embdrv/lc3/Encoder/BitstreamEncoding.hpp

/*
 * BitstreamEncoding.hpp
 *
 * Copyright 2021 HIMSA II K/S - www.himsa.com. Represented by EHIMA -
 * www.ehima.com
 *
 * 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.
 */

#ifndef BITSTREAM_ENCODING_H_
#define BITSTREAM_ENCODING_H_

#include <cstdint>

#include "Datapoints.hpp"

namespace Lc3Enc {

class BitstreamEncoding {
 public:
  BitstreamEncoding(uint16_t NE_, uint16_t nbytes_);
  virtual ~BitstreamEncoding();

  void registerDatapoints(DatapointContainer* datapoints);

  void init(uint8_t* bytes_);
  void bandwidth(uint8_t P_bw, uint8_t nbits_bw);
  void lastNonzeroTuple(uint16_t lastnz_trunc);
  void lsbModeBit(uint8_t lsbMode);
  void globalGain(uint8_t gg_ind);
  void tnsActivationFlag(uint8_t num_tns_filters, uint8_t rc_order[]);
  void pitchPresentFlag(uint8_t pitch_present);
  void encodeScfVq1stStage(uint8_t ind_LF, uint8_t ind_HF);
  void encodeScfVq2ndStage(uint8_t shape_j, uint8_t gain_i, uint8_t LS_indA,
                           uint32_t index_joint_j);
  void ltpfData(uint8_t ltpf_active, uint16_t pitch_index);
  void noiseFactor(uint8_t F_NF);

  void ac_enc_init();
  void tnsData(uint8_t tns_lpc_weighting, uint8_t num_tns_filters,
               uint8_t rc_order[], uint8_t rc_i[]);
  void spectralData(uint16_t lastnz_trunc, uint16_t rateFlag, uint8_t lsbMode,
                    int16_t* X_q, uint16_t nbits_lsb, uint8_t* lsbs_);
  void residualDataAndFinalization(uint8_t lsbMode, uint16_t nbits_residual,
                                   uint8_t* res_bits);

 private:
  void write_bit_backward(uint8_t bytes[], uint16_t* bp, uint8_t* mask,
                          uint8_t bit);
  void write_uint_backward(uint8_t bytes[], uint16_t* bp, uint8_t* mask,
                           uint16_t val, uint8_t numbits);
  void write_uint_forward(uint8_t bytes[], uint16_t bp, uint16_t val,
                          uint8_t numbits);

  struct ac_enc_state {
    uint32_t low;
    uint32_t range;
    int32_t cache;
    int32_t carry;
    int32_t carry_count;
  };

  void ac_shift(uint8_t bytes[], uint16_t* bp, struct ac_enc_state* st);
  void ac_encode(uint8_t bytes[], uint16_t* bp, struct ac_enc_state* st,
                 short cum_freq, short sym_freq);
  void ac_enc_finish(uint8_t bytes[], uint16_t* bp, struct ac_enc_state* st);

  uint16_t nbits_side_written();
  uint16_t nbits_ari_forecast();
  uint16_t nbits_spec_written();

 public:
  const uint16_t NE;
  const uint16_t nbytes;
  const uint16_t nbits;

 private:
  uint8_t* bytes;
  uint16_t bp;
  uint16_t bp_side;
  uint8_t mask_side;
  uint16_t nbits_side_initial;
  uint16_t nlsbs;
  uint8_t* lsbs;
  struct ac_enc_state st;
};

}  // namespace Lc3Enc

#endif  // BITSTREAM_ENCODING_H_