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

   1 /*****************************************************************************
   2  * simple.c : simple channel mixer plug-in (only 7/7.1/5/5.1 -> Stereo for now)
   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
  37 /*****************************************************************************
  38  * Module descriptor
  39  *****************************************************************************/
  40 static int  Create    ( vlc_object_t * );
  41 static int  OpenFilter( vlc_object_t * );
  42
  43 vlc_module_begin ()
  44     set_description( N_("Audio filter for simple channel mixing") )
  45     set_capability( "audio filter", 10 )
  46     set_category( CAT_AUDIO )
  47     set_subcategory( SUBCAT_AUDIO_MISC )
  48     set_callbacks( Create, NULL )
  49
  50     add_submodule ()
  51     set_description( N_("audio filter for simple channel mixing") )
  52     set_capability( "audio filter2", 10 )
  53     set_callbacks( OpenFilter, NULL )
  54 vlc_module_end ()
  55
  56 /*****************************************************************************
  57  * Local prototypes
  58  *****************************************************************************/
  59 #define AOUT_CHANS_STEREO_FRONT  ( AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT )
  60 #define AOUT_CHANS_STEREO_REAR   ( AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT )
  61 #define AOUT_CHANS_STEREO_MIDDLE (AOUT_CHAN_MIDDLELEFT | AOUT_CHAN_MIDDLERIGHT )
  62
  63 #define AOUT_CHANS_2_0          AOUT_CHANS_STEREO_FRONT
  64 #define AOUT_CHANS_4_0          ( AOUT_CHANS_STEREO_FRONT | AOUT_CHANS_STEREO_REAR )
  65 #define AOUT_CHANS_4_0_MIDDLE   ( AOUT_CHANS_STEREO_FRONT | AOUT_CHANS_STEREO_MIDDLE )
  66 #define AOUT_CHANS_5_0          ( AOUT_CHANS_4_0 | AOUT_CHAN_CENTER )
  67 #define AOUT_CHANS_5_0_MIDDLE   ( AOUT_CHANS_4_0_MIDDLE | AOUT_CHAN_CENTER )
  68 #define AOUT_CHANS_6_0          ( AOUT_CHANS_STEREO_FRONT | AOUT_CHANS_STEREO_REAR | AOUT_CHANS_STEREO_MIDDLE )
  69 #define AOUT_CHANS_7_0          ( AOUT_CHANS_6_0 | AOUT_CHAN_CENTER )
  70
  71 static bool IsSupported( const audio_format_t *p_input, const audio_format_t *p_output );
  72
  73 static void DoWork    ( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
  74                         aout_buffer_t * );
  75
  76 static block_t *Filter( filter_t *, block_t * );
  77
  78 /*****************************************************************************
  79  * Create: allocate trivial channel mixer
  80  *****************************************************************************/
  81 static int Create( vlc_object_t *p_this )
  82 {
  83     aout_filter_t * p_filter = (aout_filter_t *)p_this;
  84
  85     if( !IsSupported( &p_filter->input, &p_filter->output ) )
  86         return -1;
  87
  88     p_filter->pf_do_work = DoWork;
  89     p_filter->b_in_place = 0;
  90
  91     return 0;
  92 }
  93
  94 /*****************************************************************************
  95  * DoWork: convert a buffer
  96  *****************************************************************************/
  97 static void DoWork( aout_instance_t * p_aout, aout_filter_t * p_filter,
  98                     aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
  99 {
 100     VLC_UNUSED(p_aout);
 101     const unsigned i_input_physical = p_filter->input.i_physical_channels;
 102
 103     const bool b_input_7_0 = (i_input_physical & ~AOUT_CHAN_LFE) == AOUT_CHANS_7_0;
 104     const bool b_input_5_0 = !b_input_7_0 &&
 105                              (i_input_physical & (AOUT_CHANS_5_0|AOUT_CHANS_5_0_MIDDLE));
 106     int i_input_nb = aout_FormatNbChannels( &p_filter->input );
 107     int i_output_nb = aout_FormatNbChannels( &p_filter->output );
 108     float *p_dest = (float *)p_out_buf->p_buffer;
 109     const float *p_src = (const float *)p_in_buf->p_buffer;
 110     int i;
 111
 112     p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
 113     p_out_buf->i_nb_bytes = p_in_buf->i_nb_bytes * i_output_nb / i_input_nb;
 114
 115     if( p_filter->output.i_physical_channels == AOUT_CHANS_2_0 )
 116     {
 117         if( b_input_7_0 )
 118         for( i = p_in_buf->i_nb_samples; i--; )
 119         {
 120             *p_dest = p_src[6] + 0.5 * p_src[0] + p_src[2] / 4 + p_src[4] / 4;
 121             p_dest++;
 122             *p_dest = p_src[6] + 0.5 * p_src[1] + p_src[3] / 4 + p_src[5] / 4;
 123             p_dest++;
 124
 125             p_src += 7;
 126
 127             if( p_filter->input.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 128         }
 129         else
 130         for( i = p_in_buf->i_nb_samples; i--; )
 131         {
 132             *p_dest = p_src[4] + 0.5 * p_src[0] + 0.33 * p_src[2];
 133             p_dest++;
 134             *p_dest = p_src[4] + 0.5 * p_src[1] + 0.33 * p_src[3];
 135             p_dest++;
 136
 137             p_src += 5;
 138
 139             if( p_filter->input.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 140         }
 141     }
 142     else if( p_filter->output.i_physical_channels == AOUT_CHAN_CENTER )
 143     {
 144         if( b_input_7_0 )
 145         for( i = p_in_buf->i_nb_samples; i--; )
 146         {
 147             *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;
 148             p_dest++;
 149
 150             p_src += 7;
 151
 152             if( p_filter->input.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 153         }
 154         else if( b_input_5_0 )
 155         for( i = p_in_buf->i_nb_samples; i--; )
 156         {
 157             *p_dest = p_src[4] + p_src[0] / 4 + p_src[1] / 4 + p_src[2] / 6 + p_src[3] / 6;
 158             p_dest++;
 159
 160             p_src += 5;
 161
 162             if( p_filter->input.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 163         }
 164         else
 165         for( i = p_in_buf->i_nb_samples; i--; )
 166         {
 167             *p_dest = p_src[0] / 2 + p_src[1] / 2;
 168             p_dest++;
 169
 170             p_src += 2;
 171         }
 172     }
 173     else
 174     {
 175         if( b_input_7_0 )
 176         for( i = p_in_buf->i_nb_samples; i--; )
 177         {
 178             *p_dest = p_src[6] + 0.5 * p_src[0] + p_src[2] / 6;
 179             p_dest++;
 180             *p_dest = p_src[6] + 0.5 * p_src[1] + p_src[3] / 6;
 181             p_dest++;
 182             *p_dest = p_src[2] / 6 +  p_src[4];
 183             p_dest++;
 184             *p_dest = p_src[3] / 6 +  p_src[5];
 185             p_dest++;
 186
 187             p_src += 7;
 188
 189             if( p_filter->input.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 190         }
 191         else
 192         for( i = p_in_buf->i_nb_samples; i--; )
 193         {
 194             *p_dest = p_src[4] + 0.5 * p_src[0];
 195             p_dest++;
 196             *p_dest = p_src[4] + 0.5 * p_src[1];
 197             p_dest++;
 198             *p_dest = p_src[2];
 199             p_dest++;
 200             *p_dest = p_src[3];
 201             p_dest++;
 202
 203             p_src += 5;
 204
 205             if( p_filter->input.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 206         }
 207     }
 208 }
 209
 210 /*****************************************************************************
 211  * OpenFilter:
 212  *****************************************************************************/
 213 static int OpenFilter( vlc_object_t *p_this )
 214 {
 215     filter_t *p_filter = (filter_t *)p_this;
 216
 217     audio_format_t fmt_in  = p_filter->fmt_in.audio;
 218     audio_format_t fmt_out = p_filter->fmt_out.audio;
 219
 220     fmt_in.i_format = p_filter->fmt_in.i_codec;
 221     fmt_out.i_format = p_filter->fmt_out.i_codec;
 222
 223     if( !IsSupported( &fmt_in, &fmt_out ) )
 224         return -1;
 225
 226     p_filter->pf_audio_filter = Filter;
 227
 228     return 0;
 229 }
 230
 231 /*****************************************************************************
 232  * Filter:
 233  *****************************************************************************/
 234 static block_t *Filter( filter_t *p_filter, block_t *p_block )
 235 {
 236     aout_filter_t aout_filter;
 237     aout_buffer_t in_buf, out_buf;
 238     block_t *p_out;
 239     int i_out_size;
 240
 241     if( !p_block || !p_block->i_samples )
 242     {
 243         if( p_block )
 244             block_Release( p_block );
 245         return NULL;
 246     }
 247
 248     i_out_size = p_block->i_samples *
 249       p_filter->fmt_out.audio.i_bitspersample *
 250         p_filter->fmt_out.audio.i_channels / 8;
 251
 252     p_out = p_filter->pf_audio_buffer_new( p_filter, i_out_size );
 253     if( !p_out )
 254     {
 255         msg_Warn( p_filter, "can't get output buffer" );
 256         block_Release( p_block );
 257         return NULL;
 258     }
 259
 260     p_out->i_samples = p_block->i_samples;
 261     p_out->i_dts = p_block->i_dts;
 262     p_out->i_pts = p_block->i_pts;
 263     p_out->i_length = p_block->i_length;
 264
 265     aout_filter.p_sys = (struct aout_filter_sys_t *)p_filter->p_sys;
 266     aout_filter.input = p_filter->fmt_in.audio;
 267     aout_filter.input.i_format = p_filter->fmt_in.i_codec;
 268     aout_filter.output = p_filter->fmt_out.audio;
 269     aout_filter.output.i_format = p_filter->fmt_out.i_codec;
 270
 271     in_buf.p_buffer = p_block->p_buffer;
 272     in_buf.i_nb_bytes = p_block->i_buffer;
 273     in_buf.i_nb_samples = p_block->i_samples;
 274     out_buf.p_buffer = p_out->p_buffer;
 275     out_buf.i_nb_bytes = p_out->i_buffer;
 276     out_buf.i_nb_samples = p_out->i_samples;
 277
 278     DoWork( (aout_instance_t *)p_filter, &aout_filter, &in_buf, &out_buf );
 279
 280     block_Release( p_block );
 281
 282     p_out->i_buffer = out_buf.i_nb_bytes;
 283     p_out->i_samples = out_buf.i_nb_samples;
 284
 285     return p_out;
 286 }
 287
 288 /*****************************************************************************
 289  * Helpers:
 290  *****************************************************************************/
 291 static bool IsSupported( const audio_format_t *p_input, const audio_format_t *p_output )
 292 {
 293     if( p_input->i_format != VLC_FOURCC('f','l','3','2') ||
 294           p_input->i_format != p_output->i_format ||
 295           p_input->i_rate != p_output->i_rate )
 296         return false;
 297
 298     if( p_input->i_physical_channels == p_output->i_physical_channels &&
 299         p_input->i_original_channels == p_output->i_original_channels )
 300     {
 301         return false;
 302     }
 303
 304     /* Only conversion to Mono, Stereo and 4.0 right now */
 305     if( p_output->i_physical_channels != AOUT_CHAN_CENTER &&
 306         p_output->i_physical_channels != AOUT_CHANS_2_0 &&
 307         p_output->i_physical_channels != AOUT_CHANS_4_0 )
 308     {
 309         return false;
 310     }
 311
 312     /* Only from 7/7.1/5/5.1/2.0
 313      * XXX 5.X rear and middle are handled the same way */
 314     if( (p_input->i_physical_channels & ~AOUT_CHAN_LFE) != AOUT_CHANS_7_0 &&
 315         (p_input->i_physical_channels & ~AOUT_CHAN_LFE) != AOUT_CHANS_5_0 &&
 316         (p_input->i_physical_channels & ~AOUT_CHAN_LFE) != AOUT_CHANS_5_0_MIDDLE &&
 317          p_input->i_physical_channels != AOUT_CHANS_2_0 )
 318     {
 319         return false;
 320     }
 321
 322     /* Only if we downmix */
 323     if( aout_FormatNbChannels( p_input ) <= aout_FormatNbChannels( p_output ) )
 324         return false;
 325
 326     return true;
 327 }
 328