pulp::signal::StftT< SampleType > Class Template Reference

Allocation-stable STFT processor with single-thread ownership. More...

#include <stft.hpp>

Public Member Functions
	StftT ()=default
	StftT (const StftConfig &config)
void	configure (const StftConfig &config)
	RT contract: configure() allocates FFT/window/ring/frame storage and is not audio-thread safe.
bool	push_samples (const SampleType *samples, int count)
	Feed audio samples.
const StftFrameT< SampleType > &	latest_frame () const
	Access the latest computed frame.
bool	frame_ready () const
	Whether at least one frame has been computed.
int	num_bins () const
	Number of frequency bins (fft_size/2 + 1).
SampleType	window_sum () const
	Sum of the configured analysis-window coefficients.
int	fft_size () const
	Current FFT size.
int	hop_size () const
	Current hop size.
std::vector< SampleType >	latest_magnitude_db (SampleType floor_db=SampleType{-120.0f}) const
	Get the latest frame magnitudes in dB. Not RT-safe; returns a vector.
void	reset ()

Static Public Member Functions
static void	to_db (SampleType *magnitudes, int count, SampleType floor_db=SampleType{-120.0f})
	Convert linear magnitudes to dB in-place.

Detailed Description

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

Allocation-stable STFT processor with single-thread ownership.

Feed samples via push_samples(). When enough samples accumulate for a hop, a complete windowed FFT frame is computed. The latest frame is available via latest_frame().

Intended usage keeps push and read on one thread. For realtime visualization, VisualizationBridge copies audio into fixed SPSC storage in the callback, then its UI-owned poll path calls push_samples(), reads the frame, and publishes a snapshot through TripleBuffer.

The STFT itself is NOT thread-safe for concurrent push/read. A TripleBuffer can publish completed results, but does not make concurrent access to this object safe.

Constructor & Destructor Documentation

StftT() [1/2]

template<typename SampleType = float>

pulp::signal::StftT< SampleType >::StftT ( )

default

StftT() [2/2]

template<typename SampleType = float>

pulp::signal::StftT< SampleType >::StftT ( const StftConfig & config )

inlineexplicit

Member Function Documentation

configure()

template<typename SampleType = float>

void pulp::signal::StftT< SampleType >::configure ( const StftConfig & config )

inline

RT contract: configure() allocates FFT/window/ring/frame storage and is not audio-thread safe.

After configure(), push_samples(), latest_frame(), frame_ready(), accessors, to_db(), and reset() are allocation-free, but FFT cost still makes callback use an explicit product-level decision. latest_magnitude_db() returns a vector copy and is not RT-safe.

fft_size()

template<typename SampleType = float>

int pulp::signal::StftT< SampleType >::fft_size ( ) const

inline

Current FFT size.

frame_ready()

template<typename SampleType = float>

bool pulp::signal::StftT< SampleType >::frame_ready ( ) const

inline

Whether at least one frame has been computed.

hop_size()

template<typename SampleType = float>

int pulp::signal::StftT< SampleType >::hop_size ( ) const

inline

Current hop size.

latest_frame()

template<typename SampleType = float>

const StftFrameT< SampleType > & pulp::signal::StftT< SampleType >::latest_frame ( ) const

inline

Access the latest computed frame.

latest_magnitude_db()

template<typename SampleType = float>

std::vector< SampleType > pulp::signal::StftT< SampleType >::latest_magnitude_db ( SampleType floor_db = SampleType{-120.0f} ) const

inline

Get the latest frame magnitudes in dB. Not RT-safe; returns a vector.

num_bins()

template<typename SampleType = float>

int pulp::signal::StftT< SampleType >::num_bins ( ) const

inline

Number of frequency bins (fft_size/2 + 1).

push_samples()

template<typename SampleType = float>

bool pulp::signal::StftT< SampleType >::push_samples ( const SampleType * samples, int count )

inline

Feed audio samples.

Call from the audio thread. Returns true if a new frame was computed during this call.

reset()

template<typename SampleType = float>

void pulp::signal::StftT< SampleType >::reset ( )

inline

to_db()

template<typename SampleType = float>

void pulp::signal::StftT< SampleType >::to_db ( SampleType * magnitudes, int count, SampleType floor_db = SampleType{-120.0f} )

inlinestatic

Convert linear magnitudes to dB in-place.

window_sum()

template<typename SampleType = float>

SampleType pulp::signal::StftT< SampleType >::window_sum ( ) const

inline

Sum of the configured analysis-window coefficients.

Consumers that need absolute amplitude calibration can divide DC/Nyquist magnitudes by this value and other one-sided real-FFT magnitudes by half this value.

---

The documentation for this class was generated from the following file:

• /home/runner/work/pulp/pulp/core/signal/include/pulp/signal/stft.hpp