Enum FrameDecodeStatus 

pub enum FrameDecodeStatus {
    DtxOrLost,
    LayerNotWired(OperatingMode),
    SilkParamsDecoded,
    SilkStereoDecoded,
    SilkDecodeError,
    CeltSilence,
    CeltDecodeError,
    CeltCoarseEnergyDecoded,
    CeltAllocationDecoded,
}

Why a given Opus frame produced the samples it did.

The packet-level orchestration is complete, but the per-frame audio decode lands incrementally. This status lets a caller (and the crate’s own tests) distinguish “decoded real audio” from “emitted silence because the layer’s range-coded decode is not wired yet” or “emitted silence for a DTX / lost frame”.

Variants

DtxOrLost

A §3.2.1 zero-length frame: DTX or a lost/packet-loss marker. Per §4.6 the floor behaviour is to emit silence; a real PLC model is a separate milestone.

LayerNotWired(OperatingMode)

The frame’s operating mode does not yet have a composed sample-producing decode path in this crate, so silence of the correct length was emitted. The variant carries the mode so the caller knows which layer is pending.

SilkParamsDecoded

A mono SILK-only frame whose full §4.2.7 bitstream (frame type, gains, LSF chain, LTP, LCG seed, excitation) was decoded in Table-5 order via crate::silk_decode::decode_silk_frame, then synthesized through the §4.2.7.9 LTP / LPC filters (crate::silk_synthesis::synthesize_silk_frame) and resampled to 48 kHz (§4.2.9, non-normative). The emitted PCM is real audio.

SilkStereoDecoded

A stereo SILK-only frame whose §4.2.3 / §4.2.4 header bits and the §4.2.5 / §4.2.6 interleaved mid/side SILK frames were decoded in §4.2.2 order (mid frame then side frame per 20 ms interval, the side frame skipped when the §4.2.7.2 mid-only flag is set), each channel synthesized through the §4.2.7.9 filters, converted from mid/side to left/right via §4.2.8 stereo unmixing (crate::silk_stereo::stereo_ms_to_lr), then resampled to 48 kHz (§4.2.9, non-normative). The emitted interleaved L/R PCM is real audio.

SilkDecodeError

A SILK-only frame whose §4.2.7 bitstream decode latched an error (a malformed / truncated frame). Silence of the correct length was emitted in its place per the §4.6 floor.

CeltSilence

A CELT-only frame whose §4.3.7.1 silence flag was set: the real range-coded frame prefix (silence + post-filter group) was decoded and the §4.3.6→§4.3.7.2 synthesis backend was advanced with all-zero band shapes / energies, emitting silence PCM while carrying the MDCT overlap-add and de-emphasis state forward for the next frame. (Distinct from Self::LayerNotWired: the bitstream is actually consumed and the synthesis state is real, not stubbed.)

CeltDecodeError

A CELT-only frame whose §4.3.7.1 prefix decode latched a range-coder error (a malformed / truncated frame). Silence of the correct length was emitted in its place per the §4.6 floor.

CeltCoarseEnergyDecoded

A non-silent CELT-only frame whose §4.3.7.1 prefix and §4.3.2.1 coarse-energy were decoded from the real range coder: the per-band coarse log-energy envelope was reconstructed (the 2-D predictor recurrence in crate::celt_coarse_energy) and threaded into the cross-frame predictor state. The remaining band-data stages (bit allocation, §4.3.4 PVQ band shapes, §4.3.2.2 fine energy) are not yet wired, so silence of the correct length is still emitted and the synthesis backend’s overlap-add / de-emphasis state is advanced — but the coarse-energy front half of the entropy decode is now real. (Distinct from Self::LayerNotWired: the frame prefix and coarse energy are actually consumed.)

CeltAllocationDecoded

A non-silent CELT-only frame that additionally decoded the §4.3.3 allocation header from the real range coder, on top of the §4.3.7.1 prefix and §4.3.2.1 coarse energy: the §4.3.3 band boosts (crate::celt_band_boost::decode_band_boosts), the §4.3.3 allocation trim (crate::celt_alloc_trim::decode_alloc_trim), and the §4.3.3 anti-collapse / skip / intensity-stereo / dual-stereo reservations (crate::celt_reservations::reserve_block) were consumed in §4.3.3 order, advancing the range-coder position through the entire signalled part of the allocation. The remaining §4.3.3 implicit allocation (the interp_bits2pulses per-band pulse / fine-energy split — reference-code-only, absent from the RFC narrative body) plus the §4.3.4 PVQ band shapes and §4.3.2.2 fine energy are still pending, so silence of the correct length is emitted and the synthesis backend’s overlap-add / de-emphasis state is advanced with all-zero bands. The signalled allocation header is now real. (Distinct from Self::CeltCoarseEnergyDecoded: the boost / trim / reservation symbols are actually consumed.)

Trait Implementations

impl Clone for FrameDecodeStatus

fn clone(&self) -> FrameDecodeStatus

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for FrameDecodeStatus

impl Debug for FrameDecodeStatus

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

Formats the value using the given formatter.

impl Eq for FrameDecodeStatus

impl PartialEq for FrameDecodeStatus

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for FrameDecodeStatus