Torpora

Grind to a halt, spin back.

Tape stop: the sound slows down and drops in pitch to a halt over the stop time, then spins back up over the start time (0 = cut straight back in). Curve bends the slowdown from a sudden drag (negative) to a long coast (positive). Trigger: 0 = the Stop control (on above half), 1 = the host transport stopping and starting, 2 = either.

● Freeorg.sournd.performance.torpora

Hear it

The real engine runs in your browser. Try the test sounds, your own file or a microphone, move the parameters or press Randomise, and switch bypass to compare.

Details

Engine id: org.sournd.performance.torpora
Category: Performance
Type: Tape stop
Licence: Free (Apache-2.0)
Version: 1.0.0
Parameters: 6
Latency: none
Tail: 4.5 s
Sidechain input: no
Channels: mono or stereo

Parameters

The id is the C ABI parameter id and the JUCE parameter id (as a decimal string).

Id	Key	Name	Min	Max	Default	Unit	Taper
0	`stop`	Stop	0	1	0	-	linear
1	`trigger`	Trigger	0	2	0	-	linear
2	`stop_ms`	Stop time	50	4000	800	ms	log
3	`start_ms`	Start time	0	4000	300	ms	linear
4	`curve`	Curve	-1	1	0	-	linear
5	`mix`	Mix	0	100	100	%	linear

How it is made

Original sOURnd design: a stereo ring buffer read behind the write point at a variable speed following a power-curve ramp (the read lag grows by one minus the speed each sample), linear-interpolated reads, a level fade over the last quarter of the speed range, and an equal-power hand-back to the live signal after spin-up; triggered by control or transport edges.

CMake

cmake

juce_add_module(path/to/sournd_engine)
target_include_directories(MyPlugin PRIVATE path/to/include)
target_link_libraries(MyPlugin PRIVATE sournd_engine path/to/libsournd_cabi.a)

Three lines. Full steps: JUCE quick start.

C++ (JUCE)

cpp

#include <sournd_engine/sournd_engine.h>

sournd::SourndEngine engine { "org.sournd.performance.torpora" };
juce::AudioProcessorValueTreeState parameters { *this, nullptr, "Parameters",
    sournd::SourndEngineParameters::createLayout (engine) };
sournd::SourndEngineParameters bridge { engine, parameters };

// prepareToPlay
engine.prepare ({ sampleRate, (juce::uint32) maximumBlock, 2 });
bridge.prepare (sampleRate);
setLatencySamples ((int) engine.latency());

// processBlock
bridge.apply ((uint32_t) buffer.getNumSamples());
juce::dsp::AudioBlock<float> block { buffer };
engine.process (juce::dsp::ProcessContextReplacing<float> { block });

// get/setStateInformation: hold getCallbackLock() around saveState / loadState,
// so state work never overlaps processBlock (full example: /docs/juce/)

Plain C

sournd_engine *e = NULL;
if (sournd_engine_create("org.sournd.performance.torpora", &e) == SOURND_OK) {
    sournd_engine_prepare(e, 48000.0, 512);
    sournd_engine_set_param(e, 0, 0); /* Stop */
    sournd_engine_process(e, in, out, 2, frames);
    sournd_engine_destroy(e);
}

Ask your AI

Paste this into your coding assistant:

Prompt

Add the sournd engine org.sournd.performance.torpora to my JUCE plugin. Follow https://sournd.com/docs/juce/index.md
and the engine reference at https://sournd.com/engines/torpora/index.md. Expose every parameter through APVTS.