1 /*****************************************************************************
2 * dtstospdif.c : encapsulates DTS frames into S/PDIF packets
3 *****************************************************************************
4 * Copyright (C) 2003 the VideoLAN team
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
53 unsigned int i_frame_size;
56 /*****************************************************************************
58 *****************************************************************************/
59 static int Create ( vlc_object_t * );
60 static void Close ( vlc_object_t * );
61 static void DoWork ( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
64 /*****************************************************************************
66 *****************************************************************************/
68 set_category( CAT_AUDIO );
69 set_subcategory( SUBCAT_AUDIO_MISC );
70 set_description( _("audio filter for DTS->S/PDIF encapsulation") );
71 set_capability( "audio filter", 10 );
72 set_callbacks( Create, Close );
75 /*****************************************************************************
77 *****************************************************************************/
78 static int Create( vlc_object_t *p_this )
80 aout_filter_t * p_filter = (aout_filter_t *)p_this;
82 if ( p_filter->input.i_format != VLC_FOURCC('d','t','s',' ')
83 || p_filter->output.i_format != VLC_FOURCC('s','p','d','i') )
88 /* Allocate the memory needed to store the module's structure */
89 p_filter->p_sys = malloc( sizeof(struct aout_filter_sys_t) );
90 if( p_filter->p_sys == NULL )
92 msg_Err( p_filter, "out of memory" );
95 memset( p_filter->p_sys, 0, sizeof(struct aout_filter_sys_t) );
96 p_filter->p_sys->p_buf = 0;
98 p_filter->pf_do_work = DoWork;
99 p_filter->b_in_place = 1;
104 /*****************************************************************************
105 * Close: free our resources
106 *****************************************************************************/
107 static void Close( vlc_object_t * p_this )
109 aout_filter_t * p_filter = (aout_filter_t *)p_this;
110 if( p_filter->p_sys->i_frame_size ) free( p_filter->p_sys->p_buf );
111 free( p_filter->p_sys );
114 /*****************************************************************************
115 * DoWork: convert a buffer
116 *****************************************************************************/
117 static void DoWork( aout_instance_t * p_aout, aout_filter_t * p_filter,
118 aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
120 uint16_t i_fz = p_in_buf->i_nb_samples * 4;
121 uint16_t i_frame, i_length = p_in_buf->i_nb_bytes;
122 static const uint8_t p_sync[6] = { 0x72, 0xF8, 0x1F, 0x4E, 0x00, 0x00 };
124 if( p_in_buf->i_nb_bytes != p_filter->p_sys->i_frame_size )
126 /* Frame size changed, reset everything */
127 p_filter->p_sys->i_frame_size = p_in_buf->i_nb_bytes;
128 p_filter->p_sys->p_buf = realloc( p_filter->p_sys->p_buf,
129 p_in_buf->i_nb_bytes * 3 );
130 p_filter->p_sys->i_frames = 0;
134 p_filter->p_vlc->pf_memcpy( p_filter->p_sys->p_buf + p_in_buf->i_nb_bytes *
135 p_filter->p_sys->i_frames, p_in_buf->p_buffer,
136 p_in_buf->i_nb_bytes );
138 p_filter->p_sys->i_frames++;
140 if( p_filter->p_sys->i_frames < 3 )
142 if( !p_filter->p_sys->i_frames )
143 /* We'll need the starting date */
144 p_filter->p_sys->start_date = p_in_buf->start_date;
146 /* Not enough data */
147 p_out_buf->i_nb_samples = 0;
148 p_out_buf->i_nb_bytes = 0;
152 p_filter->p_sys->i_frames = 0;
154 for( i_frame = 0; i_frame < 3; i_frame++ )
156 byte_t * p_out = p_out_buf->p_buffer + (i_frame * i_fz);
157 byte_t * p_in = p_filter->p_sys->p_buf + (i_frame * i_length);
159 /* Copy the S/PDIF headers. */
160 memcpy( p_out, p_sync, 6 );
162 switch( p_in_buf->i_nb_samples )
164 case 512: *(p_out + 4) = 0x0B; break;
165 case 1024: *(p_out + 4) = 0x0C; break;
166 case 2048: *(p_out + 4) = 0x0D; break;
169 *(p_out + 6) = (i_length * 8) & 0xff;
170 *(p_out + 7) = (i_length * 8) >> 8;
172 if( p_in[0] == 0x1f || p_in[0] == 0x7f )
174 /* We are dealing with a big endian bitstream.
175 * Convert to little endian */
177 swab( p_in, p_out + 8, i_length );
182 for( i = i_length / 2 ; i-- ; )
184 tmp = p_in[0]; /* in-place filter */
187 p_tmp += 2; p_in += 2;
194 memcpy( p_out + 8, p_in, i_length );
197 if( i_fz > i_length + 8 )
199 p_filter->p_vlc->pf_memset( p_out + 8 + i_length, 0,
200 i_fz - i_length - 8 );
204 p_out_buf->start_date = p_filter->p_sys->start_date;
205 p_out_buf->i_nb_samples = p_in_buf->i_nb_samples * 3;
206 p_out_buf->i_nb_bytes = p_out_buf->i_nb_samples * 4;