2x half-band downsampler. More...

#include <halfband_iir.hpp>

Public Member Functions
	HalfBandDownsampler2xT () noexcept
	HalfBandDownsampler2xT (std::span< const SampleType > coeffs_a, std::span< const SampleType > coeffs_b) noexcept
std::size_t	sections_a () const noexcept
std::size_t	sections_b () const noexcept
bool	configured () const noexcept
void	reset () noexcept
SampleType	process (SampleType in_lo, SampleType in_hi) noexcept
	Consume two input samples (lo = even phase, hi = odd phase) and return one decimated output sample.
void	process_block (std::span< const SampleType > input, std::span< SampleType > output) noexcept
	Block helper.

Detailed Description

template<typename SampleType = float>
class pulp::signal::HalfBandDownsampler2xT< SampleType >

2x half-band downsampler.

Each call to process(in_lo, in_hi) consumes two input samples at the higher rate and emits one decimated output. in_lo is the input-stream sample at index 2n and in_hi the one at 2n+1, fed in chronological order. The odd-phase input drives path A and the even-phase input path B, which is the decimation polyphase identity: H's output kept at odd phases, one high-rate sample ahead of H's own delay. Content in the stopband (above 0.29 of the input rate with the default coefficients) aliases into the output at or below the design's stopband floor (-94.8 dB with the default coefficients).

A thin wrapper over HalfBandIirStageT; the same coefficient-shape rule as HalfBandUpsampler2xT applies.

RT contract: no member allocates, including the constructors.