84be940c698adf541173a1d556094cf3f784fd1c
[vlc.git] / src / audio_output / filters.c
1 /*****************************************************************************
2  * filters.c : audio output filters management
3  *****************************************************************************
4  * Copyright (C) 2002-2004 the VideoLAN team
5  * $Id$
6  *
7  * Authors: Christophe Massiot <massiot@via.ecp.fr>
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
22  *****************************************************************************/
23
24 /*****************************************************************************
25  * Preamble
26  *****************************************************************************/
27 #include <stdlib.h>                            /* calloc(), malloc(), free() */
28 #include <string.h>
29
30 #include <vlc/vlc.h>
31
32 #ifdef HAVE_ALLOCA_H
33 #   include <alloca.h>
34 #endif
35
36 #include "audio_output.h"
37 #include "aout_internal.h"
38
39 /*****************************************************************************
40  * FindFilter: find an audio filter for a specific transformation
41  *****************************************************************************/
42 static aout_filter_t * FindFilter( aout_instance_t * p_aout,
43                              const audio_sample_format_t * p_input_format,
44                              const audio_sample_format_t * p_output_format )
45 {
46     aout_filter_t * p_filter = vlc_object_create( p_aout,
47                                                   sizeof(aout_filter_t) );
48
49     if ( p_filter == NULL ) return NULL;
50     vlc_object_attach( p_filter, p_aout );
51
52     memcpy( &p_filter->input, p_input_format, sizeof(audio_sample_format_t) );
53     memcpy( &p_filter->output, p_output_format,
54             sizeof(audio_sample_format_t) );
55     p_filter->p_module = module_Need( p_filter, "audio filter", NULL, 0 );
56     if ( p_filter->p_module == NULL )
57     {
58         vlc_object_detach( p_filter );
59         vlc_object_destroy( p_filter );
60         return NULL;
61     }
62
63     p_filter->b_continuity = VLC_FALSE;
64
65     return p_filter;
66 }
67
68 /*****************************************************************************
69  * SplitConversion: split a conversion in two parts
70  *****************************************************************************
71  * Returns the number of conversions required by the first part - 0 if only
72  * one conversion was asked.
73  * Beware : p_output_format can be modified during this function if the
74  * developer passed SplitConversion( toto, titi, titi, ... ). That is legal.
75  * SplitConversion( toto, titi, toto, ... ) isn't.
76  *****************************************************************************/
77 static int SplitConversion( const audio_sample_format_t * p_input_format,
78                             const audio_sample_format_t * p_output_format,
79                             audio_sample_format_t * p_middle_format )
80 {
81     vlc_bool_t b_format =
82              (p_input_format->i_format != p_output_format->i_format);
83     vlc_bool_t b_rate = (p_input_format->i_rate != p_output_format->i_rate);
84     vlc_bool_t b_channels =
85         (p_input_format->i_physical_channels
86           != p_output_format->i_physical_channels)
87      || (p_input_format->i_original_channels
88           != p_output_format->i_original_channels);
89     int i_nb_conversions = b_format + b_rate + b_channels;
90
91     if ( i_nb_conversions <= 1 ) return 0;
92
93     memcpy( p_middle_format, p_output_format, sizeof(audio_sample_format_t) );
94
95     if ( i_nb_conversions == 2 )
96     {
97         if ( !b_format || !b_channels )
98         {
99             p_middle_format->i_rate = p_input_format->i_rate;
100             aout_FormatPrepare( p_middle_format );
101             return 1;
102         }
103
104         /* !b_rate */
105         p_middle_format->i_physical_channels
106              = p_input_format->i_physical_channels;
107         p_middle_format->i_original_channels
108              = p_input_format->i_original_channels;
109         aout_FormatPrepare( p_middle_format );
110         return 1;
111     }
112
113     /* i_nb_conversion == 3 */
114     p_middle_format->i_rate = p_input_format->i_rate;
115     aout_FormatPrepare( p_middle_format );
116     return 2;
117 }
118
119 /*****************************************************************************
120  * aout_FiltersCreatePipeline: create a filters pipeline to transform a sample
121  *                             format to another
122  *****************************************************************************
123  * TODO : allow the user to add/remove specific filters
124  *****************************************************************************/
125 int aout_FiltersCreatePipeline( aout_instance_t * p_aout,
126                                 aout_filter_t ** pp_filters,
127                                 int * pi_nb_filters,
128                                 const audio_sample_format_t * p_input_format,
129                                 const audio_sample_format_t * p_output_format )
130 {
131     audio_sample_format_t temp_format;
132     int i_nb_conversions;
133
134     if ( AOUT_FMTS_IDENTICAL( p_input_format, p_output_format ) )
135     {
136         msg_Dbg( p_aout, "no need for any filter" );
137         *pi_nb_filters = 0;
138         return 0;
139     }
140
141     aout_FormatsPrint( p_aout, "filter(s)", p_input_format, p_output_format );
142
143     /* Try to find a filter to do the whole conversion. */
144     pp_filters[0] = FindFilter( p_aout, p_input_format, p_output_format );
145     if ( pp_filters[0] != NULL )
146     {
147         msg_Dbg( p_aout, "found a filter for the whole conversion" );
148         *pi_nb_filters = 1;
149         return 0;
150     }
151
152     /* We'll have to split the conversion. We always do the downmixing
153      * before the resampling, because the audio decoder can probably do it
154      * for us. */
155     i_nb_conversions = SplitConversion( p_input_format,
156                                         p_output_format, &temp_format );
157     if ( !i_nb_conversions )
158     {
159         /* There was only one conversion to do, and we already failed. */
160         msg_Err( p_aout, "couldn't find a filter for the conversion" );
161         return -1;
162     }
163
164     pp_filters[0] = FindFilter( p_aout, p_input_format, &temp_format );
165     if ( pp_filters[0] == NULL && i_nb_conversions == 2 )
166     {
167         /* Try with only one conversion. */
168         SplitConversion( p_input_format, &temp_format, &temp_format );
169         pp_filters[0] = FindFilter( p_aout, p_input_format, &temp_format );
170     }
171     if ( pp_filters[0] == NULL )
172     {
173         msg_Err( p_aout,
174               "couldn't find a filter for the first part of the conversion" );
175         return -1;
176     }
177
178     /* We have the first stage of the conversion. Find a filter for
179      * the rest. */
180     pp_filters[1] = FindFilter( p_aout, &pp_filters[0]->output,
181                                 p_output_format );
182     if ( pp_filters[1] == NULL )
183     {
184         /* Try to split the conversion. */
185         i_nb_conversions = SplitConversion( &pp_filters[0]->output,
186                                            p_output_format, &temp_format );
187         if ( !i_nb_conversions )
188         {
189             vlc_object_detach( pp_filters[0] );
190             vlc_object_destroy( pp_filters[0] );
191             msg_Err( p_aout,
192               "couldn't find a filter for the second part of the conversion" );
193         }
194         pp_filters[1] = FindFilter( p_aout, &pp_filters[0]->output,
195                                     &temp_format );
196         pp_filters[2] = FindFilter( p_aout, &temp_format,
197                                     p_output_format );
198
199         if ( pp_filters[1] == NULL || pp_filters[2] == NULL )
200         {
201             vlc_object_detach( pp_filters[0] );
202             vlc_object_destroy( pp_filters[0] );
203             if ( pp_filters[1] != NULL )
204             {
205                 vlc_object_detach( pp_filters[1] );
206                 vlc_object_destroy( pp_filters[1] );
207             }
208             if ( pp_filters[2] != NULL )
209             {
210                 vlc_object_detach( pp_filters[2] );
211                 vlc_object_destroy( pp_filters[2] );
212             }
213             msg_Err( p_aout,
214                "couldn't find filters for the second part of the conversion" );
215         }
216         *pi_nb_filters = 3;
217     }
218     else
219     {
220         *pi_nb_filters = 2;
221     }
222
223     /* We have enough filters. */
224     msg_Dbg( p_aout, "found %d filters for the whole conversion",
225              *pi_nb_filters );
226     return 0;
227 }
228
229 /*****************************************************************************
230  * aout_FiltersDestroyPipeline: deallocate a filters pipeline
231  *****************************************************************************/
232 void aout_FiltersDestroyPipeline( aout_instance_t * p_aout,
233                                   aout_filter_t ** pp_filters,
234                                   int i_nb_filters )
235 {
236     int i;
237
238     for ( i = 0; i < i_nb_filters; i++ )
239     {
240         module_Unneed( pp_filters[i], pp_filters[i]->p_module );
241         vlc_object_detach( pp_filters[i] );
242         vlc_object_destroy( pp_filters[i] );
243     }
244 }
245
246 /*****************************************************************************
247  * aout_FiltersHintBuffers: fill in aout_alloc_t structures to optimize
248  *                          buffer allocations
249  *****************************************************************************/
250 void aout_FiltersHintBuffers( aout_instance_t * p_aout,
251                               aout_filter_t ** pp_filters,
252                               int i_nb_filters, aout_alloc_t * p_first_alloc )
253 {
254     int i;
255
256     (void)p_aout; /* unused */
257
258     for ( i = i_nb_filters - 1; i >= 0; i-- )
259     {
260         aout_filter_t * p_filter = pp_filters[i];
261
262         int i_output_size = p_filter->output.i_bytes_per_frame
263                              * p_filter->output.i_rate
264                              / p_filter->output.i_frame_length;
265         int i_input_size = p_filter->input.i_bytes_per_frame
266                              * p_filter->input.i_rate
267                              / p_filter->input.i_frame_length;
268
269         p_first_alloc->i_bytes_per_sec = __MAX( p_first_alloc->i_bytes_per_sec,
270                                                 i_output_size );
271
272         if ( p_filter->b_in_place )
273         {
274             p_first_alloc->i_bytes_per_sec = __MAX(
275                                          p_first_alloc->i_bytes_per_sec,
276                                          i_input_size );
277             p_filter->output_alloc.i_alloc_type = AOUT_ALLOC_NONE;
278         }
279         else
280         {
281             /* We're gonna need a buffer allocation. */
282             memcpy( &p_filter->output_alloc, p_first_alloc,
283                     sizeof(aout_alloc_t) );
284             p_first_alloc->i_alloc_type = AOUT_ALLOC_STACK;
285             p_first_alloc->i_bytes_per_sec = i_input_size;
286         }
287     }
288 }
289
290 /*****************************************************************************
291  * aout_FiltersPlay: play a buffer
292  *****************************************************************************/
293 void aout_FiltersPlay( aout_instance_t * p_aout,
294                        aout_filter_t ** pp_filters,
295                        int i_nb_filters, aout_buffer_t ** pp_input_buffer )
296 {
297     int i;
298
299     for ( i = 0; i < i_nb_filters; i++ )
300     {
301         aout_filter_t * p_filter = pp_filters[i];
302         aout_buffer_t * p_output_buffer;
303
304         /* Resamplers can produce slightly more samples than (i_in_nb *
305          * p_filter->output.i_rate / p_filter->input.i_rate) so we need
306          * slightly bigger buffers. */
307         aout_BufferAlloc( &p_filter->output_alloc,
308             ((mtime_t)(*pp_input_buffer)->i_nb_samples + 2)
309             * 1000000 / p_filter->input.i_rate,
310             *pp_input_buffer, p_output_buffer );
311         if ( p_output_buffer == NULL )
312         {
313             msg_Err( p_aout, "out of memory" );
314             return;
315         }
316         /* Please note that p_output_buffer->i_nb_samples & i_nb_bytes
317          * shall be set by the filter plug-in. */
318
319         p_filter->pf_do_work( p_aout, p_filter, *pp_input_buffer,
320                               p_output_buffer );
321
322         if ( !p_filter->b_in_place )
323         {
324             aout_BufferFree( *pp_input_buffer );
325             *pp_input_buffer = p_output_buffer;
326         }
327     }
328 }
329