pulp::gpu_audio::GpuSpectralStack Class Reference

GPU-resident engine: the captured layer spectra live on the GPU and every hop runs advance + smear + weighted-sum + one inverse FFT on the device, reading back only the single synthesized frame. More...

#include <spectral_stack.hpp>

Public Member Functions
bool	prepare (uint32_t fft_size, uint32_t hop, uint32_t num_layers, render::GpuCompute *shared_device=nullptr)
	shared_device (optional) reuses an existing GpuCompute so the stack and a sibling don't each spin up a device; null = create + own one.
uint32_t	fft_size () const override
uint32_t	num_layers () const override
bool	available () const override
	True if this stack's compute backend is live.
bool	capture (uint32_t layer, const float *frame_in) override
	Analyze frame_in (fft_size real samples) with the analysis window and freeze its magnitude + phase into layer, activating it.
void	clear (uint32_t layer) override
	Deactivate a layer (its magnitude goes silent; phase keeps advancing).
bool	layer_active (uint32_t layer) const override
bool	render (float *frame_out, const float *weights, float smear, float jitter) override
	Advance + smear + weighted-sum the stack into frame_out (fft_size real samples).
std::string	backend () const
	GPU backend name ("Metal"/"D3D12"/"Vulkan"), or "" if no device.

Detailed Description

GPU-resident engine: the captured layer spectra live on the GPU and every hop runs advance + smear + weighted-sum + one inverse FFT on the device, reading back only the single synthesized frame.

Wins over the CPU at high layer counts (the per-bin smear + the N-layer reduce parallelize). available() is true only with a GPU device; capture's forward FFT is done on the CPU (cheap, once per freeze). Not real-time-safe (blocks on the readback) — drive it off the audio thread. May share a device with a sibling primitive (e.g. GpuStft).

The layer spectra live on the device prepared here, so the stack records the device's generation at prepare(). Once the device reports loss or a new generation, available() goes false and capture()/render() refuse (render writes a silent frame) until the stack is prepared again.

Member Function Documentation

available()

bool pulp::gpu_audio::GpuSpectralStack::available ( ) const

overridevirtual

True if this stack's compute backend is live.

The CPU stack is always available; the GPU stack is available only with a GPU device.

Implements pulp::gpu_audio::SpectralStack.

backend()

std::string pulp::gpu_audio::GpuSpectralStack::backend

(

)

const

GPU backend name ("Metal"/"D3D12"/"Vulkan"), or "" if no device.

capture()

bool pulp::gpu_audio::GpuSpectralStack::capture ( uint32_t layer, const float * frame_in )

overridevirtual

Analyze frame_in (fft_size real samples) with the analysis window and freeze its magnitude + phase into layer, activating it.

Implements pulp::gpu_audio::SpectralStack.

clear()

void pulp::gpu_audio::GpuSpectralStack::clear ( uint32_t layer )

overridevirtual

Deactivate a layer (its magnitude goes silent; phase keeps advancing).

Implements pulp::gpu_audio::SpectralStack.

fft_size()

uint32_t pulp::gpu_audio::GpuSpectralStack::fft_size ( ) const

inlineoverridevirtual

Implements pulp::gpu_audio::SpectralStack.

layer_active()

bool pulp::gpu_audio::GpuSpectralStack::layer_active ( uint32_t layer ) const

overridevirtual

Implements pulp::gpu_audio::SpectralStack.

num_layers()

uint32_t pulp::gpu_audio::GpuSpectralStack::num_layers ( ) const

inlineoverridevirtual

Implements pulp::gpu_audio::SpectralStack.

prepare()

bool pulp::gpu_audio::GpuSpectralStack::prepare	(	uint32_t	fft_size,
		uint32_t	hop,
		uint32_t	num_layers,
		render::GpuCompute *	shared_device = nullptr )

shared_device (optional) reuses an existing GpuCompute so the stack and a sibling don't each spin up a device; null = create + own one.

render()

bool pulp::gpu_audio::GpuSpectralStack::render ( float * frame_out, const float * weights, float smear, float jitter )

overridevirtual

Advance + smear + weighted-sum the stack into frame_out (fft_size real samples).

weights (length num_layers) scales each layer; smear (0..1) blurs magnitude across frequency; jitter (0..1) adds phase wander. Returns false if no layer is active or the backend is unavailable.

Implements pulp::gpu_audio::SpectralStack.

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

• /home/runner/work/pulp/pulp/core/gpu_audio/include/pulp/gpu_audio/spectral_stack.hpp