1 /*****************************************************************************
2 * trivial.c : trivial mixer plug-in (1 input, no downmixing)
3 *****************************************************************************
4 * Copyright (C) 2002 VideoLAN
5 * $Id: trivial.c,v 1.8 2002/09/28 13:05:16 massiot Exp $
7 * Authors: Christophe Massiot <massiot@via.ecp.fr>
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.
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.
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 *****************************************************************************/
24 /*****************************************************************************
26 *****************************************************************************/
28 #include <stdlib.h> /* malloc(), free() */
32 #include "audio_output.h"
33 #include "aout_internal.h"
35 /*****************************************************************************
37 *****************************************************************************/
38 static int Create ( vlc_object_t * );
40 static void DoWork ( aout_instance_t *, aout_buffer_t * );
42 /*****************************************************************************
44 *****************************************************************************/
46 set_description( _("trivial audio mixer module") );
47 set_capability( "audio mixer", 1 );
48 set_callbacks( Create, NULL );
51 /*****************************************************************************
52 * Create: allocate trivial mixer
53 *****************************************************************************/
54 static int Create( vlc_object_t *p_this )
56 aout_instance_t * p_aout = (aout_instance_t *)p_this;
58 if ( p_aout->mixer.mixer.i_format != AOUT_FMT_FLOAT32
59 && p_aout->mixer.mixer.i_format != AOUT_FMT_FIXED32 )
64 p_aout->mixer.pf_do_work = DoWork;
69 /*****************************************************************************
70 * DoWork: mix a new output buffer
71 *****************************************************************************/
72 static void DoWork( aout_instance_t * p_aout, aout_buffer_t * p_buffer )
75 aout_input_t * p_input = p_aout->pp_inputs[i];
76 int i_nb_bytes = p_buffer->i_nb_samples * sizeof(s32)
77 * p_aout->mixer.mixer.i_channels;
81 while ( p_input->b_error )
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. */
87 p_in = p_input->p_first_byte_to_mix;
88 p_out = p_buffer->p_buffer;
92 ptrdiff_t i_available_bytes = (p_input->fifo.p_first->p_buffer
94 + p_input->fifo.p_first->i_nb_samples
96 * p_aout->mixer.mixer.i_channels;
98 if ( i_available_bytes < i_nb_bytes )
100 aout_buffer_t * p_old_buffer;
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;
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 )
112 msg_Err( p_aout, "internal amix error" );
115 p_in = p_input->fifo.p_first->p_buffer;
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;
126 /* Empty other FIFOs to avoid a memory leak. */
127 for ( i++; i < p_aout->i_nb_inputs; i++ )
129 aout_fifo_t * p_fifo;
130 aout_buffer_t * p_deleted;
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 )
138 aout_buffer_t * p_next = p_deleted->p_next;
139 aout_BufferFree( p_deleted );
142 p_fifo->p_first = NULL;
143 p_fifo->pp_last = &p_fifo->p_first;