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 static bool IsSupported( const audio_format_t *p_input, const audio_format_t *p_output );
  56
  57 struct filter_sys_t
  58 {
  59     void (*pf_dowork)(filter_t *, block_t *, block_t * );
  60 };
  61
  62 static block_t *Filter( filter_t *, block_t * );
  63
  64 static void DoWork_7_x_to_2_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
  65     float *p_dest = (float *)p_out_buf->p_buffer;
  66     const float *p_src = (const float *)p_in_buf->p_buffer;
  67     for( int i = p_in_buf->i_nb_samples; i--; )
  68     {
  69         *p_dest++ = p_src[6] + 0.5 * p_src[0] + p_src[2] / 4 + p_src[4] / 4;
  70         *p_dest++ = p_src[6] + 0.5 * p_src[1] + p_src[3] / 4 + p_src[5] / 4;
  71
  72         p_src += 7;
  73
  74         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
  75     }
  76 }
  77
  78 static void DoWork_5_x_to_2_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
  79     float *p_dest = (float *)p_out_buf->p_buffer;
  80     const float *p_src = (const float *)p_in_buf->p_buffer;
  81     for( int i = p_in_buf->i_nb_samples; i--; )
  82     {
  83         *p_dest++ = p_src[0] + 0.7071 * (p_src[4] + p_src[2]);
  84         *p_dest++ = p_src[1] + 0.7071 * (p_src[4] + p_src[3]);
  85
  86         p_src += 5;
  87
  88         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
  89     }
  90 }
  91
  92 static void DoWork_4_0_to_2_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
  93     VLC_UNUSED(p_filter);
  94     float *p_dest = (float *)p_out_buf->p_buffer;
  95     const float *p_src = (const float *)p_in_buf->p_buffer;
  96     for( int i = p_in_buf->i_nb_samples; i--; )
  97     {
  98         *p_dest++ = p_src[2] + p_src[3] + 0.5 * p_src[0];
  99         *p_dest++ = p_src[2] + p_src[3] + 0.5 * p_src[1];
 100         p_src += 4;
 101     }
 102 }
 103
 104 static void DoWork_3_x_to_2_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 105     float *p_dest = (float *)p_out_buf->p_buffer;
 106     const float *p_src = (const float *)p_in_buf->p_buffer;
 107     for( int i = p_in_buf->i_nb_samples; i--; )
 108     {
 109         *p_dest++ = p_src[2] + 0.5 * p_src[0];
 110         *p_dest++ = p_src[2] + 0.5 * p_src[1];
 111
 112         p_src += 3;
 113
 114         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 115     }
 116 }
 117
 118 static void DoWork_7_x_to_1_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 119     float *p_dest = (float *)p_out_buf->p_buffer;
 120     const float *p_src = (const float *)p_in_buf->p_buffer;
 121     for( int i = p_in_buf->i_nb_samples; i--; )
 122     {
 123         *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;
 124
 125         p_src += 7;
 126
 127         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 128     }
 129 }
 130
 131 static void DoWork_5_x_to_1_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 132     float *p_dest = (float *)p_out_buf->p_buffer;
 133     const float *p_src = (const float *)p_in_buf->p_buffer;
 134     for( int i = p_in_buf->i_nb_samples; i--; )
 135     {
 136         *p_dest++ = 0.7071 * (p_src[0] + p_src[1]) + p_src[4] + 0.5f * (p_src[2] + p_src[3]);
 137
 138         p_src += 5;
 139
 140         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 141     }
 142 }
 143
 144 static void DoWork_4_0_to_1_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 145     VLC_UNUSED(p_filter);
 146     float *p_dest = (float *)p_out_buf->p_buffer;
 147     const float *p_src = (const float *)p_in_buf->p_buffer;
 148     for( int i = p_in_buf->i_nb_samples; i--; )
 149     {
 150         *p_dest++ = p_src[2] + p_src[3] + p_src[0] / 4 + p_src[1] / 4;
 151         p_src += 4;
 152     }
 153 }
 154
 155 static void DoWork_3_x_to_1_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 156     float *p_dest = (float *)p_out_buf->p_buffer;
 157     const float *p_src = (const float *)p_in_buf->p_buffer;
 158     for( int i = p_in_buf->i_nb_samples; i--; )
 159     {
 160         *p_dest++ = p_src[2] + p_src[0] / 4 + p_src[1] / 4;
 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_2_x_to_1_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 169     VLC_UNUSED(p_filter);
 170     float *p_dest = (float *)p_out_buf->p_buffer;
 171     const float *p_src = (const float *)p_in_buf->p_buffer;
 172     for( int i = p_in_buf->i_nb_samples; i--; )
 173     {
 174         *p_dest++ = p_src[0] / 2 + p_src[1] / 2;
 175
 176         p_src += 2;
 177     }
 178 }
 179
 180 static void DoWork_7_x_to_4_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 181     float *p_dest = (float *)p_out_buf->p_buffer;
 182     const float *p_src = (const float *)p_in_buf->p_buffer;
 183     for( int i = p_in_buf->i_nb_samples; i--; )
 184     {
 185         *p_dest++ = p_src[6] + 0.5 * p_src[0] + p_src[2] / 6;
 186         *p_dest++ = p_src[6] + 0.5 * p_src[1] + p_src[3] / 6;
 187         *p_dest++ = p_src[2] / 6 +  p_src[4];
 188         *p_dest++ = p_src[3] / 6 +  p_src[5];
 189
 190         p_src += 7;
 191
 192         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 193     }
 194 }
 195
 196 static void DoWork_5_x_to_4_0( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 197     float *p_dest = (float *)p_out_buf->p_buffer;
 198     const float *p_src = (const float *)p_in_buf->p_buffer;
 199     for( int i = p_in_buf->i_nb_samples; i--; )
 200     {
 201         *p_dest++ = p_src[0] + p_src[4] * 0.7071;
 202         *p_dest++ = p_src[1] + p_src[4] * 0.7071;
 203         *p_dest++ = p_src[2];
 204         *p_dest++ = p_src[3];
 205
 206         p_src += 5;
 207
 208         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 209     }
 210 }
 211
 212 static void DoWork_7_x_to_5_x( filter_t * p_filter,  block_t * p_in_buf, block_t * p_out_buf ) {
 213     float *p_dest = (float *)p_out_buf->p_buffer;
 214     const float *p_src = (const float *)p_in_buf->p_buffer;
 215     for( int i = p_in_buf->i_nb_samples; i--; )
 216     {
 217         *p_dest++ = p_src[0];
 218         *p_dest++ = p_src[1];
 219         *p_dest++ = (p_src[2] + p_src[4]) * 0.5;
 220         *p_dest++ = (p_src[3] + p_src[5]) * 0.5;
 221         *p_dest++ = p_src[6];
 222
 223         p_src += 7;
 224
 225         if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE &&
 226             p_filter->fmt_out.audio.i_physical_channels & AOUT_CHAN_LFE )
 227             *p_dest++ = *p_src++;
 228         else if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 229     }
 230 }
 231
 232
 233 /*****************************************************************************
 234  * OpenFilter:
 235  *****************************************************************************/
 236 static int OpenFilter( vlc_object_t *p_this )
 237 {
 238     filter_t *p_filter = (filter_t *)p_this;
 239     filter_sys_t *p_sys;
 240
 241     audio_format_t fmt_in  = p_filter->fmt_in.audio;
 242     audio_format_t fmt_out = p_filter->fmt_out.audio;
 243
 244     fmt_in.i_format = p_filter->fmt_in.i_codec;
 245     fmt_out.i_format = p_filter->fmt_out.i_codec;
 246
 247     if( !IsSupported( &fmt_in, &fmt_out ) )
 248         return VLC_EGENERIC;
 249
 250     p_filter->p_sys = malloc( sizeof(*p_sys) );
 251     if( unlikely(!p_filter->p_sys) )
 252         return VLC_ENOMEM;
 253
 254     p_filter->pf_audio_filter = Filter;
 255
 256     const unsigned i_input_physical = p_filter->fmt_in.audio.i_physical_channels;
 257     const bool b_input_7_0 = (i_input_physical & ~AOUT_CHAN_LFE) == AOUT_CHANS_7_0;
 258     const bool b_input_5_0 = !b_input_7_0 &&
 259                              ( (i_input_physical & AOUT_CHANS_5_0) == AOUT_CHANS_5_0 ||
 260                                (i_input_physical & AOUT_CHANS_5_0_MIDDLE) == AOUT_CHANS_5_0_MIDDLE );
 261     const bool b_input_4_center_rear =  !b_input_7_0 && !b_input_5_0 &&
 262                              (i_input_physical & ~AOUT_CHAN_LFE) == AOUT_CHANS_4_CENTER_REAR;
 263     const bool b_input_3_0 = !b_input_7_0 && !b_input_5_0 && !b_input_4_center_rear &&
 264                              (i_input_physical & ~AOUT_CHAN_LFE) == AOUT_CHANS_3_0;
 265
 266     if( p_filter->fmt_out.audio.i_physical_channels == AOUT_CHANS_2_0 )
 267     {
 268         if( b_input_7_0 )
 269             p_filter->p_sys->pf_dowork = DoWork_7_x_to_2_0;
 270         else if( b_input_5_0 )
 271             p_filter->p_sys->pf_dowork = DoWork_5_x_to_2_0;
 272         else if( b_input_4_center_rear )
 273             p_filter->p_sys->pf_dowork = DoWork_4_0_to_2_0;
 274         else if( b_input_3_0 )
 275             p_filter->p_sys->pf_dowork = DoWork_3_x_to_2_0;
 276     }
 277     else if( p_filter->fmt_out.audio.i_physical_channels == AOUT_CHAN_CENTER )
 278     {
 279         if( b_input_7_0 )
 280             p_filter->p_sys->pf_dowork = DoWork_7_x_to_1_0;
 281         else if( b_input_5_0 )
 282             p_filter->p_sys->pf_dowork = DoWork_5_x_to_1_0;
 283         else if( b_input_4_center_rear )
 284             p_filter->p_sys->pf_dowork = DoWork_4_0_to_1_0;
 285         else if( b_input_3_0 )
 286             p_filter->p_sys->pf_dowork = DoWork_3_x_to_1_0;
 287         else
 288             p_filter->p_sys->pf_dowork = DoWork_2_x_to_1_0;
 289     }
 290     else if(p_filter->fmt_out.audio.i_physical_channels == AOUT_CHANS_4_0)
 291     {
 292         if( b_input_7_0 )
 293             p_filter->p_sys->pf_dowork = DoWork_7_x_to_4_0;
 294         else
 295             p_filter->p_sys->pf_dowork = DoWork_5_x_to_4_0;
 296     }
 297     else
 298     {
 299         assert( b_input_7_0 );
 300         p_filter->p_sys->pf_dowork = DoWork_7_x_to_5_x;
 301     }
 302
 303     return VLC_SUCCESS;
 304 }
 305
 306 static void CloseFilter( vlc_object_t *p_this )
 307 {
 308     filter_t *p_filter = (filter_t *) p_this;
 309     filter_sys_t *p_sys = p_filter->p_sys;
 310     free( p_sys );
 311 }
 312
 313 /*****************************************************************************
 314  * Filter:
 315  *****************************************************************************/
 316 static block_t *Filter( filter_t *p_filter, block_t *p_block )
 317 {
 318     filter_sys_t *p_sys = (filter_sys_t *)p_filter->p_sys;
 319     if( !p_block || !p_block->i_nb_samples )
 320     {
 321         if( p_block )
 322             block_Release( p_block );
 323         return NULL;
 324     }
 325
 326     size_t i_out_size = p_block->i_nb_samples *
 327       p_filter->fmt_out.audio.i_bitspersample *
 328         p_filter->fmt_out.audio.i_channels / 8;
 329
 330     block_t *p_out = block_Alloc( i_out_size );
 331     if( !p_out )
 332     {
 333         msg_Warn( p_filter, "can't get output buffer" );
 334         block_Release( p_block );
 335         return NULL;
 336     }
 337
 338     p_out->i_nb_samples = p_block->i_nb_samples;
 339     p_out->i_dts = p_block->i_dts;
 340     p_out->i_pts = p_block->i_pts;
 341     p_out->i_length = p_block->i_length;
 342
 343     int i_input_nb = aout_FormatNbChannels( &p_filter->fmt_in.audio );
 344     int i_output_nb = aout_FormatNbChannels( &p_filter->fmt_out.audio );
 345     p_out->i_nb_samples = p_block->i_nb_samples;
 346     p_out->i_buffer = p_block->i_buffer * i_output_nb / i_input_nb;
 347
 348     p_sys->pf_dowork( p_filter, p_block, p_out );
 349
 350     block_Release( p_block );
 351
 352     return p_out;
 353 }
 354
 355 /*****************************************************************************
 356  * Helpers:
 357  *****************************************************************************/
 358 static bool IsSupported( const audio_format_t *p_input, const audio_format_t *p_output )
 359 {
 360     if( p_input->i_format != VLC_CODEC_FL32 ||
 361           p_input->i_format != p_output->i_format ||
 362           p_input->i_rate != p_output->i_rate )
 363         return false;
 364
 365     if( p_input->i_physical_channels == p_output->i_physical_channels &&
 366         p_input->i_original_channels == p_output->i_original_channels )
 367     {
 368         return false;
 369     }
 370
 371     /* Only conversion to Mono, Stereo and 4.0 right now */
 372     if( p_output->i_physical_channels != AOUT_CHAN_CENTER &&
 373         p_output->i_physical_channels != AOUT_CHANS_2_0 &&
 374         p_output->i_physical_channels != AOUT_CHANS_4_0 &&
 375         p_output->i_physical_channels != AOUT_CHANS_5_1 )
 376     {
 377         return false;
 378     }
 379
 380     /* Only from 7/7.1/5/5.1/3/3.1/2.0
 381      * XXX 5.X rear and middle are handled the same way */
 382     if( (p_input->i_physical_channels & ~AOUT_CHAN_LFE) != AOUT_CHANS_7_0 &&
 383         (p_input->i_physical_channels & ~AOUT_CHAN_LFE) != AOUT_CHANS_5_0 &&
 384         (p_input->i_physical_channels & ~AOUT_CHAN_LFE) != AOUT_CHANS_5_0_MIDDLE &&
 385         (p_input->i_physical_channels & ~AOUT_CHAN_LFE) != AOUT_CHANS_3_0 &&
 386         (p_input->i_physical_channels & ~AOUT_CHAN_LFE) != AOUT_CHANS_4_CENTER_REAR &&
 387          p_input->i_physical_channels != AOUT_CHANS_2_0 )
 388     {
 389         return false;
 390     }
 391
 392     /* Only if we downmix */
 393     if( aout_FormatNbChannels( p_input ) <= aout_FormatNbChannels( p_output ) )
 394         return false;
 395
 396     return true;
 397 }
 398