equalizer.c: compile fix for old compilers (thx sam)
[vlc.git] / modules / audio_mixer / trivial.c
1 /*****************************************************************************
2  * trivial.c : trivial mixer plug-in (1 input, no downmixing)
3  *****************************************************************************
4  * Copyright (C) 2002 VideoLAN
5  * $Id: trivial.c,v 1.14 2004/01/25 17:20:18 kuehne Exp $
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., 59 Temple Place - Suite 330, Boston, MA  02111, 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_buffer_t * );
40
41 /*****************************************************************************
42  * Module descriptor
43  *****************************************************************************/
44 vlc_module_begin();
45     set_description( _("Trivial audio mixer") );
46     set_capability( "audio mixer", 1 );
47     set_callbacks( Create, NULL );
48 vlc_module_end();
49
50 /*****************************************************************************
51  * Create: allocate trivial mixer
52  *****************************************************************************/
53 static int Create( vlc_object_t *p_this )
54 {
55     aout_instance_t * p_aout = (aout_instance_t *)p_this;
56
57     if ( p_aout->mixer.mixer.i_format != VLC_FOURCC('f','l','3','2')
58           && p_aout->mixer.mixer.i_format != VLC_FOURCC('f','i','3','2') )
59     {
60         return -1;
61     }
62
63     p_aout->mixer.pf_do_work = DoWork;
64
65     return 0;
66 }
67
68 /*****************************************************************************
69  * DoWork: mix a new output buffer
70  *****************************************************************************/
71 static void DoWork( aout_instance_t * p_aout, aout_buffer_t * p_buffer )
72 {
73     int i = 0;
74     aout_input_t * p_input = p_aout->pp_inputs[i];
75     int i_nb_channels = aout_FormatNbChannels( &p_aout->mixer.mixer );
76     int i_nb_bytes = p_buffer->i_nb_samples * sizeof(int32_t)
77                       * i_nb_channels;
78     byte_t * p_in;
79     byte_t * p_out;
80
81     while ( p_input->b_error )
82     {
83         p_input = p_aout->pp_inputs[++i];
84         /* This can't crash because if no input has b_error == 0, the
85          * audio mixer cannot run and we can't be here. */
86     }
87     p_in = p_input->p_first_byte_to_mix;
88     p_out = p_buffer->p_buffer;
89
90     for ( ; ; )
91     {
92         ptrdiff_t i_available_bytes = (p_input->fifo.p_first->p_buffer
93                                         - p_in)
94                                         + p_input->fifo.p_first->i_nb_samples
95                                            * sizeof(int32_t)
96                                            * i_nb_channels;
97
98         if ( i_available_bytes < i_nb_bytes )
99         {
100             aout_buffer_t * p_old_buffer;
101
102             if ( i_available_bytes > 0 )
103                 p_aout->p_vlc->pf_memcpy( p_out, p_in, i_available_bytes );
104             i_nb_bytes -= i_available_bytes;
105             p_out += i_available_bytes;
106
107             /* Next buffer */
108             p_old_buffer = aout_FifoPop( p_aout, &p_input->fifo );
109             aout_BufferFree( p_old_buffer );
110             if ( p_input->fifo.p_first == NULL )
111             {
112                 msg_Err( p_aout, "internal amix error" );
113                 return;
114             }
115             p_in = p_input->fifo.p_first->p_buffer;
116         }
117         else
118         {
119             if ( i_nb_bytes > 0 )
120                 p_aout->p_vlc->pf_memcpy( p_out, p_in, i_nb_bytes );
121             p_input->p_first_byte_to_mix = p_in + i_nb_bytes;
122             break;
123         }
124     }
125
126     /* Empty other FIFOs to avoid a memory leak. */
127     for ( i++; i < p_aout->i_nb_inputs; i++ )
128     {
129         aout_fifo_t * p_fifo;
130         aout_buffer_t * p_deleted;
131
132         p_input = p_aout->pp_inputs[i];
133         if ( p_input->b_error ) continue;
134         p_fifo = &p_input->fifo;
135         p_deleted = p_fifo->p_first;
136         while ( p_deleted != NULL )
137         {
138             aout_buffer_t * p_next = p_deleted->p_next;
139             aout_BufferFree( p_deleted );
140             p_deleted = p_next;
141         }
142         p_fifo->p_first = NULL;
143         p_fifo->pp_last = &p_fifo->p_first;
144     }
145 }
146