Add a growl (http://growl.info/) notification plugin (most of code from msn.c)
[vlc.git] / modules / audio_filter / channel_mixer / trivial.c
1 /*****************************************************************************
2  * trivial.c : trivial channel mixer plug-in (drops unwanted channels)
3  *****************************************************************************
4  * Copyright (C) 2002 the VideoLAN team
5  * $Id$
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., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
22  *****************************************************************************/
23
24 /*****************************************************************************
25  * Preamble
26  *****************************************************************************/
27 #include <stdlib.h>                                      /* malloc(), free() */
28 #include <string.h>
29
30 #include <vlc/vlc.h>
31 #include "audio_output.h"
32 #include "aout_internal.h"
33
34 /*****************************************************************************
35  * Local prototypes
36  *****************************************************************************/
37 static int  Create    ( vlc_object_t * );
38
39 static void DoWork    ( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
40                         aout_buffer_t * );
41
42 /*****************************************************************************
43  * Module descriptor
44  *****************************************************************************/
45 vlc_module_begin();
46     set_description( _("audio filter for trivial channel mixing") );
47     set_capability( "audio filter", 1 );
48     set_category( CAT_AUDIO );
49     set_subcategory( SUBCAT_AUDIO_MISC );
50     set_callbacks( Create, NULL );
51 vlc_module_end();
52
53 /*****************************************************************************
54  * Create: allocate trivial channel mixer
55  *****************************************************************************/
56 static int Create( vlc_object_t *p_this )
57 {
58     aout_filter_t * p_filter = (aout_filter_t *)p_this;
59
60     if ( (p_filter->input.i_physical_channels
61            == p_filter->output.i_physical_channels
62            && p_filter->input.i_original_channels
63                == p_filter->output.i_original_channels)
64           || p_filter->input.i_format != p_filter->output.i_format
65           || p_filter->input.i_rate != p_filter->output.i_rate
66           || (p_filter->input.i_format != VLC_FOURCC('f','l','3','2')
67                && p_filter->input.i_format != VLC_FOURCC('f','i','3','2')) )
68     {
69         return -1;
70     }
71
72     p_filter->pf_do_work = DoWork;
73     if ( aout_FormatNbChannels( &p_filter->input )
74            > aout_FormatNbChannels( &p_filter->output ) )
75     {
76         /* Downmixing */
77         p_filter->b_in_place = 1;
78     }
79     else
80     {
81         /* Upmixing */
82         p_filter->b_in_place = 0;
83     }
84
85     return 0;
86 }
87
88 /*****************************************************************************
89  * SparseCopy: trivially downmix or upmix a buffer
90  *****************************************************************************/
91 static void SparseCopy( int32_t * p_dest, const int32_t * p_src, size_t i_len,
92                         int i_output_stride, int i_input_stride )
93 {
94     int i;
95     for ( i = i_len; i--; )
96     {
97         int j;
98         for ( j = 0; j < i_output_stride; j++ )
99         {
100             p_dest[j] = p_src[j % i_input_stride];
101         }
102         p_src += i_input_stride;
103         p_dest += i_output_stride;
104     }
105 }
106
107 /*****************************************************************************
108  * DoWork: convert a buffer
109  *****************************************************************************/
110 static void DoWork( aout_instance_t * p_aout, aout_filter_t * p_filter,
111                     aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
112 {
113     int i_input_nb = aout_FormatNbChannels( &p_filter->input );
114     int i_output_nb = aout_FormatNbChannels( &p_filter->output );
115     int32_t * p_dest = (int32_t *)p_out_buf->p_buffer;
116     int32_t * p_src = (int32_t *)p_in_buf->p_buffer;
117
118     p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
119     p_out_buf->i_nb_bytes = p_in_buf->i_nb_bytes * i_output_nb / i_input_nb;
120
121     if ( (p_filter->output.i_original_channels & AOUT_CHAN_PHYSMASK)
122                 != (p_filter->input.i_original_channels & AOUT_CHAN_PHYSMASK)
123            && (p_filter->input.i_original_channels & AOUT_CHAN_PHYSMASK)
124                 == (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT) )
125     {
126         int i;
127         /* This is a bit special. */
128         if ( !(p_filter->output.i_original_channels & AOUT_CHAN_LEFT) )
129         {
130             p_src++;
131         }
132         if ( p_filter->output.i_physical_channels == AOUT_CHAN_CENTER )
133         {
134             /* Mono mode */
135             for ( i = p_in_buf->i_nb_samples; i--; )
136             {
137                 *p_dest = *p_src;
138                 p_dest++;
139                 p_src += 2;
140             }
141         }
142         else
143         {
144             /* Fake-stereo mode */
145             for ( i = p_in_buf->i_nb_samples; i--; )
146             {
147                 *p_dest = *p_src;
148                 p_dest++;
149                 *p_dest = *p_src;
150                 p_dest++;
151                 p_src += 2;
152             }
153         }
154     }
155     else if ( p_filter->output.i_original_channels
156                                     & AOUT_CHAN_REVERSESTEREO )
157     {
158         /* Reverse-stereo mode */
159         int i;
160         for ( i = p_in_buf->i_nb_samples; i--; )
161         {
162             *p_dest = p_src[1];
163             p_dest++;
164             *p_dest = p_src[0];
165             p_dest++;
166             p_src += 2;
167         }
168     }
169     else
170     {
171         SparseCopy( p_dest, p_src, p_in_buf->i_nb_samples, i_output_nb,
172                     i_input_nb );
173     }
174 }
175