dvb_si/descriptors/extension/
c2_bundle_delivery_system.rs

1//! C2 Bundle Delivery System Descriptor — ETSI EN 300 468 §6.4.6.4 (tag_extension 0x16).
2use super::*;
3
4use super::c2_delivery_system::{ActiveOfdmSymbolDuration, C2GuardInterval, C2TuningFrequencyType};
5
6impl<'a> ExtensionBodyDef<'a> for C2BundleDeliverySystem {
7    const TAG_EXTENSION: u8 = 0x16;
8    const NAME: &'static str = "C2_BUNDLE_DELIVERY_SYSTEM";
9}
10/// One C2 bundle entry (Table 139 inner loop).
11#[derive(Debug, Clone, Copy, PartialEq, Eq)]
12#[cfg_attr(feature = "serde", derive(serde::Serialize))]
13pub struct C2BundleEntry {
14    /// plp_id(8).
15    pub plp_id: u8,
16    /// data_slice_id(8).
17    pub data_slice_id: u8,
18    /// C2_System_tuning_frequency(32).
19    pub c2_system_tuning_frequency: u32,
20    /// C2_System_tuning_frequency_type(2) — Table 116.
21    pub c2_system_tuning_frequency_type: C2TuningFrequencyType,
22    /// active_OFDM_symbol_duration(3).
23    pub active_ofdm_symbol_duration: ActiveOfdmSymbolDuration,
24    /// guard_interval(3).
25    pub guard_interval: C2GuardInterval,
26    /// primary_channel(1).
27    pub primary_channel: bool,
28}
29
30/// C2_bundle_delivery_system body (Table 139) — fully typed.
31#[derive(Debug, Clone, PartialEq, Eq)]
32#[cfg_attr(feature = "serde", derive(serde::Serialize))]
33pub struct C2BundleDeliverySystem {
34    /// Bundle entries in wire order.
35    pub entries: Vec<C2BundleEntry>,
36}
37
38impl<'a> Parse<'a> for C2BundleDeliverySystem {
39    type Error = crate::error::Error;
40    fn parse(sel: &'a [u8]) -> Result<Self> {
41        if sel.len() % C2_BUNDLE_ENTRY_LEN != 0 {
42            return Err(invalid(
43                "C2_bundle_delivery_system: not a whole number of entries",
44            ));
45        }
46        let mut entries = Vec::with_capacity(sel.len() / C2_BUNDLE_ENTRY_LEN);
47        for chunk in sel.chunks_exact(C2_BUNDLE_ENTRY_LEN) {
48            let packed = chunk[6];
49            entries.push(C2BundleEntry {
50                plp_id: chunk[0],
51                data_slice_id: chunk[1],
52                c2_system_tuning_frequency: u32::from_be_bytes([
53                    chunk[2], chunk[3], chunk[4], chunk[5],
54                ]),
55                c2_system_tuning_frequency_type: C2TuningFrequencyType::from_u8(packed >> 6),
56                active_ofdm_symbol_duration: ActiveOfdmSymbolDuration::from_u8(
57                    (packed >> 3) & 0x07,
58                ),
59                guard_interval: C2GuardInterval::from_u8(packed & 0x07),
60                primary_channel: (chunk[7] & 0x80) != 0,
61            });
62        }
63        Ok(C2BundleDeliverySystem { entries })
64    }
65}
66
67impl Serialize for C2BundleDeliverySystem {
68    type Error = crate::error::Error;
69    fn serialized_len(&self) -> usize {
70        self.entries.len() * C2_BUNDLE_ENTRY_LEN
71    }
72    fn serialize_into(&self, buf: &mut [u8]) -> Result<usize> {
73        let len = self.serialized_len();
74        if buf.len() < len {
75            return Err(Error::OutputBufferTooSmall {
76                need: len,
77                have: buf.len(),
78            });
79        }
80        let mut p = 0;
81        for e in &self.entries {
82            buf[p] = e.plp_id;
83            buf[p + 1] = e.data_slice_id;
84            buf[p + 2..p + 6].copy_from_slice(&e.c2_system_tuning_frequency.to_be_bytes());
85            buf[p + 6] = (e.c2_system_tuning_frequency_type.to_u8() << 6)
86                | ((e.active_ofdm_symbol_duration.to_u8() & 0x07) << 3)
87                | (e.guard_interval.to_u8() & 0x07);
88            buf[p + 7] = u8::from(e.primary_channel) << 7;
89            p += C2_BUNDLE_ENTRY_LEN;
90        }
91        Ok(len)
92    }
93}
94
95#[cfg(test)]
96mod tests {
97    use super::*;
98    use crate::descriptors::extension::test_support::*;
99    use crate::descriptors::extension::{ExtensionBody, ExtensionDescriptor};
100
101    #[test]
102    fn parse_c2_bundle_two_entries() {
103        let entry = |off: u8| {
104            let packed = (0x01u8 << 6) | 0x01;
105            [off, off + 1, 0x00, 0x00, 0x10, 0x00, packed, 0x80]
106        };
107        let mut sel = Vec::new();
108        sel.extend_from_slice(&entry(0x01));
109        sel.extend_from_slice(&entry(0x05));
110        let bytes = wrap(0x16, &sel);
111        let d = ExtensionDescriptor::parse(&bytes).unwrap();
112        match &d.body {
113            ExtensionBody::C2BundleDeliverySystem(b) => {
114                assert_eq!(b.entries.len(), 2);
115                assert_eq!(b.entries[0].plp_id, 0x01);
116                assert!(b.entries[0].primary_channel);
117                assert_eq!(
118                    b.entries[0].c2_system_tuning_frequency_type,
119                    C2TuningFrequencyType::C2SystemCentreFrequency
120                );
121                assert_eq!(b.entries[1].plp_id, 0x05);
122                assert_eq!(b.entries[1].guard_interval, C2GuardInterval::G1_64);
123            }
124            other => panic!("expected C2BundleDeliverySystem, got {other:?}"),
125        }
126        round_trip(&d);
127    }
128
129    #[test]
130    fn parse_c2_bundle_rejects_partial_entry() {
131        let sel = [0x01, 0x02, 0x03];
132        let bytes = wrap(0x16, &sel);
133        assert!(matches!(
134            ExtensionDescriptor::parse(&bytes).unwrap_err(),
135            crate::error::Error::InvalidDescriptor {
136                tag: super::TAG,
137                ..
138            }
139        ));
140    }
141}
dvb_si/descriptors/extension/c2_bundle_delivery_system.rs

dvb_si/descriptors/extension/
c2_bundle_delivery_system.rs
