58 lines
1.2 KiB
C
58 lines
1.2 KiB
C
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#ifndef NOISE_SHAPE_H_INCLUDED
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#define NOISE_SHAPE_H_INCLUDED
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#ifdef __cpluspluc
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extern "C" {
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#endif
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typedef struct noise_shape_ctx_s {
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int sos_count; /* number of second order sections */
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const float *bbaa; /* filter coefficients, owned by user */
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float *t1, *t2; /* filter state, owned by ns library */
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} noise_shape_ctx;
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/**
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* initializes a noise_shaper context
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* returns an error code or 0
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*/
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extern int noise_shape_init(
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noise_shape_ctx *ctx,
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int sos_count,
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const float *coeffs);
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/**
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* destroys a noise_shaper context
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*/
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extern void noise_shape_destroy(
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noise_shape_ctx *ctx);
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/**
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* initializes a noise_shaper context so that its state
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* is a copy of a given context
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* returns an error code or 0
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*/
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extern int noise_shape_clone(
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const noise_shape_ctx *from, noise_shape_ctx *to);
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/**
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* computes the next "noise shaping sample". Note: This call
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* alters the internal state. xxx_get and xxx_update must be
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* called in an alternating manner.
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*/
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extern float noise_shape_get(
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noise_shape_ctx *ctx);
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/**
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* updates the noise shaper's state with the
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* last quantization error
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*/
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extern void noise_shape_update(
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noise_shape_ctx *ctx, float qerror);
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#ifdef __cpluspluc
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} /* extern "C" */
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#endif
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#endif /* NOISE_SHAPE_H_INCLUDED */
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