bw_ring_mod

Ring modulator with variable modulation amount.

Examples

Here you can download one or more example VST3 plugins for Windows, macOS and Linux. Source code of the audio engine(s) is included in the archive(s).

VST® is a trademark of Steinberg Media Technologies GmbH, registered in Europe and other countries.

API

Module type: DSP

bw_ring_mod_coeffs

typedef struct bw_ring_mod_coeffs bw_ring_mod_coeffs;

Coefficients and related.

bw_ring_mod_init()

static inline void bw_ring_mod_init(
	bw_ring_mod_coeffs * BW_RESTRICT coeffs);

Initializes input parameter values in coeffs.

bw_ring_mod_set_sample_rate()

static inline void bw_ring_mod_set_sample_rate(
	bw_ring_mod_coeffs * BW_RESTRICT coeffs,
	float                            sample_rate);

Sets the sample_rate (Hz) value in coeffs.

bw_ring_mod_reset_coeffs()

static inline void bw_ring_mod_reset_coeffs(
	bw_ring_mod_coeffs * BW_RESTRICT coeffs);

Resets coefficients in coeffs to assume their target values.

bw_ring_mod_update_coeffs_ctrl()

static inline void bw_ring_mod_update_coeffs_ctrl(
	bw_ring_mod_coeffs * BW_RESTRICT coeffs);

Triggers control-rate update of coefficients in coeffs.

bw_ring_mod_update_coeffs_audio()

static inline void bw_ring_mod_update_coeffs_audio(
	bw_ring_mod_coeffs * BW_RESTRICT coeffs);

Triggers audio-rate update of coefficients in coeffs.

bw_ring_mod_process1()

static inline float bw_ring_mod_process1(
	const bw_ring_mod_coeffs * BW_RESTRICT coeffs,
	float                                  x_mod,
	float                                  x_car);

Processes one modulation input sample x_mod and one carrier input sample x_car using coeffs and returns the corresponding output sample.

bw_ring_mod_process()

static inline void bw_ring_mod_process(
	bw_ring_mod_coeffs * BW_RESTRICT coeffs,
	const float *                    x_mod,
	const float *                    x_car,
	float *                          y,
	size_t                           n_samples);

Processes the first n_samples of the modulation input buffer x_mod and of the carrier input buffer x_car and fills the first n_samples of the output buffer y, while using and updating coeffs (control and audio rate).

bw_ring_mod_process_multi()

static inline void bw_ring_mod_process_multi(
	bw_ring_mod_coeffs * BW_RESTRICT coeffs,
	const float * const *            x_mod,
	const float * const *            x_car,
	float * const *                  y,
	size_t                           n_channels,
	size_t                           n_samples);

Processes the first n_samples of the n_channels modulation input buffers x_mod and of the n_channels carrier input buffers x_car, and fills the first n_samples of the n_channels output buffers y, while using and updating the common coeffs (control and audio rate).

bw_ring_mod_set_amount()

static inline void bw_ring_mod_set_amount(
	bw_ring_mod_coeffs * BW_RESTRICT coeffs,
	float                            value);

Sets the modulation amount parameter to the given value (0.f = no modulation, 1.f = full modulation, -1.f = full modulation with inverted polarity) in coeffs.

Valid range: [-1.f (full modulation with inverted polarity), 1.f (full modulation)].

Default value: 1.f.

bw_ring_mod_coeffs_is_valid()

static inline char bw_ring_mod_coeffs_is_valid(
	const bw_ring_mod_coeffs * BW_RESTRICT coeffs);

Tries to determine whether coeffs is valid and returns non-0 if it seems to be the case and 0 if it is certainly not. False positives are possible, false negatives are not.

coeffs must at least point to a readable memory block of size greater than or equal to that of bw_ring_mod_coeffs.

C++ wrapper

Brickworks::RingMod

template<size_t N_CHANNELS = 1>
class RingMod {
public:
	RingMod();

	void setSampleRate(
		float sampleRate);

	void reset();

	void process(
		const float * const * xMod,
		const float * const * xCar,
		float * const *       y,
		size_t                nSamples);

# ifndef BW_CXX_NO_ARRAY
	void process(
		std::array<const float *, N_CHANNELS> xMod,
		std::array<const float *, N_CHANNELS> xCar,
		std::array<float *, N_CHANNELS>       y,
		size_t                                nSamples);
# endif

	void setAmount(float value);
...
}

Changelog

• Version 1.2.1:
  • Added default value for N_CHANNELS in C++ API.
  • Updated dependencies.
• Version 1.2.0:
  • Added support for BW_INCLUDE_WITH_QUOTES, BW_NO_CXX, and BW_CXX_NO_EXTERN_C.
  • Added debugging checks from bw_ring_mod_process() to bw_ring_mod_process_multi().
  • Added debugging checks in bw_ring_mod_process_multi() to ensure that buffers used for both input and output appear at the same channel indices.
• Version 1.1.0:
  • Now using BW_NULL and BW_CXX_NO_ARRAY.
• Version 1.0.0:
  • Module renamed as bw_ring_mod.
  • bw_ring_mod_process() and bw_ring_mod_process_multi() now use size_t to count samples and channels.
  • Added more const specifiers to input arguments.
  • Moved C++ code to C header.
  • Added overloaded C++ process() function taking C-style arrays as arguments.
  • Removed usage of reserved identifiers.
  • Fixed inverted-polarity modulation (for real this time).
  • Clearly specified parameter validity ranges.
  • Added debugging code.
• Version 0.6.0:
  • Removed dependency on bw_config.
• Version 0.5.0:
  • Added bw_ringmod_process_multi().
  • Fixed inverted-polarity modulation.
  • "modulator signal" -> "modulation signal" in documentation.
  • Added C++ wrapper.
• Version 0.4.0:
  • First release.