)*(0-d_z) )
 150                           / d_c * i_rate );
 151     if ( d_x < 0 )
 152     {
 153         p_data->p_atomic_operations[i_next_atomic_operation + 1]
 154             .d_amplitude_factor = d_channel_amplitude_factor * 0.9 / 2;
 155     }
 156     else if ( d_x > 0 )
 157     {
 158         p_data->p_atomic_operations[i_next_atomic_operation + 1]
 159             .d_amplitude_factor = d_channel_amplitude_factor * 1.1 / 2;
 160     }
 161     else
 162     {
 163         p_data->p_atomic_operations[i_next_atomic_operation + 1]
 164             .d_amplitude_factor = d_channel_amplitude_factor / 2;
 165     }
 166 }
 167
 168 static int Init ( aout_filter_t * p_filter , struct aout_filter_sys_t * p_data
 169         , unsigned int i_nb_channels , uint32_t i_physical_channels
 170         , unsigned int i_rate )
 171 {
 172     double d_x = config_GetInt ( p_filter , "headphone-dim" );
 173     double d_z = d_x;
 174     double d_z_rear = -d_x/3;
 175     unsigned int i_next_atomic_operation;
 176     int i_source_channel_offset;
 177     unsigned int i;
 178
 179     if ( p_data == NULL )
 180     {
 181         msg_Dbg ( p_filter, "passing a null pointer as argument" );
 182         return 0;
 183     }
 184
 185     /* Number of elementary operations */
 186     p_data->i_nb_atomic_operations = i_nb_channels * 2;
 187     if ( i_physical_channels & AOUT_CHAN_CENTER )
 188     {
 189         p_data->i_nb_atomic_operations += 2;
 190     }
 191     p_data->p_atomic_operations = malloc ( sizeof(struct atomic_operation_t)
 192             * p_data->i_nb_atomic_operations );
 193     if ( p_data->p_atomic_operations == NULL )
 194     {
 195         msg_Err( p_filter, "out of memory" );
 196         return -1;
 197     }
 198
 199     /* For each virtual speaker, computes elementary wave propagation time
 200      * to each ear */
 201     i_next_atomic_operation = 0;
 202     i_source_channel_offset = 0;
 203     if ( i_physical_channels & AOUT_CHAN_LEFT )
 204     {
 205         ComputeChannelOperations ( p_data , i_rate
 206                 , i_next_atomic_operation , i_source_channel_offset
 207                 , -d_x , d_z , 2.0 / i_nb_channels );
 208         i_next_atomic_operation += 2;
 209         i_source_channel_offset++;
 210     }
 211     if ( i_physical_channels & AOUT_CHAN_RIGHT )
 212     {
 213         ComputeChannelOperations ( p_data , i_rate
 214                 , i_next_atomic_operation , i_source_channel_offset
 215                 , d_x , d_z , 2.0 / i_nb_channels );
 216         i_next_atomic_operation += 2;
 217         i_source_channel_offset++;
 218     }
 219     if ( i_physical_channels & AOUT_CHAN_MIDDLELEFT )
 220     {
 221         ComputeChannelOperations ( p_data , i_rate
 222                 , i_next_atomic_operation , i_source_channel_offset
 223                 , -d_x , 0 , 1.5 / i_nb_channels );
 224         i_next_atomic_operation += 2;
 225         i_source_channel_offset++;
 226     }
 227     if ( i_physical_channels & AOUT_CHAN_MIDDLERIGHT )
 228     {
 229         ComputeChannelOperations ( p_data , i_rate
 230                 , i_next_atomic_operation , i_source_channel_offset
 231                 , d_x , 0 , 1.5 / i_nb_channels );
 232         i_next_atomic_operation += 2;
 233         i_source_channel_offset++;
 234     }
 235     if ( i_physical_channels & AOUT_CHAN_REARLEFT )
 236     {
 237         ComputeChannelOperations ( p_data , i_rate
 238                 , i_next_atomic_operation , i_source_channel_offset
 239                 , -d_x , d_z_rear , 1.5 / i_nb_channels );
 240         i_next_atomic_operation += 2;
 241         i_source_channel_offset++;
 242     }
 243     if ( i_physical_channels & AOUT_CHAN_REARRIGHT )
 244     {
 245         ComputeChannelOperations ( p_data , i_rate
 246                 , i_next_atomic_operation , i_source_channel_offset
 247                 , d_x , d_z_rear , 1.5 / i_nb_channels );
 248         i_next_atomic_operation += 2;
 249         i_source_channel_offset++;
 250     }
 251     if ( i_physical_channels & AOUT_CHAN_REARCENTER )
 252     {
 253         ComputeChannelOperations ( p_data , i_rate
 254                 , i_next_atomic_operation , i_source_channel_offset
 255                 , 0 , -d_z , 1.5 / i_nb_channels );
 256         i_next_atomic_operation += 2;
 257         i_source_channel_offset++;
 258     }
 259     if ( i_physical_channels & AOUT_CHAN_CENTER )
 260     {
 261         /* having two center channels increases the spatialization effect */
 262         ComputeChannelOperations ( p_data , i_rate
 263                 , i_next_atomic_operation , i_source_channel_offset
 264                 , d_x / 5.0 , d_z , 0.75 / i_nb_channels );
 265         i_next_atomic_operation += 2;
 266         ComputeChannelOperations ( p_data , i_rate
 267                 , i_next_atomic_operation , i_source_channel_offset
 268                 , -d_x / 5.0 , d_z , 0.75 / i_nb_channels );
 269         i_next_atomic_operation += 2;
 270         i_source_channel_offset++;
 271     }
 272     if ( i_physical_channels & AOUT_CHAN_LFE )
 273     {
 274         ComputeChannelOperations ( p_data , i_rate
 275                 , i_next_atomic_operation , i_source_channel_offset
 276                 , 0 , d_z_rear , 5.0 / i_nb_channels );
 277         i_next_atomic_operation += 2;
 278         i_source_channel_offset++;
 279     }
 280
 281     /* Initialize the overflow buffer
 282      * we need it because the process induce a delay in the samples */
 283     p_data->i_overflow_buffer_size = 0;
 284     for ( i = 0 ; i < p_data->i_nb_atomic_operations ; i++ )
 285     {
 286         if ( p_data->i_overflow_buffer_size
 287                 < p_data->p_atomic_operations[i].i_delay * i_nb_channels
 288                 * sizeof (float) )
 289         {
 290             p_data->i_overflow_buffer_size
 291                 = p_data->p_atomic_operations[i].i_delay * i_nb_channels
 292                 * sizeof (float);
 293         }
 294     }
 295     p_data->p_overflow_buffer = malloc ( p_data->i_overflow_buffer_size );
 296     if ( p_data->p_atomic_operations == NULL )
 297     {
 298         msg_Err( p_filter, "out of memory" );
 299         return -1;
 300     }
 301     memset ( p_data->p_overflow_buffer , 0 , p_data->i_overflow_buffer_size );
 302
 303     /* end */
 304     return 0;
 305 }
 306
 307 /*****************************************************************************
 308  * Create: allocate headphone downmixer
 309  *****************************************************************************/
 310 static int Create( vlc_object_t *p_this )
 311 {
 312     aout_filter_t * p_filter = (aout_filter_t *)p_this;
 313     vlc_bool_t b_fit = VLC_TRUE;
 314
 315     /* Activate this filter only with stereo devices */
 316     if ( p_filter->output.i_physical_channels != (AOUT_CHAN_LEFT|AOUT_CHAN_RIGHT)
 317           || p_filter->output.i_physical_channels
 318                 != ( p_filter->output.i_original_channels & AOUT_CHAN_PHYSMASK )
 319           || p_filter->input.i_physical_channels
 320                 != ( p_filter->input.i_original_channels & AOUT_CHAN_PHYSMASK ) )
 321     {
 322         msg_Dbg( p_filter, "Filter discarded (incompatible format)" );
 323         return VLC_EGENERIC;
 324     }
 325
 326     /* Request a specific format if not already compatible */
 327     if ( p_filter->input.i_format != VLC_FOURCC('f','l','3','2')
 328           || p_filter->output.i_format != VLC_FOURCC('f','l','3','2') )
 329     {
 330         b_fit = VLC_FALSE;
 331         p_filter->input.i_format = VLC_FOURCC('f','l','3','2');
 332         p_filter->output.i_format = VLC_FOURCC('f','l','3','2');
 333     }
 334     if ( p_filter->input.i_rate != p_filter->output.i_rate )
 335     {
 336         b_fit = VLC_FALSE;
 337         p_filter->input.i_rate = p_filter->output.i_rate;
 338     }
 339     if ( p_filter->input.i_physical_channels == (AOUT_CHAN_LEFT|AOUT_CHAN_RIGHT)
 340           && ( p_filter->input.i_original_channels & AOUT_CHAN_DOLBYSTEREO ) )
 341     {
 342         b_fit = VLC_FALSE;
 343         p_filter->input.i_physical_channels = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT |
 344                                               AOUT_CHAN_CENTER |
 345                                               AOUT_CHAN_REARLEFT |
 346                                               AOUT_CHAN_REARRIGHT;
 347         p_filter->input.i_original_channels = p_filter->input.i_physical_channels;
 348     }
 349     if ( ! b_fit )
 350     {
 351         msg_Dbg( p_filter, "Requesting specific format" );
 352         return VLC_EGENERIC;
 353     }
 354
 355     /* Allocate the memory needed to store the module's structure */
 356     p_filter->p_sys = malloc( sizeof(struct aout_filter_sys_t) );
 357     if ( p_filter->p_sys == NULL )
 358     {
 359         msg_Err( p_filter, "Out of memory" );
 360         return VLC_EGENERIC;
 361     }
 362     p_filter->p_sys->i_overflow_buffer_size = 0;
 363     p_filter->p_sys->p_overflow_buffer = NULL;
 364     p_filter->p_sys->i_nb_atomic_operations = 0;
 365     p_filter->p_sys->p_atomic_operations = NULL;
 366
 367     if ( Init( p_filter , p_filter->p_sys
 368                 , aout_FormatNbChannels ( &p_filter->input )
 369                 , p_filter->input.i_physical_channels
 370                 ,  p_filter->input.i_rate ) < 0 )
 371     {
 372         return VLC_EGENERIC;
 373     }
 374
 375     p_filter->pf_do_work = DoWork;
 376     p_filter->b_in_place = 0;
 377
 378     return VLC_SUCCESS;
 379 }
 380
 381 /*****************************************************************************
 382  * Destroy: deallocate resources associated with headphone downmixer
 383  *****************************************************************************/
 384 static void Destroy( vlc_object_t *p_this )
 385 {
 386     aout_filter_t * p_filter = (aout_filter_t *)p_this;
 387
 388     if ( p_filter->p_sys != NULL )
 389     {
 390         if ( p_filter->p_sys->p_overflow_buffer != NULL )
 391         {
 392             free ( p_filter->p_sys->p_overflow_buffer );
 393         }
 394         if ( p_filter->p_sys->p_atomic_operations != NULL )
 395         {
 396             free ( p_filter->p_sys->p_atomic_operations );
 397         }
 398         free ( p_filter->p_sys );
 399         p_filter->p_sys = NULL;
 400     }
 401 }
 402
 403 /*****************************************************************************
 404  * DoWork: convert a buffer
 405  *****************************************************************************/
 406 static void DoWork( aout_instance_t * p_aout, aout_filter_t * p_filter,
 407                     aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
 408 {
 409     int i_input_nb = aout_FormatNbChannels( &p_filter->input );
 410     int i_output_nb = aout_FormatNbChannels( &p_filter->output );
 411
 412     float * p_in = (float*) p_in_buf->p_buffer;
 413     byte_t * p_out;
 414     byte_t * p_overflow;
 415     byte_t * p_slide;
 416
 417     size_t i_overflow_size;/* in bytes */
 418     size_t i_out_size;/* in bytes */
 419
 420     unsigned int i, j;
 421
 422     int i_source_channel_offset;
 423     int i_dest_channel_offset;
 424     unsigned int i_delay;
 425     double d_amplitude_factor;
 426
 427
 428     /* out buffer characterisitcs */
 429     p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
 430     p_out_buf->i_nb_bytes = p_in_buf->i_nb_bytes * i_output_nb / i_input_nb;
 431     p_out = p_out_buf->p_buffer;
 432     i_out_size = p_out_buf->i_nb_bytes;
 433
 434     if ( p_filter->p_sys != NULL )
 435     {
 436         /* Slide the overflow buffer */
 437         p_overflow = p_filter->p_sys->p_overflow_buffer;
 438         i_overflow_size = p_filter->p_sys->i_overflow_buffer_size;
 439
 440         memset ( p_out , 0 , i_out_size );
 441         if ( i_out_size > i_overflow_size )
 442             memcpy ( p_out , p_overflow , i_overflow_size );
 443         else
 444             memcpy ( p_out , p_overflow , i_out_size );
 445
 446         p_slide = p_filter->p_sys->p_overflow_buffer;
 447         while ( p_slide < p_overflow + i_overflow_size )
 448         {
 449             if ( p_slide + i_out_size < p_overflow + i_overflow_size )
 450             {
 451                 memset ( p_slide , 0 , i_out_size );
 452                 if ( p_slide + 2 * i_out_size < p_overflow + i_overflow_size )
 453                     memcpy ( p_slide , p_slide + i_out_size , i_out_size );
 454                 else
 455                     memcpy ( p_slide , p_slide + i_out_size
 456                       , p_overflow + i_overflow_size - ( p_slide + i_out_size ) );
 457             }
 458             else
 459             {
 460                 memset ( p_slide , 0 , p_overflow + i_overflow_size - p_slide );
 461             }
 462             p_slide += i_out_size;
 463         }
 464
 465         /* apply the atomic operations */
 466         for ( i = 0 ; i < p_filter->p_sys->i_nb_atomic_operations ; i++ )
 467         {
 468             /* shorter variable names */
 469             i_source_channel_offset
 470                 = p_filter->p_sys->p_atomic_operations[i].i_source_channel_offset;
 471             i_dest_channel_offset
 472                 = p_filter->p_sys->p_atomic_operations[i].i_dest_channel_offset;
 473             i_delay = p_filter->p_sys->p_atomic_operations[i].i_delay;
 474             d_amplitude_factor
 475                 = p_filter->p_sys->p_atomic_operations[i].d_amplitude_factor;
 476
 477             if ( p_out_buf->i_nb_samples > i_delay )
 478             {
 479                 /* current buffer coefficients */
 480                 for ( j = 0 ; j < p_out_buf->i_nb_samples - i_delay ; j++ )
 481                 {
 482                     ((float*)p_out)[ (i_delay+j)*i_output_nb + i_dest_channel_offset ]
 483                         += p_in[ j * i_input_nb + i_source_channel_offset ]
 484                            * d_amplitude_factor;
 485                 }
 486
 487                 /* overflow buffer coefficients */
 488                 for ( j = 0 ; j < i_delay ; j++ )
 489                 {
 490                     ((float*)p_overflow)[ j*i_output_nb + i_dest_channel_offset ]
 491                         += p_in[ (p_out_buf->i_nb_samples - i_delay + j)
 492                            * i_input_nb + i_source_channel_offset ]
 493                            * d_amplitude_factor;
 494                 }
 495             }
 496             else
 497             {
 498                 /* overflow buffer coefficients only */
 499                 for ( j = 0 ; j < p_out_buf->i_nb_samples ; j++ )
 500                 {
 501                     ((float*)p_overflow)[ (i_delay - p_out_buf->i_nb_samples + j)
 502                         * i_output_nb + i_dest_channel_offset ]
 503                         += p_in[ j * i_input_nb + i_source_channel_offset ]
 504                            * d_amplitude_factor;
 505                 }
 506             }
 507         }
 508     }
 509     else
 510     {
 511         memset ( p_out , 0 , i_out_size );
 512     }
 513 }