1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
|
/* GStreamer
* Copyright (C) 2003 Martin Soto <martinsoto@users.sourceforge.net>
*
* ac3_padder.h: Pad AC3 frames for use with an SPDIF interface.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifndef AC3_PADDER_INC
#define AC3_PADDER_INC
#include <glib.h>
/* Size of an IEC958 padded AC3 frame. */
#define AC3P_IEC_FRAME_SIZE 6144
/* Size of the IEC958 header. */
#define AC3P_IEC_HEADER_SIZE 8
/* Size of the AC3 header. */
#define AC3P_AC3_HEADER_SIZE 7
/* An IEC958 padded AC3 frame. */
typedef struct {
/* IEC header. */
guchar header[AC3P_IEC_HEADER_SIZE];
/* Begin of AC3 header. */
guchar sync_byte1;
guchar sync_byte2;
guchar crc1[2];
guchar code;
guchar bsidmod;
guchar acmod;
/* End of AC3 header. */
unsigned char data[AC3P_IEC_FRAME_SIZE - AC3P_IEC_HEADER_SIZE
- AC3P_AC3_HEADER_SIZE];
} ac3p_iec958_burst_frame;
/* Possible states for the reading automaton: */
/* Searching for sync byte 1. */
#define AC3P_STATE_SYNC1 1
/* Searching for sync byte 2. */
#define AC3P_STATE_SYNC2 2
/* Reading AC3 header. */
#define AC3P_STATE_HEADER 3
/* Reading packet contents.*/
#define AC3P_STATE_CONTENT 4
/* Events generated by the parse function: */
/* The parser needs new data to be pushed. */
#define AC3P_EVENT_PUSH 1
/* There is a new padded frame ready to read from the padder structure. */
#define AC3P_EVENT_FRAME 2
/* The internal state for the padder. */
typedef struct {
guint state; /* State of the reading automaton. */
guchar *in_ptr; /* Input pointer, marking the current
postion in the input buffer. */
guint remaining; /* The number of bytes remaining in the current
reading buffer. */
guchar *out_ptr; /* Output pointer, marking the current
position in the output frame. */
guint bytes_to_copy;
/* Number of bytes that still must be copied
to the output frame *during this reading
stage*. */
guint ac3_frame_size;
/* The size in bytes of the pure AC3 portion
of the current frame. */
ac3p_iec958_burst_frame frame;
/* The current output frame. */
} ac3_padder;
extern void
ac3p_init(ac3_padder *padder);
extern void
ac3p_push_data(ac3_padder *padder, guchar *data, guint size);
extern int
ac3p_parse(ac3_padder *padder);
/*
* ac3p_frame
* @padder The padder structure.
*
* Returns a pointer to the padded frame contained in the padder.
*/
#define ac3p_frame(padder) ((guint *) &((padder)->frame))
/*
* ac3p_frame_size
* @padder The padder structure.
*
* Returns the length in bytes of the last read raw AC3 frame.
*/
#define ac3p_frame_size(padder) ((padder)->ac3_frame_size)
#endif
|
