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			88 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			C++
		
	
			
		
		
	
	
			88 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			C++
		
	
| /*
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|  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
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|  *
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|  *  Use of this source code is governed by a BSD-style license
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|  *  that can be found in the LICENSE file in the root of the source
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|  *  tree. An additional intellectual property rights grant can be found
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|  *  in the file PATENTS.  All contributing project authors may
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|  *  be found in the AUTHORS file in the root of the source tree.
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|  */
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| 
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| #ifndef WEBRTC_MODULES_AUDIO_CODING_NETEQ_PREEMPTIVE_EXPAND_H_
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| #define WEBRTC_MODULES_AUDIO_CODING_NETEQ_PREEMPTIVE_EXPAND_H_
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| 
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| #include <assert.h>
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| 
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| #include "webrtc/base/constructormagic.h"
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| #include "webrtc/modules/audio_coding/neteq/audio_multi_vector.h"
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| #include "webrtc/modules/audio_coding/neteq/time_stretch.h"
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| #include "webrtc/typedefs.h"
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| 
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| namespace webrtc {
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| 
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| // Forward declarations.
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| class BackgroundNoise;
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| 
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| // This class implements the PreemptiveExpand operation. Most of the work is
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| // done in the base class TimeStretch, which is shared with the Accelerate
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| // operation. In the PreemptiveExpand class, the operations that are specific to
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| // PreemptiveExpand are implemented.
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| class PreemptiveExpand : public TimeStretch {
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|  public:
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|   PreemptiveExpand(int sample_rate_hz,
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|                    size_t num_channels,
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|                    const BackgroundNoise& background_noise,
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|                    int overlap_samples)
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|       : TimeStretch(sample_rate_hz, num_channels, background_noise),
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|         old_data_length_per_channel_(-1),
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|         overlap_samples_(overlap_samples) {
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|   }
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| 
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|   virtual ~PreemptiveExpand() {}
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| 
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|   // This method performs the actual PreemptiveExpand operation. The samples are
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|   // read from |input|, of length |input_length| elements, and are written to
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|   // |output|. The number of samples added through time-stretching is
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|   // is provided in the output |length_change_samples|. The method returns
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|   // the outcome of the operation as an enumerator value.
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|   ReturnCodes Process(const int16_t *pw16_decoded,
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|                       int len,
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|                       int old_data_len,
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|                       AudioMultiVector* output,
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|                       int16_t* length_change_samples);
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| 
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|  protected:
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|   // Sets the parameters |best_correlation| and |peak_index| to suitable
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|   // values when the signal contains no active speech.
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|   virtual void SetParametersForPassiveSpeech(size_t len,
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|                                              int16_t* w16_bestCorr,
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|                                              int* w16_bestIndex) const;
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| 
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|   // Checks the criteria for performing the time-stretching operation and,
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|   // if possible, performs the time-stretching.
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|   virtual ReturnCodes CheckCriteriaAndStretch(
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|       const int16_t *pw16_decoded, size_t len, size_t w16_bestIndex,
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|       int16_t w16_bestCorr, bool w16_VAD,
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|       AudioMultiVector* output) const;
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| 
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|  private:
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|   int old_data_length_per_channel_;
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|   int overlap_samples_;
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| 
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|   DISALLOW_COPY_AND_ASSIGN(PreemptiveExpand);
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| };
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| 
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| struct PreemptiveExpandFactory {
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|   PreemptiveExpandFactory() {}
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|   virtual ~PreemptiveExpandFactory() {}
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| 
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|   virtual PreemptiveExpand* Create(
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|       int sample_rate_hz,
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|       size_t num_channels,
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|       const BackgroundNoise& background_noise,
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|       int overlap_samples) const;
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| };
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| 
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| }  // namespace webrtc
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| #endif  // WEBRTC_MODULES_AUDIO_CODING_NETEQ_PREEMPTIVE_EXPAND_H_
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