Enum SignallingKind 

#[non_exhaustive]
pub enum SignallingKind {
    Bufs {
        bufs: u16,
        units: BufsUnit,
    },
    Tto {
        tto_e: u8,
        tto_m: u8,
        tto_l: u8,
    },
    BufStat {
        bufstat: u16,
        units: BufsUnit,
    },
    Reserved(u32),
}

Decoded BUFS/TTO signalling — EN 302 755 Annex C, Table C.1.

The 11 prefix in the first ISSY byte selects one of two alternatives: BUFS (buffer status) or TTO (time-to-output), indicated by bits [5:4].

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Bufs

BUFS — maximum size of the requested receiver buffer.

Fields: (bufs, units) where bufs is the 10-bit buffer status and units is the 2-bit unit selector.

Fields

bufs: u16

10-bit buffer status value.

units: BufsUnit

2-bit unit selector (Table C.1).

Tto

TTO — time-to-output (mantissa + exponent form).

The output time is TTO = (tto_m + tto_l / 256) * 2^tto_e where tto_l is zero when ISCRshort is in use.

Fields

tto_e: u8

5-bit exponent TTO_E.

tto_m: u8

7-bit mantissa TTO_M.

tto_l: u8

8-bit low-fraction TTO_L (zero when ISCRshort is in use).

BufStat

BUFSTAT — actual receiver-buffer fill status (DVB-S2 only).

EN 302 307-1 Annex D Table D.1: selected by bits [5:4] = 0b10 (the ISSY code range 0xE_XXXX). Same field layout as Self::Bufs — a 2-bit units selector and a 10-bit value (the number of filled bits, scaled by units). Not used in DVB-T2, where EN 302 755 Annex C reserves this code range (“shall not be transmitted in DVB-T2”) and replaces it with Self::Tto; decoding it as BUFSTAT here is correct for DVB-S2 streams and harmless for T2 (the range is not transmitted).

Fields

bufstat: u16

10-bit buffer-status value (filled bits, scaled by units).

units: BufsUnit

2-bit unit selector (EN 302 307-1 Annex D Table D.1; note S2 marks 0b11 reserved whereas T2’s BufsUnit::Kbits8 uses it).

Reserved(u32)

Reserved signalling type (bits [5:4] = 0b11).

Holds the low 20 bits of the signalling payload; the 2-bit kind selector is not retained. This is a decode-only view — the wire bytes live in Bbheader::issy_in_header and are serialized verbatim, so the dropped selector does not affect round-trip fidelity.

Implementations

impl SignallingKind

pub fn bufs_bits(&self) -> Option<u64>

Decoded BUFS buffer size in bits, or None if this is not a BUFS variant.

bufs_bits = bufs × units.multiplier_bits()

See EN 302 755 Annex C Table C.1 + §BUFS/TTO semantics (dvb-bbframe/docs/enums/en_302_755/bufs_unit.md).

Note on encoders

Only decode accessors are provided. No set_* or from_* encoders are added because the physical-value → mantissa/exponent TTO encoding is lossy and the wire round-trip is already guaranteed by the existing raw-field serialization in Bbheader. Use the raw-field constructors (SignallingKind::Bufs { … } / SignallingKind::Tto { … }) for encoding.

pub fn bufs_bytes(&self) -> Option<u64>

Decoded BUFS buffer size in bytes (integer floor), or None.

bufs_bytes = bufs_bits() / 8. Integer division is used: BUFS is a maximum-size bound per the standard, so a floor is appropriate.

See EN 302 755 Annex C Table C.1 + §BUFS/TTO semantics (dvb-bbframe/docs/enums/en_302_755/bufs_unit.md).

pub fn bufstat_bits(&self) -> Option<u64>

Decoded BUFSTAT fill status in bits, or None if this is not a BUFSTAT variant (DVB-S2 only — EN 302 307-1 Annex D Table D.1).

bufstat_bits = bufstat × units.multiplier_bits()

pub fn bufstat_bytes(&self) -> Option<u64>

Decoded BUFSTAT fill status in bytes (integer floor), or None.

pub fn tto_t_over_256(&self) -> Option<u64>

Decoded time-to-output in units of T/256, or None if this is not a TTO variant.

tto_t_over_256 = ((TTO_M × 256) + TTO_L) × 2^TTO_E

This is TTO × 256 in units of the elementary period T (see EN 302 755 §9.5 / Table 65). The TTO_L / 256 fractional term is preserved exactly without floating point; consumers divide by 256.0 to obtain TTO in units of T.

Per EN 302 755 Annex C Table C.1 + §8.3.3 (dvb-bbframe/docs/enums/en_302_755/bufs_unit.md).

pub fn name(&self) -> &'static str

Human-readable spec display name for the signalling kind.

Trait Implementations

impl Clone for SignallingKind

fn clone(&self) -> SignallingKind

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for SignallingKind

impl Debug for SignallingKind

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for SignallingKind

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for SignallingKind

impl PartialEq for SignallingKind

fn eq(&self, other: &SignallingKind) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl Serialize for SignallingKind

Available on crate feature serde only.

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for SignallingKind