1 /* 2 * Copyright (C) 2010 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not 5 * use this file except in compliance with the License. You may obtain a copy of 6 * the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 13 * License for the specific language governing permissions and limitations under 14 * the License. 15 */ 16 17 #ifndef WINDOW_INTERFACE_H 18 #define WINDOW_INTERFACE_H 19 20 class Window { 21 public: 22 Window(int size) : mWindowWeights(0), mWindowSize(0) { 23 windowCreate(size); 24 } 25 26 Window() : mWindowWeights(0), mWindowSize(0) { 27 } 28 29 virtual ~Window(void) { 30 windowCleanup(); 31 } 32 33 /* Create a Hann window of length size. This allocates memory that 34 should be freed using window_cleanup(). */ 35 void windowCreate(int size); 36 37 /* Free up memory and reset size to 0. */ 38 void windowCleanup(void); 39 40 41 /* Multiply the signal in data by the window weights. Place the 42 resulting window_size floating-point values in output. If preemp 43 is != 0.0, apply a 1st-order preemphasis filter, and assume that 44 there are window_size+1 samples available in data. */ 45 void window(short* data, float* output, float preemp); 46 47 int getWindowSize() { return mWindowSize; } 48 49 float* getWindowWeights() { return mWindowWeights; } 50 51 private: 52 float* mWindowWeights; 53 int mWindowSize; 54 55 }; 56 57 #endif /* WINDOW_INTERFACE_H */ 58
