dvb-t2mi

Complete, spec-compliant ETSI TS 102 773 v1.4.1 DVB-T2 Modulator Interface (T2-MI) parser and builder in Rust.

What is T2-MI?

T2-MI is the protocol between a DVB-T2 Gateway and a DVB-T2 modulator. It carries:

• Baseband Frames (BBFRAME) — the actual DVB-T2 user data
• L1 signalling — configuration for each T2 frame (L1-pre and L1-post)
• Auxiliary I/Q data — pilot and correction cell values
• DVB-T2 timestamps — SFN synchronisation
• Future Extension Frames (FEF) — composite signal support (e.g. T2-Base + T2-Lite)

Each T2-MI packet is a 6-byte header + variable payload + 4-byte CRC-32, encapsulated in MPEG-2 TS via data piping.

Quick start

use dvb_t2mi::pump::T2miPump;
use dvb_t2mi::payload::AnyPayload;

let mut pump = T2miPump::new(0x0006);       // T2-MI PID from the PMT
for packet in ts_packets {                  // each aligned 188-byte packet
    for event in pump.feed_ts(packet) {     // CRC-valid packets only
        match event.payload()? {
            AnyPayload::Bbframe(bb)   => println!("BBFrame plp_id={}", bb.plp_id),
            AnyPayload::L1Current(l1) => { /* l1.l1_pre(), l1.l1_post() */ }
            AnyPayload::Timestamp(ts) => { let _ = ts; }
            AnyPayload::Unknown { packet_type, .. } => eprintln!("0x{packet_type:02X}"),
            _ => {}
        }
    }
}

For un-encapsulated .t2mi byte streams use T2miPump::raw() + feed_raw. The dvb-tools t2mi CLI is the complete wrapper (cargo run -p dvb-tools -- t2mi file.ts [--pid 0xNNN|raw] [--inner] [--plp N]).

Inner-TS recovery in one call

[inner_ts::InnerTsRecovery] folds the full chain (T2miPump → AnyPayload::Bbframe → Bbheader → CarryOverExtractor, NM/HEM + carry-over) into a single feed-and-collect driver — feed outer TS packets, get inner TS packets out:

# #[cfg(feature = "ts")] {
use dvb_t2mi::inner_ts::InnerTsRecovery;

let mut rec = InnerTsRecovery::new(0x1000); // the T2-MI PID
for outer in ts_packets() {                 // 188-byte outer TS packets
    for inner in rec.feed(&outer) {          // recovered inner TS packets
        assert_eq!(inner[0], 0x47);
    }
}
# fn ts_packets() -> Vec<[u8; 188]> { vec![] }
# }

InnerTsRecovery::with_plp(pid, plp_id) filters to a single PLP.

What's implemented

Packet types — all 12 (ETSI TS 102 773 Table 1)

All 12 are in the declare_payloads! list in payload/any.rs; each has a Parse + Serialize impl and round-trip tests. The AnyPayload dispatcher routes every packet type to its typed struct; unknown/reserved values fall through to AnyPayload::Unknown with raw bytes preserved.

L1 signalling (EN 302 755 §7.2)

L1CurrentPayload and L1FuturePayload expose typed l1_pre() / l1_post() accessors that parse the L1-pre and L1-post signalling structures directly from the payload bytes. Decoded enums (L1PreType, Papr, S1Field, S2Field, FftMode, Gi, Pp, Mimo, etc.) live in payload::l1::enums.

DVB-T2 timestamp decoded accessors

T2TimestampPayload exposes emission_offset() (per-bandwidth T_sub units, §5.2.7 Table 4) and the is_null / is_relative flags. The chrono feature adds a utc_emission_time() accessor returning DateTime<Utc>.

PLP filter

T2miPump::new(pid) passes all PLPs through; InnerTsRecovery::with_plp(pid, plp_id) restricts the inner-TS recovery to a single PLP. The T2miEvent exposes plp_id() for caller-side filtering on the individual BBFrame events.

Private / custom packet types

PayloadRegistry lets you register owned types for packet_type values not in PacketType (or override built-in ones). Call event.payload_with(&reg) instead of event.payload(); the registry's parser wins, producing AnyPayload::Other { packet_type, value } where value can be downcast to your concrete type.

Feature flags

MSRV

Rust 1.81.

References

• ETSI TS 102 773 v1.4.1 — DVB-T2 Modulator Interface (T2-MI)
• ETSI EN 302 755 v1.4.1 — DVB-T2 Frame structure, channel coding and modulation

License

Licensed under either of MIT (LICENSE-MIT) or Apache-2.0 (LICENSE-APACHE), at your option.