1 /*****************************************************************************
2 * dtstospdif.c : encapsulates DTS frames into S/PDIF packets
3 *****************************************************************************
4 * Copyright (C) 2003 VideoLAN
5 * $Id: dtstospdif.c,v 1.1 2003/03/09 20:07:47 jlj Exp $
7 * Authors: Jon Lech Johansen <jon-vl@nanocrew.net>
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 *****************************************************************************/
27 #include <stdlib.h> /* malloc(), free() */
36 #include "audio_output.h"
37 #include "aout_internal.h"
39 /*****************************************************************************
41 *****************************************************************************/
42 static int Create ( vlc_object_t * );
43 static void DoWork ( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
46 /*****************************************************************************
48 *****************************************************************************/
50 set_description( _("audio filter for DTS->S/PDIF encapsulation") );
51 set_capability( "audio filter", 10 );
52 set_callbacks( Create, NULL );
55 /*****************************************************************************
57 *****************************************************************************/
58 static int Create( vlc_object_t *p_this )
60 aout_filter_t * p_filter = (aout_filter_t *)p_this;
62 if ( p_filter->input.i_format != VLC_FOURCC('d','t','s',' ')
63 || p_filter->output.i_format != VLC_FOURCC('s','p','d','i') )
68 p_filter->pf_do_work = DoWork;
69 p_filter->b_in_place = 0;
74 /*****************************************************************************
75 * DoWork: convert a buffer
76 *****************************************************************************/
77 static void DoWork( aout_instance_t * p_aout, aout_filter_t * p_filter,
78 aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
80 uint16_t i_fz = (p_in_buf->i_nb_samples / 3) * 4;
81 uint16_t i_frame, i_length = p_in_buf->i_nb_bytes / 3;
82 static const uint8_t p_sync[6] = { 0x72, 0xF8, 0x1F, 0x4E, 0x00, 0x00 };
84 for( i_frame = 0; i_frame < 3; i_frame++ )
90 byte_t * p_out = p_out_buf->p_buffer + (i_frame * i_fz);
91 byte_t * p_in = p_in_buf->p_buffer + (i_frame * i_length);
93 /* Copy the S/PDIF headers. */
94 memcpy( p_out, p_sync, 6 );
96 switch( p_in_buf->i_nb_samples / 3 )
98 case 512: *(p_out + 4) = 0x0B; break;
99 case 1024: *(p_out + 4) = 0x0C; break;
100 case 2048: *(p_out + 4) = 0x0D; break;
103 *(p_out + 6) = (i_length * 8) & 0xff;
104 *(p_out + 7) = (i_length * 8) >> 8;
107 swab( p_in, p_out + 8, i_length );
110 for( i = i_length / 2 ; i-- ; )
114 p_tmp += 2; p_in += 2;
118 p_filter->p_vlc->pf_memset( p_out + 8 + i_length, 0,
119 i_fz - i_length - 8 );
122 p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
123 p_out_buf->i_nb_bytes = p_out_buf->i_nb_samples * 4;