dvb_si/tables/
rst.rs

1//! Running Status Table — ETSI EN 300 468 §5.2.8.
2//!
3//! Carried on PID `0x0013` with `table_id = 0x71`. A SHORT-FORM section — there
4//! is no version/section header and no CRC. The body is a flat loop of 9-byte
5//! entries, each giving the running status of one event:
6//!
7//! ```text
8//! transport_stream_id(16) original_network_id(16) service_id(16)
9//! event_id(16) reserved_future_use(5) running_status(3)
10//! ```
11
12use crate::error::{Error, Result};
13use crate::traits::Table;
14use dvb_common::{Parse, Serialize};
15
16/// table_id for the Running Status Table.
17pub const TABLE_ID: u8 = 0x71;
18/// Well-known PID on which the RST is carried.
19pub const PID: u16 = 0x0013;
20
21const HEADER_LEN: usize = 3;
22/// Each entry is 9 bytes: tsid(2) + onid(2) + sid(2) + evid(2) + status(1).
23const ENTRY_LEN: usize = 9;
24
25/// One RST entry — the running status of a single event.
26///
27/// `running_status` is the 3-bit code from EN 300 468 Table 6: 0 undefined,
28/// 1 not running, 2 starts in a few seconds, 3 pausing, 4 running,
29/// 5 service off-air, 6–7 reserved.
30#[derive(Debug, Clone, Copy, PartialEq, Eq)]
31#[cfg_attr(feature = "serde", derive(serde::Serialize))]
32pub struct RstEntry {
33    /// Transport stream carrying the event.
34    pub transport_stream_id: u16,
35    /// Originating network.
36    pub original_network_id: u16,
37    /// Service (matches `program_number` in the PAT).
38    pub service_id: u16,
39    /// Event identifier.
40    pub event_id: u16,
41    /// 3-bit running_status code (EN 300 468 Table 6).
42    pub running_status: u8,
43}
44
45/// Running Status Table (§5.2.8, Table 10).
46#[derive(Debug, Clone, PartialEq, Eq)]
47#[cfg_attr(feature = "serde", derive(serde::Serialize))]
48pub struct Rst {
49    /// Entries in wire order.
50    pub entries: Vec<RstEntry>,
51}
52
53impl<'a> Parse<'a> for Rst {
54    type Error = crate::error::Error;
55
56    fn parse(bytes: &'a [u8]) -> Result<Self> {
57        if bytes.len() < HEADER_LEN {
58            return Err(Error::BufferTooShort {
59                need: HEADER_LEN,
60                have: bytes.len(),
61                what: "Rst",
62            });
63        }
64        if bytes[0] != TABLE_ID {
65            return Err(Error::UnexpectedTableId {
66                table_id: bytes[0],
67                what: "Rst",
68                expected: &[TABLE_ID],
69            });
70        }
71        let section_length = ((bytes[1] & 0x0F) as usize) << 8 | bytes[2] as usize;
72        let total = HEADER_LEN + section_length;
73        if bytes.len() < total {
74            return Err(Error::SectionLengthOverflow {
75                declared: section_length,
76                available: bytes.len() - HEADER_LEN,
77            });
78        }
79        if section_length % ENTRY_LEN != 0 {
80            return Err(Error::SectionLengthOverflow {
81                declared: section_length,
82                available: (section_length / ENTRY_LEN) * ENTRY_LEN,
83            });
84        }
85        let mut entries = Vec::with_capacity(section_length / ENTRY_LEN);
86        let mut off = HEADER_LEN;
87        while off + ENTRY_LEN <= total {
88            entries.push(RstEntry {
89                transport_stream_id: u16::from_be_bytes([bytes[off], bytes[off + 1]]),
90                original_network_id: u16::from_be_bytes([bytes[off + 2], bytes[off + 3]]),
91                service_id: u16::from_be_bytes([bytes[off + 4], bytes[off + 5]]),
92                event_id: u16::from_be_bytes([bytes[off + 6], bytes[off + 7]]),
93                running_status: bytes[off + 8] & 0x07,
94            });
95            off += ENTRY_LEN;
96        }
97        Ok(Rst { entries })
98    }
99}
100
101impl Serialize for Rst {
102    type Error = crate::error::Error;
103
104    fn serialized_len(&self) -> usize {
105        HEADER_LEN + self.entries.len() * ENTRY_LEN
106    }
107
108    fn serialize_into(&self, buf: &mut [u8]) -> Result<usize> {
109        let len = self.serialized_len();
110        if buf.len() < len {
111            return Err(Error::OutputBufferTooSmall {
112                need: len,
113                have: buf.len(),
114            });
115        }
116        let section_length = (len - HEADER_LEN) as u16;
117        buf[0] = TABLE_ID;
118        // section_syntax_indicator=0 (short form), reserved_future_use=1,
119        // reserved=11, section_length high nibble.
120        buf[1] = 0x70 | ((section_length >> 8) as u8 & 0x0F);
121        buf[2] = (section_length & 0xFF) as u8;
122        let mut off = HEADER_LEN;
123        for e in &self.entries {
124            buf[off..off + 2].copy_from_slice(&e.transport_stream_id.to_be_bytes());
125            buf[off + 2..off + 4].copy_from_slice(&e.original_network_id.to_be_bytes());
126            buf[off + 4..off + 6].copy_from_slice(&e.service_id.to_be_bytes());
127            buf[off + 6..off + 8].copy_from_slice(&e.event_id.to_be_bytes());
128            // reserved_future_use(5)=1, running_status(3).
129            buf[off + 8] = 0xF8 | (e.running_status & 0x07);
130            off += ENTRY_LEN;
131        }
132        Ok(len)
133    }
134}
135
136impl<'a> Table<'a> for Rst {
137    const TABLE_ID: u8 = TABLE_ID;
138    const PID: u16 = PID;
139}
140
141impl<'a> crate::traits::TableDef<'a> for Rst {
142    const TABLE_ID_RANGES: &'static [(u8, u8)] = &[(TABLE_ID, TABLE_ID)];
143    const NAME: &'static str = "RUNNING_STATUS";
144}
145
146#[cfg(test)]
147mod tests {
148    use super::*;
149
150    fn build_rst(entries: &[RstEntry]) -> Vec<u8> {
151        let section_length = (entries.len() * ENTRY_LEN) as u16;
152        let mut v = vec![
153            TABLE_ID,
154            0x70 | ((section_length >> 8) as u8 & 0x0F),
155            (section_length & 0xFF) as u8,
156        ];
157        for e in entries {
158            v.extend_from_slice(&e.transport_stream_id.to_be_bytes());
159            v.extend_from_slice(&e.original_network_id.to_be_bytes());
160            v.extend_from_slice(&e.service_id.to_be_bytes());
161            v.extend_from_slice(&e.event_id.to_be_bytes());
162            v.push(0xF8 | (e.running_status & 0x07));
163        }
164        v
165    }
166
167    fn entry(tsid: u16, onid: u16, sid: u16, evid: u16, rs: u8) -> RstEntry {
168        RstEntry {
169            transport_stream_id: tsid,
170            original_network_id: onid,
171            service_id: sid,
172            event_id: evid,
173            running_status: rs,
174        }
175    }
176
177    #[test]
178    fn parse_empty() {
179        let rst = Rst::parse(&build_rst(&[])).unwrap();
180        assert!(rst.entries.is_empty());
181    }
182
183    #[test]
184    fn parse_single_entry() {
185        let e = entry(0x1234, 0x0001, 0xABCD, 0x4000, 4);
186        let rst = Rst::parse(&build_rst(&[e])).unwrap();
187        assert_eq!(rst.entries.len(), 1);
188        assert_eq!(rst.entries[0], e);
189        assert_eq!(rst.entries[0].running_status, 4); // running
190    }
191
192    #[test]
193    fn parse_multiple_entries() {
194        let es = [
195            entry(0x0001, 0x1000, 0x0010, 0x0100, 1),
196            entry(0x0002, 0x2000, 0x0020, 0x0200, 4),
197            entry(0x0003, 0x3000, 0x0030, 0x0300, 5),
198        ];
199        let rst = Rst::parse(&build_rst(&es)).unwrap();
200        assert_eq!(rst.entries, es);
201    }
202
203    #[test]
204    fn parse_rejects_wrong_tag() {
205        let mut bytes = build_rst(&[]);
206        bytes[0] = 0x72;
207        assert!(matches!(
208            Rst::parse(&bytes).unwrap_err(),
209            Error::UnexpectedTableId { table_id: 0x72, .. }
210        ));
211    }
212
213    #[test]
214    fn parse_rejects_short_buffer() {
215        assert!(matches!(
216            Rst::parse(&[0x71, 0x70]).unwrap_err(),
217            Error::BufferTooShort { .. }
218        ));
219    }
220
221    #[test]
222    fn parse_rejects_non_multiple_loop() {
223        // section_length = 4 (not a multiple of 9)
224        let bytes = [TABLE_ID, 0x70, 0x04, 0x00, 0x00, 0x00, 0x00];
225        assert!(matches!(
226            Rst::parse(&bytes).unwrap_err(),
227            Error::SectionLengthOverflow { .. }
228        ));
229    }
230
231    #[test]
232    fn serialize_round_trip() {
233        let es = [
234            entry(0xCAFE, 0xBEEF, 0x1234, 0x5678, 4),
235            entry(0x0001, 0x0002, 0x0003, 0x0004, 5),
236        ];
237        let rst = Rst::parse(&build_rst(&es)).unwrap();
238        let mut buf = vec![0u8; rst.serialized_len()];
239        rst.serialize_into(&mut buf).unwrap();
240        assert_eq!(buf, build_rst(&es));
241        assert_eq!(Rst::parse(&buf).unwrap(), rst);
242    }
243
244    #[test]
245    fn serialize_empty_round_trip() {
246        let rst = Rst { entries: vec![] };
247        let mut buf = vec![0u8; rst.serialized_len()];
248        rst.serialize_into(&mut buf).unwrap();
249        assert_eq!(Rst::parse(&buf).unwrap(), rst);
250    }
251
252    #[test]
253    fn table_trait_constants() {
254        assert_eq!(<Rst as Table>::TABLE_ID, 0x71);
255        assert_eq!(<Rst as Table>::PID, 0x0013);
256    }
257
258    #[test]
259    fn serde_json_serializes_fields() {
260        // Serialize-only: assert the emitted JSON re-parses (serialize-stable).
261        let rst = Rst::parse(&build_rst(&[entry(1, 2, 3, 4, 4)])).unwrap();
262        let j = serde_json::to_string(&rst).unwrap();
263        let v: serde_json::Value = serde_json::from_str(&j).unwrap();
264        assert_eq!(v["entries"][0]["service_id"], 3);
265    }
266}
dvb_si/tables/rst.rs

dvb_si/tables/
rst.rs
