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6719017d19
NetEq was (up until this CL) capable of fading over to generating a
constant background noise when voice expansion had lasted too long.
However, the code has for a really long time only ever used the "off"
mode, which meant that long expansions are faded down to complete
silence (only zeros), i.e., background noise fill was not used.
Removing the other two modes ("on" and "fade") simplifies the code.
Bug: webrtc:9180
Change-Id: Ia2d46960208f3d75c9659ad3f027c52e5ecfb6b0
Reviewed-on: https://webrtc-review.googlesource.com/71485
Commit-Queue: Henrik Lundin <henrik.lundin@webrtc.org>
Reviewed-by: Minyue Li <minyue@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22969}
131 lines
4.1 KiB
C++
131 lines
4.1 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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#ifndef MODULES_AUDIO_CODING_NETEQ_BACKGROUND_NOISE_H_
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#define MODULES_AUDIO_CODING_NETEQ_BACKGROUND_NOISE_H_
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#include <string.h> // size_t
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#include <memory>
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#include "modules/audio_coding/neteq/audio_multi_vector.h"
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#include "modules/audio_coding/neteq/include/neteq.h"
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#include "rtc_base/constructormagic.h"
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#include "typedefs.h" // NOLINT(build/include)
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namespace webrtc {
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// Forward declarations.
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class PostDecodeVad;
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// This class handles estimation of background noise parameters.
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class BackgroundNoise {
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public:
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// TODO(hlundin): For 48 kHz support, increase kMaxLpcOrder to 10.
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// Will work anyway, but probably sound a little worse.
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static const size_t kMaxLpcOrder = 8; // 32000 / 8000 + 4.
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explicit BackgroundNoise(size_t num_channels);
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virtual ~BackgroundNoise();
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void Reset();
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// Updates the parameter estimates based on the signal currently in the
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// |sync_buffer|, and on the latest decision in |vad| if it is running.
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void Update(const AudioMultiVector& sync_buffer,
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const PostDecodeVad& vad);
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// Returns |energy_| for |channel|.
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int32_t Energy(size_t channel) const;
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// Sets the value of |mute_factor_| for |channel| to |value|.
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void SetMuteFactor(size_t channel, int16_t value);
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// Returns |mute_factor_| for |channel|.
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int16_t MuteFactor(size_t channel) const;
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// Returns a pointer to |filter_| for |channel|.
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const int16_t* Filter(size_t channel) const;
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// Returns a pointer to |filter_state_| for |channel|.
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const int16_t* FilterState(size_t channel) const;
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// Copies |length| elements from |input| to the filter state. Will not copy
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// more than |kMaxLpcOrder| elements.
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void SetFilterState(size_t channel, const int16_t* input, size_t length);
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// Returns |scale_| for |channel|.
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int16_t Scale(size_t channel) const;
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// Returns |scale_shift_| for |channel|.
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int16_t ScaleShift(size_t channel) const;
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// Accessors.
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bool initialized() const { return initialized_; }
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private:
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static const int kThresholdIncrement = 229; // 0.0035 in Q16.
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static const size_t kVecLen = 256;
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static const int kLogVecLen = 8; // log2(kVecLen).
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static const size_t kResidualLength = 64;
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static const int16_t kLogResidualLength = 6; // log2(kResidualLength)
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struct ChannelParameters {
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// Constructor.
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ChannelParameters() {
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Reset();
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}
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void Reset() {
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energy = 2500;
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max_energy = 0;
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energy_update_threshold = 500000;
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low_energy_update_threshold = 0;
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memset(filter_state, 0, sizeof(filter_state));
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memset(filter, 0, sizeof(filter));
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filter[0] = 4096;
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mute_factor = 0;
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scale = 20000;
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scale_shift = 24;
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}
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int32_t energy;
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int32_t max_energy;
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int32_t energy_update_threshold;
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int32_t low_energy_update_threshold;
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int16_t filter_state[kMaxLpcOrder];
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int16_t filter[kMaxLpcOrder + 1];
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int16_t mute_factor;
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int16_t scale;
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int16_t scale_shift;
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};
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int32_t CalculateAutoCorrelation(const int16_t* signal,
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size_t length,
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int32_t* auto_correlation) const;
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// Increments the energy threshold by a factor 1 + |kThresholdIncrement|.
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void IncrementEnergyThreshold(size_t channel, int32_t sample_energy);
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// Updates the filter parameters.
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void SaveParameters(size_t channel,
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const int16_t* lpc_coefficients,
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const int16_t* filter_state,
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int32_t sample_energy,
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int32_t residual_energy);
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size_t num_channels_;
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std::unique_ptr<ChannelParameters[]> channel_parameters_;
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bool initialized_;
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RTC_DISALLOW_COPY_AND_ASSIGN(BackgroundNoise);
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};
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} // namespace webrtc
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#endif // MODULES_AUDIO_CODING_NETEQ_BACKGROUND_NOISE_H_
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