1 /*****************************************************************************
2 * dtstospdif.c : encapsulates DTS frames into S/PDIF packets
3 *****************************************************************************
4 * Copyright (C) 2003 VideoLAN
5 * $Id: dtstospdif.c,v 1.3 2004/02/04 23:03:36 gbazin 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 struct aout_filter_sys_t
44 /* 3 DTS frames have to be packed into an S/PDIF frame.
45 * We accumulate DTS frames from the decoder until we have enough to
51 unsigned int i_frame_size;
54 /*****************************************************************************
56 *****************************************************************************/
57 static int Create ( vlc_object_t * );
58 static void Close ( vlc_object_t * );
59 static void DoWork ( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
62 /*****************************************************************************
64 *****************************************************************************/
66 set_description( _("audio filter for DTS->S/PDIF encapsulation") );
67 set_capability( "audio filter", 10 );
68 set_callbacks( Create, Close );
71 /*****************************************************************************
73 *****************************************************************************/
74 static int Create( vlc_object_t *p_this )
76 aout_filter_t * p_filter = (aout_filter_t *)p_this;
78 if ( p_filter->input.i_format != VLC_FOURCC('d','t','s',' ')
79 || p_filter->output.i_format != VLC_FOURCC('s','p','d','i') )
84 /* Allocate the memory needed to store the module's structure */
85 p_filter->p_sys = malloc( sizeof(struct aout_filter_sys_t) );
86 if( p_filter->p_sys == NULL )
88 msg_Err( p_filter, "out of memory" );
91 memset( p_filter->p_sys, 0, sizeof(struct aout_filter_sys_t) );
92 p_filter->p_sys->p_buf = 0;
94 p_filter->pf_do_work = DoWork;
95 p_filter->b_in_place = 1;
100 /*****************************************************************************
101 * Close: free our resources
102 *****************************************************************************/
103 static void Close( vlc_object_t * p_this )
105 aout_filter_t * p_filter = (aout_filter_t *)p_this;
106 if( p_filter->p_sys->i_frame_size ) free( p_filter->p_sys->p_buf );
107 free( p_filter->p_sys );
110 /*****************************************************************************
111 * DoWork: convert a buffer
112 *****************************************************************************/
113 static void DoWork( aout_instance_t * p_aout, aout_filter_t * p_filter,
114 aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
116 uint16_t i_fz = p_in_buf->i_nb_samples * 4;
117 uint16_t i_frame, i_length = p_in_buf->i_nb_bytes;
118 static const uint8_t p_sync[6] = { 0x72, 0xF8, 0x1F, 0x4E, 0x00, 0x00 };
120 if( p_in_buf->i_nb_bytes != p_filter->p_sys->i_frame_size )
122 /* Frame size changed, reset everything */
123 p_filter->p_sys->i_frame_size = p_in_buf->i_nb_bytes;
124 p_filter->p_sys->p_buf = realloc( p_filter->p_sys->p_buf,
125 p_in_buf->i_nb_bytes * 3 );
126 p_filter->p_sys->i_frames = 0;
130 p_filter->p_vlc->pf_memcpy( p_filter->p_sys->p_buf + p_in_buf->i_nb_bytes *
131 p_filter->p_sys->i_frames, p_in_buf->p_buffer,
132 p_in_buf->i_nb_bytes );
134 p_filter->p_sys->i_frames++;
136 if( p_filter->p_sys->i_frames < 3 )
138 /* Not enough data */
139 p_out_buf->i_nb_samples = 0;
140 p_out_buf->i_nb_bytes = 0;
144 p_filter->p_sys->i_frames = 0;
146 for( i_frame = 0; i_frame < 3; i_frame++ )
152 byte_t * p_out = p_out_buf->p_buffer + (i_frame * i_fz);
153 byte_t * p_in = p_filter->p_sys->p_buf + (i_frame * i_length);
155 /* Copy the S/PDIF headers. */
156 memcpy( p_out, p_sync, 6 );
158 switch( p_in_buf->i_nb_samples )
160 case 512: *(p_out + 4) = 0x0B; break;
161 case 1024: *(p_out + 4) = 0x0C; break;
162 case 2048: *(p_out + 4) = 0x0D; break;
165 *(p_out + 6) = (i_length * 8) & 0xff;
166 *(p_out + 7) = (i_length * 8) >> 8;
169 swab( p_in, p_out + 8, i_length );
172 for( i = i_length / 2 ; i-- ; )
176 p_tmp += 2; p_in += 2;
180 p_filter->p_vlc->pf_memset( p_out + 8 + i_length, 0,
181 i_fz - i_length - 8 );
184 p_out_buf->i_nb_samples = p_in_buf->i_nb_samples * 3;
185 p_out_buf->i_nb_bytes = p_out_buf->i_nb_samples * 4;