1 /*****************************************************************************
2 * dtstospdif.c : encapsulates DTS frames into S/PDIF packets
3 *****************************************************************************
4 * Copyright (C) 2003, 2006 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., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
22 *****************************************************************************/
24 /*****************************************************************************
26 *****************************************************************************/
31 #include <vlc_common.h>
32 #include <vlc_plugin.h>
41 /*****************************************************************************
43 *****************************************************************************/
44 struct aout_filter_sys_t
46 /* 3 DTS frames have to be packed into an S/PDIF frame.
47 * We accumulate DTS frames from the decoder until we have enough to
55 unsigned int i_frame_size;
58 /*****************************************************************************
60 *****************************************************************************/
61 static int Create ( vlc_object_t * );
62 static void Close ( vlc_object_t * );
63 static void DoWork ( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
66 /*****************************************************************************
68 *****************************************************************************/
70 set_category( CAT_AUDIO )
71 set_subcategory( SUBCAT_AUDIO_MISC )
72 set_description( N_("Audio filter for DTS->S/PDIF encapsulation") )
73 set_capability( "audio filter", 10 )
74 set_callbacks( Create, Close )
77 /*****************************************************************************
79 *****************************************************************************/
80 static int Create( vlc_object_t *p_this )
82 aout_filter_t * p_filter = (aout_filter_t *)p_this;
84 if( p_filter->input.i_format != VLC_CODEC_DTS ||
85 ( p_filter->output.i_format != VLC_CODEC_SPDIFL &&
86 p_filter->output.i_format != VLC_CODEC_SPDIFB ) )
91 /* Allocate the memory needed to store the module's structure */
92 p_filter->p_sys = calloc( 1, sizeof(struct aout_filter_sys_t) );
93 if( !p_filter->p_sys )
96 p_filter->pf_do_work = DoWork;
97 p_filter->b_in_place = 1;
102 /*****************************************************************************
103 * Close: free our resources
104 *****************************************************************************/
105 static void Close( vlc_object_t * p_this )
107 aout_filter_t * p_filter = (aout_filter_t *)p_this;
108 if( p_filter->p_sys->i_frame_size ) free( p_filter->p_sys->p_buf );
109 free( p_filter->p_sys );
112 /*****************************************************************************
113 * DoWork: convert a buffer
114 *****************************************************************************/
115 static void DoWork( aout_instance_t * p_aout, aout_filter_t * p_filter,
116 aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
118 uint32_t i_ac5_spdif_type = 0;
119 uint16_t i_fz = p_in_buf->i_nb_samples * 4;
120 uint16_t i_frame, i_length = p_in_buf->i_nb_bytes;
121 static const uint8_t p_sync_le[6] = { 0x72, 0xF8, 0x1F, 0x4E, 0x00, 0x00 };
122 static const uint8_t p_sync_be[6] = { 0xF8, 0x72, 0x4E, 0x1F, 0x00, 0x00 };
124 if( p_in_buf->i_nb_bytes != p_filter->p_sys->i_frame_size )
126 /* Frame size changed, reset everything */
127 msg_Warn( p_aout, "Frame size changed from %u to %u, "
128 "resetting everything.",
129 p_filter->p_sys->i_frame_size,
130 (unsigned)p_in_buf->i_nb_bytes );
132 p_filter->p_sys->i_frame_size = p_in_buf->i_nb_bytes;
133 p_filter->p_sys->p_buf = realloc( p_filter->p_sys->p_buf,
134 p_in_buf->i_nb_bytes * 3 );
135 p_filter->p_sys->i_frames = 0;
139 vlc_memcpy( p_filter->p_sys->p_buf + p_in_buf->i_nb_bytes *
140 p_filter->p_sys->i_frames,
141 p_in_buf->p_buffer, p_in_buf->i_nb_bytes );
143 p_filter->p_sys->i_frames++;
145 if( p_filter->p_sys->i_frames < 3 )
147 if( p_filter->p_sys->i_frames == 1 )
148 /* We'll need the starting date */
149 p_filter->p_sys->start_date = p_in_buf->i_pts;
151 /* Not enough data */
152 p_out_buf->i_nb_samples = 0;
153 p_out_buf->i_nb_bytes = 0;
157 p_filter->p_sys->i_frames = 0;
159 for( i_frame = 0; i_frame < 3; i_frame++ )
161 uint16_t i_length_padded = i_length;
162 uint8_t * p_out = p_out_buf->p_buffer + (i_frame * i_fz);
163 uint8_t * p_in = p_filter->p_sys->p_buf + (i_frame * i_length);
165 switch( p_in_buf->i_nb_samples )
167 case 512: i_ac5_spdif_type = 0x0B; break;
168 case 1024: i_ac5_spdif_type = 0x0C; break;
169 case 2048: i_ac5_spdif_type = 0x0D; break;
172 /* Copy the S/PDIF headers. */
173 if( p_filter->output.i_format == VLC_CODEC_SPDIFB )
175 vlc_memcpy( p_out, p_sync_be, 6 );
176 p_out[5] = i_ac5_spdif_type;
177 p_out[6] = (( i_length ) >> 5 ) & 0xFF;
178 p_out[7] = ( i_length << 3 ) & 0xFF;
182 vlc_memcpy( p_out, p_sync_le, 6 );
183 p_out[4] = i_ac5_spdif_type;
184 p_out[6] = ( i_length << 3 ) & 0xFF;
185 p_out[7] = (( i_length ) >> 5 ) & 0xFF;
188 if( ( (p_in[0] == 0x1F || p_in[0] == 0x7F) && p_filter->output.i_format == VLC_CODEC_SPDIFL ) ||
189 ( (p_in[0] == 0xFF || p_in[0] == 0xFE) && p_filter->output.i_format == VLC_CODEC_SPDIFB ) )
191 /* We are dealing with a big endian bitstream and a little endian output
192 * or a little endian bitstream and a big endian output.
193 * Byteswap the stream */
194 swab( p_in, p_out + 8, i_length );
196 /* If i_length is odd, we have to adjust swapping a bit.. */
199 p_out[8+i_length-1] = 0;
200 p_out[8+i_length] = p_in[i_length-1];
206 vlc_memcpy( p_out + 8, p_in, i_length );
209 if( i_fz > i_length + 8 )
211 vlc_memset( p_out + 8 + i_length_padded, 0,
212 i_fz - i_length_padded - 8 );
216 p_out_buf->i_pts = p_filter->p_sys->start_date;
217 p_out_buf->i_nb_samples = p_in_buf->i_nb_samples * 3;
218 p_out_buf->i_nb_bytes = p_out_buf->i_nb_samples * 4;