git.sesse.net Git - vlc/blob - modules/audio_filter/resampler/ugly.c

   1 /*****************************************************************************
   2  * ugly.c : ugly resampler (changes pitch)
   3  *****************************************************************************
   4  * Copyright (C) 2002, 2006 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Samuel Hocevar <sam@zoy.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
  28 #ifdef HAVE_CONFIG_H
  29 # include "config.h"
  30 #endif
  31
  32 #include <vlc/vlc.h>
  33 #include <vlc_aout.h>
  34
  35 /*****************************************************************************
  36  * Local prototypes
  37  *****************************************************************************/
  38 static int  Create    ( vlc_object_t * );
  39
  40 static void DoWork    ( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
  41                         aout_buffer_t * );
  42
  43 /*****************************************************************************
  44  * Module descriptor
  45  *****************************************************************************/
  46 vlc_module_begin();
  47     set_description( _("Audio filter for ugly resampling") );
  48     set_capability( "audio filter", 2 );
  49     set_category( CAT_AUDIO );
  50     set_subcategory( SUBCAT_AUDIO_MISC );
  51     set_callbacks( Create, NULL );
  52 vlc_module_end();
  53
  54 /*****************************************************************************
  55  * Create: allocate ugly resampler
  56  *****************************************************************************/
  57 static int Create( vlc_object_t *p_this )
  58 {
  59     aout_filter_t * p_filter = (aout_filter_t *)p_this;
  60
  61     if ( p_filter->input.i_rate == p_filter->output.i_rate
  62           || p_filter->input.i_format != p_filter->output.i_format
  63           || p_filter->input.i_physical_channels
  64               != p_filter->output.i_physical_channels
  65           || p_filter->input.i_original_channels
  66               != p_filter->output.i_original_channels
  67           || (p_filter->input.i_format != VLC_FOURCC('f','l','3','2')
  68                && p_filter->input.i_format != VLC_FOURCC('f','i','3','2')) )
  69     {
  70         return VLC_EGENERIC;
  71     }
  72
  73     p_filter->pf_do_work = DoWork;
  74
  75     /* We don't want a new buffer to be created because we're not sure we'll
  76      * actually need to resample anything. */
  77     p_filter->b_in_place = VLC_TRUE;
  78
  79     return VLC_SUCCESS;
  80 }
  81
  82 /*****************************************************************************
  83  * DoWork: convert a buffer
  84  *****************************************************************************/
  85 static void DoWork( aout_instance_t * p_aout, aout_filter_t * p_filter,
  86                     aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
  87 {
  88     int32_t *p_in, *p_out = (int32_t*)p_out_buf->p_buffer;
  89 #ifndef HAVE_ALLOCA
  90     int32_t *p_in_orig;
  91 #endif
  92
  93     unsigned int i_nb_channels = aout_FormatNbChannels( &p_filter->input );
  94     unsigned int i_in_nb = p_in_buf->i_nb_samples;
  95     unsigned int i_out_nb = i_in_nb * p_filter->output.i_rate
  96                                     / p_filter->input.i_rate;
  97     unsigned int i_sample_bytes = i_nb_channels * sizeof(int32_t);
  98     unsigned int i_out, i_chan, i_remainder = 0;
  99
 100     /* Check if we really need to run the resampler */
 101     if( p_aout->mixer.mixer.i_rate == p_filter->input.i_rate )
 102     {
 103         return;
 104     }
 105
 106 #ifdef HAVE_ALLOCA
 107     p_in = (int32_t *)alloca( p_in_buf->i_nb_bytes );
 108 #else
 109     p_in_orig = p_in = (int32_t *)malloc( p_in_buf->i_nb_bytes );
 110 #endif
 111     if( p_in == NULL )
 112     {
 113         return;
 114     }
 115
 116     p_aout->p_libvlc->pf_memcpy( p_in, p_in_buf->p_buffer, p_in_buf->i_nb_bytes );
 117
 118     for( i_out = i_out_nb ; i_out-- ; )
 119     {
 120         for( i_chan = i_nb_channels ; i_chan ; )
 121         {
 122             i_chan--;
 123             p_out[i_chan] = p_in[i_chan];
 124         }
 125         p_out += i_nb_channels;
 126
 127         i_remainder += p_filter->input.i_rate;
 128         while( i_remainder >= p_filter->output.i_rate )
 129         {
 130             p_in += i_nb_channels;
 131             i_remainder -= p_filter->output.i_rate;
 132         }
 133     }
 134
 135     p_out_buf->i_nb_samples = i_out_nb;
 136     p_out_buf->i_nb_bytes = i_out_nb * i_sample_bytes;
 137     p_out_buf->start_date = p_in_buf->start_date;
 138     p_out_buf->end_date = p_out_buf->start_date + p_out_buf->i_nb_samples *
 139         1000000 / p_filter->output.i_rate;
 140
 141 #ifndef HAVE_ALLOCA
 142     free( p_in_orig );
 143 #endif
 144
 145 }