1 /*****************************************************************************
2 * s16tofloat32swab.c : converter from signed 16 bits integer to float32
3 * with endianness change
4 *****************************************************************************
5 * Copyright (C) 2002-2006 the VideoLAN team
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., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
24 *****************************************************************************/
26 /*****************************************************************************
28 *****************************************************************************/
29 #include <stdlib.h> /* malloc(), free() */
42 #include "audio_output.h"
43 #include "aout_internal.h"
45 /*****************************************************************************
47 *****************************************************************************/
48 static int Create ( vlc_object_t * );
50 static void DoWork ( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
52 static void DoWork24 ( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
55 /*****************************************************************************
57 *****************************************************************************/
59 set_category( CAT_AUDIO );
60 set_subcategory( SUBCAT_AUDIO_MISC );
62 _("Audio filter for s16->float32 with endianness conversion") );
63 set_capability( "audio filter", 1 );
64 set_callbacks( Create, NULL );
67 /*****************************************************************************
68 * Create: allocate trivial mixer
69 *****************************************************************************
70 * This function allocates and initializes a Crop vout method.
71 *****************************************************************************/
72 static int Create( vlc_object_t *p_this )
74 aout_filter_t * p_filter = (aout_filter_t *)p_this;
76 if ( !AOUT_FMTS_SIMILAR( &p_filter->input, &p_filter->output ) )
81 if ( (p_filter->input.i_format == VLC_FOURCC('s','1','6','l') ||
82 p_filter->input.i_format == VLC_FOURCC('s','1','6','b'))
83 && p_filter->output.i_format == VLC_FOURCC('f','l','3','2')
84 && p_filter->input.i_format != AOUT_FMT_S16_NE )
86 p_filter->pf_do_work = DoWork;
87 p_filter->b_in_place = VLC_TRUE;
92 if ( (p_filter->input.i_format == VLC_FOURCC('s','2','4','l') ||
93 p_filter->input.i_format == VLC_FOURCC('s','2','4','b'))
94 && p_filter->output.i_format == VLC_FOURCC('f','l','3','2')
95 && p_filter->input.i_format != AOUT_FMT_S24_NE )
97 p_filter->pf_do_work = DoWork24;
98 p_filter->b_in_place = VLC_TRUE;
106 /*****************************************************************************
107 * DoWork: convert a buffer
108 *****************************************************************************/
109 static void DoWork( aout_instance_t * p_aout, aout_filter_t * p_filter,
110 aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
112 int i = p_in_buf->i_nb_samples * aout_FormatNbChannels( &p_filter->input );
114 /* We start from the end because b_in_place is true */
116 float * p_out = (float *)p_out_buf->p_buffer + i - 1;
120 int16_t * p_swabbed = alloca( i * sizeof(int16_t) );
122 int16_t * p_swabbed = malloc( i * sizeof(int16_t) );
125 swab( p_in_buf->p_buffer, (void *)p_swabbed, i * sizeof(int16_t) );
126 p_in = p_swabbed + i - 1;
130 p_in = (int16_t *)p_in_buf->p_buffer + i - 1;
136 p_tmp[0] = ((byte_t *)p_in)[1];
137 p_tmp[1] = ((byte_t *)p_in)[0];
138 *p_out = (float)( *(int16_t *)p_tmp ) / 32768.0;
140 *p_out = (float)*p_in / 32768.0;
151 p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
152 p_out_buf->i_nb_bytes = p_in_buf->i_nb_bytes * 2;
155 static void DoWork24( aout_instance_t * p_aout, aout_filter_t * p_filter,
156 aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
158 int i = p_in_buf->i_nb_samples * aout_FormatNbChannels( &p_filter->input );
160 /* We start from the end because b_in_place is true */
161 uint8_t * p_in = (uint8_t *)p_in_buf->p_buffer + (i - 1) * 3;
162 float * p_out = (float *)p_out_buf->p_buffer + i - 1;
172 #ifdef WORDS_BIGENDIAN
173 *p_out = ((float)( (((int32_t)*(int16_t *)(p_tmp)) << 8) + p_tmp[2]))
175 *p_out = ((float)( (((int32_t)*(int16_t *)(p_tmp+1)) << 8) + p_tmp[0]))
182 p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
183 p_out_buf->i_nb_bytes = p_in_buf->i_nb_bytes * 4 / 3;