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104 lines
2.8 KiB
C
104 lines
2.8 KiB
C
/******************************************************************************
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*
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* Copyright 2022 Google LLC
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at:
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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******************************************************************************/
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/**
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* LC3 - Spectral Noise Shaping
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*
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* Reference : Low Complexity Communication Codec (LC3)
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* Bluetooth Specification v1.0
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*/
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#ifndef __LC3_SNS_H
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#define __LC3_SNS_H
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#include "common.h"
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#include "bits.h"
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/**
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* Bitstream data
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*/
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typedef struct lc3_sns_data {
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int lfcb, hfcb;
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int shape, gain;
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int idx_a, idx_b;
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bool ls_a, ls_b;
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} lc3_sns_data_t;
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/* ----------------------------------------------------------------------------
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* Encoding
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* -------------------------------------------------------------------------- */
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/**
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* SNS analysis
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* dt, sr Duration and samplerate of the frame
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* eb Energy estimation per bands, and count of bands
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* att 1: Attack detected 0: Otherwise
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* data Return bitstream data
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* x Spectral coefficients
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* y Return shapped coefficients
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*
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* `x` and `y` can be the same buffer
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*/
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void lc3_sns_analyze(enum lc3_dt dt, enum lc3_srate sr,
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const float *eb, bool att, lc3_sns_data_t *data,
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const float *x, float *y);
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/**
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* Return number of bits coding the bitstream data
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* return Bit consumption
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*/
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int lc3_sns_get_nbits(void);
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/**
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* Put bitstream data
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* bits Bitstream context
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* data Bitstream data
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*/
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void lc3_sns_put_data(lc3_bits_t *bits, const lc3_sns_data_t *data);
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/* ----------------------------------------------------------------------------
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* Decoding
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* -------------------------------------------------------------------------- */
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/**
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* Get bitstream data
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* bits Bitstream context
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* data Return SNS data
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* return 0: Ok -1: Invalid SNS data
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*/
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int lc3_sns_get_data(lc3_bits_t *bits, lc3_sns_data_t *data);
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/**
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* SNS synthesis
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* dt, sr Duration and samplerate of the frame
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* data Bitstream data
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* x Spectral coefficients
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* y Return shapped coefficients
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*
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* `x` and `y` can be the same buffer
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*/
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void lc3_sns_synthesize(enum lc3_dt dt, enum lc3_srate sr,
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const lc3_sns_data_t *data, const float *x, float *y);
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#endif /* __LC3_SNS_H */
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