Wireshark  4.3.0
The Wireshark network protocol analyzer
mpeg-audio.h
Go to the documentation of this file.
1 
11 #ifndef MPA_H
12 #define MPA_H 1
13 
14 #include <stdint.h>
15 #include "ws_symbol_export.h"
16 
17 struct mpa {
18  unsigned int emphasis :2;
19  unsigned int original :1;
20  unsigned int copyright :1;
21  unsigned int modeext :2;
22  unsigned int mode :2;
23  unsigned int priv :1;
24  unsigned int padding :1;
25  unsigned int frequency :2;
26  unsigned int bitrate :4;
27  unsigned int protection :1;
28  unsigned int layer :2;
29  unsigned int version :2;
30  unsigned int sync :11;
31 };
32 
33 #define MPA_UNMARSHAL_SYNC(n) ((n) >> 21 & 0x7ff)
34 #define MPA_UNMARSHAL_VERSION(n) ((n) >> 19 & 0x3)
35 #define MPA_UNMARSHAL_LAYER(n) ((n) >> 17 & 0x3)
36 #define MPA_UNMARSHAL_PROTECTION(n) ((n) >> 16 & 0x1)
37 #define MPA_UNMARSHAL_BITRATE(n) ((n) >> 12 & 0xf)
38 #define MPA_UNMARSHAL_FREQUENCY(n) ((n) >> 10 & 0x3)
39 #define MPA_UNMARSHAL_PADDING(n) ((n) >> 9 & 0x1)
40 #define MPA_UNMARSHAL_PRIVATE(n) ((n) >> 8 & 0x1)
41 #define MPA_UNMARSHAL_MODE(n) ((n) >> 6 & 0x3)
42 #define MPA_UNMARSHAL_MODEEXT(n) ((n) >> 4 & 0x3)
43 #define MPA_UNMARSHAL_COPYRIGHT(n) ((n) >> 3 & 0x1)
44 #define MPA_UNMARSHAL_ORIGINAL(n) ((n) >> 2 & 0x1)
45 #define MPA_UNMARSHAL_EMPHASIS(n) ((n) >> 0 & 0x3)
46 
47 #define MPA_UNMARSHAL(mpa, n) do { \
48  (mpa)->sync = MPA_UNMARSHAL_SYNC(n); \
49  (mpa)->version = MPA_UNMARSHAL_VERSION(n); \
50  (mpa)->layer = MPA_UNMARSHAL_LAYER(n); \
51  (mpa)->protection = MPA_UNMARSHAL_PROTECTION(n); \
52  (mpa)->bitrate = MPA_UNMARSHAL_BITRATE(n); \
53  (mpa)->frequency = MPA_UNMARSHAL_FREQUENCY(n); \
54  (mpa)->padding = MPA_UNMARSHAL_PADDING(n); \
55  (mpa)->priv = MPA_UNMARSHAL_PRIVATE(n); \
56  (mpa)->mode = MPA_UNMARSHAL_MODE(n); \
57  (mpa)->modeext = MPA_UNMARSHAL_MODEEXT(n); \
58  (mpa)->copyright = MPA_UNMARSHAL_COPYRIGHT(n); \
59  (mpa)->original = MPA_UNMARSHAL_ORIGINAL(n); \
60  (mpa)->emphasis = MPA_UNMARSHAL_EMPHASIS(n); \
61  } while (0)
62 
63 WS_DLL_PUBLIC
64 int mpa_version(const struct mpa *);
65 WS_DLL_PUBLIC
66 int mpa_layer(const struct mpa *);
67 WS_DLL_PUBLIC
68 unsigned int mpa_samples(const struct mpa *);
69 WS_DLL_PUBLIC
70 unsigned int mpa_bitrate(const struct mpa *);
71 WS_DLL_PUBLIC
72 unsigned int mpa_frequency(const struct mpa *);
73 WS_DLL_PUBLIC
74 unsigned int mpa_padding(const struct mpa *);
75 WS_DLL_PUBLIC
76 uint32_t decode_synchsafe_int(uint32_t);
77 
78 #define MPA_DATA_BYTES(mpa) (mpa_bitrate(mpa) * mpa_samples(mpa) \
79  / mpa_frequency(mpa) / 8)
80 #define MPA_BYTES(mpa) (MPA_DATA_BYTES(mpa) + mpa_padding(mpa))
81 #define MPA_DURATION_NS(mpa) \
82  (1000000000 / mpa_frequency(mpa) * mpa_samples(mpa))
83 
84 enum { MPA_SYNC = 0x7ff };
85 
86 #define MPA_SYNC_VALID(mpa) ((mpa)->sync == MPA_SYNC)
87 #define MPA_VERSION_VALID(mpa) (mpa_version(mpa) >= 0)
88 #define MPA_LAYER_VALID(mpa) (mpa_layer(mpa) >= 0)
89 #define MPA_BITRATE_VALID(mpa) (mpa_bitrate(mpa) > 0)
90 #define MPA_FREQUENCY_VALID(mpa) (mpa_frequency(mpa) > 0)
91 #define MPA_VALID(mpa) (MPA_SYNC_VALID(mpa) \
92  && MPA_VERSION_VALID(mpa) && MPA_LAYER_VALID(mpa) \
93  && MPA_BITRATE_VALID(mpa) && MPA_FREQUENCY_VALID(mpa))
94 
95 #endif
Definition: mpeg-audio.h:17