Fix a bunch of warnings and errors
[vlc.git] / modules / audio_filter / resampler / trivial.c
1 /*****************************************************************************
2  * trivial.c : trivial resampler (skips samples or pads with zeroes)
3  *****************************************************************************
4  * Copyright (C) 2002, 2006 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 resampling") );
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 resampler
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_rate == p_filter->output.i_rate
61           || p_filter->input.i_format != p_filter->output.i_format
62           || p_filter->input.i_physical_channels
63               != p_filter->output.i_physical_channels
64           || p_filter->input.i_original_channels
65               != p_filter->output.i_original_channels
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     p_filter->b_in_place = VLC_TRUE;
74
75     return 0;
76 }
77
78 /*****************************************************************************
79  * DoWork: convert a buffer
80  *****************************************************************************/
81 static void DoWork( aout_instance_t * p_aout, aout_filter_t * p_filter,
82                     aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
83 {
84     int i_in_nb = p_in_buf->i_nb_samples;
85     int i_out_nb = i_in_nb * p_filter->output.i_rate
86                     / p_filter->input.i_rate;
87     int i_sample_bytes = aout_FormatNbChannels( &p_filter->input )
88                           * sizeof(int32_t);
89
90     /* Check if we really need to run the resampler */
91     if( p_aout->mixer.mixer.i_rate == p_filter->input.i_rate )
92     {
93         return;
94     }
95
96     if ( p_out_buf != p_in_buf )
97     {
98         /* For whatever reason the buffer allocator decided to allocate
99          * a new buffer. Currently, this never happens. */
100         p_aout->p_vlc->pf_memcpy( p_out_buf->p_buffer, p_in_buf->p_buffer,
101                                   __MIN(i_out_nb, i_in_nb) * i_sample_bytes );
102     }
103
104     if ( i_out_nb > i_in_nb )
105     {
106         /* Pad with zeroes. */
107         memset( p_out_buf->p_buffer + i_in_nb * i_sample_bytes,
108                 0, (i_out_nb - i_in_nb) * i_sample_bytes );
109     }
110
111     p_out_buf->i_nb_samples = i_out_nb;
112     p_out_buf->i_nb_bytes = i_out_nb * i_sample_bytes;
113     p_out_buf->start_date = p_in_buf->start_date;
114     p_out_buf->end_date = p_out_buf->start_date + p_out_buf->i_nb_samples *
115         1000000 / p_filter->output.i_rate;
116 }