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_5_0 ( AOUT_CHANS_4_0 | AOUT_CHAN_CENTER )
  66 #define AOUT_CHANS_6_0 (AOUT_CHANS_STEREO_FRONT | AOUT_CHANS_STEREO_REAR | AOUT_CHANS_STEREO_MIDDLE )
  67 #define AOUT_CHANS_7_0 ( AOUT_CHANS_6_0 | AOUT_CHAN_CENTER )
  68
  69 static bool IsSupported( const audio_format_t *p_input, const audio_format_t *p_output );
  70
  71 static void DoWork    ( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
  72                         aout_buffer_t * );
  73
  74 static block_t *Filter( filter_t *, block_t * );
  75
  76 /*****************************************************************************
  77  * Create: allocate trivial channel mixer
  78  *****************************************************************************/
  79 static int Create( vlc_object_t *p_this )
  80 {
  81     aout_filter_t * p_filter = (aout_filter_t *)p_this;
  82
  83     if( !IsSupported( &p_filter->input, &p_filter->output ) )
  84         return -1;
  85
  86     p_filter->pf_do_work = DoWork;
  87     p_filter->b_in_place = 0;
  88
  89     return 0;
  90 }
  91
  92 /*****************************************************************************
  93  * DoWork: convert a buffer
  94  *****************************************************************************/
  95 static void DoWork( aout_instance_t * p_aout, aout_filter_t * p_filter,
  96                     aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
  97 {
  98     VLC_UNUSED(p_aout);
  99     int i_input_nb = aout_FormatNbChannels( &p_filter->input );
 100     int i_output_nb = aout_FormatNbChannels( &p_filter->output );
 101     float *p_dest = (float *)p_out_buf->p_buffer;
 102     const float *p_src = (const float *)p_in_buf->p_buffer;
 103     int i;
 104
 105     p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
 106     p_out_buf->i_nb_bytes = p_in_buf->i_nb_bytes * i_output_nb / i_input_nb;
 107
 108     if( p_filter->output.i_physical_channels == AOUT_CHANS_2_0 )
 109     {
 110         if( p_filter->input.i_physical_channels & AOUT_CHAN_MIDDLELEFT )
 111         for( i = p_in_buf->i_nb_samples; i--; )
 112         {
 113             *p_dest = p_src[6] + 0.5 * p_src[0] + p_src[2] / 4 + p_src[4] / 4;
 114             p_dest++;
 115             *p_dest = p_src[6] + 0.5 * p_src[1] + p_src[3] / 4 + p_src[5] / 4;
 116             p_dest++;
 117
 118             p_src += 7;
 119
 120             if( p_filter->input.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 121         }
 122         else
 123         for( i = p_in_buf->i_nb_samples; i--; )
 124         {
 125             *p_dest = p_src[4] + 0.5 * p_src[0] + 0.33 * p_src[2];
 126             p_dest++;
 127             *p_dest = p_src[4] + 0.5 * p_src[1] + 0.33 * p_src[3];
 128             p_dest++;
 129
 130             p_src += 5;
 131
 132             if( p_filter->input.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 133         }
 134     }
 135     else if( p_filter->output.i_physical_channels == AOUT_CHAN_CENTER )
 136     {
 137         if( p_filter->input.i_physical_channels & AOUT_CHAN_MIDDLELEFT )
 138         for( i = p_in_buf->i_nb_samples; i--; )
 139         {
 140             *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;
 141             p_dest++;
 142
 143             p_src += 7;
 144
 145             if( p_filter->input.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 146         }
 147         else if( p_filter->input.i_physical_channels & AOUT_CHAN_REARLEFT )
 148         for( i = p_in_buf->i_nb_samples; i--; )
 149         {
 150             *p_dest = p_src[4] + p_src[0] / 4 + p_src[1] / 4 + p_src[2] / 6 + p_src[3] / 6;
 151             p_dest++;
 152
 153             p_src += 5;
 154
 155             if( p_filter->input.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 156         }
 157         else
 158         for( i = p_in_buf->i_nb_samples; i--; )
 159         {
 160             *p_dest = p_src[0] / 2 + p_src[1] / 2;
 161             p_dest++;
 162
 163             p_src += 2;
 164         }
 165     }
 166     else
 167     {
 168         if( p_filter->input.i_physical_channels & AOUT_CHAN_MIDDLELEFT )
 169         for( i = p_in_buf->i_nb_samples; i--; )
 170         {
 171             *p_dest = p_src[6] + 0.5 * p_src[0] + p_src[2] / 6;
 172             p_dest++;
 173             *p_dest = p_src[6] + 0.5 * p_src[1] + p_src[3] / 6;
 174             p_dest++;
 175             *p_dest = p_src[2] / 6 +  p_src[4];
 176             p_dest++;
 177             *p_dest = p_src[3] / 6 +  p_src[5];
 178             p_dest++;
 179
 180             p_src += 7;
 181
 182             if( p_filter->input.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 183         }
 184         else
 185         for( i = p_in_buf->i_nb_samples; i--; )
 186         {
 187             *p_dest = p_src[4] + 0.5 * p_src[0];
 188             p_dest++;
 189             *p_dest = p_src[4] + 0.5 * p_src[1];
 190             p_dest++;
 191             *p_dest = p_src[2];
 192             p_dest++;
 193             *p_dest = p_src[3];
 194             p_dest++;
 195
 196             p_src += 5;
 197
 198             if( p_filter->input.i_physical_channels & AOUT_CHAN_LFE ) p_src++;
 199         }
 200     }
 201 }
 202
 203 /*****************************************************************************
 204  * OpenFilter:
 205  *****************************************************************************/
 206 static int OpenFilter( vlc_object_t *p_this )
 207 {
 208     filter_t *p_filter = (filter_t *)p_this;
 209
 210     audio_format_t fmt_in  = p_filter->fmt_in.audio;
 211     audio_format_t fmt_out = p_filter->fmt_out.audio;
 212
 213     fmt_in.i_format = p_filter->fmt_in.i_codec;
 214     fmt_out.i_format = p_filter->fmt_out.i_codec;
 215
 216     if( !IsSupported( &fmt_in, &fmt_out ) )
 217         return -1;
 218
 219     p_filter->pf_audio_filter = Filter;
 220
 221     return 0;
 222 }
 223
 224 /*****************************************************************************
 225  * Filter:
 226  *****************************************************************************/
 227 static block_t *Filter( filter_t *p_filter, block_t *p_block )
 228 {
 229     aout_filter_t aout_filter;
 230     aout_buffer_t in_buf, out_buf;
 231     block_t *p_out;
 232     int i_out_size;
 233
 234     if( !p_block || !p_block->i_samples )
 235     {
 236         if( p_block )
 237             block_Release( p_block );
 238         return NULL;
 239     }
 240
 241     i_out_size = p_block->i_samples *
 242       p_filter->fmt_out.audio.i_bitspersample *
 243         p_filter->fmt_out.audio.i_channels / 8;
 244
 245     p_out = p_filter->pf_audio_buffer_new( p_filter, i_out_size );
 246     if( !p_out )
 247     {
 248         msg_Warn( p_filter, "can't get output buffer" );
 249         block_Release( p_block );
 250         return NULL;
 251     }
 252
 253     p_out->i_samples = p_block->i_samples;
 254     p_out->i_dts = p_block->i_dts;
 255     p_out->i_pts = p_block->i_pts;
 256     p_out->i_length = p_block->i_length;
 257
 258     aout_filter.p_sys = (struct aout_filter_sys_t *)p_filter->p_sys;
 259     aout_filter.input = p_filter->fmt_in.audio;
 260     aout_filter.input.i_format = p_filter->fmt_in.i_codec;
 261     aout_filter.output = p_filter->fmt_out.audio;
 262     aout_filter.output.i_format = p_filter->fmt_out.i_codec;
 263
 264     in_buf.p_buffer = p_block->p_buffer;
 265     in_buf.i_nb_bytes = p_block->i_buffer;
 266     in_buf.i_nb_samples = p_block->i_samples;
 267     out_buf.p_buffer = p_out->p_buffer;
 268     out_buf.i_nb_bytes = p_out->i_buffer;
 269     out_buf.i_nb_samples = p_out->i_samples;
 270
 271     DoWork( (aout_instance_t *)p_filter, &aout_filter, &in_buf, &out_buf );
 272
 273     block_Release( p_block );
 274
 275     p_out->i_buffer = out_buf.i_nb_bytes;
 276     p_out->i_samples = out_buf.i_nb_samples;
 277
 278     return p_out;
 279 }
 280
 281 /*****************************************************************************
 282  * Helpers:
 283  *****************************************************************************/
 284 static bool IsSupported( const audio_format_t *p_input, const audio_format_t *p_output )
 285 {
 286     if( p_input->i_format != VLC_FOURCC('f','l','3','2') ||
 287           p_input->i_format != p_output->i_format ||
 288           p_input->i_rate != p_output->i_rate )
 289         return false;
 290
 291     if( p_input->i_physical_channels == p_output->i_physical_channels &&
 292         p_input->i_original_channels == p_output->i_original_channels )
 293     {
 294         return false;
 295     }
 296
 297     /* Only conversion to Mono, Stereo and 4.0 right now */
 298     if( p_output->i_physical_channels != AOUT_CHAN_CENTER &&
 299         p_output->i_physical_channels != AOUT_CHANS_2_0 &&
 300         p_output->i_physical_channels != AOUT_CHANS_4_0 )
 301     {
 302         return false;
 303     }
 304
 305     /* Only from 7/7.1/5/5.1/2.0 */
 306     if( (p_input->i_physical_channels & ~AOUT_CHAN_LFE) != AOUT_CHANS_7_0 &&
 307         (p_input->i_physical_channels & ~AOUT_CHAN_LFE) != AOUT_CHANS_5_0 &&
 308          p_input->i_physical_channels != AOUT_CHANS_2_0 )
 309     {
 310         return false;
 311     }
 312
 313     /* Only if we downmix */
 314     if( aout_FormatNbChannels( p_input ) <= aout_FormatNbChannels( p_output ) )
 315         return false;
 316
 317     return true;
 318 }
 319