1 /*****************************************************************************
2 * filters.c : audio output filters management
3 *****************************************************************************
4 * Copyright (C) 2002-2007 the VideoLAN team
7 * Authors: Christophe Massiot <massiot@via.ecp.fr>
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.
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.
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., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
22 *****************************************************************************/
24 /*****************************************************************************
26 *****************************************************************************/
33 #include <vlc_common.h>
34 #include <vlc_dialog.h>
35 #include <vlc_modules.h>
38 #include <vlc_filter.h>
39 #include "aout_internal.h"
42 block_t *aout_FilterBufferNew( filter_t *p_filter, int size )
45 return block_Alloc( size );
48 /*****************************************************************************
49 * FindFilter: find an audio filter for a specific transformation
50 *****************************************************************************/
51 static filter_t * FindFilter( aout_instance_t * p_aout,
52 const audio_sample_format_t * p_input_format,
53 const audio_sample_format_t * p_output_format )
55 static const char typename[] = "audio filter";
58 p_filter = vlc_custom_create( p_aout, sizeof(*p_filter),
59 VLC_OBJECT_GENERIC, typename );
61 if ( p_filter == NULL ) return NULL;
63 memcpy( &p_filter->fmt_in.audio, p_input_format,
64 sizeof(audio_sample_format_t) );
65 p_filter->fmt_in.i_codec = p_input_format->i_format;
66 memcpy( &p_filter->fmt_out.audio, p_output_format,
67 sizeof(audio_sample_format_t) );
68 p_filter->fmt_out.i_codec = p_output_format->i_format;
69 p_filter->pf_audio_buffer_new = aout_FilterBufferNew;
71 p_filter->p_module = module_need( p_filter, "audio filter", NULL, false );
72 if ( p_filter->p_module == NULL )
74 vlc_object_release( p_filter );
78 assert( p_filter->pf_audio_filter );
82 /*****************************************************************************
83 * SplitConversion: split a conversion in two parts
84 *****************************************************************************
85 * Returns the number of conversions required by the first part - 0 if only
86 * one conversion was asked.
87 * Beware : p_output_format can be modified during this function if the
88 * developer passed SplitConversion( toto, titi, titi, ... ). That is legal.
89 * SplitConversion( toto, titi, toto, ... ) isn't.
90 *****************************************************************************/
91 static int SplitConversion( const audio_sample_format_t * p_input_format,
92 const audio_sample_format_t * p_output_format,
93 audio_sample_format_t * p_middle_format )
96 (p_input_format->i_format != p_output_format->i_format);
97 bool b_rate = (p_input_format->i_rate != p_output_format->i_rate);
99 (p_input_format->i_physical_channels
100 != p_output_format->i_physical_channels)
101 || (p_input_format->i_original_channels
102 != p_output_format->i_original_channels);
103 int i_nb_conversions = b_format + b_rate + b_channels;
105 if ( i_nb_conversions <= 1 ) return 0;
107 memcpy( p_middle_format, p_output_format, sizeof(audio_sample_format_t) );
109 if ( i_nb_conversions == 2 )
111 if ( !b_format || !b_channels )
113 p_middle_format->i_rate = p_input_format->i_rate;
114 aout_FormatPrepare( p_middle_format );
119 p_middle_format->i_physical_channels
120 = p_input_format->i_physical_channels;
121 p_middle_format->i_original_channels
122 = p_input_format->i_original_channels;
123 aout_FormatPrepare( p_middle_format );
127 /* i_nb_conversion == 3 */
128 p_middle_format->i_rate = p_input_format->i_rate;
129 aout_FormatPrepare( p_middle_format );
133 static void ReleaseFilter( filter_t * p_filter )
135 module_unneed( p_filter, p_filter->p_module );
136 vlc_object_release( p_filter );
139 /*****************************************************************************
140 * aout_FiltersCreatePipeline: create a filters pipeline to transform a sample
142 *****************************************************************************
143 * pi_nb_filters must be initialized before calling this function
144 *****************************************************************************/
145 int aout_FiltersCreatePipeline( aout_instance_t * p_aout,
146 filter_t ** pp_filters_start,
148 const audio_sample_format_t * p_input_format,
149 const audio_sample_format_t * p_output_format )
151 filter_t** pp_filters = pp_filters_start + *pi_nb_filters;
152 audio_sample_format_t temp_format;
153 int i_nb_conversions;
155 if ( AOUT_FMTS_IDENTICAL( p_input_format, p_output_format ) )
157 msg_Dbg( p_aout, "no need for any filter" );
161 aout_FormatsPrint( p_aout, "filter(s)", p_input_format, p_output_format );
163 if( *pi_nb_filters + 1 > AOUT_MAX_FILTERS )
165 msg_Err( p_aout, "max filter reached (%d)", AOUT_MAX_FILTERS );
166 dialog_Fatal( p_aout, _("Audio filtering failed"),
167 _("The maximum number of filters (%d) was reached."),
172 /* Try to find a filter to do the whole conversion. */
173 pp_filters[0] = FindFilter( p_aout, p_input_format, p_output_format );
174 if ( pp_filters[0] != NULL )
176 msg_Dbg( p_aout, "found a filter for the whole conversion" );
181 /* We'll have to split the conversion. We always do the downmixing
182 * before the resampling, because the audio decoder can probably do it
184 i_nb_conversions = SplitConversion( p_input_format,
185 p_output_format, &temp_format );
186 if ( !i_nb_conversions )
188 /* There was only one conversion to do, and we already failed. */
189 msg_Err( p_aout, "couldn't find a filter for the conversion "
191 (const char *)&p_input_format->i_format,
192 (const char *)&p_output_format->i_format );
196 pp_filters[0] = FindFilter( p_aout, p_input_format, &temp_format );
197 if ( pp_filters[0] == NULL && i_nb_conversions == 2 )
199 /* Try with only one conversion. */
200 SplitConversion( p_input_format, &temp_format, &temp_format );
201 pp_filters[0] = FindFilter( p_aout, p_input_format, &temp_format );
203 if ( pp_filters[0] == NULL )
206 "couldn't find a filter for the first part of the conversion" );
210 /* We have the first stage of the conversion. Find a filter for
212 if( *pi_nb_filters + 2 > AOUT_MAX_FILTERS )
214 ReleaseFilter( pp_filters[0] );
215 msg_Err( p_aout, "max filter reached (%d)", AOUT_MAX_FILTERS );
216 dialog_Fatal( p_aout, _("Audio filtering failed"),
217 _("The maximum number of filters (%d) was reached."),
221 pp_filters[1] = FindFilter( p_aout, &pp_filters[0]->fmt_out.audio,
223 if ( pp_filters[1] == NULL )
225 /* Try to split the conversion. */
226 i_nb_conversions = SplitConversion( &pp_filters[0]->fmt_out.audio,
227 p_output_format, &temp_format );
228 if ( !i_nb_conversions )
230 ReleaseFilter( pp_filters[0] );
232 "couldn't find a filter for the second part of the conversion" );
235 if( *pi_nb_filters + 3 > AOUT_MAX_FILTERS )
237 ReleaseFilter( pp_filters[0] );
238 msg_Err( p_aout, "max filter reached (%d)", AOUT_MAX_FILTERS );
239 dialog_Fatal( p_aout, _("Audio filtering failed"),
240 _("The maximum number of filters (%d) was reached."),
244 pp_filters[1] = FindFilter( p_aout, &pp_filters[0]->fmt_out.audio,
246 pp_filters[2] = FindFilter( p_aout, &temp_format,
249 if ( pp_filters[1] == NULL || pp_filters[2] == NULL )
251 ReleaseFilter( pp_filters[0] );
252 if ( pp_filters[1] != NULL )
254 ReleaseFilter( pp_filters[1] );
256 if ( pp_filters[2] != NULL )
258 ReleaseFilter( pp_filters[2] );
261 "couldn't find filters for the second part of the conversion" );
265 msg_Dbg( p_aout, "found 3 filters for the whole conversion" );
270 msg_Dbg( p_aout, "found 2 filters for the whole conversion" );
276 /*****************************************************************************
277 * aout_FiltersDestroyPipeline: deallocate a filters pipeline
278 *****************************************************************************/
279 void aout_FiltersDestroyPipeline( aout_instance_t * p_aout,
280 filter_t ** pp_filters,
286 for ( i = 0; i < i_nb_filters; i++ )
288 filter_t *p_filter = pp_filters[i];
290 module_unneed( p_filter, p_filter->p_module );
291 free( p_filter->p_owner );
292 vlc_object_release( p_filter );
296 /*****************************************************************************
297 * aout_FiltersHintBuffers: fill in aout_alloc_t structures to optimize
299 *****************************************************************************/
300 void aout_FiltersHintBuffers( aout_instance_t * p_aout,
301 filter_t ** pp_filters,
302 int i_nb_filters, aout_alloc_t * p_first_alloc )
306 (void)p_aout; /* unused */
308 for ( i = i_nb_filters - 1; i >= 0; i-- )
310 filter_t * p_filter = pp_filters[i];
312 int i_output_size = p_filter->fmt_out.audio.i_bytes_per_frame
313 * p_filter->fmt_out.audio.i_rate * AOUT_MAX_INPUT_RATE
314 / p_filter->fmt_out.audio.i_frame_length;
315 int i_input_size = p_filter->fmt_in.audio.i_bytes_per_frame
316 * p_filter->fmt_in.audio.i_rate * AOUT_MAX_INPUT_RATE
317 / p_filter->fmt_in.audio.i_frame_length;
319 if( i_output_size > p_first_alloc->i_bytes_per_sec )
320 p_first_alloc->i_bytes_per_sec = i_output_size;
321 if( i_input_size > p_first_alloc->i_bytes_per_sec )
322 p_first_alloc->i_bytes_per_sec = i_input_size;
326 /*****************************************************************************
327 * aout_FiltersPlay: play a buffer
328 *****************************************************************************/
329 void aout_FiltersPlay( filter_t ** pp_filters,
330 unsigned i_nb_filters, block_t ** pp_block )
332 block_t *p_block = *pp_block;
334 /* TODO: use filter chain */
335 for( unsigned i = 0; i < i_nb_filters; i++ )
337 filter_t * p_filter = pp_filters[i];
339 /* Please note that p_block->i_nb_samples & i_buffer
340 * shall be set by the filter plug-in. */
341 p_block = p_filter->pf_audio_filter( p_filter, p_block );