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
8 * Authors: Boris Dorès <babal@via.ecp.fr>
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.
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.
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 *****************************************************************************/
25 /*****************************************************************************
27 *****************************************************************************/
28 #include <stdlib.h> /* malloc(), free() */
30 #include <math.h> /* sqrt */
33 #include "audio_output.h"
34 #include "aout_internal.h"
36 /*****************************************************************************
38 *****************************************************************************/
39 static int Create ( vlc_object_t * );
40 static void Destroy ( vlc_object_t * );
42 static void DoWork ( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
45 /*****************************************************************************
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 " \
56 #define HEADPHONE_DIM_TEXT N_("Characteristic dimension")
57 #define HEADPHONE_DIM_LONGTEXT N_( \
58 "Distance between front left speaker and listener in meters.")
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.")
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.")
72 set_description( N_("Headphone virtual spatialization effect") );
73 set_shortname( _("Headphone effect") );
74 set_category( CAT_AUDIO );
75 set_subcategory( SUBCAT_AUDIO_AFILTER );
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 );
84 set_capability( "audio filter", 0 );
85 set_callbacks( Create, Destroy );
86 add_shortcut( "headphone" );
90 /*****************************************************************************
91 * Internal data structures
92 *****************************************************************************/
93 struct atomic_operation_t
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;
101 struct aout_filter_sys_t
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;
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 :
123 * rear left rear right
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 )
132 double d_c = 340; /*sound celerity (unit: m/s)*/
133 double d_compensation_delay = (d_compensation_length-0.1) / d_c * i_rate;
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 );
145 p_data->p_atomic_operations[i_next_atomic_operation]
146 .d_amplitude_factor = d_channel_amplitude_factor * 1.1 / 2;
150 p_data->p_atomic_operations[i_next_atomic_operation]
151 .d_amplitude_factor = d_channel_amplitude_factor * 0.9 / 2;
155 p_data->p_atomic_operations[i_next_atomic_operation]
156 .d_amplitude_factor = d_channel_amplitude_factor / 2;
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 );
169 p_data->p_atomic_operations[i_next_atomic_operation + 1]
170 .d_amplitude_factor = d_channel_amplitude_factor * 0.9 / 2;
174 p_data->p_atomic_operations[i_next_atomic_operation + 1]
175 .d_amplitude_factor = d_channel_amplitude_factor * 1.1 / 2;
179 p_data->p_atomic_operations[i_next_atomic_operation + 1]
180 .d_amplitude_factor = d_channel_amplitude_factor / 2;
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 )
188 double d_x = config_GetInt ( p_filter , "headphone-dim" );
190 double d_z_rear = -d_x/3;
192 unsigned int i_next_atomic_operation;
193 int i_source_channel_offset;
196 if ( p_data == NULL )
198 msg_Dbg ( p_filter, "passing a null pointer as argument" );
202 if ( config_GetInt ( p_filter , "headphone-compensate" ) )
204 /* minimal distance to any speaker */
205 if ( i_physical_channels & AOUT_CHAN_REARCENTER )
215 /* Number of elementary operations */
216 p_data->i_nb_atomic_operations = i_nb_channels * 2;
217 if ( i_physical_channels & AOUT_CHAN_CENTER )
219 p_data->i_nb_atomic_operations += 2;
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 )
225 msg_Err( p_filter, "out of memory" );
229 /* For each virtual speaker, computes elementary wave propagation time
231 i_next_atomic_operation = 0;
232 i_source_channel_offset = 0;
233 if ( i_physical_channels & AOUT_CHAN_LEFT )
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++;
241 if ( i_physical_channels & AOUT_CHAN_RIGHT )
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++;
249 if ( i_physical_channels & AOUT_CHAN_MIDDLELEFT )
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++;
257 if ( i_physical_channels & AOUT_CHAN_MIDDLERIGHT )
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++;
265 if ( i_physical_channels & AOUT_CHAN_REARLEFT )
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++;
273 if ( i_physical_channels & AOUT_CHAN_REARRIGHT )
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++;
281 if ( i_physical_channels & AOUT_CHAN_REARCENTER )
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++;
289 if ( i_physical_channels & AOUT_CHAN_CENTER )
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++;
302 if ( i_physical_channels & AOUT_CHAN_LFE )
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++;
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++ )
316 if ( p_data->i_overflow_buffer_size
317 < p_data->p_atomic_operations[i].i_delay * 2 * sizeof (float) )
319 p_data->i_overflow_buffer_size
320 = p_data->p_atomic_operations[i].i_delay * 2 * sizeof (float);
323 p_data->p_overflow_buffer = malloc ( p_data->i_overflow_buffer_size );
324 if ( p_data->p_atomic_operations == NULL )
326 msg_Err( p_filter, "out of memory" );
329 memset ( p_data->p_overflow_buffer , 0 , p_data->i_overflow_buffer_size );
335 /*****************************************************************************
336 * Create: allocate headphone downmixer
337 *****************************************************************************/
338 static int Create( vlc_object_t *p_this )
340 aout_filter_t * p_filter = (aout_filter_t *)p_this;
341 vlc_bool_t b_fit = VLC_TRUE;
343 /* Activate this filter only with stereo devices */
344 if ( p_filter->output.i_physical_channels
345 != (AOUT_CHAN_LEFT|AOUT_CHAN_RIGHT) )
347 msg_Dbg( p_filter, "Filter discarded (incompatible format)" );
351 /* Request a specific format if not already compatible */
352 if ( p_filter->input.i_original_channels
353 != p_filter->output.i_original_channels )
356 p_filter->input.i_original_channels =
357 p_filter->output.i_original_channels;
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') )
363 p_filter->input.i_format = VLC_FOURCC('f','l','3','2');
364 p_filter->output.i_format = VLC_FOURCC('f','l','3','2');
366 if ( p_filter->input.i_rate != p_filter->output.i_rate )
369 p_filter->input.i_rate = p_filter->output.i_rate;
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" ) )
376 p_filter->input.i_physical_channels = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT |
383 msg_Dbg( p_filter, "Requesting specific format" );
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 )
391 msg_Err( p_filter, "Out of memory" );
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;
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 )
407 p_filter->pf_do_work = DoWork;
408 p_filter->b_in_place = 0;
413 /*****************************************************************************
414 * Destroy: deallocate resources associated with headphone downmixer
415 *****************************************************************************/
416 static void Destroy( vlc_object_t *p_this )
418 aout_filter_t * p_filter = (aout_filter_t *)p_this;
420 if ( p_filter->p_sys != NULL )
422 if ( p_filter->p_sys->p_overflow_buffer != NULL )
424 free ( p_filter->p_sys->p_overflow_buffer );
426 if ( p_filter->p_sys->p_atomic_operations != NULL )
428 free ( p_filter->p_sys->p_atomic_operations );
430 free ( p_filter->p_sys );
431 p_filter->p_sys = NULL;
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 )
441 int i_input_nb = aout_FormatNbChannels( &p_filter->input );
442 int i_output_nb = aout_FormatNbChannels( &p_filter->output );
444 float * p_in = (float*) p_in_buf->p_buffer;
449 size_t i_overflow_size;/* in bytes */
450 size_t i_out_size;/* in bytes */
454 int i_source_channel_offset;
455 int i_dest_channel_offset;
456 unsigned int i_delay;
457 double d_amplitude_factor;
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;
466 if ( p_filter->p_sys != NULL )
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;
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 );
476 memcpy ( p_out , p_overflow , i_out_size );
478 p_slide = p_filter->p_sys->p_overflow_buffer;
479 while ( p_slide < p_overflow + i_overflow_size )
481 if ( p_slide + i_out_size < p_overflow + i_overflow_size )
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 );
487 memcpy ( p_slide , p_slide + i_out_size
488 , p_overflow + i_overflow_size - ( p_slide + i_out_size ) );
492 memset ( p_slide , 0 , p_overflow + i_overflow_size - p_slide );
494 p_slide += i_out_size;
497 /* apply the atomic operations */
498 for ( i = 0 ; i < p_filter->p_sys->i_nb_atomic_operations ; i++ )
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;
507 = p_filter->p_sys->p_atomic_operations[i].d_amplitude_factor;
509 if ( p_out_buf->i_nb_samples > i_delay )
511 /* current buffer coefficients */
512 for ( j = 0 ; j < p_out_buf->i_nb_samples - i_delay ; j++ )
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;
519 /* overflow buffer coefficients */
520 for ( j = 0 ; j < i_delay ; j++ )
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;
530 /* overflow buffer coefficients only */
531 for ( j = 0 ; j < p_out_buf->i_nb_samples ; j++ )
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;
543 memset ( p_out , 0 , i_out_size );