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>
37 #include <vlc_filter.h>
38 #include "aout_internal.h"
41 block_t *aout_FilterBufferNew( filter_t *p_filter, int size )
44 return block_Alloc( size );
47 /*****************************************************************************
48 * FindFilter: find an audio filter for a specific transformation
49 *****************************************************************************/
50 static filter_t * FindFilter( aout_instance_t * p_aout,
51 const audio_sample_format_t * p_input_format,
52 const audio_sample_format_t * p_output_format )
54 static const char typename[] = "audio filter";
57 p_filter = vlc_custom_create( p_aout, sizeof(*p_filter),
58 VLC_OBJECT_GENERIC, typename );
60 if ( p_filter == NULL ) return NULL;
61 vlc_object_attach( p_filter, p_aout );
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_detach( p_filter );
75 vlc_object_release( p_filter );
79 assert( p_filter->pf_audio_filter );
83 /*****************************************************************************
84 * SplitConversion: split a conversion in two parts
85 *****************************************************************************
86 * Returns the number of conversions required by the first part - 0 if only
87 * one conversion was asked.
88 * Beware : p_output_format can be modified during this function if the
89 * developer passed SplitConversion( toto, titi, titi, ... ). That is legal.
90 * SplitConversion( toto, titi, toto, ... ) isn't.
91 *****************************************************************************/
92 static int SplitConversion( const audio_sample_format_t * p_input_format,
93 const audio_sample_format_t * p_output_format,
94 audio_sample_format_t * p_middle_format )
97 (p_input_format->i_format != p_output_format->i_format);
98 bool b_rate = (p_input_format->i_rate != p_output_format->i_rate);
100 (p_input_format->i_physical_channels
101 != p_output_format->i_physical_channels)
102 || (p_input_format->i_original_channels
103 != p_output_format->i_original_channels);
104 int i_nb_conversions = b_format + b_rate + b_channels;
106 if ( i_nb_conversions <= 1 ) return 0;
108 memcpy( p_middle_format, p_output_format, sizeof(audio_sample_format_t) );
110 if ( i_nb_conversions == 2 )
112 if ( !b_format || !b_channels )
114 p_middle_format->i_rate = p_input_format->i_rate;
115 aout_FormatPrepare( p_middle_format );
120 p_middle_format->i_physical_channels
121 = p_input_format->i_physical_channels;
122 p_middle_format->i_original_channels
123 = p_input_format->i_original_channels;
124 aout_FormatPrepare( p_middle_format );
128 /* i_nb_conversion == 3 */
129 p_middle_format->i_rate = p_input_format->i_rate;
130 aout_FormatPrepare( p_middle_format );
134 static void ReleaseFilter( filter_t * p_filter )
136 module_unneed( p_filter, p_filter->p_module );
137 vlc_object_detach( p_filter );
138 vlc_object_release( p_filter );
141 /*****************************************************************************
142 * aout_FiltersCreatePipeline: create a filters pipeline to transform a sample
144 *****************************************************************************
145 * pi_nb_filters must be initialized before calling this function
146 *****************************************************************************/
147 int aout_FiltersCreatePipeline( aout_instance_t * p_aout,
148 filter_t ** pp_filters_start,
150 const audio_sample_format_t * p_input_format,
151 const audio_sample_format_t * p_output_format )
153 filter_t** pp_filters = pp_filters_start + *pi_nb_filters;
154 audio_sample_format_t temp_format;
155 int i_nb_conversions;
157 if ( AOUT_FMTS_IDENTICAL( p_input_format, p_output_format ) )
159 msg_Dbg( p_aout, "no need for any filter" );
163 aout_FormatsPrint( p_aout, "filter(s)", p_input_format, p_output_format );
165 if( *pi_nb_filters + 1 > AOUT_MAX_FILTERS )
167 msg_Err( p_aout, "max filter reached (%d)", AOUT_MAX_FILTERS );
168 dialog_Fatal( p_aout, _("Audio filtering failed"),
169 _("The maximum number of filters (%d) was reached."),
174 /* Try to find a filter to do the whole conversion. */
175 pp_filters[0] = FindFilter( p_aout, p_input_format, p_output_format );
176 if ( pp_filters[0] != NULL )
178 msg_Dbg( p_aout, "found a filter for the whole conversion" );
183 /* We'll have to split the conversion. We always do the downmixing
184 * before the resampling, because the audio decoder can probably do it
186 i_nb_conversions = SplitConversion( p_input_format,
187 p_output_format, &temp_format );
188 if ( !i_nb_conversions )
190 /* There was only one conversion to do, and we already failed. */
191 msg_Err( p_aout, "couldn't find a filter for the conversion" );
195 pp_filters[0] = FindFilter( p_aout, p_input_format, &temp_format );
196 if ( pp_filters[0] == NULL && i_nb_conversions == 2 )
198 /* Try with only one conversion. */
199 SplitConversion( p_input_format, &temp_format, &temp_format );
200 pp_filters[0] = FindFilter( p_aout, p_input_format, &temp_format );
202 if ( pp_filters[0] == NULL )
205 "couldn't find a filter for the first part of the conversion" );
209 /* We have the first stage of the conversion. Find a filter for
211 if( *pi_nb_filters + 2 > AOUT_MAX_FILTERS )
213 ReleaseFilter( pp_filters[0] );
214 msg_Err( p_aout, "max filter reached (%d)", AOUT_MAX_FILTERS );
215 dialog_Fatal( p_aout, _("Audio filtering failed"),
216 _("The maximum number of filters (%d) was reached."),
220 pp_filters[1] = FindFilter( p_aout, &pp_filters[0]->fmt_out.audio,
222 if ( pp_filters[1] == NULL )
224 /* Try to split the conversion. */
225 i_nb_conversions = SplitConversion( &pp_filters[0]->fmt_out.audio,
226 p_output_format, &temp_format );
227 if ( !i_nb_conversions )
229 ReleaseFilter( pp_filters[0] );
231 "couldn't find a filter for the second part of the conversion" );
234 if( *pi_nb_filters + 3 > AOUT_MAX_FILTERS )
236 ReleaseFilter( pp_filters[0] );
237 msg_Err( p_aout, "max filter reached (%d)", AOUT_MAX_FILTERS );
238 dialog_Fatal( p_aout, _("Audio filtering failed"),
239 _("The maximum number of filters (%d) was reached."),
243 pp_filters[1] = FindFilter( p_aout, &pp_filters[0]->fmt_out.audio,
245 pp_filters[2] = FindFilter( p_aout, &temp_format,
248 if ( pp_filters[1] == NULL || pp_filters[2] == NULL )
250 ReleaseFilter( pp_filters[0] );
251 if ( pp_filters[1] != NULL )
253 ReleaseFilter( pp_filters[1] );
255 if ( pp_filters[2] != NULL )
257 ReleaseFilter( pp_filters[2] );
260 "couldn't find filters for the second part of the conversion" );
264 msg_Dbg( p_aout, "found 3 filters for the whole conversion" );
269 msg_Dbg( p_aout, "found 2 filters for the whole conversion" );
275 /*****************************************************************************
276 * aout_FiltersDestroyPipeline: deallocate a filters pipeline
277 *****************************************************************************/
278 void aout_FiltersDestroyPipeline( aout_instance_t * p_aout,
279 filter_t ** pp_filters,
285 for ( i = 0; i < i_nb_filters; i++ )
287 filter_t *p_filter = pp_filters[i];
289 module_unneed( p_filter, p_filter->p_module );
290 free( p_filter->p_owner );
291 vlc_object_detach( p_filter );
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 );