1 /*****************************************************************************
2 * trivial.c : trivial mixer plug-in (1 input, no downmixing)
3 *****************************************************************************
4 * Copyright (C) 2002 VideoLAN
5 * $Id: trivial.c,v 1.7 2002/09/20 23:27:03 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 )
74 aout_input_t * p_input = p_aout->pp_inputs[0];
75 int i_nb_bytes = p_buffer->i_nb_samples * sizeof(s32)
76 * p_aout->mixer.mixer.i_channels;
77 byte_t * p_in = p_input->p_first_byte_to_mix;
78 byte_t * p_out = p_buffer->p_buffer;
80 if ( p_input->b_error ) return;
84 ptrdiff_t i_available_bytes = (p_input->fifo.p_first->p_buffer
86 + p_input->fifo.p_first->i_nb_samples
88 * p_aout->mixer.mixer.i_channels;
90 if ( i_available_bytes < i_nb_bytes )
92 aout_buffer_t * p_old_buffer;
94 if ( i_available_bytes > 0 )
95 p_aout->p_vlc->pf_memcpy( p_out, p_in, i_available_bytes );
96 i_nb_bytes -= i_available_bytes;
97 p_out += i_available_bytes;
100 p_old_buffer = aout_FifoPop( p_aout, &p_input->fifo );
101 aout_BufferFree( p_old_buffer );
102 if ( p_input->fifo.p_first == NULL )
104 msg_Err( p_aout, "internal amix error" );
107 p_in = p_input->fifo.p_first->p_buffer;
111 if ( i_nb_bytes > 0 )
112 p_aout->p_vlc->pf_memcpy( p_out, p_in, i_nb_bytes );
113 p_input->p_first_byte_to_mix = p_in + i_nb_bytes;