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         *p_dest++ = p_src[6] + 0.5 * p_src[0] + p_src[2] / 4 + p_src[4] / 4;
 120         *p_dest++ = p_src[6] + 0.5 * p_src[1] + p_src[3] / 4 + p_src[5] / 4;
 121
 122         p_src += 7;
 123
 124         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 125     }
 126 }
 127
 128 static void DoWork_6_1_to_2_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 129     VLC_UNUSED(p_filter);
 130     float *p_dest = (float *)p_out_buf->p_buffer;
 131     const float *p_src = (const float *)p_in_buf->p_buffer;
 132     for( int i = p_in_buf->i_nb_samples; i--; )
 133     {
 134         *p_dest++ = p_src[0] + 0.7071 * (p_src[3] + (p_src[2] + p_src[5]) / 2);
 135         *p_dest++ = p_src[1] + 0.7071 * (p_src[4] + (p_src[2] + p_src[5]) / 2);
 136
 137         p_src += 6;
 138
 139         /* We always have LFE here */
 140         p_src++;
 141     }
 142 }
 143
 144 static void DoWork_5_x_to_2_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 145     float *p_dest = (float *)p_out_buf->p_buffer;
 146     const float *p_src = (const float *)p_in_buf->p_buffer;
 147     for( int i = p_in_buf->i_nb_samples; i--; )
 148     {
 149         *p_dest++ = p_src[0] + 0.7071 * (p_src[4] + p_src[2]);
 150         *p_dest++ = p_src[1] + 0.7071 * (p_src[4] + p_src[3]);
 151
 152         p_src += 5;
 153
 154         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 155     }
 156 }
 157
 158 static void DoWork_4_0_to_2_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 159     VLC_UNUSED(p_filter);
 160     float *p_dest = (float *)p_out_buf->p_buffer;
 161     const float *p_src = (const float *)p_in_buf->p_buffer;
 162     for( int i = p_in_buf->i_nb_samples; i--; )
 163     {
 164         *p_dest++ = p_src[2] + p_src[3] + 0.5 * p_src[0];
 165         *p_dest++ = p_src[2] + p_src[3] + 0.5 * p_src[1];
 166         p_src += 4;
 167     }
 168 }
 169
 170 static void DoWork_3_x_to_2_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 171     float *p_dest = (float *)p_out_buf->p_buffer;
 172     const float *p_src = (const float *)p_in_buf->p_buffer;
 173     for( int i = p_in_buf->i_nb_samples; i--; )
 174     {
 175         *p_dest++ = p_src[2] + 0.5 * p_src[0];
 176         *p_dest++ = p_src[2] + 0.5 * p_src[1];
 177
 178         p_src += 3;
 179
 180         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 181     }
 182 }
 183
 184 static void DoWork_7_x_to_1_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 185     float *p_dest = (float *)p_out_buf->p_buffer;
 186     const float *p_src = (const float *)p_in_buf->p_buffer;
 187     for( int i = p_in_buf->i_nb_samples; i--; )
 188     {
 189         *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;
 190
 191         p_src += 7;
 192
 193         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 194     }
 195 }
 196
 197 static void DoWork_5_x_to_1_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 198     float *p_dest = (float *)p_out_buf->p_buffer;
 199     const float *p_src = (const float *)p_in_buf->p_buffer;
 200     for( int i = p_in_buf->i_nb_samples; i--; )
 201     {
 202         *p_dest++ = 0.7071 * (p_src[0] + p_src[1]) + p_src[4] + 0.5f * (p_src[2] + p_src[3]);
 203
 204         p_src += 5;
 205
 206         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 207     }
 208 }
 209
 210 static void DoWork_4_0_to_1_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 211     VLC_UNUSED(p_filter);
 212     float *p_dest = (float *)p_out_buf->p_buffer;
 213     const float *p_src = (const float *)p_in_buf->p_buffer;
 214     for( int i = p_in_buf->i_nb_samples; i--; )
 215     {
 216         *p_dest++ = p_src[2] + p_src[3] + p_src[0] / 4 + p_src[1] / 4;
 217         p_src += 4;
 218     }
 219 }
 220
 221 static void DoWork_3_x_to_1_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 222     float *p_dest = (float *)p_out_buf->p_buffer;
 223     const float *p_src = (const float *)p_in_buf->p_buffer;
 224     for( int i = p_in_buf->i_nb_samples; i--; )
 225     {
 226         *p_dest++ = p_src[2] + p_src[0] / 4 + p_src[1] / 4;
 227
 228         p_src += 3;
 229
 230         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 231     }
 232 }
 233
 234 static void DoWork_2_x_to_1_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 235     VLC_UNUSED(p_filter);
 236     float *p_dest = (float *)p_out_buf->p_buffer;
 237     const float *p_src = (const float *)p_in_buf->p_buffer;
 238     for( int i = p_in_buf->i_nb_samples; i--; )
 239     {
 240         *p_dest++ = p_src[0] / 2 + p_src[1] / 2;
 241
 242         p_src += 2;
 243     }
 244 }
 245
 246 static void DoWork_7_x_to_4_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 247     float *p_dest = (float *)p_out_buf->p_buffer;
 248     const float *p_src = (const float *)p_in_buf->p_buffer;
 249     for( int i = p_in_buf->i_nb_samples; i--; )
 250     {
 251         *p_dest++ = p_src[6] + 0.5 * p_src[0] + p_src[2] / 6;
 252         *p_dest++ = p_src[6] + 0.5 * p_src[1] + p_src[3] / 6;
 253         *p_dest++ = p_src[2] / 6 +  p_src[4];
 254         *p_dest++ = p_src[3] / 6 +  p_src[5];
 255
 256         p_src += 7;
 257
 258         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 259     }
 260 }
 261
 262 static void DoWork_5_x_to_4_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 263     float *p_dest = (float *)p_out_buf->p_buffer;
 264     const float *p_src = (const float *)p_in_buf->p_buffer;
 265     for( int i = p_in_buf->i_nb_samples; i--; )
 266     {
 267         *p_dest++ = p_src[0] + p_src[4] * 0.7071;
 268         *p_dest++ = p_src[1] + p_src[4] * 0.7071;
 269         *p_dest++ = p_src[2];
 270         *p_dest++ = p_src[3];
 271
 272         p_src += 5;
 273
 274         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 275     }
 276 }
 277
 278 static void DoWork_7_x_to_5_x( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 279     float *p_dest = (float *)p_out_buf->p_buffer;
 280     const float *p_src = (const float *)p_in_buf->p_buffer;
 281     for( int i = p_in_buf->i_nb_samples; i--; )
 282     {
 283         *p_dest++ = p_src[0];
 284         *p_dest++ = p_src[1];
 285         *p_dest++ = (p_src[2] + p_src[4]) * 0.5;
 286         *p_dest++ = (p_src[3] + p_src[5]) * 0.5;
 287         *p_dest++ = p_src[6];
 288
 289         p_src += 7;
 290
 291         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE &&
 292             p_filter->fmt_out.audio.i_physical_channels & AOUT_CHAN_LFE )
 293             *p_dest++ = *p_src++;
 294         else if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 295     }
 296 }
 297
 298 static void DoWork_6_1_to_5_x( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 299     VLC_UNUSED(p_filter);
 300     float *p_dest = (float *)p_out_buf->p_buffer;
 301     const float *p_src = (const float *)p_in_buf->p_buffer;
 302     for( int i = p_in_buf->i_nb_samples; i--; )
 303     {
 304         *p_dest++ = p_src[0];
 305         *p_dest++ = p_src[1];
 306         *p_dest++ = (p_src[2] + p_src[4]) * 0.5;
 307         *p_dest++ = (p_src[3] + p_src[4]) * 0.5;
 308         *p_dest++ = p_src[5];
 309
 310         p_src += 6;
 311
 312         /* We always have LFE here */
 313         *p_dest++ = *p_src++;
 314     }
 315 }
 316
 317
 318 /*****************************************************************************
 319  * OpenFilter:
 320  *****************************************************************************/
 321 static int OpenFilter( vlc_object_t *p_this )
 322 {
 323     filter_t *p_filter = (filter_t *)p_this;
 324     filter_sys_t *p_sys;
 325
 326     audio_format_t fmt_in  = p_filter->fmt_in.audio;
 327     audio_format_t fmt_out = p_filter->fmt_out.audio;
 328
 329     fmt_in.i_format = p_filter->fmt_in.i_codec;
 330     fmt_out.i_format = p_filter->fmt_out.i_codec;
 331
 332     if( !IsSupported( &fmt_in, &fmt_out ) )
 333         return VLC_EGENERIC;
 334
 335     p_filter->p_sys = malloc( sizeof(*p_sys) );
 336     if( unlikely(!p_filter->p_sys) )
 337         return VLC_ENOMEM;
 338
 339     p_filter->pf_audio_filter = Filter;
 340
 341     const unsigned i_input_physical = p_filter->fmt_in.audio.i_physical_channels;
 342     const bool b_input_7_0 = (i_input_physical & ~AOUT_CHAN_LFE) == AOUT_CHANS_7_0;
 343     const bool b_input_6_1 = !b_input_7_0 &&
 344                              i_input_physical == AOUT_CHANS_6_1_MIDDLE;
 345     const bool b_input_5_0 = !b_input_7_0 && !b_input_6_1 &&
 346                              ( (i_input_physical & AOUT_CHANS_5_0) == AOUT_CHANS_5_0 ||
 347                                (i_input_physical & AOUT_CHANS_5_0_MIDDLE) == AOUT_CHANS_5_0_MIDDLE );
 348     const bool b_input_4_center_rear =  !b_input_7_0 && !b_input_5_0 &&
 349                              (i_input_physical & ~AOUT_CHAN_LFE) == AOUT_CHANS_4_CENTER_REAR;
 350     const bool b_input_3_0 = !b_input_7_0 && !b_input_5_0 && !b_input_4_center_rear &&
 351                              (i_input_physical & ~AOUT_CHAN_LFE) == AOUT_CHANS_3_0;
 352
 353     if( p_filter->fmt_out.audio.i_physical_channels == AOUT_CHANS_2_0 )
 354     {
 355         if( b_input_7_0 )
 356             p_filter->p_sys->pf_dowork = DoWork_7_x_to_2_0;
 357         else if( b_input_6_1 )
 358             p_filter->p_sys->pf_dowork = DoWork_6_1_to_2_0;
 359         else if( b_input_5_0 )
 360             p_filter->p_sys->pf_dowork = DoWork_5_x_to_2_0;
 361         else if( b_input_4_center_rear )
 362             p_filter->p_sys->pf_dowork = DoWork_4_0_to_2_0;
 363         else if( b_input_3_0 )
 364             p_filter->p_sys->pf_dowork = DoWork_3_x_to_2_0;
 365     }
 366     else if( p_filter->fmt_out.audio.i_physical_channels == AOUT_CHAN_CENTER )
 367     {
 368         if( b_input_7_0 )
 369             p_filter->p_sys->pf_dowork = DoWork_7_x_to_1_0;
 370         else if( b_input_5_0 )
 371             p_filter->p_sys->pf_dowork = DoWork_5_x_to_1_0;
 372         else if( b_input_4_center_rear )
 373             p_filter->p_sys->pf_dowork = DoWork_4_0_to_1_0;
 374         else if( b_input_3_0 )
 375             p_filter->p_sys->pf_dowork = DoWork_3_x_to_1_0;
 376         else
 377             p_filter->p_sys->pf_dowork = DoWork_2_x_to_1_0;
 378     }
 379     else if(p_filter->fmt_out.audio.i_physical_channels == AOUT_CHANS_4_0)
 380     {
 381         if( b_input_7_0 )
 382             p_filter->p_sys->pf_dowork = DoWork_7_x_to_4_0;
 383         else
 384             p_filter->p_sys->pf_dowork = DoWork_5_x_to_4_0;
 385     }
 386     else
 387     {
 388         assert( b_input_7_0 || b_input_6_1 );
 389         if( b_input_7_0 )
 390             p_filter->p_sys->pf_dowork = DoWork_7_x_to_5_x;
 391         else
 392             p_filter->p_sys->pf_dowork = DoWork_6_1_to_5_x;
 393     }
 394
 395     return VLC_SUCCESS;
 396 }
 397
 398 static void CloseFilter( vlc_object_t *p_this )
 399 {
 400     filter_t *p_filter = (filter_t *) p_this;
 401     filter_sys_t *p_sys = p_filter->p_sys;
 402     free( p_sys );
 403 }
 404
 405 /*****************************************************************************
 406  * Filter:
 407  *****************************************************************************/
 408 static block_t *Filter( filter_t *p_filter, block_t *p_block )
 409 {
 410     filter_sys_t *p_sys = (filter_sys_t *)p_filter->p_sys;
 411     if( !p_block || !p_block->i_nb_samples )
 412     {
 413         if( p_block )
 414             block_Release( p_block );
 415         return NULL;
 416     }
 417
 418     size_t i_out_size = p_block->i_nb_samples *
 419       p_filter->fmt_out.audio.i_bitspersample *
 420         p_filter->fmt_out.audio.i_channels / 8;
 421
 422     block_t *p_out = block_Alloc( i_out_size );
 423     if( !p_out )
 424     {
 425         msg_Warn( p_filter, "can't get output buffer" );
 426         block_Release( p_block );
 427         return NULL;
 428     }
 429
 430     p_out->i_nb_samples = p_block->i_nb_samples;
 431     p_out->i_dts = p_block->i_dts;
 432     p_out->i_pts = p_block->i_pts;
 433     p_out->i_length = p_block->i_length;
 434
 435     int i_input_nb = aout_FormatNbChannels( &p_filter->fmt_in.audio );
 436     int i_output_nb = aout_FormatNbChannels( &p_filter->fmt_out.audio );
 437     p_out->i_nb_samples = p_block->i_nb_samples;
 438     p_out->i_buffer = p_block->i_buffer * i_output_nb / i_input_nb;
 439
 440     p_sys->pf_dowork( p_filter, p_block, p_out );
 441
 442     block_Release( p_block );
 443
 444     return p_out;
 445 }
 446