Level-independent transient detector: the normalized excess of a fast envelope follower over a slow one. More...

#include <envelope.hpp>

Public Member Functions
void	prepare (SampleType sample_rate)
void	set_fast_ms (SampleType ms)
void	set_slow_ms (SampleType ms)
void	reset ()
SampleType	process (SampleType input)

Static Public Attributes
static constexpr SampleType	kDefaultFastMs = SampleType{2}
	Fast enough to sit on the attack itself.
static constexpr SampleType	kDefaultSlowMs = SampleType{40}
	Slow enough to represent "the level this material has been running at".

Detailed Description

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

Level-independent transient detector: the normalized excess of a fast envelope follower over a slow one.

out = max(0, (fast - slow) / max(slow, epsilon))

The division is what makes it level-independent: the same musical gesture at -6 dBFS and at -30 dBFS produces the same output, because both followers scale with the input and the ratio does not. An absolute-difference detector needs its threshold re-tuned for every source; this one does not.

RT contract: two BallisticsFilterT instances of scalar state. process() and reset() allocate nothing.

USE: input duckers; adaptive transient shapers; "how hard was that hit" as a modulation source; striking an LpgT from a live input's attacks so an effect breathes with the playing rather than with a fixed clock.