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120 lines
3.8 KiB
C
120 lines
3.8 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 coefficients encoding/decoding
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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_SPEC_H
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#define __LC3_SPEC_H
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#include "common.h"
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#include "tables.h"
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#include "bwdet.h"
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#include "ltpf.h"
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#include "tns.h"
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#include "sns.h"
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/**
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* Spectral quantization side data
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*/
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typedef struct lc3_spec_side {
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int g_idx, nq;
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bool lsb_mode;
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} lc3_spec_side_t;
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/* ----------------------------------------------------------------------------
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* Encoding
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* -------------------------------------------------------------------------- */
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/**
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* Spectrum analysis
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* dt, sr, nbytes Duration, samplerate and size of the frame
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* pitch, tns Pitch present indication and TNS bistream data
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* spec Context of analysis
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* x Spectral coefficients, scaled as output
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* xq, side Return quantization data
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*
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* The spectral coefficients `xq` storage is :
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* b0 0:positive or zero 1:negative
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* b15..b1 Absolute value
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*/
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void lc3_spec_analyze(enum lc3_dt dt, enum lc3_srate sr,
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int nbytes, bool pitch, const lc3_tns_data_t *tns,
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lc3_spec_analysis_t *spec, float *x, uint16_t *xq, lc3_spec_side_t *side);
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/**
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* Put spectral quantization side data
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* bits Bitstream context
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* dt, sr Duration and samplerate of the frame
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* side Spectral quantization side data
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*/
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void lc3_spec_put_side(lc3_bits_t *bits,
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enum lc3_dt dt, enum lc3_srate sr, const lc3_spec_side_t *side);
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/**
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* Encode spectral coefficients
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* bits Bitstream context
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* dt, sr, bw Duration, samplerate, bandwidth
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* nbytes and size of the frame
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* xq, side Quantization data
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* x Scaled spectral coefficients
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*
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* The spectral coefficients `xq` storage is :
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* b0 0:positive or zero 1:negative
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* b15..b1 Absolute value
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*/
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void lc3_spec_encode(lc3_bits_t *bits,
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enum lc3_dt dt, enum lc3_srate sr, enum lc3_bandwidth bw, int nbytes,
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const uint16_t *xq, const lc3_spec_side_t *side, const float *x);
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/* ----------------------------------------------------------------------------
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* Decoding
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* -------------------------------------------------------------------------- */
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/**
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* Get spectral quantization side data
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* bits Bitstream context
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* dt, sr Duration and samplerate of the frame
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* side Return quantization side data
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* return 0: Ok -1: Invalid bandwidth indication
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*/
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int lc3_spec_get_side(lc3_bits_t *bits,
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enum lc3_dt dt, enum lc3_srate sr, lc3_spec_side_t *side);
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/**
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* Decode spectral coefficients
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* bits Bitstream context
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* dt, sr, bw Duration, samplerate, bandwidth
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* nbytes and size of the frame
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* side Quantization side data
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* x Spectral coefficients
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* return 0: Ok -1: Invalid bitstream data
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*/
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int lc3_spec_decode(lc3_bits_t *bits, enum lc3_dt dt, enum lc3_srate sr,
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enum lc3_bandwidth bw, int nbytes, const lc3_spec_side_t *side, float *x);
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#endif /* __LC3_SPEC_H */
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