Livt.Signal

Livt.Signal provides reusable, hardware-oriented signal-processing components for Livt projects. Version 0.1.1 includes signed Q1.15 sample streams, moving statistics, filters, window functions, sample-rate conversion, FFT/IFFT, oscillators, and mixers.

📦 Package

[dependencies]
Livt.Signal = "0.1.1"

Version 0.1.1 publishes package discovery metadata, this README, the changelog, and the MIT license. Its component API is unchanged from 0.1.0.

Livt.Signal depends on Livt.Base 1.2.1, Livt.Math 1.7.2, and Livt.Collections 1.4.2.

Components

The Livt.Signal.Stream namespace provides the common stream contracts:

• IQ15SampleStream — signed Q1.15 samples with valid/ready flow control and first/last frame markers.
• Q15SampleEncoding — exact sign-extending decode and saturating encode at the stream/arithmetic boundary.
• Q15SampleDelay<STAGES> — a registered, globally stallable alignment pipeline with nominal latency STAGES, initiation interval one, and capacity STAGES.
• Q15SampleFifo<CAPACITY> — a bounded FIFO that preserves samples and frame markers under backpressure.
• IInt16SampleStream, IInt32SampleStream, and IUInt32SampleStream — explicitly scaled integer streams using the same flow-control contract.

The Livt.Signal.Statistics namespace provides exact full-window MovingSumInt16, MovingMeanInt16, MovingRmsInt16, and MovingVarianceInt16 components. All accept one sample per clock after fill; their fixed arithmetic latency and capacity are exposed as public constants.

The Livt.Signal.Filter namespace provides FirQ15 and SymmetricFirQ15 with configurable signed coefficient formats, nearest-even output rounding, saturation, and stall-safe timing. ReloadableFirQ15 supports complete coefficient-set loading and atomic activation. BiquadQ15 provides a fixed-coefficient IIR section using the normalized second-order-section convention and quantized stability checks. See the FIR contract and the biquad contract.

The Livt.Signal.Window namespace provides arbitrary fixed WindowQ15 tables and symmetric or periodic Hann, Hamming, and Blackman components. Window position follows the stream's frame markers and remains coherent under stalls. See the window contract.

The Livt.Signal.RateChange namespace provides CicDecimatorQ15 and CicInterpolatorQ15 for compile-time integer sample-rate changes. They expose accumulator growth and output cadence, support automatic or explicit output scaling, and preserve stream backpressure. See the CIC contract.

The Livt.Signal.Transform namespace defines complex sample streams and explicit FFT/IFFT direction, ordering, and scaling contracts. SequentialFftQ15 supports power-of-two transform sizes from 8 through 4096. See the FFT/IFFT contract.

The Livt.Signal.Oscillator namespace provides CordicNcoQ15, a numerically controlled oscillator with 16- through 32-bit modulo phase accumulation. Livt.Signal.Mixer provides real and complex Q1.15 mixers. Their paired valid/ready inputs keep oscillator phase coherent with samples under backpressure. See the NCO and mixer contract.

A token transfers on an active clock edge when valid && ready. A producer holds the complete token stable while stalled. All interfaces are single-clock; crossing a clock or reset domain requires an explicit CDC component.

See the usage guide for numeric, framing, reset, timing, and composition details.

Package boundary

Livt.Signal owns reusable sample-stream processing. Scalar fixed-point arithmetic, complex Q15 helpers, square root, and CORDIC remain in Livt.Math. Protocol-specific transport, media framing, and application processing are outside the package's scope.

Build and test

livt sync
livt test

License

This project is licensed under the MIT License. See LICENSE.