1 /*****************************************************************************
2 * s16tofloat32.c : converter from signed 16 bits integer to float32
3 * with endianness change
4 *****************************************************************************
5 * Copyright (C) 2002 VideoLAN
6 * $Id: s16tofloat32swab.c,v 1.2 2002/09/18 12:20:37 sam Exp $
8 * Authors: Samuel Hocevar <sam@zoy.org>
9 * Henri Fallon <henri@videolan.org>
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
24 *****************************************************************************/
26 /*****************************************************************************
28 *****************************************************************************/
30 #include <stdlib.h> /* malloc(), free() */
39 #include "audio_output.h"
40 #include "aout_internal.h"
42 /*****************************************************************************
44 *****************************************************************************/
45 static int Create ( vlc_object_t * );
47 static void DoWork ( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
50 /*****************************************************************************
52 *****************************************************************************/
55 _("audio filter for s16->float32 with endianness conversion") );
56 set_capability( "audio filter", 1 );
57 set_callbacks( Create, NULL );
60 /*****************************************************************************
61 * Create: allocate trivial mixer
62 *****************************************************************************
63 * This function allocates and initializes a Crop vout method.
64 *****************************************************************************/
65 static int Create( vlc_object_t *p_this )
67 aout_filter_t * p_filter = (aout_filter_t *)p_this;
69 if ( !AOUT_FMTS_SIMILAR( &p_filter->input, &p_filter->output ) )
74 if ( (p_filter->input.i_format == AOUT_FMT_S16_LE ||
75 p_filter->input.i_format == AOUT_FMT_S16_BE)
76 && p_filter->output.i_format == AOUT_FMT_FLOAT32
77 && p_filter->input.i_format != AOUT_FMT_S16_NE )
79 p_filter->pf_do_work = DoWork;
80 p_filter->b_in_place = VLC_TRUE;
88 /*****************************************************************************
89 * DoWork: convert a buffer
90 *****************************************************************************/
91 static void DoWork( aout_instance_t * p_aout, aout_filter_t * p_filter,
92 aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
94 int i = p_in_buf->i_nb_samples * p_filter->input.i_channels;
96 /* We start from the end because b_in_place is true */
97 s16 * p_in = (s16 *)p_in_buf->p_buffer + i - 1;
98 float * p_out = (float *)p_out_buf->p_buffer + i - 1;
101 s16 * p_swabbed = malloc( i * sizeof(s16) );
102 swab( p_in_buf->p_buffer, p_swabbed, i * sizeof(s16) );
104 p_in = p_swabbed + i - 1;
112 p_tmp[0] = ((byte_t*)p_in)[1];
113 p_tmp[1] = ((byte_t*)p_in)[0];
114 *p_out = (float)*p_tmp / 32768.0;
116 *p_out = (float)*p_in / 32768.0;
125 p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
126 p_out_buf->i_nb_bytes = p_in_buf->i_nb_bytes * 2;