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 *****************************************************************************/
27 #include <stdlib.h> /* calloc(), malloc(), free() */
31 #include <vlc_interface.h>
38 #include "aout_internal.h"
40 /*****************************************************************************
41 * FindFilter: find an audio filter for a specific transformation
42 *****************************************************************************/
43 static aout_filter_t * FindFilter( aout_instance_t * p_aout,
44 const audio_sample_format_t * p_input_format,
45 const audio_sample_format_t * p_output_format )
47 aout_filter_t * p_filter = vlc_object_create( p_aout,
48 sizeof(aout_filter_t) );
50 if ( p_filter == NULL ) return NULL;
51 vlc_object_attach( p_filter, p_aout );
53 memcpy( &p_filter->input, p_input_format, sizeof(audio_sample_format_t) );
54 memcpy( &p_filter->output, p_output_format,
55 sizeof(audio_sample_format_t) );
56 p_filter->p_module = module_Need( p_filter, "audio filter", NULL, 0 );
57 if ( p_filter->p_module == NULL )
59 vlc_object_detach( p_filter );
60 vlc_object_destroy( p_filter );
64 p_filter->b_continuity = VLC_FALSE;
69 /*****************************************************************************
70 * SplitConversion: split a conversion in two parts
71 *****************************************************************************
72 * Returns the number of conversions required by the first part - 0 if only
73 * one conversion was asked.
74 * Beware : p_output_format can be modified during this function if the
75 * developer passed SplitConversion( toto, titi, titi, ... ). That is legal.
76 * SplitConversion( toto, titi, toto, ... ) isn't.
77 *****************************************************************************/
78 static int SplitConversion( const audio_sample_format_t * p_input_format,
79 const audio_sample_format_t * p_output_format,
80 audio_sample_format_t * p_middle_format )
83 (p_input_format->i_format != p_output_format->i_format);
84 vlc_bool_t b_rate = (p_input_format->i_rate != p_output_format->i_rate);
85 vlc_bool_t b_channels =
86 (p_input_format->i_physical_channels
87 != p_output_format->i_physical_channels)
88 || (p_input_format->i_original_channels
89 != p_output_format->i_original_channels);
90 int i_nb_conversions = b_format + b_rate + b_channels;
92 if ( i_nb_conversions <= 1 ) return 0;
94 memcpy( p_middle_format, p_output_format, sizeof(audio_sample_format_t) );
96 if ( i_nb_conversions == 2 )
98 if ( !b_format || !b_channels )
100 p_middle_format->i_rate = p_input_format->i_rate;
101 aout_FormatPrepare( p_middle_format );
106 p_middle_format->i_physical_channels
107 = p_input_format->i_physical_channels;
108 p_middle_format->i_original_channels
109 = p_input_format->i_original_channels;
110 aout_FormatPrepare( p_middle_format );
114 /* i_nb_conversion == 3 */
115 p_middle_format->i_rate = p_input_format->i_rate;
116 aout_FormatPrepare( p_middle_format );
120 static void ReleaseFilter( aout_filter_t * p_filter )
122 module_Unneed( p_filter, p_filter->p_module );
123 vlc_object_detach( p_filter );
124 vlc_object_destroy( p_filter );
127 /*****************************************************************************
128 * aout_FiltersCreatePipeline: create a filters pipeline to transform a sample
130 *****************************************************************************
131 * pi_nb_filters must be initialized before calling this function
132 *****************************************************************************/
133 int aout_FiltersCreatePipeline( aout_instance_t * p_aout,
134 aout_filter_t ** pp_filters_start,
136 const audio_sample_format_t * p_input_format,
137 const audio_sample_format_t * p_output_format )
139 aout_filter_t** pp_filters = pp_filters_start + *pi_nb_filters;
140 audio_sample_format_t temp_format;
141 int i_nb_conversions;
143 if ( AOUT_FMTS_IDENTICAL( p_input_format, p_output_format ) )
145 msg_Dbg( p_aout, "no need for any filter" );
149 aout_FormatsPrint( p_aout, "filter(s)", p_input_format, p_output_format );
151 if( *pi_nb_filters + 1 > AOUT_MAX_FILTERS )
153 msg_Err( p_aout, "max filter reached (%d)", AOUT_MAX_FILTERS );
154 intf_UserFatal( p_aout, VLC_FALSE, _("Audio filtering failed"),
155 _("The maximum number of filters (%d) was reached."),
160 /* Try to find a filter to do the whole conversion. */
161 pp_filters[0] = FindFilter( p_aout, p_input_format, p_output_format );
162 if ( pp_filters[0] != NULL )
164 msg_Dbg( p_aout, "found a filter for the whole conversion" );
169 /* We'll have to split the conversion. We always do the downmixing
170 * before the resampling, because the audio decoder can probably do it
172 i_nb_conversions = SplitConversion( p_input_format,
173 p_output_format, &temp_format );
174 if ( !i_nb_conversions )
176 /* There was only one conversion to do, and we already failed. */
177 msg_Err( p_aout, "couldn't find a filter for the conversion" );
181 pp_filters[0] = FindFilter( p_aout, p_input_format, &temp_format );
182 if ( pp_filters[0] == NULL && i_nb_conversions == 2 )
184 /* Try with only one conversion. */
185 SplitConversion( p_input_format, &temp_format, &temp_format );
186 pp_filters[0] = FindFilter( p_aout, p_input_format, &temp_format );
188 if ( pp_filters[0] == NULL )
191 "couldn't find a filter for the first part of the conversion" );
195 /* We have the first stage of the conversion. Find a filter for
197 if( *pi_nb_filters + 2 > AOUT_MAX_FILTERS )
199 ReleaseFilter( pp_filters[0] );
200 msg_Err( p_aout, "max filter reached (%d)", AOUT_MAX_FILTERS );
201 intf_UserFatal( p_aout, VLC_FALSE, _("Audio filtering failed"),
202 _("The maximum number of filters (%d) was reached."),
206 pp_filters[1] = FindFilter( p_aout, &pp_filters[0]->output,
208 if ( pp_filters[1] == NULL )
210 /* Try to split the conversion. */
211 i_nb_conversions = SplitConversion( &pp_filters[0]->output,
212 p_output_format, &temp_format );
213 if ( !i_nb_conversions )
215 ReleaseFilter( pp_filters[0] );
217 "couldn't find a filter for the second part of the conversion" );
220 if( *pi_nb_filters + 3 > AOUT_MAX_FILTERS )
222 ReleaseFilter( pp_filters[0] );
223 msg_Err( p_aout, "max filter reached (%d)", AOUT_MAX_FILTERS );
224 intf_UserFatal( p_aout, VLC_FALSE, _("Audio filtering failed"),
225 _("The maximum number of filters (%d) was reached."),
229 pp_filters[1] = FindFilter( p_aout, &pp_filters[0]->output,
231 pp_filters[2] = FindFilter( p_aout, &temp_format,
234 if ( pp_filters[1] == NULL || pp_filters[2] == NULL )
236 ReleaseFilter( pp_filters[0] );
237 if ( pp_filters[1] != NULL )
239 ReleaseFilter( pp_filters[1] );
241 if ( pp_filters[2] != NULL )
243 ReleaseFilter( pp_filters[2] );
246 "couldn't find filters for the second part of the conversion" );
250 msg_Dbg( p_aout, "found 3 filters for the whole conversion" );
255 msg_Dbg( p_aout, "found 2 filters for the whole conversion" );
261 /*****************************************************************************
262 * aout_FiltersDestroyPipeline: deallocate a filters pipeline
263 *****************************************************************************/
264 void aout_FiltersDestroyPipeline( aout_instance_t * p_aout,
265 aout_filter_t ** pp_filters,
271 for ( i = 0; i < i_nb_filters; i++ )
273 module_Unneed( pp_filters[i], pp_filters[i]->p_module );
274 vlc_object_detach( pp_filters[i] );
275 vlc_object_destroy( pp_filters[i] );
279 /*****************************************************************************
280 * aout_FiltersHintBuffers: fill in aout_alloc_t structures to optimize
282 *****************************************************************************/
283 void aout_FiltersHintBuffers( aout_instance_t * p_aout,
284 aout_filter_t ** pp_filters,
285 int i_nb_filters, aout_alloc_t * p_first_alloc )
289 (void)p_aout; /* unused */
291 for ( i = i_nb_filters - 1; i >= 0; i-- )
293 aout_filter_t * p_filter = pp_filters[i];
295 int i_output_size = p_filter->output.i_bytes_per_frame
296 * p_filter->output.i_rate * AOUT_MAX_INPUT_RATE
297 / p_filter->output.i_frame_length;
298 int i_input_size = p_filter->input.i_bytes_per_frame
299 * p_filter->input.i_rate * AOUT_MAX_INPUT_RATE
300 / p_filter->input.i_frame_length;
302 p_first_alloc->i_bytes_per_sec = __MAX( p_first_alloc->i_bytes_per_sec,
305 if ( p_filter->b_in_place )
307 p_first_alloc->i_bytes_per_sec = __MAX(
308 p_first_alloc->i_bytes_per_sec,
310 p_filter->output_alloc.i_alloc_type = AOUT_ALLOC_NONE;
314 /* We're gonna need a buffer allocation. */
315 memcpy( &p_filter->output_alloc, p_first_alloc,
316 sizeof(aout_alloc_t) );
317 p_first_alloc->i_alloc_type = AOUT_ALLOC_STACK;
318 p_first_alloc->i_bytes_per_sec = i_input_size;
323 /*****************************************************************************
324 * aout_FiltersPlay: play a buffer
325 *****************************************************************************/
326 void aout_FiltersPlay( aout_instance_t * p_aout,
327 aout_filter_t ** pp_filters,
328 int i_nb_filters, aout_buffer_t ** pp_input_buffer )
332 for ( i = 0; i < i_nb_filters; i++ )
334 aout_filter_t * p_filter = pp_filters[i];
335 aout_buffer_t * p_output_buffer;
337 /* Resamplers can produce slightly more samples than (i_in_nb *
338 * p_filter->output.i_rate / p_filter->input.i_rate) so we need
339 * slightly bigger buffers. */
340 aout_BufferAlloc( &p_filter->output_alloc,
341 ((mtime_t)(*pp_input_buffer)->i_nb_samples + 2)
342 * 1000000 / p_filter->input.i_rate,
343 *pp_input_buffer, p_output_buffer );
344 if ( p_output_buffer == NULL )
346 msg_Err( p_aout, "out of memory" );
349 /* Please note that p_output_buffer->i_nb_samples & i_nb_bytes
350 * shall be set by the filter plug-in. */
352 p_filter->pf_do_work( p_aout, p_filter, *pp_input_buffer,
355 if ( !p_filter->b_in_place )
357 aout_BufferFree( *pp_input_buffer );
358 *pp_input_buffer = p_output_buffer;
361 if( p_output_buffer->i_nb_samples <= 0 )