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
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
use std::fmt;
use hex_slice::AsHex;
#[derive(Debug)]
pub enum Descriptor<'buf> {
Reserved { tag: u8, payload: &'buf[u8]},
VideoStream { payload: &'buf[u8]},
AudioStream { payload: &'buf[u8]},
Hierarchy { payload: &'buf[u8]},
Registration { payload: &'buf[u8] },
DataStreamAlignment { payload: &'buf[u8]},
TargetBackgroundGrid { payload: &'buf[u8]},
VideoWindow { payload: &'buf[u8]},
CA { payload: &'buf[u8]},
ISO639Language { payload: &'buf[u8]},
SystemClock { payload: &'buf[u8]},
MultiplexBufferUtilization { payload: &'buf[u8]},
Copyright { payload: &'buf[u8]},
MaximumBitrate { payload: &'buf[u8]},
PrivateDataIndicator { payload: &'buf[u8]},
SmoothingBuffer { payload: &'buf[u8]},
STD { payload: &'buf[u8]},
IBP { payload: &'buf[u8]},
IsoIec13818dash6 { tag: u8, payload: &'buf[u8]},
MPEG4Video { payload: &'buf[u8]},
MPEG4Audio { payload: &'buf[u8]},
IOD { payload: &'buf[u8]},
SL { payload: &'buf[u8]},
FMC { payload: &'buf[u8]},
ExternalESID { payload: &'buf[u8]},
MuxCode { payload: &'buf[u8]},
FmxBufferSize { payload: &'buf[u8]},
MultiplexBuffer { payload: &'buf[u8]},
UserPrivate { tag: u8, payload: &'buf[u8]},
}
impl<'buf> Descriptor<'buf> {
pub fn new(buf: &'buf[u8]) -> Descriptor<'buf> {
assert!(buf.len() >= 2);
let tag = buf[0];
let len = buf[1] as usize;
let payload = &buf[2..2+len];
match tag {
0|1|36...63 => Descriptor::Reserved { tag, payload },
2 => Descriptor::VideoStream { payload },
3 => Descriptor::AudioStream { payload },
4 => Descriptor::Hierarchy { payload },
5 => Descriptor::Registration { payload },
6 => Descriptor::DataStreamAlignment { payload },
7 => Descriptor::TargetBackgroundGrid { payload },
8 => Descriptor::VideoWindow { payload },
9 => Descriptor::CA { payload },
10 => Descriptor::ISO639Language { payload },
11 => Descriptor::SystemClock { payload },
12 => Descriptor::MultiplexBufferUtilization { payload },
13 => Descriptor::Copyright { payload },
14 => Descriptor::MaximumBitrate { payload },
15 => Descriptor::PrivateDataIndicator { payload },
16 => Descriptor::SmoothingBuffer { payload },
17 => Descriptor::STD { payload },
18 => Descriptor::IBP { payload },
19...26 => Descriptor::IsoIec13818dash6 { tag, payload },
27 => Descriptor::MPEG4Video { payload },
28 => Descriptor::MPEG4Audio { payload },
29 => Descriptor::IOD { payload },
30 => Descriptor::SL { payload },
31 => Descriptor::FMC { payload },
32 => Descriptor::ExternalESID { payload },
33 => Descriptor::MuxCode { payload },
34 => Descriptor::FmxBufferSize { payload },
35 => Descriptor::MultiplexBuffer { payload },
64...255 => Descriptor::UserPrivate { tag, payload },
_ => unimplemented!("tag {}", tag)
}
}
}
pub struct DescriptorIter<'buf> {
buf: &'buf[u8]
}
impl<'buf> DescriptorIter<'buf> {
pub fn new(buf: &'buf[u8]) -> DescriptorIter<'buf> {
DescriptorIter { buf }
}
}
impl<'buf> Iterator for DescriptorIter<'buf> {
type Item = Result<Descriptor<'buf>, ()>;
fn next(&mut self) -> Option<Self::Item> {
if self.buf.len() == 0 {
return None;
}
let _tag = self.buf[0];
let len = self.buf[1] as usize;
if len > self.buf.len()-2 {
self.buf = &self.buf[0..0];
Some(Err(()))
} else {
let (desc, rest) = self.buf.split_at(len+2);
self.buf = rest;
Some(Ok(Descriptor::new(desc)))
}
}
}
pub enum DescriptorError {
NotEnoughData { actual: usize, expected: usize }
}
pub struct RegistrationDescriptor<'buf> {
buf: &'buf[u8],
}
impl<'buf> RegistrationDescriptor<'buf> {
pub fn new(buf: &'buf[u8]) -> Result<RegistrationDescriptor<'buf>, DescriptorError> {
if buf.len() < 4 {
Err(DescriptorError::NotEnoughData { actual: buf.len(), expected: 4 })
} else {
Ok(RegistrationDescriptor { buf })
}
}
pub fn format_identifier(&self) -> u32 {
u32::from(self.buf[0]) << 24
| u32::from(self.buf[1]) << 16
| u32::from(self.buf[2]) << 8
| u32::from(self.buf[3])
}
pub fn additional_identification_info(&self) -> &[u8] {
&self.buf[4..]
}
}
impl<'buf> fmt::Debug for RegistrationDescriptor<'buf> {
fn fmt(&self, f: &mut fmt::Formatter) -> Result<(),fmt::Error> {
f.debug_struct("RegistrationDescriptor")
.field("format_identifier", &self.format_identifier())
.field("additional_identification_info", &format!("{:x}", self.additional_identification_info().as_hex()))
.finish()
}
}
#[cfg(test)]
mod test {
use data_encoding::hex;
use super::*;
#[test]
fn descriptor() {
let data = hex::decode(b"050443554549").unwrap();
let desc = Descriptor::new(&data);
assert_matches!(desc, Descriptor::Registration{ payload: b"CUEI" });
}
}