Line data    Source code

       1             : /*
       2             :  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
       3             :  *
       4             :  *  Use of this source code is governed by a BSD-style license
       5             :  *  that can be found in the LICENSE file in the root of the source
       6             :  *  tree. An additional intellectual property rights grant can be found
       7             :  *  in the file PATENTS.  All contributing project authors may
       8             :  *  be found in the AUTHORS file in the root of the source tree.
       9             :  */
      10             : 
      11             : #ifndef WEBRTC_MODULES_AUDIO_PROCESSING_VAD_POLE_ZERO_FILTER_H_
      12             : #define WEBRTC_MODULES_AUDIO_PROCESSING_VAD_POLE_ZERO_FILTER_H_
      13             : 
      14             : #include <cstddef>
      15             : 
      16             : #include "webrtc/typedefs.h"
      17             : 
      18             : namespace webrtc {
      19             : 
      20             : class PoleZeroFilter {
      21             :  public:
      22           0 :   ~PoleZeroFilter() {}
      23             : 
      24             :   static PoleZeroFilter* Create(const float* numerator_coefficients,
      25             :                                 size_t order_numerator,
      26             :                                 const float* denominator_coefficients,
      27             :                                 size_t order_denominator);
      28             : 
      29             :   int Filter(const int16_t* in, size_t num_input_samples, float* output);
      30             : 
      31             :  private:
      32             :   PoleZeroFilter(const float* numerator_coefficients,
      33             :                  size_t order_numerator,
      34             :                  const float* denominator_coefficients,
      35             :                  size_t order_denominator);
      36             : 
      37             :   static const int kMaxFilterOrder = 24;
      38             : 
      39             :   int16_t past_input_[kMaxFilterOrder * 2];
      40             :   float past_output_[kMaxFilterOrder * 2];
      41             : 
      42             :   float numerator_coefficients_[kMaxFilterOrder + 1];
      43             :   float denominator_coefficients_[kMaxFilterOrder + 1];
      44             : 
      45             :   size_t order_numerator_;
      46             :   size_t order_denominator_;
      47             :   size_t highest_order_;
      48             : };
      49             : 
      50             : }  // namespace webrtc
      51             : 
      52             : #endif  // WEBRTC_MODULES_AUDIO_PROCESSING_VAD_POLE_ZERO_FILTER_H_