ossia::meters::ppm Struct Reference

Detailed Description

Quasi-peak programme meter (IEC 60268-10).

The rise follows the signal's rectified value through a one-pole charge whose speed is set so that a 5 kHz tone burst lasting the integration time reads 2 dB below the same tone held steady; the fall is exponential at the standard's rate. Type I (DIN, Nordic): 5 ms, 20 dB in 1.5 s. Type II (BBC, EBU): 10 ms, 24 dB in 2.8 s.

Public Types
enum	type { type_i , type_ii }

Public Member Functions
void	prepare (double rate, type t) noexcept
void	process (const auto *in, int n) noexcept
double	level () const noexcept
double	tone_reading (double rate, double duration) noexcept
	Highest reading reached during a 5 kHz unit sine lasting duration.

Static Public Member Functions
static constexpr double	integration_time (type t) noexcept
static constexpr double	fall_db_per_s (type t) noexcept

Public Attributes
double	env {}
double	attack {}
double	fall {}
double	gain {1.}
double	designed_rate {}
	The design the coefficients were computed for: preparing again for the same one only clears the envelope.
type	designed_type {}