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/******************************************************************************
*
* Copyright 2022 Google LLC
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
******************************************************************************/
/**
* LC3 - Temporal Noise Shaping
*
* Reference : Low Complexity Communication Codec (LC3)
* Bluetooth Specification v1.0
*/
#ifndef __LC3_TNS_H
#define __LC3_TNS_H
#include "common.h"
#include "bits.h"
/**
* Bitstream data
*/
typedef struct lc3_tns_data {
int nfilters;
bool lpc_weighting;
int rc_order[2];
int rc[2][8];
} lc3_tns_data_t;
/* ----------------------------------------------------------------------------
* Encoding
* -------------------------------------------------------------------------- */
/**
* TNS analysis
* dt, bw Duration and bandwidth of the frame
* nn_flag True when high energy detected near Nyquist frequency
* nbytes Size in bytes of the frame
* data Return bitstream data
* x Spectral coefficients, filtered as output
*/
void lc3_tns_analyze(enum lc3_dt dt, enum lc3_bandwidth bw,
bool nn_flag, int nbytes, lc3_tns_data_t *data, float *x);
/**
* Return number of bits coding the data
* data Bitstream data
* return Bit consumption
*/
int lc3_tns_get_nbits(const lc3_tns_data_t *data);
/**
* Put bitstream data
* bits Bitstream context
* data Bitstream data
*/
void lc3_tns_put_data(lc3_bits_t *bits, const lc3_tns_data_t *data);
/* ----------------------------------------------------------------------------
* Decoding
* -------------------------------------------------------------------------- */
/**
* Get bitstream data
* bits Bitstream context
* dt, bw Duration and bandwidth of the frame
* nbytes Size in bytes of the frame
* data Bitstream data
*/
void lc3_tns_get_data(lc3_bits_t *bits,
enum lc3_dt dt, enum lc3_bandwidth bw, int nbytes, lc3_tns_data_t *data);
/**
* TNS synthesis
* dt, bw Duration and bandwidth of the frame
* data Bitstream data
* x Spectral coefficients, filtered as output
*/
void lc3_tns_synthesize(enum lc3_dt dt, enum lc3_bandwidth bw,
const lc3_tns_data_t *data, float *x);
#endif /* __LC3_TNS_H */
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