1 /*****************************************************************************
2 * s16tofloat32swab.c : converter from signed 16 bits integer to float32
3 * with endianness change
4 *****************************************************************************
5 * Copyright (C) 2002 VideoLAN
6 * $Id: s16tofloat32swab.c,v 1.3 2002/09/20 23:27:03 massiot 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() */
43 #include "audio_output.h"
44 #include "aout_internal.h"
46 /*****************************************************************************
48 *****************************************************************************/
49 static int Create ( vlc_object_t * );
51 static void DoWork ( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
54 /*****************************************************************************
56 *****************************************************************************/
59 _("audio filter for s16->float32 with endianness conversion") );
60 set_capability( "audio filter", 1 );
61 set_callbacks( Create, NULL );
64 /*****************************************************************************
65 * Create: allocate trivial mixer
66 *****************************************************************************
67 * This function allocates and initializes a Crop vout method.
68 *****************************************************************************/
69 static int Create( vlc_object_t *p_this )
71 aout_filter_t * p_filter = (aout_filter_t *)p_this;
73 if ( !AOUT_FMTS_SIMILAR( &p_filter->input, &p_filter->output ) )
78 if ( (p_filter->input.i_format == AOUT_FMT_S16_LE ||
79 p_filter->input.i_format == AOUT_FMT_S16_BE)
80 && p_filter->output.i_format == AOUT_FMT_FLOAT32
81 && p_filter->input.i_format != AOUT_FMT_S16_NE )
83 p_filter->pf_do_work = DoWork;
84 p_filter->b_in_place = VLC_TRUE;
92 /*****************************************************************************
93 * DoWork: convert a buffer
94 *****************************************************************************/
95 static void DoWork( aout_instance_t * p_aout, aout_filter_t * p_filter,
96 aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
98 int i = p_in_buf->i_nb_samples * p_filter->input.i_channels;
100 /* We start from the end because b_in_place is true */
102 float * p_out = (float *)p_out_buf->p_buffer + i - 1;
105 s16 * p_swabbed = alloca( i * sizeof(s16) );
106 swab( p_in_buf->p_buffer, p_swabbed, i * sizeof(s16) );
107 p_in = p_swabbed + i - 1;
110 p_in = (s16 *)p_in_buf->p_buffer + i - 1;
116 p_tmp[0] = ((byte_t *)p_in)[1];
117 p_tmp[1] = ((byte_t *)p_in)[0];
118 *p_out = (float)*( *(s16 *)p_tmp ) / 32768.0;
120 *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;