81 lines
3.2 KiB
C
81 lines
3.2 KiB
C
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/*
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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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#ifndef MODULES_AUDIO_CODING_NETEQ_ACCELERATE_H_
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#define MODULES_AUDIO_CODING_NETEQ_ACCELERATE_H_
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#include <stddef.h>
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#include <stdint.h>
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#include "modules/audio_coding/neteq/time_stretch.h"
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#include "rtc_base/constructor_magic.h"
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namespace webrtc {
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class AudioMultiVector;
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class BackgroundNoise;
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// This class implements the Accelerate operation. Most of the work is done
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// in the base class TimeStretch, which is shared with the PreemptiveExpand
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// operation. In the Accelerate class, the operations that are specific to
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// Accelerate are implemented.
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class Accelerate : public TimeStretch {
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public:
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Accelerate(int sample_rate_hz,
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size_t num_channels,
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const BackgroundNoise& background_noise)
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: TimeStretch(sample_rate_hz, num_channels, background_noise) {}
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// This method performs the actual Accelerate 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 removed 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. If |fast_accelerate|
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// is true, the algorithm will relax the requirements on finding strong
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// correlations, and may remove multiple pitch periods if possible.
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ReturnCodes Process(const int16_t* input,
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size_t input_length,
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bool fast_accelerate,
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AudioMultiVector* output,
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size_t* length_change_samples);
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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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void SetParametersForPassiveSpeech(size_t len,
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int16_t* best_correlation,
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size_t* peak_index) const override;
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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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ReturnCodes CheckCriteriaAndStretch(const int16_t* input,
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size_t input_length,
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size_t peak_index,
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int16_t best_correlation,
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bool active_speech,
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bool fast_mode,
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AudioMultiVector* output) const override;
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private:
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RTC_DISALLOW_COPY_AND_ASSIGN(Accelerate);
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};
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struct AccelerateFactory {
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AccelerateFactory() {}
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virtual ~AccelerateFactory() {}
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virtual Accelerate* Create(int sample_rate_hz,
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size_t num_channels,
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const BackgroundNoise& background_noise) const;
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};
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} // namespace webrtc
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#endif // MODULES_AUDIO_CODING_NETEQ_ACCELERATE_H_
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