git.sesse.net Git - vlc/blob - modules/audio_mixer/trivial.c

   1 /*****************************************************************************
   2  * trivial.c : trivial mixer plug-in (1 input, no downmixing)
   3  *****************************************************************************
   4  * Copyright (C) 2002 VideoLAN
   5  * $Id: trivial.c,v 1.2 2002/08/08 00:35:10 sam Exp $
   6  *
   7  * Authors: Christophe Massiot <massiot@via.ecp.fr>
   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., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  22  *****************************************************************************/
  23
  24 /*****************************************************************************
  25  * Preamble
  26  *****************************************************************************/
  27 #include <errno.h>
  28 #include <stdlib.h>                                      /* malloc(), free() */
  29 #include <string.h>
  30
  31 #include <vlc/vlc.h>
  32 #include "audio_output.h"
  33 #include "aout_internal.h"
  34
  35 /*****************************************************************************
  36  * Local prototypes
  37  *****************************************************************************/
  38 static int  Create    ( vlc_object_t * );
  39
  40 static void DoWork    ( aout_instance_t *, aout_buffer_t * );
  41
  42 /*****************************************************************************
  43  * Module descriptor
  44  *****************************************************************************/
  45 vlc_module_begin();
  46     set_description( _("trivial aout mixer module") );
  47     set_capability( "audio mixer", 1 );
  48     add_shortcut( "trivial" );
  49     set_callbacks( Create, NULL );
  50 vlc_module_end();
  51
  52 /*****************************************************************************
  53  * Create: allocate trivial mixer
  54  *****************************************************************************
  55  * This function allocates and initializes a Crop vout method.
  56  *****************************************************************************/
  57 static int Create( vlc_object_t *p_this )
  58 {
  59     aout_instance_t * p_aout = (aout_instance_t *)p_this;
  60
  61     if ( p_aout->mixer.output.i_format != AOUT_FMT_FLOAT32
  62           && p_aout->mixer.output.i_format != AOUT_FMT_FIXED32 )
  63     {
  64         return -1;
  65     }
  66
  67     p_aout->mixer.pf_do_work = DoWork;
  68
  69     return 0;
  70 }
  71
  72 /*****************************************************************************
  73  * SparseCopy: trivially downmix or upmix a buffer
  74  *****************************************************************************/
  75 static void SparseCopy( u32 * p_dest, const u32 * p_src, size_t i_len,
  76                         int i_output_stride, int i_input_stride )
  77 {
  78     int i;
  79     for ( i = 0; i < i_len; i++ )
  80     {
  81         int j;
  82         for ( j = 0; j < i_output_stride; j++ )
  83         {
  84             p_dest[j] = p_src[j];
  85         }
  86         p_src += i_input_stride;
  87         p_dest += i_output_stride;
  88     }
  89 }
  90
  91 /*****************************************************************************
  92  * DoWork: mix a new output buffer
  93  *****************************************************************************/
  94 static void DoWork( aout_instance_t * p_aout, aout_buffer_t * p_buffer )
  95 {
  96     aout_input_t * p_input = p_aout->pp_inputs[0];
  97
  98     if ( p_input->input.i_channels == p_aout->mixer.output.i_channels )
  99     {
 100         int i_nb_bytes = p_buffer->i_nb_samples * sizeof(u32)
 101                           * p_input->input.i_channels;
 102         byte_t * p_in = (p_input->p_first_byte_to_mix == NULL) ?
 103                         p_input->fifo.p_first->p_buffer :
 104                         p_input->p_first_byte_to_mix;
 105         byte_t * p_out = p_buffer->p_buffer;
 106
 107         for ( ; ; )
 108         {
 109             ptrdiff_t i_available_bytes = (p_input->fifo.p_first->p_buffer
 110                                            - p_in)
 111                                            + p_input->fifo.p_first->i_nb_samples
 112                                               * sizeof(u32)
 113                                               * p_input->input.i_channels;
 114
 115             if ( i_available_bytes < i_nb_bytes )
 116             {
 117                 aout_buffer_t * p_old_buffer;
 118
 119                 if ( i_available_bytes > 0 )
 120                     p_aout->p_vlc->pf_memcpy( p_out, p_in, i_available_bytes );
 121                 i_nb_bytes -= i_available_bytes;
 122                 p_out += i_available_bytes;
 123
 124                 /* Next buffer */
 125                 p_old_buffer = aout_FifoPop( p_aout, &p_input->fifo );
 126                 aout_BufferFree( p_old_buffer );
 127                 if ( p_input->fifo.p_first == NULL )
 128                 {
 129                     msg_Err( p_aout, "internal amix error" );
 130                     return;
 131                 }
 132                 p_in = p_input->fifo.p_first->p_buffer;
 133             }
 134             else
 135             {
 136                 p_aout->p_vlc->pf_memcpy( p_out, p_in, i_nb_bytes );
 137                 p_input->p_first_byte_to_mix = p_in + i_nb_bytes;
 138                 break;
 139             }
 140         }
 141     }
 142     else
 143     {
 144         /* Downmixing or upmixing. */
 145         int i_nb_samples = p_buffer->i_nb_samples;
 146         u32 * p_in = (p_input->p_first_byte_to_mix == NULL) ?
 147                      (u32 *)p_input->fifo.p_first->p_buffer :
 148                      (u32 *)p_input->p_first_byte_to_mix;
 149         u32 * p_out = (u32 *)p_buffer->p_buffer;
 150
 151
 152         if ( p_input->input.i_channels < p_aout->mixer.output.i_channels )
 153         {
 154             /* Zero out the destination buffer, to avoid static on unavailable
 155              * channels. */
 156             memset( p_buffer->p_buffer, 0,
 157                     p_buffer->i_nb_samples * sizeof(u32)
 158                      * p_aout->mixer.output.i_channels );
 159         }
 160
 161         for ( ; ; )
 162         {
 163             ptrdiff_t i_available_bytes = (p_input->fifo.p_first->p_buffer
 164                                            - (byte_t *)p_in)
 165                                            + p_input->fifo.p_first->i_nb_samples
 166                                               * sizeof(u32)
 167                                               * p_input->input.i_channels;
 168             int i_available_samples = i_available_bytes
 169                                        / p_input->input.i_channels
 170                                        / sizeof(u32);
 171
 172             if ( i_available_samples < i_nb_samples )
 173             {
 174                 aout_buffer_t * p_old_buffer;
 175
 176                 if ( i_available_samples > 0 )
 177                     SparseCopy( p_out, p_in, i_available_samples,
 178                                 p_aout->mixer.output.i_channels,
 179                                 p_input->input.i_channels );
 180                 i_nb_samples -= i_available_samples;
 181                 p_out += i_available_samples * p_aout->mixer.output.i_channels;
 182
 183                 /* Next buffer */
 184                 p_old_buffer = aout_FifoPop( p_aout, &p_input->fifo );
 185                 aout_BufferFree( p_old_buffer );
 186                 if ( p_input->fifo.p_first == NULL )
 187                 {
 188                     msg_Err( p_aout, "internal amix error" );
 189                     return;
 190                 }
 191                 p_in = (u32 *)p_input->fifo.p_first->p_buffer;
 192             }
 193             else
 194             {
 195                 SparseCopy( p_out, p_in, i_nb_samples,
 196                             p_aout->mixer.output.i_channels,
 197                             p_input->input.i_channels );
 198                 p_input->p_first_byte_to_mix = (byte_t *)p_in
 199                                + i_nb_samples * p_input->input.i_channels
 200                                   * sizeof(u32);
 201                 break;
 202             }
 203         }
 204     }
 205 }
 206