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_5_x_to_2_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 129     float *p_dest = (float *)p_out_buf->p_buffer;
 130     const float *p_src = (const float *)p_in_buf->p_buffer;
 131     for( int i = p_in_buf->i_nb_samples; i--; )
 132     {
 133         *p_dest++ = p_src[0] + 0.7071 * (p_src[4] + p_src[2]);
 134         *p_dest++ = p_src[1] + 0.7071 * (p_src[4] + p_src[3]);
 135
 136         p_src += 5;
 137
 138         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 139     }
 140 }
 141
 142 static void DoWork_4_0_to_2_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 143     VLC_UNUSED(p_filter);
 144     float *p_dest = (float *)p_out_buf->p_buffer;
 145     const float *p_src = (const float *)p_in_buf->p_buffer;
 146     for( int i = p_in_buf->i_nb_samples; i--; )
 147     {
 148         *p_dest++ = p_src[2] + p_src[3] + 0.5 * p_src[0];
 149         *p_dest++ = p_src[2] + p_src[3] + 0.5 * p_src[1];
 150         p_src += 4;
 151     }
 152 }
 153
 154 static void DoWork_3_x_to_2_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 155     float *p_dest = (float *)p_out_buf->p_buffer;
 156     const float *p_src = (const float *)p_in_buf->p_buffer;
 157     for( int i = p_in_buf->i_nb_samples; i--; )
 158     {
 159         *p_dest++ = p_src[2] + 0.5 * p_src[0];
 160         *p_dest++ = p_src[2] + 0.5 * p_src[1];
 161
 162         p_src += 3;
 163
 164         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 165     }
 166 }
 167
 168 static void DoWork_7_x_to_1_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 169     float *p_dest = (float *)p_out_buf->p_buffer;
 170     const float *p_src = (const float *)p_in_buf->p_buffer;
 171     for( int i = p_in_buf->i_nb_samples; i--; )
 172     {
 173         *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;
 174
 175         p_src += 7;
 176
 177         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 178     }
 179 }
 180
 181 static void DoWork_5_x_to_1_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 182     float *p_dest = (float *)p_out_buf->p_buffer;
 183     const float *p_src = (const float *)p_in_buf->p_buffer;
 184     for( int i = p_in_buf->i_nb_samples; i--; )
 185     {
 186         *p_dest++ = 0.7071 * (p_src[0] + p_src[1]) + p_src[4] + 0.5f * (p_src[2] + p_src[3]);
 187
 188         p_src += 5;
 189
 190         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 191     }
 192 }
 193
 194 static void DoWork_4_0_to_1_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 195     VLC_UNUSED(p_filter);
 196     float *p_dest = (float *)p_out_buf->p_buffer;
 197     const float *p_src = (const float *)p_in_buf->p_buffer;
 198     for( int i = p_in_buf->i_nb_samples; i--; )
 199     {
 200         *p_dest++ = p_src[2] + p_src[3] + p_src[0] / 4 + p_src[1] / 4;
 201         p_src += 4;
 202     }
 203 }
 204
 205 static void DoWork_3_x_to_1_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 206     float *p_dest = (float *)p_out_buf->p_buffer;
 207     const float *p_src = (const float *)p_in_buf->p_buffer;
 208     for( int i = p_in_buf->i_nb_samples; i--; )
 209     {
 210         *p_dest++ = p_src[2] + p_src[0] / 4 + p_src[1] / 4;
 211
 212         p_src += 3;
 213
 214         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 215     }
 216 }
 217
 218 static void DoWork_2_x_to_1_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 219     VLC_UNUSED(p_filter);
 220     float *p_dest = (float *)p_out_buf->p_buffer;
 221     const float *p_src = (const float *)p_in_buf->p_buffer;
 222     for( int i = p_in_buf->i_nb_samples; i--; )
 223     {
 224         *p_dest++ = p_src[0] / 2 + p_src[1] / 2;
 225
 226         p_src += 2;
 227     }
 228 }
 229
 230 static void DoWork_7_x_to_4_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 231     float *p_dest = (float *)p_out_buf->p_buffer;
 232     const float *p_src = (const float *)p_in_buf->p_buffer;
 233     for( int i = p_in_buf->i_nb_samples; i--; )
 234     {
 235         *p_dest++ = p_src[6] + 0.5 * p_src[0] + p_src[2] / 6;
 236         *p_dest++ = p_src[6] + 0.5 * p_src[1] + p_src[3] / 6;
 237         *p_dest++ = p_src[2] / 6 +  p_src[4];
 238         *p_dest++ = p_src[3] / 6 +  p_src[5];
 239
 240         p_src += 7;
 241
 242         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 243     }
 244 }
 245
 246 static void DoWork_5_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[0] + p_src[4] * 0.7071;
 252         *p_dest++ = p_src[1] + p_src[4] * 0.7071;
 253         *p_dest++ = p_src[2];
 254         *p_dest++ = p_src[3];
 255
 256         p_src += 5;
 257
 258         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 259     }
 260 }
 261
 262 static void DoWork_7_x_to_5_x( 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];
 268         *p_dest++ = p_src[1];
 269         *p_dest++ = (p_src[2] + p_src[4]) * 0.5;
 270         *p_dest++ = (p_src[3] + p_src[5]) * 0.5;
 271         *p_dest++ = p_src[6];
 272
 273         p_src += 7;
 274
 275         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE &&
 276             p_filter->fmt_out.audio.i_physical_channels & AOUT_CHAN_LFE )
 277             *p_dest++ = *p_src++;
 278         else if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 279     }
 280 }
 281
 282 static void DoWork_6_1_to_5_x( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 283     float *p_dest = (float *)p_out_buf->p_buffer;
 284     const float *p_src = (const float *)p_in_buf->p_buffer;
 285     for( int i = p_in_buf->i_nb_samples; i--; )
 286     {
 287         *p_dest++ = p_src[0];
 288         *p_dest++ = p_src[1];
 289         *p_dest++ = (p_src[2] + p_src[4]) * 0.5;
 290         *p_dest++ = (p_src[3] + p_src[4]) * 0.5;
 291         *p_dest++ = p_src[5];
 292
 293         p_src += 6;
 294
 295         /* We always have LFE here */
 296         *p_dest++ = *p_src++;
 297     }
 298 }
 299
 300
 301 /*****************************************************************************
 302  * OpenFilter:
 303  *****************************************************************************/
 304 static int OpenFilter( vlc_object_t *p_this )
 305 {
 306     filter_t *p_filter = (filter_t *)p_this;
 307     filter_sys_t *p_sys;
 308
 309     audio_format_t fmt_in  = p_filter->fmt_in.audio;
 310     audio_format_t fmt_out = p_filter->fmt_out.audio;
 311
 312     fmt_in.i_format = p_filter->fmt_in.i_codec;
 313     fmt_out.i_format = p_filter->fmt_out.i_codec;
 314
 315     if( !IsSupported( &fmt_in, &fmt_out ) )
 316         return VLC_EGENERIC;
 317
 318     p_filter->p_sys = malloc( sizeof(*p_sys) );
 319     if( unlikely(!p_filter->p_sys) )
 320         return VLC_ENOMEM;
 321
 322     p_filter->pf_audio_filter = Filter;
 323
 324     const unsigned i_input_physical = p_filter->fmt_in.audio.i_physical_channels;
 325     const bool b_input_7_0 = (i_input_physical & ~AOUT_CHAN_LFE) == AOUT_CHANS_7_0;
 326     const bool b_input_6_1 = !b_input_7_0 &&
 327                              i_input_physical == AOUT_CHANS_6_1_MIDDLE;
 328     const bool b_input_5_0 = !b_input_7_0 && !b_input_6_1 &&
 329                              ( (i_input_physical & AOUT_CHANS_5_0) == AOUT_CHANS_5_0 ||
 330                                (i_input_physical & AOUT_CHANS_5_0_MIDDLE) == AOUT_CHANS_5_0_MIDDLE );
 331     const bool b_input_4_center_rear =  !b_input_7_0 && !b_input_5_0 &&
 332                              (i_input_physical & ~AOUT_CHAN_LFE) == AOUT_CHANS_4_CENTER_REAR;
 333     const bool b_input_3_0 = !b_input_7_0 && !b_input_5_0 && !b_input_4_center_rear &&
 334                              (i_input_physical & ~AOUT_CHAN_LFE) == AOUT_CHANS_3_0;
 335
 336     if( p_filter->fmt_out.audio.i_physical_channels == AOUT_CHANS_2_0 )
 337     {
 338         if( b_input_7_0 )
 339             p_filter->p_sys->pf_dowork = DoWork_7_x_to_2_0;
 340         else if( b_input_5_0 )
 341             p_filter->p_sys->pf_dowork = DoWork_5_x_to_2_0;
 342         else if( b_input_4_center_rear )
 343             p_filter->p_sys->pf_dowork = DoWork_4_0_to_2_0;
 344         else if( b_input_3_0 )
 345             p_filter->p_sys->pf_dowork = DoWork_3_x_to_2_0;
 346     }
 347     else if( p_filter->fmt_out.audio.i_physical_channels == AOUT_CHAN_CENTER )
 348     {
 349         if( b_input_7_0 )
 350             p_filter->p_sys->pf_dowork = DoWork_7_x_to_1_0;
 351         else if( b_input_5_0 )
 352             p_filter->p_sys->pf_dowork = DoWork_5_x_to_1_0;
 353         else if( b_input_4_center_rear )
 354             p_filter->p_sys->pf_dowork = DoWork_4_0_to_1_0;
 355         else if( b_input_3_0 )
 356             p_filter->p_sys->pf_dowork = DoWork_3_x_to_1_0;
 357         else
 358             p_filter->p_sys->pf_dowork = DoWork_2_x_to_1_0;
 359     }
 360     else if(p_filter->fmt_out.audio.i_physical_channels == AOUT_CHANS_4_0)
 361     {
 362         if( b_input_7_0 )
 363             p_filter->p_sys->pf_dowork = DoWork_7_x_to_4_0;
 364         else
 365             p_filter->p_sys->pf_dowork = DoWork_5_x_to_4_0;
 366     }
 367     else
 368     {
 369         assert( b_input_7_0 || b_input_6_1 );
 370         if( b_input_7_0 )
 371             p_filter->p_sys->pf_dowork = DoWork_7_x_to_5_x;
 372         else
 373             p_filter->p_sys->pf_dowork = DoWork_6_1_to_5_x;
 374     }
 375
 376     return VLC_SUCCESS;
 377 }
 378
 379 static void CloseFilter( vlc_object_t *p_this )
 380 {
 381     filter_t *p_filter = (filter_t *) p_this;
 382     filter_sys_t *p_sys = p_filter->p_sys;
 383     free( p_sys );
 384 }
 385
 386 /*****************************************************************************
 387  * Filter:
 388  *****************************************************************************/
 389 static block_t *Filter( filter_t *p_filter, block_t *p_block )
 390 {
 391     filter_sys_t *p_sys = (filter_sys_t *)p_filter->p_sys;
 392     if( !p_block || !p_block->i_nb_samples )
 393     {
 394         if( p_block )
 395             block_Release( p_block );
 396         return NULL;
 397     }
 398
 399     size_t i_out_size = p_block->i_nb_samples *
 400       p_filter->fmt_out.audio.i_bitspersample *
 401         p_filter->fmt_out.audio.i_channels / 8;
 402
 403     block_t *p_out = block_Alloc( i_out_size );
 404     if( !p_out )
 405     {
 406         msg_Warn( p_filter, "can't get output buffer" );
 407         block_Release( p_block );
 408         return NULL;
 409     }
 410
 411     p_out->i_nb_samples = p_block->i_nb_samples;
 412     p_out->i_dts = p_block->i_dts;
 413     p_out->i_pts = p_block->i_pts;
 414     p_out->i_length = p_block->i_length;
 415
 416     int i_input_nb = aout_FormatNbChannels( &p_filter->fmt_in.audio );
 417     int i_output_nb = aout_FormatNbChannels( &p_filter->fmt_out.audio );
 418     p_out->i_nb_samples = p_block->i_nb_samples;
 419     p_out->i_buffer = p_block->i_buffer * i_output_nb / i_input_nb;
 420
 421     p_sys->pf_dowork( p_filter, p_block, p_out );
 422
 423     block_Release( p_block );
 424
 425     return p_out;
 426 }
 427
 428