* ./modules/audio_output/oss.c: compilation fixes.
[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 1.2 2002/08/08 00:35:10 sam 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 <errno.h>
28 #include <stdlib.h>                                      /* malloc(), free() */
29 #include <string.h>
30
31 #include <vlc/vlc.h>
32 #include "audio_output.h"
33 #include "aout_internal.h"
34
35 /*****************************************************************************
36  * Local prototypes
37  *****************************************************************************/
38 static int  Create    ( vlc_object_t * );
39
40 static void DoWork    ( aout_instance_t *, aout_buffer_t * );
41
42 /*****************************************************************************
43  * Module descriptor
44  *****************************************************************************/
45 vlc_module_begin();
46     set_description( _("trivial aout mixer module") );
47     set_capability( "audio mixer", 1 );
48     add_shortcut( "trivial" );
49     set_callbacks( Create, NULL );
50 vlc_module_end();
51
52 /*****************************************************************************
53  * Create: allocate trivial mixer
54  *****************************************************************************
55  * This function allocates and initializes a Crop vout method.
56  *****************************************************************************/
57 static int Create( vlc_object_t *p_this )
58 {
59     aout_instance_t * p_aout = (aout_instance_t *)p_this;
60
61     if ( p_aout->mixer.output.i_format != AOUT_FMT_FLOAT32
62           && p_aout->mixer.output.i_format != AOUT_FMT_FIXED32 )
63     {
64         return -1;
65     }
66
67     p_aout->mixer.pf_do_work = DoWork;
68
69     return 0;
70 }
71
72 /*****************************************************************************
73  * SparseCopy: trivially downmix or upmix a buffer
74  *****************************************************************************/
75 static void SparseCopy( u32 * p_dest, const u32 * p_src, size_t i_len,
76                         int i_output_stride, int i_input_stride )
77 {
78     int i;
79     for ( i = 0; i < i_len; i++ )
80     {
81         int j;
82         for ( j = 0; j < i_output_stride; j++ )
83         {
84             p_dest[j] = p_src[j];
85         }
86         p_src += i_input_stride;
87         p_dest += i_output_stride;
88     }
89 }
90
91 /*****************************************************************************
92  * DoWork: mix a new output buffer
93  *****************************************************************************/
94 static void DoWork( aout_instance_t * p_aout, aout_buffer_t * p_buffer )
95 {
96     aout_input_t * p_input = p_aout->pp_inputs[0];
97
98     if ( p_input->input.i_channels == p_aout->mixer.output.i_channels )
99     {
100         int i_nb_bytes = p_buffer->i_nb_samples * sizeof(u32)
101                           * p_input->input.i_channels;
102         byte_t * p_in = (p_input->p_first_byte_to_mix == NULL) ?
103                         p_input->fifo.p_first->p_buffer :
104                         p_input->p_first_byte_to_mix;
105         byte_t * p_out = p_buffer->p_buffer;
106
107         for ( ; ; )
108         {
109             ptrdiff_t i_available_bytes = (p_input->fifo.p_first->p_buffer
110                                            - p_in)
111                                            + p_input->fifo.p_first->i_nb_samples
112                                               * sizeof(u32)
113                                               * p_input->input.i_channels;
114
115             if ( i_available_bytes < i_nb_bytes )
116             {
117                 aout_buffer_t * p_old_buffer;
118
119                 if ( i_available_bytes > 0 )
120                     p_aout->p_vlc->pf_memcpy( p_out, p_in, i_available_bytes );
121                 i_nb_bytes -= i_available_bytes;
122                 p_out += i_available_bytes;
123
124                 /* Next buffer */
125                 p_old_buffer = aout_FifoPop( p_aout, &p_input->fifo );
126                 aout_BufferFree( p_old_buffer );
127                 if ( p_input->fifo.p_first == NULL )
128                 {
129                     msg_Err( p_aout, "internal amix error" );
130                     return;
131                 }
132                 p_in = p_input->fifo.p_first->p_buffer;
133             }
134             else
135             {
136                 p_aout->p_vlc->pf_memcpy( p_out, p_in, i_nb_bytes );
137                 p_input->p_first_byte_to_mix = p_in + i_nb_bytes;
138                 break;
139             }
140         }
141     }
142     else
143     {
144         /* Downmixing or upmixing. */
145         int i_nb_samples = p_buffer->i_nb_samples;
146         u32 * p_in = (p_input->p_first_byte_to_mix == NULL) ?
147                      (u32 *)p_input->fifo.p_first->p_buffer :
148                      (u32 *)p_input->p_first_byte_to_mix;
149         u32 * p_out = (u32 *)p_buffer->p_buffer;
150
151
152         if ( p_input->input.i_channels < p_aout->mixer.output.i_channels )
153         {
154             /* Zero out the destination buffer, to avoid static on unavailable
155              * channels. */
156             memset( p_buffer->p_buffer, 0,
157                     p_buffer->i_nb_samples * sizeof(u32)
158                      * p_aout->mixer.output.i_channels );
159         }
160
161         for ( ; ; )
162         {
163             ptrdiff_t i_available_bytes = (p_input->fifo.p_first->p_buffer
164                                            - (byte_t *)p_in)
165                                            + p_input->fifo.p_first->i_nb_samples
166                                               * sizeof(u32)
167                                               * p_input->input.i_channels;
168             int i_available_samples = i_available_bytes
169                                        / p_input->input.i_channels
170                                        / sizeof(u32);
171
172             if ( i_available_samples < i_nb_samples )
173             {
174                 aout_buffer_t * p_old_buffer;
175
176                 if ( i_available_samples > 0 )
177                     SparseCopy( p_out, p_in, i_available_samples,
178                                 p_aout->mixer.output.i_channels,
179                                 p_input->input.i_channels );
180                 i_nb_samples -= i_available_samples;
181                 p_out += i_available_samples * p_aout->mixer.output.i_channels;
182
183                 /* Next buffer */
184                 p_old_buffer = aout_FifoPop( p_aout, &p_input->fifo );
185                 aout_BufferFree( p_old_buffer );
186                 if ( p_input->fifo.p_first == NULL )
187                 {
188                     msg_Err( p_aout, "internal amix error" );
189                     return;
190                 }
191                 p_in = (u32 *)p_input->fifo.p_first->p_buffer;
192             }
193             else
194             {
195                 SparseCopy( p_out, p_in, i_nb_samples,
196                             p_aout->mixer.output.i_channels,
197                             p_input->input.i_channels );
198                 p_input->p_first_byte_to_mix = (byte_t *)p_in
199                                + i_nb_samples * p_input->input.i_channels
200                                   * sizeof(u32);
201                 break;
202             }
203         }
204     }
205 }
206