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* Support little endian streams on Big endian output. In theory at least, the Mendels...
[vlc] / modules / audio_filter / converter / dtstospdif.c
1 /*****************************************************************************
2  * dtstospdif.c : encapsulates DTS frames into S/PDIF packets
3  *****************************************************************************
4  * Copyright (C) 2003 the VideoLAN team
5  * $Id$
6  *
7  * Authors: Jon Lech Johansen <jon-vl@nanocrew.net>
8  *
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.
13  * 
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.
18  *
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  *****************************************************************************/
23
24 /*****************************************************************************
25  * Preamble
26  *****************************************************************************/
27 #include <stdlib.h>                                      /* malloc(), free() */
28 #include <string.h>
29
30 #include <vlc/vlc.h>
31
32 #ifdef HAVE_UNISTD_H
33 #   include <unistd.h>
34 #endif
35
36 #include "audio_output.h"
37 #include "aout_internal.h"
38
39 /*****************************************************************************
40  * Local structures
41  *****************************************************************************/
42 struct aout_filter_sys_t
43 {
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
46      * send. */
47
48     uint8_t *p_buf;
49
50     mtime_t start_date;
51
52     int i_frames;
53     unsigned int i_frame_size;
54 };
55
56 /*****************************************************************************
57  * Local prototypes
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 *,
62                         aout_buffer_t * );
63
64 /*****************************************************************************
65  * Module descriptor
66  *****************************************************************************/
67 vlc_module_begin();
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 );
73 vlc_module_end();
74
75 /*****************************************************************************
76  * Create:
77  *****************************************************************************/
78 static int Create( vlc_object_t *p_this )
79 {
80     aout_filter_t * p_filter = (aout_filter_t *)p_this;
81
82     if( p_filter->input.i_format != VLC_FOURCC('d','t','s',' ') ||
83         ( p_filter->output.i_format != VLC_FOURCC('s','p','d','i') &&
84           p_filter->output.i_format != VLC_FOURCC('s','p','d','b') ) )
85     {
86         return -1;
87     }
88
89     /* Allocate the memory needed to store the module's structure */
90     p_filter->p_sys = malloc( sizeof(struct aout_filter_sys_t) );
91     if( p_filter->p_sys == NULL )
92     {
93         msg_Err( p_filter, "out of memory" );
94         return VLC_ENOMEM;
95     }
96     memset( p_filter->p_sys, 0, sizeof(struct aout_filter_sys_t) );
97     p_filter->p_sys->p_buf = 0;
98
99     p_filter->pf_do_work = DoWork;
100     p_filter->b_in_place = 1;
101
102     return 0;
103 }
104
105 /*****************************************************************************
106  * Close: free our resources
107  *****************************************************************************/
108 static void Close( vlc_object_t * p_this )
109 {
110     aout_filter_t * p_filter = (aout_filter_t *)p_this;
111     if( p_filter->p_sys->i_frame_size ) free( p_filter->p_sys->p_buf );
112     free( p_filter->p_sys );
113 }
114
115 /*****************************************************************************
116  * DoWork: convert a buffer
117  *****************************************************************************/
118 static void DoWork( aout_instance_t * p_aout, aout_filter_t * p_filter,
119                     aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
120 {
121     uint32_t i_ac5_spdif_type = 0;
122     uint16_t i_fz = p_in_buf->i_nb_samples * 4;
123     uint16_t i_frame, i_length = p_in_buf->i_nb_bytes;
124     static const uint8_t p_sync_le[6] = { 0x72, 0xF8, 0x1F, 0x4E, 0x00, 0x00 };
125     static const uint8_t p_sync_be[6] = { 0xF8, 0x72, 0x4E, 0x1F, 0x00, 0x00 };
126
127     if( p_in_buf->i_nb_bytes != p_filter->p_sys->i_frame_size )
128     {
129         /* Frame size changed, reset everything */
130         p_filter->p_sys->i_frame_size = p_in_buf->i_nb_bytes;
131         p_filter->p_sys->p_buf = realloc( p_filter->p_sys->p_buf,
132                                           p_in_buf->i_nb_bytes * 3 );
133         p_filter->p_sys->i_frames = 0;
134     }
135
136     /* Backup frame */
137     p_filter->p_vlc->pf_memcpy( p_filter->p_sys->p_buf + p_in_buf->i_nb_bytes *
138                                 p_filter->p_sys->i_frames, p_in_buf->p_buffer,
139                                 p_in_buf->i_nb_bytes );
140
141     p_filter->p_sys->i_frames++;
142
143     if( p_filter->p_sys->i_frames < 3 )
144     {
145         if( !p_filter->p_sys->i_frames )
146             /* We'll need the starting date */
147             p_filter->p_sys->start_date = p_in_buf->start_date;
148
149         /* Not enough data */
150         p_out_buf->i_nb_samples = 0;
151         p_out_buf->i_nb_bytes = 0;
152         return;
153     }
154
155     p_filter->p_sys->i_frames = 0;
156
157     for( i_frame = 0; i_frame < 3; i_frame++ )
158     {
159         byte_t * p_out = p_out_buf->p_buffer + (i_frame * i_fz);
160         byte_t * p_in = p_filter->p_sys->p_buf + (i_frame * i_length);
161
162         switch( p_in_buf->i_nb_samples )
163         {
164             case  512: i_ac5_spdif_type = 0x0B; break;
165             case 1024: i_ac5_spdif_type = 0x0C; break;
166             case 2048: i_ac5_spdif_type = 0x0D; break;
167         }
168
169         /* Copy the S/PDIF headers. */
170         if( p_filter->output.i_format == VLC_FOURCC('s','p','d','b') )
171         {
172             p_filter->p_vlc->pf_memcpy( p_out, p_sync_be, 6 );
173             p_out[5] = i_ac5_spdif_type;
174             p_out[6] = (( i_length ) >> 5 ) & 0xFF;
175             p_out[7] = ( i_length << 3 ) & 0xFF;
176         }
177         else
178         {
179             p_filter->p_vlc->pf_memcpy( p_out, p_sync_le, 6 );
180             p_out[4] = i_ac5_spdif_type;
181             p_out[6] = ( i_length << 3 ) & 0xFF;
182             p_out[7] = (( i_length ) >> 5 ) & 0xFF;
183         }
184
185         if( ( (p_in[0] == 0x1F || p_in[0] == 0x7F) && p_filter->output.i_format == VLC_FOURCC('s','p','d','i') ) ||
186             ( (p_in[0] == 0xFF || p_in[0] == 0xFE) && p_filter->output.i_format == VLC_FOURCC('s','p','d','b') ) )
187         {
188             /* We are dealing with a big endian bitstream and a little endian output
189              * or a little endian bitstream and a big endian output.
190              * Byteswap the stream */
191 #ifdef HAVE_SWAB
192             swab( p_in, p_out + 8, i_length );
193 #else
194             uint16_t i;
195             byte_t * p_tmp, tmp;
196             p_tmp = p_out + 8;
197             for( i = i_length / 2 ; i-- ; )
198             {
199                 tmp = p_in[0]; /* in-place filter */
200                 p_tmp[0] = p_in[1];
201                 p_tmp[1] = tmp;
202                 p_tmp += 2; p_in += 2;
203             }
204 #endif
205         }
206         else
207         {
208             p_filter->p_vlc->pf_memcpy( p_out + 8, p_in, i_length );
209         }
210
211         if( i_fz > i_length + 8 )
212         {
213             p_filter->p_vlc->pf_memset( p_out + 8 + i_length, 0,
214                                         i_fz - i_length - 8 );
215         }
216     }
217
218     p_out_buf->start_date = p_filter->p_sys->start_date;
219     p_out_buf->i_nb_samples = p_in_buf->i_nb_samples * 3;
220     p_out_buf->i_nb_bytes = p_out_buf->i_nb_samples * 4;
221 }