Add "audio resampler" capability to resamplers
[vlc.git] / 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_common.h>
33 #include <vlc_plugin.h>
34 #include <vlc_aout.h>
35 #include <vlc_filter.h>
36
37 /*****************************************************************************
38  * Local prototypes
39  *****************************************************************************/
40 static int  Create    ( vlc_object_t * );
41
42 static block_t *DoWork( filter_t *, block_t * );
43
44 /*****************************************************************************
45  * Module descriptor
46  *****************************************************************************/
47 vlc_module_begin ()
48     set_description( N_("Nearest-neighbor audio resampler") )
49     set_capability( "audio filter", 2 )
50     set_category( CAT_AUDIO )
51     set_subcategory( SUBCAT_AUDIO_MISC )
52     set_callbacks( Create, NULL )
53
54     add_submodule()
55     set_capability( "audio resampler", 2 )
56     set_callbacks( Create, NULL )
57 vlc_module_end ()
58
59 /*****************************************************************************
60  * Create: allocate ugly resampler
61  *****************************************************************************/
62 static int Create( vlc_object_t *p_this )
63 {
64     filter_t * p_filter = (filter_t *)p_this;
65
66     if( p_filter->fmt_in.audio.i_rate == p_filter->fmt_out.audio.i_rate
67      || p_filter->fmt_in.audio.i_format != p_filter->fmt_out.audio.i_format
68      || p_filter->fmt_in.audio.i_physical_channels
69                                  != p_filter->fmt_out.audio.i_physical_channels
70      || p_filter->fmt_in.audio.i_original_channels
71                                  != p_filter->fmt_out.audio.i_original_channels
72      || !AOUT_FMT_LINEAR( &p_filter->fmt_in.audio ) )
73         return VLC_EGENERIC;
74
75     p_filter->pf_audio_filter = DoWork;
76     return VLC_SUCCESS;
77 }
78
79 /*****************************************************************************
80  * DoWork: convert a buffer
81  *****************************************************************************/
82 static block_t *DoWork( filter_t * p_filter, block_t * p_in_buf )
83 {
84     /* Check if we really need to run the resampler */
85     if( p_filter->fmt_out.audio.i_rate == p_filter->fmt_in.audio.i_rate )
86         return p_in_buf;
87
88     block_t *p_out_buf = p_in_buf;
89     unsigned int i_out_nb = p_in_buf->i_nb_samples
90         * p_filter->fmt_out.audio.i_rate / p_filter->fmt_in.audio.i_rate;
91     const unsigned framesize = (p_filter->fmt_in.audio.i_bitspersample / 8)
92         * aout_FormatNbChannels( &p_filter->fmt_in.audio );
93
94     if( p_filter->fmt_out.audio.i_rate > p_filter->fmt_in.audio.i_rate )
95     {
96         p_out_buf = block_Alloc( i_out_nb * framesize );
97         if( !p_out_buf )
98             goto out;
99     }
100
101     unsigned char *p_out = p_out_buf->p_buffer;
102     unsigned char *p_in = p_in_buf->p_buffer;
103     unsigned int i_remainder = 0;
104
105     p_out_buf->i_nb_samples = i_out_nb;
106     p_out_buf->i_buffer = i_out_nb * framesize;
107     p_out_buf->i_pts = p_in_buf->i_pts;
108     p_out_buf->i_length = p_out_buf->i_nb_samples *
109         1000000 / p_filter->fmt_out.audio.i_rate;
110
111     while( i_out_nb )
112     {
113         if( p_out != p_in )
114             memcpy( p_out, p_in, framesize );
115         p_out += framesize;
116         i_out_nb--;
117
118         i_remainder += p_filter->fmt_in.audio.i_rate;
119         while( i_remainder >= p_filter->fmt_out.audio.i_rate )
120         {
121             p_in += framesize;
122             i_remainder -= p_filter->fmt_out.audio.i_rate;
123         }
124     }
125
126     if( p_in_buf != p_out_buf )
127 out:
128         block_Release( p_in_buf );
129     return p_out_buf;
130 }