embdrv/lc3/Decoder/DecoderFrame.hpp

/*
 * DecoderFrame.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 __DECODER_FRAME_HPP_
#define __DECODER_FRAME_HPP_

#include <cstdint>

#include "ArithmeticDec.hpp"
#include "Datapoints.hpp"
#include "Lc3Config.hpp"
#include "LongTermPostfilter.hpp"
#include "MdctDec.hpp"
#include "PacketLossConcealment.hpp"
#include "ResidualSpectrum.hpp"
#include "SideInformation.hpp"
#include "SpectralNoiseShaping.hpp"

namespace Lc3Dec {

class DecoderFrame {
 public:
  DecoderFrame(ResidualSpectrum& residualSpectrum_,
               SpectralNoiseShaping& spectralNoiseShaping_,
               PacketLossConcealment& packetLossConcealment_, MdctDec& mdctDec_,
               const Lc3Config& lc3Config_, uint16_t nbytes_);
  virtual ~DecoderFrame();

  void registerDatapoints(DatapointContainer* datapoints_);

  template <typename T>
  void run(const uint8_t* bytes, uint8_t BFI,
           uint16_t bits_per_audio_sample_dec, T* x_out, uint8_t& BEC_detect) {
    if (!lc3Config.isValid()) {
      return;
    }

    // main decoder implementation: 3.4.1 until 3.4.9 (d09r06)
    runFloat(bytes, BFI, BEC_detect);

    // 3.4.10 Output signal scaling and rounding   (d09r06)
    const uint32_t outputScale = 1UL << (-15 + bits_per_audio_sample_dec - 1);
    for (uint16_t k = 0; k < lc3Config.NF; k++) {
      double x_hat_clip_local;
      if (longTermPostfilter.x_hat_ltpf[k] > 32767) {
        x_hat_clip_local = 32767;
      } else if (longTermPostfilter.x_hat_ltpf[k] < -32768) {
        x_hat_clip_local = -32768;
      } else {
        x_hat_clip_local = longTermPostfilter.x_hat_ltpf[k];
      }

      // datapoint buffer for x_hat_clip only prepared when datapoints are
      // available
      if (nullptr != x_hat_clip) {
        x_hat_clip[k] = x_hat_clip_local;
      }

      // Round 𝑥 to nearest integer, e.g., ⌊−4.5⌉ = −5, ⌊−3.2⌉ = −3, ⌊3.2⌉ = 3,
      // ⌊4.5⌉ = 5,
      if (x_hat_clip_local > 0) {
        x_out[k] = outputScale * x_hat_clip_local + 0.5;
      } else {
        x_out[k] = outputScale * x_hat_clip_local - 0.5;
      }
    }

    if (nullptr != datapoints) {
      datapoints->log("x_out", &x_out[0], sizeof(T) * lc3Config.NF);
      datapoints->log("BER_detect", &BEC_detect, sizeof(BEC_detect));
    }
  }

  void linkPreviousFrame(DecoderFrame* previousFrame);

  // per instance constant parameter
  const uint16_t nbytes;
  const uint16_t nbits;
  const Lc3Config& lc3Config;
  const uint8_t tns_lpc_weighting;

 private:
  void runFloat(const uint8_t* bytes, uint8_t BFI, uint8_t& BEC_detect);

  void noiseFilling();
  void applyGlobalGain();
  void temporalNoiseShaping();

  SideInformation sideInformation;
  ArithmeticDec arithmeticDec;
  ResidualSpectrum& residualSpectrum;
  SpectralNoiseShaping& spectralNoiseShaping;
  PacketLossConcealment& packetLossConcealment;
  MdctDec& mdctDec;
  LongTermPostfilter longTermPostfilter;

  DatapointContainer* datapoints;

  // states & outputs
  int16_t frameN;

  int16_t lastnz;
  int16_t P_BW;
  uint8_t lsbMode;
  int16_t gg_ind;
  int16_t num_tns_filters;
  int16_t rc_order[2];
  uint8_t pitch_present;
  int16_t pitch_index;
  int16_t ltpf_active;
  int16_t F_NF;
  int16_t ind_LF;
  int16_t ind_HF;
  int16_t Gind;
  int16_t LS_indA;
  int16_t LS_indB;
  int32_t idxA;
  int16_t idxB;
  uint16_t nf_seed;
  uint16_t zeroFrame;
  int16_t gg_off;
  double* X_hat_q_nf;
  double* X_hat_f;
  double* X_s_tns;
  double* X_hat_ss;
  double* x_hat_clip;
};

}  // namespace Lc3Dec

#endif  // __DECODER_FRAME_HPP_