git.sesse.net Git - vlc/blob - src/audio_output/filters.c

   1 /*****************************************************************************
   2  * filters.c : audio output filters management
   3  *****************************************************************************
   4  * Copyright (C) 2002 VideoLAN
   5  * $Id: filters.c,v 1.11 2002/09/30 21:32:33 massiot Exp $
   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 );
  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     return p_filter;
  64 }
  65
  66 /*****************************************************************************
  67  * SplitConversion: split a conversion in two parts
  68  *****************************************************************************
  69  * Returns the number of conversions required by the first part - 0 if only
  70  * one conversion was asked.
  71  * Beware : p_output_format can be modified during this function if the
  72  * developer passed SplitConversion( toto, titi, titi, ... ). That is legal.
  73  * SplitConversion( toto, titi, toto, ... ) isn't.
  74  *****************************************************************************/
  75 static int SplitConversion( aout_instance_t * p_aout,
  76                              const audio_sample_format_t * p_input_format,
  77                              const audio_sample_format_t * p_output_format,
  78                              audio_sample_format_t * p_middle_format )
  79 {
  80     vlc_bool_t b_format =
  81              (p_input_format->i_format != p_output_format->i_format);
  82     vlc_bool_t b_rate = (p_input_format->i_rate != p_output_format->i_rate);
  83     vlc_bool_t b_channels =
  84              (p_input_format->i_channels != p_output_format->i_channels);
  85     int i_nb_conversions = b_format + b_rate + b_channels;
  86
  87     if ( i_nb_conversions <= 1 ) return 0;
  88
  89     memcpy( p_middle_format, p_output_format, sizeof(audio_sample_format_t) );
  90
  91     if ( i_nb_conversions == 2 )
  92     {
  93         if ( !b_format || !b_channels )
  94         {
  95             p_middle_format->i_rate = p_input_format->i_rate;
  96             return 1;
  97         }
  98
  99         /* !b_rate */
 100         p_middle_format->i_channels = p_input_format->i_channels;
 101         return 1;
 102     }
 103
 104     /* i_nb_conversion == 3 */
 105     p_middle_format->i_rate = p_input_format->i_rate;
 106     return 2;
 107 }
 108
 109 /*****************************************************************************
 110  * aout_FiltersCreatePipeline: create a filters pipeline to transform a sample
 111  *                             format to another
 112  *****************************************************************************
 113  * TODO : allow the user to add/remove specific filters
 114  *****************************************************************************/
 115 int aout_FiltersCreatePipeline( aout_instance_t * p_aout,
 116                                 aout_filter_t ** pp_filters,
 117                                 int * pi_nb_filters,
 118                                 const audio_sample_format_t * p_input_format,
 119                                 const audio_sample_format_t * p_output_format )
 120 {
 121     audio_sample_format_t temp_format;
 122     int i_nb_conversions;
 123
 124     if ( AOUT_FMTS_IDENTICAL( p_input_format, p_output_format ) )
 125     {
 126         msg_Dbg( p_aout, "no need for any filter" );
 127         *pi_nb_filters = 0;
 128         return 0;
 129     }
 130
 131     msg_Dbg( p_aout, "filter(s) format=%4.4s->%4.4s rate=%d->%d channels=%d->%d",
 132              (char *)&p_input_format->i_format,
 133              (char *)&p_output_format->i_format,
 134              p_input_format->i_rate, p_output_format->i_rate,
 135              p_input_format->i_channels, p_output_format->i_channels );
 136
 137     /* Try to find a filter to do the whole conversion. */
 138     pp_filters[0] = FindFilter( p_aout, p_input_format, p_output_format );
 139     if ( pp_filters[0] != NULL )
 140     {
 141         msg_Dbg( p_aout, "found a filter for the whole conversion" );
 142         *pi_nb_filters = 1;
 143         return 0;
 144     }
 145
 146     /* We'll have to split the conversion. We always do the downmixing
 147      * before the resampling, because the audio decoder can probably do it
 148      * for us. */
 149     i_nb_conversions = SplitConversion( p_aout, p_input_format,
 150                                         p_output_format, &temp_format );
 151     if ( !i_nb_conversions )
 152     {
 153         /* There was only one conversion to do, and we already failed. */
 154         msg_Err( p_aout, "couldn't find a filter for the conversion" );
 155         return -1;
 156     }
 157
 158     pp_filters[0] = FindFilter( p_aout, p_input_format, &temp_format );
 159     if ( pp_filters[0] == NULL && i_nb_conversions == 2 )
 160     {
 161         /* Try with only one conversion. */
 162         SplitConversion( p_aout, p_input_format, &temp_format,
 163                          &temp_format );
 164         pp_filters[0] = FindFilter( p_aout, p_input_format,
 165                                     &temp_format );
 166     }
 167     if ( pp_filters[0] == NULL )
 168     {
 169         msg_Err( p_aout,
 170               "couldn't find a filter for the first part of the conversion" );
 171         return -1;
 172     }
 173
 174     /* We have the first stage of the conversion. Find a filter for
 175      * the rest. */
 176     pp_filters[1] = FindFilter( p_aout, &pp_filters[0]->output,
 177                                 p_output_format );
 178     if ( pp_filters[1] == NULL )
 179     {
 180         /* Try to split the conversion. */
 181         i_nb_conversions = SplitConversion( p_aout,
 182                                     &pp_filters[0]->output,
 183                                     p_output_format, &temp_format );
 184         if ( !i_nb_conversions )
 185         {
 186             vlc_object_detach( pp_filters[0] );
 187             vlc_object_destroy( pp_filters[0] );
 188             msg_Err( p_aout,
 189               "couldn't find a filter for the second part of the conversion" );
 190         }
 191         pp_filters[1] = FindFilter( p_aout, &pp_filters[0]->output,
 192                                     &temp_format );
 193         pp_filters[2] = FindFilter( p_aout, &temp_format,
 194                                     p_output_format );
 195
 196         if ( pp_filters[1] == NULL || pp_filters[2] == NULL )
 197         {
 198             vlc_object_detach( pp_filters[0] );
 199             vlc_object_destroy( pp_filters[0] );
 200             if ( pp_filters[1] != NULL )
 201             {
 202                 vlc_object_detach( pp_filters[1] );
 203                 vlc_object_destroy( pp_filters[1] );
 204             }
 205             if ( pp_filters[2] != NULL )
 206             {
 207                 vlc_object_detach( pp_filters[2] );
 208                 vlc_object_destroy( pp_filters[2] );
 209             }
 210             msg_Err( p_aout,
 211                "couldn't find filters for the second part of the conversion" );
 212         }
 213         *pi_nb_filters = 3;
 214     }
 215     else
 216     {
 217         *pi_nb_filters = 2;
 218     }
 219
 220     /* We have enough filters. */
 221     msg_Dbg( p_aout, "found %d filters for the whole conversion",
 222              *pi_nb_filters );
 223     return 0;
 224 }
 225
 226 /*****************************************************************************
 227  * aout_FiltersDestroyPipeline: deallocate a filters pipeline
 228  *****************************************************************************/
 229 void aout_FiltersDestroyPipeline( aout_instance_t * p_aout,
 230                                   aout_filter_t ** pp_filters,
 231                                   int i_nb_filters )
 232 {
 233     int i;
 234
 235     for ( i = 0; i < i_nb_filters; i++ )
 236     {
 237         module_Unneed( pp_filters[i], pp_filters[i]->p_module );
 238         vlc_object_detach( pp_filters[i] );
 239         vlc_object_destroy( pp_filters[i] );
 240     }
 241 }
 242
 243 /*****************************************************************************
 244  * aout_FiltersHintBuffers: fill in aout_alloc_t structures to optimize
 245  *                          buffer allocations
 246  *****************************************************************************/
 247 void aout_FiltersHintBuffers( aout_instance_t * p_aout,
 248                               aout_filter_t ** pp_filters,
 249                               int i_nb_filters, aout_alloc_t * p_first_alloc )
 250 {
 251     int i;
 252
 253     for ( i = i_nb_filters - 1; i >= 0; i-- )
 254     {
 255         aout_filter_t * p_filter = pp_filters[i];
 256
 257         int i_output_size = p_filter->output.i_bytes_per_frame
 258                              * p_filter->output.i_rate
 259                              / p_filter->output.i_frame_length;
 260         int i_input_size = p_filter->input.i_bytes_per_frame
 261                              * p_filter->input.i_rate
 262                              / p_filter->input.i_frame_length;
 263
 264         p_first_alloc->i_bytes_per_sec = __MAX( p_first_alloc->i_bytes_per_sec,
 265                                                 i_output_size );
 266
 267         if ( p_filter->b_in_place )
 268         {
 269             p_first_alloc->i_bytes_per_sec = __MAX(
 270                                          p_first_alloc->i_bytes_per_sec,
 271                                          i_input_size );
 272             p_filter->output_alloc.i_alloc_type = AOUT_ALLOC_NONE;
 273         }
 274         else
 275         {
 276             /* We're gonna need a buffer allocation. */
 277             memcpy( &p_filter->output_alloc, p_first_alloc,
 278                     sizeof(aout_alloc_t) );
 279             p_first_alloc->i_alloc_type = AOUT_ALLOC_STACK;
 280             p_first_alloc->i_bytes_per_sec = i_input_size;
 281         }
 282     }
 283 }
 284
 285 /*****************************************************************************
 286  * aout_FiltersPlay: play a buffer
 287  *****************************************************************************/
 288 void aout_FiltersPlay( aout_instance_t * p_aout,
 289                        aout_filter_t ** pp_filters,
 290                        int i_nb_filters, aout_buffer_t ** pp_input_buffer )
 291 {
 292     int i;
 293
 294     for ( i = 0; i < i_nb_filters; i++ )
 295     {
 296         aout_filter_t * p_filter = pp_filters[i];
 297         aout_buffer_t * p_output_buffer;
 298
 299         aout_BufferAlloc( &p_filter->output_alloc,
 300                           (mtime_t)(*pp_input_buffer)->i_nb_samples * 1000000
 301                             / p_filter->input.i_rate, *pp_input_buffer,
 302                           p_output_buffer );
 303         if ( p_output_buffer == NULL )
 304         {
 305             msg_Err( p_aout, "out of memory" );
 306             return;
 307         }
 308         /* Please note that p_output_buffer->i_nb_samples & i_nb_bytes
 309          * shall be set by the filter plug-in. */
 310
 311         p_filter->pf_do_work( p_aout, p_filter, *pp_input_buffer,
 312                               p_output_buffer );
 313
 314         if ( !p_filter->b_in_place )
 315         {
 316             aout_BufferFree( *pp_input_buffer );
 317             *pp_input_buffer = p_output_buffer;
 318         }
 319     }
 320 }
 321