Wireshark  2.9.0-477-g68ec514b
The Wireshark network protocol analyzer
mpeg-audio.h
1 /* mpeg-audio.h
2  *
3  * MPEG Audio header dissection
4  * Written by Shaun Jackman <sjackman@gmail.com>
5  * Copyright 2007 Shaun Jackman
6  *
7  * Wiretap Library
8  * SPDX-License-Identifier: GPL-2.0-or-later
9  */
10 
11 #ifndef MPA_H
12 #define MPA_H 1
13 
14 #include "ws_symbol_export.h"
15 
16 struct mpa {
17  unsigned int emphasis :2;
18  unsigned int original :1;
19  unsigned int copyright :1;
20  unsigned int modeext :2;
21  unsigned int mode :2;
22  unsigned int priv :1;
23  unsigned int padding :1;
24  unsigned int frequency :2;
25  unsigned int bitrate :4;
26  unsigned int protection :1;
27  unsigned int layer :2;
28  unsigned int version :2;
29  unsigned int sync :11;
30 };
31 
32 #define MPA_UNMARSHAL_SYNC(n) ((n) >> 21 & 0x7ff)
33 #define MPA_UNMARSHAL_VERSION(n) ((n) >> 19 & 0x3)
34 #define MPA_UNMARSHAL_LAYER(n) ((n) >> 17 & 0x3)
35 #define MPA_UNMARSHAL_PROTECTION(n) ((n) >> 16 & 0x1)
36 #define MPA_UNMARSHAL_BITRATE(n) ((n) >> 12 & 0xf)
37 #define MPA_UNMARSHAL_FREQUENCY(n) ((n) >> 10 & 0x3)
38 #define MPA_UNMARSHAL_PADDING(n) ((n) >> 9 & 0x1)
39 #define MPA_UNMARSHAL_PRIVATE(n) ((n) >> 8 & 0x1)
40 #define MPA_UNMARSHAL_MODE(n) ((n) >> 6 & 0x3)
41 #define MPA_UNMARSHAL_MODEEXT(n) ((n) >> 4 & 0x3)
42 #define MPA_UNMARSHAL_COPYRIGHT(n) ((n) >> 3 & 0x1)
43 #define MPA_UNMARSHAL_ORIGINAL(n) ((n) >> 2 & 0x1)
44 #define MPA_UNMARSHAL_EMPHASIS(n) ((n) >> 0 & 0x3)
45 
46 #define MPA_UNMARSHAL(mpa, n) do { \
47  (mpa)->sync = MPA_UNMARSHAL_SYNC(n); \
48  (mpa)->version = MPA_UNMARSHAL_VERSION(n); \
49  (mpa)->layer = MPA_UNMARSHAL_LAYER(n); \
50  (mpa)->protection = MPA_UNMARSHAL_PROTECTION(n); \
51  (mpa)->bitrate = MPA_UNMARSHAL_BITRATE(n); \
52  (mpa)->frequency = MPA_UNMARSHAL_FREQUENCY(n); \
53  (mpa)->padding = MPA_UNMARSHAL_PADDING(n); \
54  (mpa)->priv = MPA_UNMARSHAL_PRIVATE(n); \
55  (mpa)->mode = MPA_UNMARSHAL_MODE(n); \
56  (mpa)->modeext = MPA_UNMARSHAL_MODEEXT(n); \
57  (mpa)->copyright = MPA_UNMARSHAL_COPYRIGHT(n); \
58  (mpa)->original = MPA_UNMARSHAL_ORIGINAL(n); \
59  (mpa)->emphasis = MPA_UNMARSHAL_EMPHASIS(n); \
60  } while (0)
61 
62 WS_DLL_PUBLIC
63 int mpa_version(const struct mpa *);
64 WS_DLL_PUBLIC
65 int mpa_layer(const struct mpa *);
66 WS_DLL_PUBLIC
67 unsigned int mpa_samples(const struct mpa *);
68 WS_DLL_PUBLIC
69 unsigned int mpa_bitrate(const struct mpa *);
70 WS_DLL_PUBLIC
71 unsigned int mpa_frequency(const struct mpa *);
72 WS_DLL_PUBLIC
73 unsigned int mpa_padding(const struct mpa *);
74 
75 #define MPA_DATA_BYTES(mpa) (mpa_bitrate(mpa) * mpa_samples(mpa) \
76  / mpa_frequency(mpa) / 8)
77 #define MPA_BYTES(mpa) (MPA_DATA_BYTES(mpa) + mpa_padding(mpa))
78 #define MPA_DURATION_NS(mpa) \
79  (1000000000 / mpa_frequency(mpa) * mpa_samples(mpa))
80 
81 enum { MPA_SYNC = 0x7ff };
82 
83 #define MPA_SYNC_VALID(mpa) ((mpa)->sync == MPA_SYNC)
84 #define MPA_VERSION_VALID(mpa) (mpa_version(mpa) >= 0)
85 #define MPA_LAYER_VALID(mpa) (mpa_layer(mpa) >= 0)
86 #define MPA_BITRATE_VALID(mpa) (mpa_bitrate(mpa) > 0)
87 #define MPA_FREQUENCY_VALID(mpa) (mpa_frequency(mpa) > 0)
88 #define MPA_VALID(mpa) (MPA_SYNC_VALID(mpa) \
89  && MPA_VERSION_VALID(mpa) && MPA_LAYER_VALID(mpa) \
90  && MPA_BITRATE_VALID(mpa) && MPA_FREQUENCY_VALID(mpa))
91 
92 #endif
Definition: mpeg-audio.h:16