Brickworks > API documentation > bw_bd_reduce

bw_bd_reduce

Description

Bit depth reducer.

This is purely an audio effect, it doesn't actually produce an output signal with a different encoding. The algorithm is deliberately crude to obtain the characteristic noise due to lo-fi A/D quantization.

Info

Module type: dsp

Version: 1.0.0

Requires:

API

bw_bd_reduce_coeffs

typedef struct bw_bd_reduce_coeffs bw_bd_reduce_coeffs;

Coefficients and related.

bw_bd_reduce_init()

static inline void bw_bd_reduce_init(
	bw_bd_reduce_coeffs * BW_RESTRICT coeffs);

Initializes input parameter values in coeffs.

bw_bw_reduce_set_sample_rate()

static inline void bw_bd_reduce_set_sample_rate(
	bw_bd_reduce_coeffs * BW_RESTRICT coeffs,
	float                             sample_rate);

Sets the sample_rate (Hz) value in coeffs.

bw_bd_reduce_reset_coeffs()

static inline void bw_bd_reduce_reset_coeffs(
	bw_bd_reduce_coeffs * BW_RESTRICT coeffs);

Resets coefficients in coeffs to assume their target values.

bw_bd_reduce_update_coeffs_ctrl()

static inline void bw_bd_reduce_update_coeffs_ctrl(
	bw_bd_reduce_coeffs * BW_RESTRICT coeffs);

Triggers control-rate update of coefficients in coeffs.

bw_bd_reduce_update_coeffs_audio()

static inline void bw_bd_reduce_update_coeffs_audio(
	bw_bd_reduce_coeffs * BW_RESTRICT coeffs);

Triggers audio-rate update of coefficients in coeffs.

bw_bd_reduce_process1()

static inline float bw_bd_reduce_process1(
	const bw_bd_reduce_coeffs * BW_RESTRICT coeffs,
	float                                   x);

Processes one input sample x using coeffs. Returns the corresponding output sample.

bw_bd_reduce_process()

static inline void bw_bd_reduce_process(
	bw_bd_reduce_coeffs * BW_RESTRICT coeffs,
	const float *                     x,
	float *                           y,
	size_t                            n_samples);

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

bw_bd_reduce_process_multi()

static inline void bw_bd_reduce_process_multi(
	bw_bd_reduce_coeffs * BW_RESTRICT coeffs,
	const float * const *             x,
	float * const *                   y,
	size_t                            n_channels,
	size_t                            n_samples);

Processes the first n_samples of the n_channels input buffers x 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_bd_reduce_set_bit_depth()

static inline void bw_bd_reduce_set_bit_depth(
	bw_bd_reduce_coeffs * BW_RESTRICT coeffs,
	char                              value);

Sets the output bit depth value in coeffs.

Valid range: [1, 64].

Default value: 16.

bw_bd_reduce_coeffs_is_valid()

static inline char bw_bd_reduce_coeffs_is_valid(
	const bw_bd_reduce_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_bd_reduce_coeffs.

C++ wrapper

Brickworks::BDReduce
template<size_t N_CHANNELS>
class BDReduce {
public:
	BDReduce();

	void setSampleRate(
		float sampleRate);

	void reset();

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

	void process(
		std::array<const float *, N_CHANNELS> x,
		std::array<float *, N_CHANNELS>       y,
		size_t                                nSamples);

	void setBitDepth(
		char value);
...
}

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