Make it possible to force a distro.mak to use. This is helpfull in cross-compile...
[vlc.git] / modules / audio_mixer / trivial.c
1 /*****************************************************************************
2  * trivial.c : trivial mixer plug-in (1 input, no downmixing)
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 <vlc_aout.h>
32
33 /*****************************************************************************
34  * Local prototypes
35  *****************************************************************************/
36 static int  Create    ( vlc_object_t * );
37
38 static void DoWork    ( aout_instance_t *, aout_buffer_t * );
39
40 /*****************************************************************************
41  * Module descriptor
42  *****************************************************************************/
43 vlc_module_begin();
44     set_category( CAT_AUDIO );
45     set_subcategory( SUBCAT_AUDIO_MISC );
46     set_description( _("Trivial audio mixer") );
47     set_capability( "audio mixer", 1 );
48     set_callbacks( Create, NULL );
49 vlc_module_end();
50
51 /*****************************************************************************
52  * Create: allocate trivial mixer
53  *****************************************************************************/
54 static int Create( vlc_object_t *p_this )
55 {
56     aout_instance_t * p_aout = (aout_instance_t *)p_this;
57
58     if ( p_aout->mixer.mixer.i_format != VLC_FOURCC('f','l','3','2')
59           && p_aout->mixer.mixer.i_format != VLC_FOURCC('f','i','3','2') )
60     {
61         return -1;
62     }
63
64     p_aout->mixer.pf_do_work = DoWork;
65
66     return 0;
67 }
68
69 /*****************************************************************************
70  * DoWork: mix a new output buffer
71  *****************************************************************************/
72 static void DoWork( aout_instance_t * p_aout, aout_buffer_t * p_buffer )
73 {
74     int i = 0;
75     aout_input_t * p_input = p_aout->pp_inputs[i];
76     int i_nb_channels = aout_FormatNbChannels( &p_aout->mixer.mixer );
77     int i_nb_bytes = p_buffer->i_nb_samples * sizeof(int32_t)
78                       * i_nb_channels;
79     byte_t * p_in;
80     byte_t * p_out;
81
82     while ( p_input->b_error )
83     {
84         p_input = p_aout->pp_inputs[++i];
85         /* This can't crash because if no input has b_error == 0, the
86          * audio mixer cannot run and we can't be here. */
87     }
88     p_in = p_input->p_first_byte_to_mix;
89     p_out = p_buffer->p_buffer;
90
91     for ( ; ; )
92     {
93         ptrdiff_t i_available_bytes = (p_input->fifo.p_first->p_buffer
94                                         - p_in)
95                                         + p_input->fifo.p_first->i_nb_samples
96                                            * sizeof(int32_t)
97                                            * i_nb_channels;
98
99         if ( i_available_bytes < i_nb_bytes )
100         {
101             aout_buffer_t * p_old_buffer;
102
103             if ( i_available_bytes > 0 )
104                 p_aout->p_libvlc->pf_memcpy( p_out, p_in, i_available_bytes );
105             i_nb_bytes -= i_available_bytes;
106             p_out += i_available_bytes;
107
108             /* Next buffer */
109             p_old_buffer = aout_FifoPop( p_aout, &p_input->fifo );
110             aout_BufferFree( p_old_buffer );
111             if ( p_input->fifo.p_first == NULL )
112             {
113                 msg_Err( p_aout, "internal amix error" );
114                 return;
115             }
116             p_in = p_input->fifo.p_first->p_buffer;
117         }
118         else
119         {
120             if ( i_nb_bytes > 0 )
121                 p_aout->p_libvlc->pf_memcpy( p_out, p_in, i_nb_bytes );
122             p_input->p_first_byte_to_mix = p_in + i_nb_bytes;
123             break;
124         }
125     }
126
127     /* Empty other FIFOs to avoid a memory leak. */
128     for ( i++; i < p_aout->i_nb_inputs; i++ )
129     {
130         aout_fifo_t * p_fifo;
131         aout_buffer_t * p_deleted;
132
133         p_input = p_aout->pp_inputs[i];
134         if ( p_input->b_error ) continue;
135         p_fifo = &p_input->fifo;
136         p_deleted = p_fifo->p_first;
137         while ( p_deleted != NULL )
138         {
139             aout_buffer_t * p_next = p_deleted->p_next;
140             aout_BufferFree( p_deleted );
141             p_deleted = p_next;
142         }
143         p_fifo->p_first = NULL;
144         p_fifo->pp_last = &p_fifo->p_first;
145     }
146 }
147