git.sesse.net Git - vlc/blob - modules/audio_filter/channel_mixer/simple.c

   1 /*****************************************************************************
   2  * simple.c : simple channel mixer plug-in
   3  *****************************************************************************
   4  * Copyright (C) 2002, 2004, 2006-2009 VLC authors and VideoLAN
   5  * $Id$
   6  *
   7  * Authors: Gildas Bazin <gbazin@videolan.org>
   8  *
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU Lesser General Public License as published by
  11  * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public License
  20  * along with this program; if not, write to the Free Software Foundation,
  21  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 /*****************************************************************************
  25  * Preamble
  26  *****************************************************************************/
  27 #ifdef HAVE_CONFIG_H
  28 # include "config.h"
  29 #endif
  30
  31 #include <vlc_common.h>
  32 #include <vlc_plugin.h>
  33 #include <vlc_aout.h>
  34 #include <vlc_filter.h>
  35 #include <vlc_block.h>
  36 #include <assert.h>
  37
  38 /*****************************************************************************
  39  * Module descriptor
  40  *****************************************************************************/
  41 static int  OpenFilter( vlc_object_t * );
  42 static void CloseFilter( vlc_object_t * );
  43
  44 vlc_module_begin ()
  45     set_description( N_("Audio filter for simple channel mixing") )
  46     set_category( CAT_AUDIO )
  47     set_subcategory( SUBCAT_AUDIO_MISC )
  48     set_capability( "audio converter", 10 )
  49     set_callbacks( OpenFilter, CloseFilter );
  50 vlc_module_end ()
  51
  52 /*****************************************************************************
  53  * Local prototypes
  54  *****************************************************************************/
  55 struct filter_sys_t
  56 {
  57     void (*pf_dowork)(filter_t *, block_t *, block_t * );
  58 };
  59
  60 /*****************************************************************************
  61  * IsSupported: can we downmix?
  62  *****************************************************************************/
  63 static bool IsSupported( const audio_format_t *p_input, const audio_format_t *p_output )
  64 {
  65     if( p_input->i_format != VLC_CODEC_FL32 ||
  66         p_input->i_format != p_output->i_format ||
  67         p_input->i_rate != p_output->i_rate )
  68     {
  69         return false;
  70     }
  71
  72     if( p_input->i_physical_channels == p_output->i_physical_channels &&
  73         p_input->i_original_channels == p_output->i_original_channels )
  74     {
  75         return false;
  76     }
  77
  78     /* Only conversion to Mono, Stereo, 4.0 and 5.1 */
  79     if( p_output->i_physical_channels != AOUT_CHAN_CENTER &&
  80         p_output->i_physical_channels != AOUT_CHANS_2_0 &&
  81         p_output->i_physical_channels != AOUT_CHANS_4_0 &&
  82         p_output->i_physical_channels != AOUT_CHANS_5_1 )
  83     {
  84         return false;
  85     }
  86
  87     /* Only from 7.x/5.x/4.0/3.x/2.0
  88      * NB 5.X rear and middle are handled the same way
  89      * We don't support 2.1 -> 2.0 (trivial can do it)
  90      * TODO: We don't support any 8.1 input
  91      * TODO: We don't support any 6.x input
  92      * TODO: We don't support 4.0 rear and 4.0 middle
  93      * */
  94     if( (p_input->i_physical_channels & ~AOUT_CHAN_LFE) != AOUT_CHANS_7_0 &&
  95         (p_input->i_physical_channels)                  != AOUT_CHANS_6_1_MIDDLE &&
  96         (p_input->i_physical_channels & ~AOUT_CHAN_LFE) != AOUT_CHANS_5_0 &&
  97         (p_input->i_physical_channels & ~AOUT_CHAN_LFE) != AOUT_CHANS_5_0_MIDDLE &&
  98         (p_input->i_physical_channels & ~AOUT_CHAN_LFE) != AOUT_CHANS_4_CENTER_REAR &&
  99         (p_input->i_physical_channels & ~AOUT_CHAN_LFE) != AOUT_CHANS_3_0 &&
 100          p_input->i_physical_channels != AOUT_CHANS_2_0 )
 101     {
 102         return false;
 103     }
 104
 105     /* Only downmixing */
 106     if( aout_FormatNbChannels( p_input ) <= aout_FormatNbChannels( p_output ) )
 107         return false;
 108
 109     return true;
 110 }
 111
 112 static block_t *Filter( filter_t *, block_t * );
 113
 114 static void DoWork_7_x_to_2_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 115     float *p_dest = (float *)p_out_buf->p_buffer;
 116     const float *p_src = (const float *)p_in_buf->p_buffer;
 117     for( int i = p_in_buf->i_nb_samples; i--; )
 118     {
 119         float ctr = p_src[6] * 0.7071f;
 120         *p_dest++ = ctr + p_src[0] + p_src[2] / 4 + p_src[4] / 4;
 121         *p_dest++ = ctr + p_src[1] + p_src[3] / 4 + p_src[5] / 4;
 122
 123         p_src += 7;
 124
 125         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 126     }
 127 }
 128
 129 static void DoWork_6_1_to_2_0( filter_t *p_filter, block_t *p_in_buf,
 130                                block_t *p_out_buf )
 131 {
 132     VLC_UNUSED(p_filter);
 133     float *p_dest = (float *)p_out_buf->p_buffer;
 134     const float *p_src = (const float *)p_in_buf->p_buffer;
 135     for( int i = p_in_buf->i_nb_samples; i--; )
 136     {
 137         float ctr = (p_src[2] + p_src[5]) * 0.7071f;
 138         *p_dest++ = p_src[0] + p_src[3] + ctr;
 139         *p_dest++ = p_src[1] + p_src[4] + ctr;
 140
 141         p_src += 6;
 142
 143         /* We always have LFE here */
 144         p_src++;
 145     }
 146 }
 147
 148 static void DoWork_5_x_to_2_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 149     float *p_dest = (float *)p_out_buf->p_buffer;
 150     const float *p_src = (const float *)p_in_buf->p_buffer;
 151     for( int i = p_in_buf->i_nb_samples; i--; )
 152     {
 153         *p_dest++ = p_src[0] + 0.7071f * (p_src[4] + p_src[2]);
 154         *p_dest++ = p_src[1] + 0.7071f * (p_src[4] + p_src[3]);
 155
 156         p_src += 5;
 157
 158         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 159     }
 160 }
 161
 162 static void DoWork_4_0_to_2_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 163     VLC_UNUSED(p_filter);
 164     float *p_dest = (float *)p_out_buf->p_buffer;
 165     const float *p_src = (const float *)p_in_buf->p_buffer;
 166     for( int i = p_in_buf->i_nb_samples; i--; )
 167     {
 168         *p_dest++ = p_src[2] + p_src[3] + 0.5f * p_src[0];
 169         *p_dest++ = p_src[2] + p_src[3] + 0.5f * p_src[1];
 170         p_src += 4;
 171     }
 172 }
 173
 174 static void DoWork_3_x_to_2_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 175     float *p_dest = (float *)p_out_buf->p_buffer;
 176     const float *p_src = (const float *)p_in_buf->p_buffer;
 177     for( int i = p_in_buf->i_nb_samples; i--; )
 178     {
 179         *p_dest++ = p_src[2] + 0.5f * p_src[0];
 180         *p_dest++ = p_src[2] + 0.5f * p_src[1];
 181
 182         p_src += 3;
 183
 184         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 185     }
 186 }
 187
 188 static void DoWork_7_x_to_1_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 189     float *p_dest = (float *)p_out_buf->p_buffer;
 190     const float *p_src = (const float *)p_in_buf->p_buffer;
 191     for( int i = p_in_buf->i_nb_samples; i--; )
 192     {
 193         *p_dest++ = p_src[6] + p_src[0] / 4 + p_src[1] / 4 + p_src[2] / 8 + p_src[3] / 8 + p_src[4] / 8 + p_src[5] / 8;
 194
 195         p_src += 7;
 196
 197         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 198     }
 199 }
 200
 201 static void DoWork_5_x_to_1_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 202     float *p_dest = (float *)p_out_buf->p_buffer;
 203     const float *p_src = (const float *)p_in_buf->p_buffer;
 204     for( int i = p_in_buf->i_nb_samples; i--; )
 205     {
 206         *p_dest++ = 0.7071f * (p_src[0] + p_src[1]) + p_src[4]
 207                      + 0.5f * (p_src[2] + p_src[3]);
 208
 209         p_src += 5;
 210
 211         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 212     }
 213 }
 214
 215 static void DoWork_4_0_to_1_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 216     VLC_UNUSED(p_filter);
 217     float *p_dest = (float *)p_out_buf->p_buffer;
 218     const float *p_src = (const float *)p_in_buf->p_buffer;
 219     for( int i = p_in_buf->i_nb_samples; i--; )
 220     {
 221         *p_dest++ = p_src[2] + p_src[3] + p_src[0] / 4 + p_src[1] / 4;
 222         p_src += 4;
 223     }
 224 }
 225
 226 static void DoWork_3_x_to_1_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 227     float *p_dest = (float *)p_out_buf->p_buffer;
 228     const float *p_src = (const float *)p_in_buf->p_buffer;
 229     for( int i = p_in_buf->i_nb_samples; i--; )
 230     {
 231         *p_dest++ = p_src[2] + p_src[0] / 4 + p_src[1] / 4;
 232
 233         p_src += 3;
 234
 235         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 236     }
 237 }
 238
 239 static void DoWork_2_x_to_1_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 240     VLC_UNUSED(p_filter);
 241     float *p_dest = (float *)p_out_buf->p_buffer;
 242     const float *p_src = (const float *)p_in_buf->p_buffer;
 243     for( int i = p_in_buf->i_nb_samples; i--; )
 244     {
 245         *p_dest++ = p_src[0] / 2 + p_src[1] / 2;
 246
 247         p_src += 2;
 248     }
 249 }
 250
 251 static void DoWork_7_x_to_4_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 252     float *p_dest = (float *)p_out_buf->p_buffer;
 253     const float *p_src = (const float *)p_in_buf->p_buffer;
 254     for( int i = p_in_buf->i_nb_samples; i--; )
 255     {
 256         *p_dest++ = p_src[6] + 0.5f * p_src[0] + p_src[2] / 6;
 257         *p_dest++ = p_src[6] + 0.5f * p_src[1] + p_src[3] / 6;
 258         *p_dest++ = p_src[2] / 6 +  p_src[4];
 259         *p_dest++ = p_src[3] / 6 +  p_src[5];
 260
 261         p_src += 7;
 262
 263         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 264     }
 265 }
 266
 267 static void DoWork_5_x_to_4_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 268     float *p_dest = (float *)p_out_buf->p_buffer;
 269     const float *p_src = (const float *)p_in_buf->p_buffer;
 270     for( int i = p_in_buf->i_nb_samples; i--; )
 271     {
 272         float ctr = p_src[4] * 0.7071f;
 273         *p_dest++ = p_src[0] + ctr;
 274         *p_dest++ = p_src[1] + ctr;
 275         *p_dest++ = p_src[2];
 276         *p_dest++ = p_src[3];
 277
 278         p_src += 5;
 279
 280         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 281     }
 282 }
 283
 284 static void DoWork_7_x_to_5_x( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 285     float *p_dest = (float *)p_out_buf->p_buffer;
 286     const float *p_src = (const float *)p_in_buf->p_buffer;
 287     for( int i = p_in_buf->i_nb_samples; i--; )
 288     {
 289         *p_dest++ = p_src[0];
 290         *p_dest++ = p_src[1];
 291         *p_dest++ = (p_src[2] + p_src[4]) * 0.5f;
 292         *p_dest++ = (p_src[3] + p_src[5]) * 0.5f;
 293         *p_dest++ = p_src[6];
 294
 295         p_src += 7;
 296
 297         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE &&
 298             p_filter->fmt_out.audio.i_physical_channels & AOUT_CHAN_LFE )
 299             *p_dest++ = *p_src++;
 300         else if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 301     }
 302 }
 303
 304 static void DoWork_6_1_to_5_x( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 305     VLC_UNUSED(p_filter);
 306     float *p_dest = (float *)p_out_buf->p_buffer;
 307     const float *p_src = (const float *)p_in_buf->p_buffer;
 308     for( int i = p_in_buf->i_nb_samples; i--; )
 309     {
 310         *p_dest++ = p_src[0];
 311         *p_dest++ = p_src[1];
 312         *p_dest++ = (p_src[2] + p_src[4]) * 0.5f;
 313         *p_dest++ = (p_src[3] + p_src[4]) * 0.5f;
 314         *p_dest++ = p_src[5];
 315
 316         p_src += 6;
 317
 318         /* We always have LFE here */
 319         *p_dest++ = *p_src++;
 320     }
 321 }
 322
 323
 324 /*****************************************************************************
 325  * OpenFilter:
 326  *****************************************************************************/
 327 static int OpenFilter( vlc_object_t *p_this )
 328 {
 329     filter_t *p_filter = (filter_t *)p_this;
 330     filter_sys_t *p_sys;
 331
 332     audio_format_t fmt_in  = p_filter->fmt_in.audio;
 333     audio_format_t fmt_out = p_filter->fmt_out.audio;
 334
 335     fmt_in.i_format = p_filter->fmt_in.i_codec;
 336     fmt_out.i_format = p_filter->fmt_out.i_codec;
 337
 338     if( !IsSupported( &fmt_in, &fmt_out ) )
 339         return VLC_EGENERIC;
 340
 341     p_filter->p_sys = malloc( sizeof(*p_sys) );
 342     if( unlikely(!p_filter->p_sys) )
 343         return VLC_ENOMEM;
 344
 345     p_filter->pf_audio_filter = Filter;
 346
 347     const unsigned i_input_physical = p_filter->fmt_in.audio.i_physical_channels;
 348     const bool b_input_7_0 = (i_input_physical & ~AOUT_CHAN_LFE) == AOUT_CHANS_7_0;
 349     const bool b_input_6_1 = !b_input_7_0 &&
 350                              i_input_physical == AOUT_CHANS_6_1_MIDDLE;
 351     const bool b_input_5_0 = !b_input_7_0 && !b_input_6_1 &&
 352                              ( (i_input_physical & AOUT_CHANS_5_0) == AOUT_CHANS_5_0 ||
 353                                (i_input_physical & AOUT_CHANS_5_0_MIDDLE) == AOUT_CHANS_5_0_MIDDLE );
 354     const bool b_input_4_center_rear =  !b_input_7_0 && !b_input_5_0 &&
 355                              (i_input_physical & ~AOUT_CHAN_LFE) == AOUT_CHANS_4_CENTER_REAR;
 356     const bool b_input_3_0 = !b_input_7_0 && !b_input_5_0 && !b_input_4_center_rear &&
 357                              (i_input_physical & ~AOUT_CHAN_LFE) == AOUT_CHANS_3_0;
 358
 359     if( p_filter->fmt_out.audio.i_physical_channels == AOUT_CHANS_2_0 )
 360     {
 361         if( b_input_7_0 )
 362             p_filter->p_sys->pf_dowork = DoWork_7_x_to_2_0;
 363         else if( b_input_6_1 )
 364             p_filter->p_sys->pf_dowork = DoWork_6_1_to_2_0;
 365         else if( b_input_5_0 )
 366             p_filter->p_sys->pf_dowork = DoWork_5_x_to_2_0;
 367         else if( b_input_4_center_rear )
 368             p_filter->p_sys->pf_dowork = DoWork_4_0_to_2_0;
 369         else if( b_input_3_0 )
 370             p_filter->p_sys->pf_dowork = DoWork_3_x_to_2_0;
 371     }
 372     else if( p_filter->fmt_out.audio.i_physical_channels == AOUT_CHAN_CENTER )
 373     {
 374         if( b_input_7_0 )
 375             p_filter->p_sys->pf_dowork = DoWork_7_x_to_1_0;
 376         else if( b_input_5_0 )
 377             p_filter->p_sys->pf_dowork = DoWork_5_x_to_1_0;
 378         else if( b_input_4_center_rear )
 379             p_filter->p_sys->pf_dowork = DoWork_4_0_to_1_0;
 380         else if( b_input_3_0 )
 381             p_filter->p_sys->pf_dowork = DoWork_3_x_to_1_0;
 382         else
 383             p_filter->p_sys->pf_dowork = DoWork_2_x_to_1_0;
 384     }
 385     else if(p_filter->fmt_out.audio.i_physical_channels == AOUT_CHANS_4_0)
 386     {
 387         if( b_input_7_0 )
 388             p_filter->p_sys->pf_dowork = DoWork_7_x_to_4_0;
 389         else
 390             p_filter->p_sys->pf_dowork = DoWork_5_x_to_4_0;
 391     }
 392     else
 393     {
 394         assert( b_input_7_0 || b_input_6_1 );
 395         if( b_input_7_0 )
 396             p_filter->p_sys->pf_dowork = DoWork_7_x_to_5_x;
 397         else
 398             p_filter->p_sys->pf_dowork = DoWork_6_1_to_5_x;
 399     }
 400
 401     return VLC_SUCCESS;
 402 }
 403
 404 static void CloseFilter( vlc_object_t *p_this )
 405 {
 406     filter_t *p_filter = (filter_t *) p_this;
 407     filter_sys_t *p_sys = p_filter->p_sys;
 408     free( p_sys );
 409 }
 410
 411 /*****************************************************************************
 412  * Filter:
 413  *****************************************************************************/
 414 static block_t *Filter( filter_t *p_filter, block_t *p_block )
 415 {
 416     filter_sys_t *p_sys = (filter_sys_t *)p_filter->p_sys;
 417     if( !p_block || !p_block->i_nb_samples )
 418     {
 419         if( p_block )
 420             block_Release( p_block );
 421         return NULL;
 422     }
 423
 424     size_t i_out_size = p_block->i_nb_samples *
 425       p_filter->fmt_out.audio.i_bitspersample *
 426         p_filter->fmt_out.audio.i_channels / 8;
 427
 428     block_t *p_out = block_Alloc( i_out_size );
 429     if( !p_out )
 430     {
 431         msg_Warn( p_filter, "can't get output buffer" );
 432         block_Release( p_block );
 433         return NULL;
 434     }
 435
 436     p_out->i_nb_samples = p_block->i_nb_samples;
 437     p_out->i_dts = p_block->i_dts;
 438     p_out->i_pts = p_block->i_pts;
 439     p_out->i_length = p_block->i_length;
 440
 441     int i_input_nb = aout_FormatNbChannels( &p_filter->fmt_in.audio );
 442     int i_output_nb = aout_FormatNbChannels( &p_filter->fmt_out.audio );
 443     p_out->i_nb_samples = p_block->i_nb_samples;
 444     p_out->i_buffer = p_block->i_buffer * i_output_nb / i_input_nb;
 445
 446     p_sys->pf_dowork( p_filter, p_block, p_out );
 447
 448     block_Release( p_block );
 449
 450     return p_out;
 451 }
 452