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https://github.com/danog/libtgvoip.git
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5caaaafa42
I'm now using the entire audio processing module from WebRTC as opposed to individual DSP algorithms pulled from there before. Seems to work better this way.
92 lines
3.4 KiB
C++
92 lines
3.4 KiB
C++
/*
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* Copyright (c) 2013 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_PROCESSING_TRANSIENT_WPD_TREE_H_
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#define MODULES_AUDIO_PROCESSING_TRANSIENT_WPD_TREE_H_
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#include <stddef.h>
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#include <memory>
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#include "modules/audio_processing/transient/wpd_node.h"
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namespace webrtc {
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// Tree of a Wavelet Packet Decomposition (WPD).
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//
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// The root node contains all the data provided; for each node in the tree, the
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// left child contains the approximation coefficients extracted from the node,
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// and the right child contains the detail coefficients.
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// It preserves its state, so it can be multiple-called.
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//
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// The number of nodes in the tree will be 2 ^ levels - 1.
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//
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// Implementation details: Since the tree always will be a complete binary tree,
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// it is implemented using a single linear array instead of managing the
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// relationships in each node. For convience is better to use a array that
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// starts in 1 (instead of 0). Taking that into account, the following formulas
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// apply:
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// Root node index: 1.
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// Node(Level, Index in that level): 2 ^ Level + (Index in that level).
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// Left Child: Current node index * 2.
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// Right Child: Current node index * 2 + 1.
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// Parent: Current Node Index / 2 (Integer division).
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class WPDTree {
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public:
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// Creates a WPD tree using the data length and coefficients provided.
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WPDTree(size_t data_length,
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const float* high_pass_coefficients,
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const float* low_pass_coefficients,
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size_t coefficients_length,
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int levels);
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~WPDTree();
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// Returns the number of nodes at any given level.
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static int NumberOfNodesAtLevel(int level) { return 1 << level; }
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// Returns a pointer to the node at the given level and index(of that level).
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// Level goes from 0 to levels().
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// Index goes from 0 to the number of NumberOfNodesAtLevel(level) - 1.
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//
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// You can use the following formulas to get any node within the tree:
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// Notation: (Level, Index of node in that level).
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// Root node: (0/0).
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// Left Child: (Current node level + 1, Current node index * 2).
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// Right Child: (Current node level + 1, Current node index * 2 + 1).
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// Parent: (Current node level - 1, Current node index / 2) (Integer division)
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//
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// If level or index are out of bounds the function will return NULL.
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WPDNode* NodeAt(int level, int index);
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// Updates all the nodes of the tree with the new data. |data_length| must be
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// teh same that was used for the creation of the tree.
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// Returns 0 if correct, and -1 otherwise.
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int Update(const float* data, size_t data_length);
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// Returns the total number of levels below the root. Root is cosidered level
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// 0.
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int levels() const { return levels_; }
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// Returns the total number of nodes.
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int num_nodes() const { return num_nodes_; }
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// Returns the total number of leaves.
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int num_leaves() const { return 1 << levels_; }
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private:
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size_t data_length_;
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int levels_;
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int num_nodes_;
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std::unique_ptr<std::unique_ptr<WPDNode>[]> nodes_;
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};
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} // namespace webrtc
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#endif // MODULES_AUDIO_PROCESSING_TRANSIENT_WPD_TREE_H_
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