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, 2006 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Gildas Bazin <gbazin@videolan.org>
   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., 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  Create    ( vlc_object_t * );
  42 static int  OpenFilter( vlc_object_t * );
  43
  44 vlc_module_begin ()
  45     set_description( N_("Audio filter for simple channel mixing") )
  46     set_capability( "audio filter", 10 )
  47     set_category( CAT_AUDIO )
  48     set_subcategory( SUBCAT_AUDIO_MISC )
  49     set_callbacks( Create, NULL )
  50
  51     add_submodule ()
  52     set_description( N_("audio filter for simple channel mixing") )
  53     set_capability( "audio filter2", 10 )
  54     set_callbacks( OpenFilter, NULL )
  55 vlc_module_end ()
  56
  57 /*****************************************************************************
  58  * Local prototypes
  59  *****************************************************************************/
  60 #define AOUT_CHANS_STEREO_FRONT  ( AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT )
  61 #define AOUT_CHANS_STEREO_REAR   ( AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT )
  62 #define AOUT_CHANS_STEREO_MIDDLE (AOUT_CHAN_MIDDLELEFT | AOUT_CHAN_MIDDLERIGHT )
  63
  64 #define AOUT_CHANS_2_0          AOUT_CHANS_STEREO_FRONT
  65 #define AOUT_CHANS_3_0          ( AOUT_CHANS_STEREO_FRONT | AOUT_CHAN_CENTER )
  66 #define AOUT_CHANS_4_0          ( AOUT_CHANS_STEREO_FRONT | AOUT_CHANS_STEREO_REAR )
  67 #define AOUT_CHANS_4_0_MIDDLE   ( AOUT_CHANS_STEREO_FRONT | AOUT_CHANS_STEREO_MIDDLE )
  68 #define AOUT_CHANS_4_CENTER_REAR (AOUT_CHANS_STEREO_FRONT | AOUT_CHAN_CENTER | AOUT_CHAN_REARCENTER)
  69 #define AOUT_CHANS_5_0          ( AOUT_CHANS_4_0 | AOUT_CHAN_CENTER )
  70 #define AOUT_CHANS_5_0_MIDDLE   ( AOUT_CHANS_4_0_MIDDLE | AOUT_CHAN_CENTER )
  71 #define AOUT_CHANS_6_0          ( AOUT_CHANS_STEREO_FRONT | AOUT_CHANS_STEREO_REAR | AOUT_CHANS_STEREO_MIDDLE )
  72 #define AOUT_CHANS_7_0          ( AOUT_CHANS_6_0 | AOUT_CHAN_CENTER )
  73
  74 static bool IsSupported( const audio_format_t *p_input, const audio_format_t *p_output );
  75
  76 static void DoWork    ( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
  77                         aout_buffer_t * );
  78
  79 static block_t *Filter( filter_t *, block_t * );
  80
  81 /*****************************************************************************
  82  * Create: allocate trivial channel mixer
  83  *****************************************************************************/
  84 static int Create( vlc_object_t *p_this )
  85 {
  86     aout_filter_t * p_filter = (aout_filter_t *)p_this;
  87
  88     if( !IsSupported( &p_filter->fmt_in.audio, &p_filter->fmt_out.audio ) )
  89         return -1;
  90
  91     p_filter->pf_do_work = DoWork;
  92     p_filter->b_in_place = 0;
  93
  94     return 0;
  95 }
  96
  97 /*****************************************************************************
  98  * DoWork: convert a buffer
  99  *****************************************************************************/
 100 static void DoWork( aout_instance_t * p_aout, aout_filter_t * p_filter,
 101                     aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
 102 {
 103     VLC_UNUSED(p_aout);
 104     const unsigned i_input_physical = p_filter->fmt_in.audio.i_physical_channels;
 105
 106     const bool b_input_7_0 = (i_input_physical & ~AOUT_CHAN_LFE) == AOUT_CHANS_7_0;
 107     const bool b_input_5_0 = !b_input_7_0 &&
 108                              ( (i_input_physical & AOUT_CHANS_5_0) == AOUT_CHANS_5_0 ||
 109                                (i_input_physical & AOUT_CHANS_5_0_MIDDLE) == AOUT_CHANS_5_0_MIDDLE );
 110     const bool b_input_4_center_rear =  !b_input_7_0 && !b_input_5_0 &&
 111                              (i_input_physical & ~AOUT_CHAN_LFE) == AOUT_CHANS_4_CENTER_REAR;
 112     const bool b_input_3_0 = !b_input_7_0 && !b_input_5_0 && !b_input_4_center_rear &&
 113                              (i_input_physical & ~AOUT_CHAN_LFE) == AOUT_CHANS_3_0;
 114
 115     int i_input_nb = aout_FormatNbChannels( &p_filter->fmt_in.audio );
 116     int i_output_nb = aout_FormatNbChannels( &p_filter->fmt_out.audio );
 117     float *p_dest = (float *)p_out_buf->p_buffer;
 118     const float *p_src = (const float *)p_in_buf->p_buffer;
 119     int i;
 120
 121     p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
 122     p_out_buf->i_buffer = p_in_buf->i_buffer * i_output_nb / i_input_nb;
 123
 124     if( p_filter->fmt_out.audio.i_physical_channels == AOUT_CHANS_2_0 )
 125     {
 126         if( b_input_7_0 )
 127         for( i = p_in_buf->i_nb_samples; i--; )
 128         {
 129             *p_dest = p_src[6] + 0.5 * p_src[0] + p_src[2] / 4 + p_src[4] / 4;
 130             p_dest++;
 131             *p_dest = p_src[6] + 0.5 * p_src[1] + p_src[3] / 4 + p_src[5] / 4;
 132             p_dest++;
 133
 134             p_src += 7;
 135
 136             if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 137         }
 138         else if( b_input_5_0 )
 139         for( i = p_in_buf->i_nb_samples; i--; )
 140         {
 141             *p_dest = p_src[4] + 0.5 * p_src[0] + 0.33 * p_src[2];
 142             p_dest++;
 143             *p_dest = p_src[4] + 0.5 * p_src[1] + 0.33 * p_src[3];
 144             p_dest++;
 145
 146             p_src += 5;
 147
 148             if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 149         }
 150         else if( b_input_3_0 )
 151         for( i = p_in_buf->i_nb_samples; i--; )
 152         {
 153             *p_dest = p_src[2] + 0.5 * p_src[0];
 154             p_dest++;
 155             *p_dest = p_src[2] + 0.5 * p_src[1];
 156             p_dest++;
 157
 158             p_src += 3;
 159
 160             if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 161         }
 162         else if (b_input_4_center_rear)
 163         for( i = p_in_buf->i_nb_samples; i--; )
 164         {
 165           *p_dest = p_src[2] + p_src[3] + 0.5 * p_src[0];
 166           p_dest++;
 167           *p_dest = p_src[2] + p_src[3] + 0.5 * p_src[1];
 168           p_dest++;
 169           p_src += 4;
 170         }
 171     }
 172     else if( p_filter->fmt_out.audio.i_physical_channels == AOUT_CHAN_CENTER )
 173     {
 174         if( b_input_7_0 )
 175         for( i = p_in_buf->i_nb_samples; i--; )
 176         {
 177             *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;
 178             p_dest++;
 179
 180             p_src += 7;
 181
 182             if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 183         }
 184         else if( b_input_5_0 )
 185         for( i = p_in_buf->i_nb_samples; i--; )
 186         {
 187             *p_dest = p_src[4] + p_src[0] / 4 + p_src[1] / 4 + p_src[2] / 6 + p_src[3] / 6;
 188             p_dest++;
 189
 190             p_src += 5;
 191
 192             if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 193         }
 194         else if( b_input_3_0 )
 195         for( i = p_in_buf->i_nb_samples; i--; )
 196         {
 197             *p_dest = p_src[2] + p_src[0] / 4 + p_src[1] / 4;
 198             p_dest++;
 199
 200             p_src += 3;
 201
 202             if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 203         }
 204         else
 205         for( i = p_in_buf->i_nb_samples; i--; )
 206         {
 207             *p_dest = p_src[0] / 2 + p_src[1] / 2;
 208             p_dest++;
 209
 210             p_src += 2;
 211         }
 212     }
 213     else
 214     {
 215         assert( p_filter->fmt_out.audio.i_physical_channels == AOUT_CHANS_4_0 );
 216         assert( b_input_7_0 || b_input_5_0 );
 217
 218         if( b_input_7_0 )
 219         for( i = p_in_buf->i_nb_samples; i--; )
 220         {
 221             *p_dest = p_src[6] + 0.5 * p_src[0] + p_src[2] / 6;
 222             p_dest++;
 223             *p_dest = p_src[6] + 0.5 * p_src[1] + p_src[3] / 6;
 224             p_dest++;
 225             *p_dest = p_src[2] / 6 +  p_src[4];
 226             p_dest++;
 227             *p_dest = p_src[3] / 6 +  p_src[5];
 228             p_dest++;
 229
 230             p_src += 7;
 231
 232             if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 233         }
 234         else
 235         for( i = p_in_buf->i_nb_samples; i--; )
 236         {
 237             *p_dest = p_src[4] + 0.5 * p_src[0];
 238             p_dest++;
 239             *p_dest = p_src[4] + 0.5 * p_src[1];
 240             p_dest++;
 241             *p_dest = p_src[2];
 242             p_dest++;
 243             *p_dest = p_src[3];
 244             p_dest++;
 245
 246             p_src += 5;
 247
 248             if( p_filter->fmt_in.audio.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 249         }
 250     }
 251 }
 252
 253 /*****************************************************************************
 254  * OpenFilter:
 255  *****************************************************************************/
 256 static int OpenFilter( vlc_object_t *p_this )
 257 {
 258     filter_t *p_filter = (filter_t *)p_this;
 259
 260     audio_format_t fmt_in  = p_filter->fmt_in.audio;
 261     audio_format_t fmt_out = p_filter->fmt_out.audio;
 262
 263     fmt_in.i_format = p_filter->fmt_in.i_codec;
 264     fmt_out.i_format = p_filter->fmt_out.i_codec;
 265
 266     if( !IsSupported( &fmt_in, &fmt_out ) )
 267         return -1;
 268
 269     p_filter->pf_audio_filter = Filter;
 270
 271     return 0;
 272 }
 273
 274 /*****************************************************************************
 275  * Filter:
 276  *****************************************************************************/
 277 static block_t *Filter( filter_t *p_filter, block_t *p_block )
 278 {
 279     aout_filter_t aout_filter;
 280     aout_buffer_t in_buf, out_buf;
 281     block_t *p_out;
 282     int i_out_size;
 283
 284     if( !p_block || !p_block->i_nb_samples )
 285     {
 286         if( p_block )
 287             block_Release( p_block );
 288         return NULL;
 289     }
 290
 291     i_out_size = p_block->i_nb_samples *
 292       p_filter->fmt_out.audio.i_bitspersample *
 293         p_filter->fmt_out.audio.i_channels / 8;
 294
 295     p_out = p_filter->pf_audio_buffer_new( p_filter, i_out_size );
 296     if( !p_out )
 297     {
 298         msg_Warn( p_filter, "can't get output buffer" );
 299         block_Release( p_block );
 300         return NULL;
 301     }
 302
 303     p_out->i_nb_samples = p_block->i_nb_samples;
 304     p_out->i_dts = p_block->i_dts;
 305     p_out->i_pts = p_block->i_pts;
 306     p_out->i_length = p_block->i_length;
 307
 308     aout_filter.p_sys = (struct aout_filter_sys_t *)p_filter->p_sys;
 309     aout_filter.fmt_in.audio = p_filter->fmt_in.audio;
 310     aout_filter.fmt_in.audio.i_format = p_filter->fmt_in.i_codec;
 311     aout_filter.fmt_out.audio = p_filter->fmt_out.audio;
 312     aout_filter.fmt_out.audio.i_format = p_filter->fmt_out.i_codec;
 313
 314     in_buf.p_buffer = p_block->p_buffer;
 315     in_buf.i_buffer = p_block->i_buffer;
 316     in_buf.i_nb_samples = p_block->i_nb_samples;
 317     out_buf.p_buffer = p_out->p_buffer;
 318     out_buf.i_buffer = p_out->i_buffer;
 319     out_buf.i_nb_samples = p_out->i_nb_samples;
 320
 321     DoWork( (aout_instance_t *)p_filter, &aout_filter, &in_buf, &out_buf );
 322
 323     block_Release( p_block );
 324
 325     p_out->i_buffer = out_buf.i_buffer;
 326     p_out->i_nb_samples = out_buf.i_nb_samples;
 327
 328     return p_out;
 329 }
 330
 331 /*****************************************************************************
 332  * Helpers:
 333  *****************************************************************************/
 334 static bool IsSupported( const audio_format_t *p_input, const audio_format_t *p_output )
 335 {
 336     if( p_input->i_format != VLC_CODEC_FL32 ||
 337           p_input->i_format != p_output->i_format ||
 338           p_input->i_rate != p_output->i_rate )
 339         return false;
 340
 341     if( p_input->i_physical_channels == p_output->i_physical_channels &&
 342         p_input->i_original_channels == p_output->i_original_channels )
 343     {
 344         return false;
 345     }
 346
 347     /* Only conversion to Mono, Stereo and 4.0 right now */
 348     if( p_output->i_physical_channels != AOUT_CHAN_CENTER &&
 349         p_output->i_physical_channels != AOUT_CHANS_2_0 &&
 350         p_output->i_physical_channels != AOUT_CHANS_4_0 )
 351     {
 352         return false;
 353     }
 354
 355     /* Only from 7/7.1/5/5.1/3/3.1/2.0
 356      * XXX 5.X rear and middle are handled the same way */
 357     if( (p_input->i_physical_channels & ~AOUT_CHAN_LFE) != AOUT_CHANS_7_0 &&
 358         (p_input->i_physical_channels & ~AOUT_CHAN_LFE) != AOUT_CHANS_5_0 &&
 359         (p_input->i_physical_channels & ~AOUT_CHAN_LFE) != AOUT_CHANS_5_0_MIDDLE &&
 360         (p_input->i_physical_channels & ~AOUT_CHAN_LFE) != AOUT_CHANS_3_0 &&
 361         (p_input->i_physical_channels & ~AOUT_CHAN_LFE) != AOUT_CHANS_4_CENTER_REAR &&
 362          p_input->i_physical_channels != AOUT_CHANS_2_0 )
 363     {
 364         return false;
 365     }
 366
 367     /* Only if we downmix */
 368     if( aout_FormatNbChannels( p_input ) <= aout_FormatNbChannels( p_output ) )
 369         return false;
 370
 371     return true;
 372 }
 373