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Diffstat (limited to 'webrtc/modules/audio_processing/intelligibility/intelligibility_utils.h')
| -rw-r--r-- | webrtc/modules/audio_processing/intelligibility/intelligibility_utils.h | 160 |
1 files changed, 0 insertions, 160 deletions
diff --git a/webrtc/modules/audio_processing/intelligibility/intelligibility_utils.h b/webrtc/modules/audio_processing/intelligibility/intelligibility_utils.h deleted file mode 100644 index 4ac1167..0000000 --- a/webrtc/modules/audio_processing/intelligibility/intelligibility_utils.h +++ /dev/null @@ -1,160 +0,0 @@ -/* - * Copyright (c) 2014 The WebRTC project authors. All Rights Reserved. - * - * Use of this source code is governed by a BSD-style license - * that can be found in the LICENSE file in the root of the source - * tree. An additional intellectual property rights grant can be found - * in the file PATENTS. All contributing project authors may - * be found in the AUTHORS file in the root of the source tree. - */ - -// -// Specifies helper classes for intelligibility enhancement. -// - -#ifndef WEBRTC_MODULES_AUDIO_PROCESSING_INTELLIGIBILITY_INTELLIGIBILITY_UTILS_H_ -#define WEBRTC_MODULES_AUDIO_PROCESSING_INTELLIGIBILITY_INTELLIGIBILITY_UTILS_H_ - -#include <complex> - -#include "webrtc/base/scoped_ptr.h" - -namespace webrtc { - -namespace intelligibility { - -// Return |current| changed towards |target|, with the change being at most -// |limit|. -float UpdateFactor(float target, float current, float limit); - -// Apply a small fudge to degenerate complex values. The numbers in the array -// were chosen randomly, so that even a series of all zeroes has some small -// variability. -std::complex<float> zerofudge(std::complex<float> c); - -// Incremental mean computation. Return the mean of the series with the -// mean |mean| with added |data|. -std::complex<float> NewMean(std::complex<float> mean, - std::complex<float> data, - size_t count); - -// Updates |mean| with added |data|; -void AddToMean(std::complex<float> data, - size_t count, - std::complex<float>* mean); - -// Internal helper for computing the variances of a stream of arrays. -// The result is an array of variances per position: the i-th variance -// is the variance of the stream of data on the i-th positions in the -// input arrays. -// There are four methods of computation: -// * kStepInfinite computes variances from the beginning onwards -// * kStepDecaying uses a recursive exponential decay formula with a -// settable forgetting factor -// * kStepWindowed computes variances within a moving window -// * kStepBlocked is similar to kStepWindowed, but history is kept -// as a rolling window of blocks: multiple input elements are used for -// one block and the history then consists of the variances of these blocks -// with the same effect as kStepWindowed, but less storage, so the window -// can be longer -class VarianceArray { - public: - enum StepType { - kStepInfinite = 0, - kStepDecaying, - kStepWindowed, - kStepBlocked, - kStepBlockBasedMovingAverage - }; - - // Construct an instance for the given input array length (|freqs|) and - // computation algorithm (|type|), with the appropriate parameters. - // |window_size| is the number of samples for kStepWindowed and - // the number of blocks for kStepBlocked. |decay| is the forgetting factor - // for kStepDecaying. - VarianceArray(size_t freqs, StepType type, size_t window_size, float decay); - - // Add a new data point to the series and compute the new variances. - // TODO(bercic) |skip_fudge| is a flag for kStepWindowed and kStepDecaying, - // whether they should skip adding some small dummy values to the input - // to prevent problems with all-zero inputs. Can probably be removed. - void Step(const std::complex<float>* data, bool skip_fudge = false) { - (this->*step_func_)(data, skip_fudge); - } - // Reset variances to zero and forget all history. - void Clear(); - // Scale the input data by |scale|. Effectively multiply variances - // by |scale^2|. - void ApplyScale(float scale); - - // The current set of variances. - const float* variance() const { return variance_.get(); } - - // The mean value of the current set of variances. - float array_mean() const { return array_mean_; } - - private: - void InfiniteStep(const std::complex<float>* data, bool dummy); - void DecayStep(const std::complex<float>* data, bool dummy); - void WindowedStep(const std::complex<float>* data, bool dummy); - void BlockedStep(const std::complex<float>* data, bool dummy); - void BlockBasedMovingAverage(const std::complex<float>* data, bool dummy); - - // TODO(ekmeyerson): Switch the following running means - // and histories from rtc::scoped_ptr to std::vector. - - // The current average X and X^2. - rtc::scoped_ptr<std::complex<float>[]> running_mean_; - rtc::scoped_ptr<std::complex<float>[]> running_mean_sq_; - - // Average X and X^2 for the current block in kStepBlocked. - rtc::scoped_ptr<std::complex<float>[]> sub_running_mean_; - rtc::scoped_ptr<std::complex<float>[]> sub_running_mean_sq_; - - // Sample history for the rolling window in kStepWindowed and block-wise - // histories for kStepBlocked. - rtc::scoped_ptr<rtc::scoped_ptr<std::complex<float>[]>[]> history_; - rtc::scoped_ptr<rtc::scoped_ptr<std::complex<float>[]>[]> subhistory_; - rtc::scoped_ptr<rtc::scoped_ptr<std::complex<float>[]>[]> subhistory_sq_; - - // The current set of variances and sums for Welford's algorithm. - rtc::scoped_ptr<float[]> variance_; - rtc::scoped_ptr<float[]> conj_sum_; - - const size_t num_freqs_; - const size_t window_size_; - const float decay_; - size_t history_cursor_; - size_t count_; - float array_mean_; - bool buffer_full_; - void (VarianceArray::*step_func_)(const std::complex<float>*, bool); -}; - -// Helper class for smoothing gain changes. On each applicatiion step, the -// currently used gains are changed towards a set of settable target gains, -// constrained by a limit on the magnitude of the changes. -class GainApplier { - public: - GainApplier(size_t freqs, float change_limit); - - // Copy |in_block| to |out_block|, multiplied by the current set of gains, - // and step the current set of gains towards the target set. - void Apply(const std::complex<float>* in_block, - std::complex<float>* out_block); - - // Return the current target gain set. Modify this array to set the targets. - float* target() const { return target_.get(); } - - private: - const size_t num_freqs_; - const float change_limit_; - rtc::scoped_ptr<float[]> target_; - rtc::scoped_ptr<float[]> current_; -}; - -} // namespace intelligibility - -} // namespace webrtc - -#endif // WEBRTC_MODULES_AUDIO_PROCESSING_INTELLIGIBILITY_INTELLIGIBILITY_UTILS_H_ |