Build VLC aliases cleanly (don't need to parse argv[0])
[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
28 #include <vlc/vlc.h>
29 #include <vlc_aout.h>
30
31 /*****************************************************************************
32  * Local prototypes
33  *****************************************************************************/
34 static int  Create    ( vlc_object_t * );
35
36 static void DoWork    ( aout_instance_t *, aout_buffer_t * );
37
38 /*****************************************************************************
39  * Module descriptor
40  *****************************************************************************/
41 vlc_module_begin();
42     set_category( CAT_AUDIO );
43     set_subcategory( SUBCAT_AUDIO_MISC );
44     set_description( _("Trivial audio mixer") );
45     set_capability( "audio mixer", 1 );
46     set_callbacks( Create, NULL );
47 vlc_module_end();
48
49 /*****************************************************************************
50  * Create: allocate trivial mixer
51  *****************************************************************************/
52 static int Create( vlc_object_t *p_this )
53 {
54     aout_instance_t * p_aout = (aout_instance_t *)p_this;
55
56     if ( p_aout->mixer.mixer.i_format != VLC_FOURCC('f','l','3','2')
57           && p_aout->mixer.mixer.i_format != VLC_FOURCC('f','i','3','2') )
58     {
59         return -1;
60     }
61
62     p_aout->mixer.pf_do_work = DoWork;
63
64     return 0;
65 }
66
67 /*****************************************************************************
68  * DoWork: mix a new output buffer
69  *****************************************************************************/
70 static void DoWork( aout_instance_t * p_aout, aout_buffer_t * p_buffer )
71 {
72     int i = 0;
73     aout_input_t * p_input = p_aout->pp_inputs[i];
74     int i_nb_channels = aout_FormatNbChannels( &p_aout->mixer.mixer );
75     int i_nb_bytes = p_buffer->i_nb_samples * sizeof(int32_t)
76                       * i_nb_channels;
77     byte_t * p_in;
78     byte_t * p_out;
79
80     while ( p_input->b_error )
81     {
82         p_input = p_aout->pp_inputs[++i];
83         /* This can't crash because if no input has b_error == 0, the
84          * audio mixer cannot run and we can't be here. */
85     }
86     p_in = p_input->p_first_byte_to_mix;
87     p_out = p_buffer->p_buffer;
88
89     for ( ; ; )
90     {
91         ptrdiff_t i_available_bytes = (p_input->fifo.p_first->p_buffer
92                                         - p_in)
93                                         + p_input->fifo.p_first->i_nb_samples
94                                            * sizeof(int32_t)
95                                            * i_nb_channels;
96
97         if ( i_available_bytes < i_nb_bytes )
98         {
99             aout_buffer_t * p_old_buffer;
100
101             if ( i_available_bytes > 0 )
102                 p_aout->p_libvlc->pf_memcpy( p_out, p_in, i_available_bytes );
103             i_nb_bytes -= i_available_bytes;
104             p_out += i_available_bytes;
105
106             /* Next buffer */
107             p_old_buffer = aout_FifoPop( p_aout, &p_input->fifo );
108             aout_BufferFree( p_old_buffer );
109             if ( p_input->fifo.p_first == NULL )
110             {
111                 msg_Err( p_aout, "internal amix error" );
112                 return;
113             }
114             p_in = p_input->fifo.p_first->p_buffer;
115         }
116         else
117         {
118             if ( i_nb_bytes > 0 )
119                 p_aout->p_libvlc->pf_memcpy( p_out, p_in, i_nb_bytes );
120             p_input->p_first_byte_to_mix = p_in + i_nb_bytes;
121             break;
122         }
123     }
124
125     /* Empty other FIFOs to avoid a memory leak. */
126     for ( i++; i < p_aout->i_nb_inputs; i++ )
127     {
128         aout_fifo_t * p_fifo;
129         aout_buffer_t * p_deleted;
130
131         p_input = p_aout->pp_inputs[i];
132         if ( p_input->b_error ) continue;
133         p_fifo = &p_input->fifo;
134         p_deleted = p_fifo->p_first;
135         while ( p_deleted != NULL )
136         {
137             aout_buffer_t * p_next = p_deleted->p_next;
138             aout_BufferFree( p_deleted );
139             p_deleted = p_next;
140         }
141         p_fifo->p_first = NULL;
142         p_fifo->pp_last = &p_fifo->p_first;
143     }
144 }
145