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_CODING_NETEQ_PREEMPTIVE_EXPAND_H_
      12             : #define WEBRTC_MODULES_AUDIO_CODING_NETEQ_PREEMPTIVE_EXPAND_H_
      13             : 
      14             : #include <assert.h>
      15             : 
      16             : #include "webrtc/base/constructormagic.h"
      17             : #include "webrtc/modules/audio_coding/neteq/audio_multi_vector.h"
      18             : #include "webrtc/modules/audio_coding/neteq/time_stretch.h"
      19             : #include "webrtc/typedefs.h"
      20             : 
      21             : namespace webrtc {
      22             : 
      23             : // Forward declarations.
      24             : class BackgroundNoise;
      25             : 
      26             : // This class implements the PreemptiveExpand operation. Most of the work is
      27             : // done in the base class TimeStretch, which is shared with the Accelerate
      28             : // operation. In the PreemptiveExpand class, the operations that are specific to
      29             : // PreemptiveExpand are implemented.
      30           0 : class PreemptiveExpand : public TimeStretch {
      31             :  public:
      32           0 :   PreemptiveExpand(int sample_rate_hz,
      33             :                    size_t num_channels,
      34             :                    const BackgroundNoise& background_noise,
      35             :                    size_t overlap_samples)
      36           0 :       : TimeStretch(sample_rate_hz, num_channels, background_noise),
      37             :         old_data_length_per_channel_(0),
      38           0 :         overlap_samples_(overlap_samples) {
      39           0 :   }
      40             : 
      41             :   // This method performs the actual PreemptiveExpand operation. The samples are
      42             :   // read from |input|, of length |input_length| elements, and are written to
      43             :   // |output|. The number of samples added through time-stretching is
      44             :   // is provided in the output |length_change_samples|. The method returns
      45             :   // the outcome of the operation as an enumerator value.
      46             :   ReturnCodes Process(const int16_t *pw16_decoded,
      47             :                       size_t len,
      48             :                       size_t old_data_len,
      49             :                       AudioMultiVector* output,
      50             :                       size_t* length_change_samples);
      51             : 
      52             :  protected:
      53             :   // Sets the parameters |best_correlation| and |peak_index| to suitable
      54             :   // values when the signal contains no active speech.
      55             :   void SetParametersForPassiveSpeech(size_t input_length,
      56             :                                      int16_t* best_correlation,
      57             :                                      size_t* peak_index) const override;
      58             : 
      59             :   // Checks the criteria for performing the time-stretching operation and,
      60             :   // if possible, performs the time-stretching.
      61             :   ReturnCodes CheckCriteriaAndStretch(const int16_t* input,
      62             :                                       size_t input_length,
      63             :                                       size_t peak_index,
      64             :                                       int16_t best_correlation,
      65             :                                       bool active_speech,
      66             :                                       bool /*fast_mode*/,
      67             :                                       AudioMultiVector* output) const override;
      68             : 
      69             :  private:
      70             :   size_t old_data_length_per_channel_;
      71             :   size_t overlap_samples_;
      72             : 
      73             :   RTC_DISALLOW_COPY_AND_ASSIGN(PreemptiveExpand);
      74             : };
      75             : 
      76             : struct PreemptiveExpandFactory {
      77           0 :   PreemptiveExpandFactory() {}
      78           0 :   virtual ~PreemptiveExpandFactory() {}
      79             : 
      80             :   virtual PreemptiveExpand* Create(
      81             :       int sample_rate_hz,
      82             :       size_t num_channels,
      83             :       const BackgroundNoise& background_noise,
      84             :       size_t overlap_samples) const;
      85             : };
      86             : 
      87             : }  // namespace webrtc
      88             : #endif  // WEBRTC_MODULES_AUDIO_CODING_NETEQ_PREEMPTIVE_EXPAND_H_