| /* |
| * Copyright (c) 2012 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. |
| */ |
| |
| #ifndef WEBRTC_MODULES_AUDIO_PROCESSING_AGC_HISTOGRAM_H_ |
| #define WEBRTC_MODULES_AUDIO_PROCESSING_AGC_HISTOGRAM_H_ |
| |
| #include <string.h> |
| |
| #include "webrtc/base/scoped_ptr.h" |
| #include "webrtc/typedefs.h" |
| |
| namespace webrtc { |
| |
| // This class implements the histogram of loudness with circular buffers so that |
| // the histogram tracks the last T seconds of the loudness. |
| class Histogram { |
| public: |
| // Create a non-sliding Histogram. |
| static Histogram* Create(); |
| |
| // Create a sliding Histogram, i.e. the histogram represents the last |
| // |window_size| samples. |
| static Histogram* Create(int window_size); |
| ~Histogram(); |
| |
| // Insert RMS and the corresponding activity probability. |
| void Update(double rms, double activity_probability); |
| |
| // Reset the histogram, forget the past. |
| void Reset(); |
| |
| // Current loudness, which is actually the mean of histogram in loudness |
| // domain. |
| double CurrentRms() const; |
| |
| // Sum of the histogram content. |
| double AudioContent() const; |
| |
| // Number of times the histogram has been updated. |
| int num_updates() const { return num_updates_; } |
| |
| private: |
| Histogram(); |
| explicit Histogram(int window); |
| |
| // Find the histogram bin associated with the given |rms|. |
| int GetBinIndex(double rms); |
| |
| void RemoveOldestEntryAndUpdate(); |
| void InsertNewestEntryAndUpdate(int activity_prob_q10, int hist_index); |
| void UpdateHist(int activity_prob_q10, int hist_index); |
| void RemoveTransient(); |
| |
| // Number of histogram bins. |
| static const int kHistSize = 77; |
| |
| // Number of times the histogram is updated |
| int num_updates_; |
| // Audio content, this should be equal to the sum of the components of |
| // |bin_count_q10_|. |
| int64_t audio_content_q10_; |
| |
| // Histogram of input RMS in Q10 with |kHistSize_| bins. In each 'Update(),' |
| // we increment the associated histogram-bin with the given probability. The |
| // increment is implemented in Q10 to avoid rounding errors. |
| int64_t bin_count_q10_[kHistSize]; |
| |
| // Circular buffer for probabilities |
| rtc::scoped_ptr<int[]> activity_probability_; |
| // Circular buffer for histogram-indices of probabilities. |
| rtc::scoped_ptr<int[]> hist_bin_index_; |
| // Current index of circular buffer, where the newest data will be written to, |
| // therefore, pointing to the oldest data if buffer is full. |
| int buffer_index_; |
| // Indicating if buffer is full and we had a wrap around. |
| int buffer_is_full_; |
| // Size of circular buffer. |
| int len_circular_buffer_; |
| int len_high_activity_; |
| }; |
| |
| } // namespace webrtc |
| |
| #endif // WEBRTC_MODULES_AUDIO_PROCESSING_AGC_HISTOGRAM_H_ |