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 VideoLAN
6 * $Id: headphone.c,v 1.7 2004/01/25 18:53:06 gbazin Exp $
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., 59 Temple Place - Suite 330, Boston, MA 02111, 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 5.1 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 "Headphone virtual spatialization effect parameter: "\
59 "distance between front left speaker and listener in meters.")
62 set_description( N_("headphone channel mixer with virtual spatialization effect") );
64 add_integer( "headphone-dim", 10, NULL, HEADPHONE_DIM_TEXT,
65 HEADPHONE_DIM_LONGTEXT, VLC_FALSE );
67 set_capability( "audio filter", 0 );
68 set_callbacks( Create, Destroy );
69 add_shortcut( "headphone" );
73 /*****************************************************************************
74 * Internal data structures
75 *****************************************************************************/
76 struct atomic_operation_t
78 int i_source_channel_offset;
79 int i_dest_channel_offset;
80 unsigned int i_delay;/* in sample unit */
81 double d_amplitude_factor;
84 struct aout_filter_sys_t
86 size_t i_overflow_buffer_size;/* in bytes */
87 byte_t * p_overflow_buffer;
88 unsigned int i_nb_atomic_operations;
89 struct atomic_operation_t * p_atomic_operations;
92 /*****************************************************************************
93 * Init: initialize internal data structures
94 * and computes the needed atomic operations
95 *****************************************************************************/
96 /* x and z represent the coordinates of the virtual speaker
97 * relatively to the center of the listener's head, measured in meters :
106 * rear left rear right
110 static void ComputeChannelOperations ( struct aout_filter_sys_t * p_data
111 , unsigned int i_rate , unsigned int i_next_atomic_operation
112 , int i_source_channel_offset , double d_x , double d_z
113 , double d_channel_amplitude_factor )
115 double d_c = 340; /*sound celerity (unit: m/s)*/
118 p_data->p_atomic_operations[i_next_atomic_operation]
119 .i_source_channel_offset = i_source_channel_offset;
120 p_data->p_atomic_operations[i_next_atomic_operation]
121 .i_dest_channel_offset = 0;/* left */
122 p_data->p_atomic_operations[i_next_atomic_operation]
123 .i_delay = (int)( sqrt( (-0.1-d_x)*(-0.1-d_x) + (0-d_z)*(0-d_z) )
127 p_data->p_atomic_operations[i_next_atomic_operation]
128 .d_amplitude_factor = d_channel_amplitude_factor * 1.1 / 2;
132 p_data->p_atomic_operations[i_next_atomic_operation]
133 .d_amplitude_factor = d_channel_amplitude_factor * 0.9 / 2;
137 p_data->p_atomic_operations[i_next_atomic_operation]
138 .d_amplitude_factor = d_channel_amplitude_factor / 2;
142 p_data->p_atomic_operations[i_next_atomic_operation + 1]
143 .i_source_channel_offset = i_source_channel_offset;
144 p_data->p_atomic_operations[i_next_atomic_operation + 1]
145 .i_dest_channel_offset = 1;/* right */
146 p_data->p_atomic_operations[i_next_atomic_operation + 1]
147 .i_delay = (int)( sqrt( (0.1-d_x)*(0.1-d_x) + (0-d_z)*(0-d_z) )
151 p_data->p_atomic_operations[i_next_atomic_operation + 1]
152 .d_amplitude_factor = d_channel_amplitude_factor * 0.9 / 2;
156 p_data->p_atomic_operations[i_next_atomic_operation + 1]
157 .d_amplitude_factor = d_channel_amplitude_factor * 1.1 / 2;
161 p_data->p_atomic_operations[i_next_atomic_operation + 1]
162 .d_amplitude_factor = d_channel_amplitude_factor / 2;
166 static int Init ( aout_filter_t * p_filter , struct aout_filter_sys_t * p_data
167 , unsigned int i_nb_channels , uint32_t i_physical_channels
168 , unsigned int i_rate )
170 double d_x = config_GetInt ( p_filter , "headphone-dim" );
172 double d_z_rear = -d_x/3;
173 unsigned int i_next_atomic_operation;
174 int i_source_channel_offset;
177 if ( p_data == NULL )
179 msg_Dbg ( p_filter, "passing a null pointer as argument" );
183 /* Number of elementary operations */
184 p_data->i_nb_atomic_operations = i_nb_channels * 2;
185 p_data->p_atomic_operations = malloc ( sizeof(struct atomic_operation_t)
186 * p_data->i_nb_atomic_operations );
187 if ( p_data->p_atomic_operations == NULL )
189 msg_Err( p_filter, "out of memory" );
193 /* For each virtual speaker, computes elementary wave propagation time
195 i_next_atomic_operation = 0;
196 i_source_channel_offset = 0;
197 if ( i_physical_channels & AOUT_CHAN_LEFT )
199 ComputeChannelOperations ( p_data , i_rate
200 , i_next_atomic_operation , i_source_channel_offset
201 , -d_x , d_z , 2.0 / i_nb_channels );
202 i_next_atomic_operation += 2;
203 i_source_channel_offset++;
205 if ( i_physical_channels & AOUT_CHAN_RIGHT )
207 ComputeChannelOperations ( p_data , i_rate
208 , i_next_atomic_operation , i_source_channel_offset
209 , d_x , d_z , 2.0 / i_nb_channels );
210 i_next_atomic_operation += 2;
211 i_source_channel_offset++;
213 if ( i_physical_channels & AOUT_CHAN_REARLEFT )
215 ComputeChannelOperations ( p_data , i_rate
216 , i_next_atomic_operation , i_source_channel_offset
217 , -d_x , d_z_rear , 1.5 / i_nb_channels );
218 i_next_atomic_operation += 2;
219 i_source_channel_offset++;
221 if ( i_physical_channels & AOUT_CHAN_REARRIGHT )
223 ComputeChannelOperations ( p_data , i_rate
224 , i_next_atomic_operation , i_source_channel_offset
225 , d_x , d_z_rear , 1.5 / i_nb_channels );
226 i_next_atomic_operation += 2;
227 i_source_channel_offset++;
229 if ( i_physical_channels & AOUT_CHAN_REARCENTER )
231 ComputeChannelOperations ( p_data , i_rate
232 , i_next_atomic_operation , i_source_channel_offset
233 , 0 , -d_z , 1.5 / i_nb_channels );
234 i_next_atomic_operation += 2;
235 i_source_channel_offset++;
237 if ( i_physical_channels & AOUT_CHAN_CENTER )
239 ComputeChannelOperations ( p_data , i_rate
240 , i_next_atomic_operation , i_source_channel_offset
241 , 0 , d_z , 1.5 / i_nb_channels );
242 i_next_atomic_operation += 2;
243 i_source_channel_offset++;
245 if ( i_physical_channels & AOUT_CHAN_LFE )
247 ComputeChannelOperations ( p_data , i_rate
248 , i_next_atomic_operation , i_source_channel_offset
249 , 0 , d_z_rear , 5.0 / i_nb_channels );
250 i_next_atomic_operation += 2;
251 i_source_channel_offset++;
253 if ( i_physical_channels & AOUT_CHAN_MIDDLELEFT )
255 ComputeChannelOperations ( p_data , i_rate
256 , i_next_atomic_operation , i_source_channel_offset
257 , -d_x , 0 , 1.5 / i_nb_channels );
258 i_next_atomic_operation += 2;
259 i_source_channel_offset++;
261 if ( i_physical_channels & AOUT_CHAN_MIDDLERIGHT )
263 ComputeChannelOperations ( p_data , i_rate
264 , i_next_atomic_operation , i_source_channel_offset
265 , d_x , 0 , 1.5 / i_nb_channels );
266 i_next_atomic_operation += 2;
267 i_source_channel_offset++;
270 /* Initialize the overflow buffer
271 * we need it because the process induce a delay in the samples */
272 p_data->i_overflow_buffer_size = 0;
273 for ( i = 0 ; i < p_data->i_nb_atomic_operations ; i++ )
275 if ( p_data->i_overflow_buffer_size
276 < p_data->p_atomic_operations[i].i_delay * i_nb_channels
279 p_data->i_overflow_buffer_size
280 = p_data->p_atomic_operations[i].i_delay * i_nb_channels
284 p_data->p_overflow_buffer = malloc ( p_data->i_overflow_buffer_size );
285 if ( p_data->p_atomic_operations == NULL )
287 msg_Err( p_filter, "out of memory" );
290 memset ( p_data->p_overflow_buffer , 0 , p_data->i_overflow_buffer_size );
296 /*****************************************************************************
297 * Create: allocate headphone downmixer
298 *****************************************************************************/
299 static int Create( vlc_object_t *p_this )
301 aout_filter_t * p_filter = (aout_filter_t *)p_this;
303 if ( p_filter->output.i_physical_channels != ( AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT )
304 || p_filter->input.i_format != p_filter->output.i_format
305 || p_filter->input.i_rate != p_filter->output.i_rate
306 || (p_filter->input.i_format != VLC_FOURCC('f','l','3','2')
307 && p_filter->input.i_format != VLC_FOURCC('f','i','3','2')) )
312 /* Allocate the memory needed to store the module's structure */
313 p_filter->p_sys = malloc( sizeof(struct aout_filter_sys_t) );
314 if ( p_filter->p_sys == NULL )
316 msg_Err( p_filter, "out of memory" );
319 p_filter->p_sys->i_overflow_buffer_size = 0;
320 p_filter->p_sys->p_overflow_buffer = NULL;
321 p_filter->p_sys->i_nb_atomic_operations = 0;
322 p_filter->p_sys->p_atomic_operations = NULL;
324 if ( Init( p_filter , p_filter->p_sys
325 , aout_FormatNbChannels ( &p_filter->input )
326 , p_filter->input.i_physical_channels
327 , p_filter->input.i_rate ) < 0 )
332 p_filter->pf_do_work = DoWork;
333 p_filter->b_in_place = 0;
338 /*****************************************************************************
339 * Destroy: deallocate resources associated with headphone downmixer
340 *****************************************************************************/
341 static void Destroy( vlc_object_t *p_this )
343 aout_filter_t * p_filter = (aout_filter_t *)p_this;
345 if ( p_filter->p_sys != NULL )
347 if ( p_filter->p_sys->p_overflow_buffer != NULL )
349 free ( p_filter->p_sys->p_overflow_buffer );
351 if ( p_filter->p_sys->p_atomic_operations != NULL )
353 free ( p_filter->p_sys->p_atomic_operations );
355 free ( p_filter->p_sys );
356 p_filter->p_sys = NULL;
360 /*****************************************************************************
361 * DoWork: convert a buffer
362 *****************************************************************************/
363 static void DoWork( aout_instance_t * p_aout, aout_filter_t * p_filter,
364 aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
366 int i_input_nb = aout_FormatNbChannels( &p_filter->input );
367 int i_output_nb = aout_FormatNbChannels( &p_filter->output );
369 float * p_in = (float*) p_in_buf->p_buffer;
374 size_t i_overflow_size;/* in bytes */
375 size_t i_out_size;/* in bytes */
379 int i_source_channel_offset;
380 int i_dest_channel_offset;
381 unsigned int i_delay;
382 double d_amplitude_factor;
385 /* out buffer characterisitcs */
386 p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
387 p_out_buf->i_nb_bytes = p_in_buf->i_nb_bytes * i_output_nb / i_input_nb;
388 p_out = p_out_buf->p_buffer;
389 i_out_size = p_out_buf->i_nb_bytes;
391 if ( p_filter->p_sys != NULL )
393 /* Slide the overflow buffer */
394 p_overflow = p_filter->p_sys->p_overflow_buffer;
395 i_overflow_size = p_filter->p_sys->i_overflow_buffer_size;
397 memset ( p_out , 0 , i_out_size );
398 if ( i_out_size > i_overflow_size )
399 memcpy ( p_out , p_overflow , i_overflow_size );
401 memcpy ( p_out , p_overflow , i_out_size );
403 p_slide = p_filter->p_sys->p_overflow_buffer;
404 while ( p_slide < p_overflow + i_overflow_size )
406 if ( p_slide + i_out_size < p_overflow + i_overflow_size )
408 memset ( p_slide , 0 , i_out_size );
409 if ( p_slide + 2 * i_out_size < p_overflow + i_overflow_size )
410 memcpy ( p_slide , p_slide + i_out_size , i_out_size );
412 memcpy ( p_slide , p_slide + i_out_size
413 , p_overflow + i_overflow_size - ( p_slide + i_out_size ) );
417 memset ( p_slide , 0 , p_overflow + i_overflow_size - p_slide );
419 p_slide += i_out_size;
422 /* apply the atomic operations */
423 for ( i = 0 ; i < p_filter->p_sys->i_nb_atomic_operations ; i++ )
425 /* shorter variable names */
426 i_source_channel_offset
427 = p_filter->p_sys->p_atomic_operations[i].i_source_channel_offset;
428 i_dest_channel_offset
429 = p_filter->p_sys->p_atomic_operations[i].i_dest_channel_offset;
430 i_delay = p_filter->p_sys->p_atomic_operations[i].i_delay;
432 = p_filter->p_sys->p_atomic_operations[i].d_amplitude_factor;
434 if ( p_out_buf->i_nb_samples > i_delay )
436 /* current buffer coefficients */
437 for ( j = 0 ; j < p_out_buf->i_nb_samples - i_delay ; j++ )
439 ((float*)p_out)[ (i_delay+j)*i_output_nb + i_dest_channel_offset ]
440 += p_in[ j * i_input_nb + i_source_channel_offset ]
441 * d_amplitude_factor;
444 /* overflow buffer coefficients */
445 for ( j = 0 ; j < i_delay ; j++ )
447 ((float*)p_overflow)[ j*i_output_nb + i_dest_channel_offset ]
448 += p_in[ (p_out_buf->i_nb_samples - i_delay + j)
449 * i_input_nb + i_source_channel_offset ]
450 * d_amplitude_factor;
455 /* overflow buffer coefficients only */
456 for ( j = 0 ; j < p_out_buf->i_nb_samples ; j++ )
458 ((float*)p_overflow)[ (i_delay - p_out_buf->i_nb_samples + j)
459 * i_output_nb + i_dest_channel_offset ]
460 += p_in[ j * i_input_nb + i_source_channel_offset ]
461 * d_amplitude_factor;
468 memset ( p_out , 0 , i_out_size );