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

dvb_si/descriptors/extension/
c2_bundle_delivery_system.rs
