| /* |
| * Copyright (C) 2010 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); you may not |
| * use this file except in compliance with the License. You may obtain a copy of |
| * the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the |
| * License for the specific language governing permissions and limitations under |
| * the License. |
| */ |
| |
| #ifndef MEASURE_RMS_H |
| #define MEASURE_RMS_H |
| |
| /* Measure the rms of the non-silence segment of the signal in pcm, which |
| is of numSamples length, and sampled at sampleRate. pcm is assumed to |
| consist of silence - signal - silence, as might be logged during a |
| speech recognition attempt. The stimulus signal in this case should |
| be approximately a 3-second burst of pink noise presented at a level |
| comparable to normal speaking level. The RMS is measured using 25ms |
| duration non-overlapping windows. These are averaged over the whole |
| non-silence part of pcm, and the result is returned in rms. The |
| standard deviation of this measurement over all frames is returned in |
| stdRms, and the estimated duration of the non-silence region, in |
| seconds, is returned in duration. The target signal is taken to be |
| that segment that is onsetThresh dB above the background, and is |
| expected to be continuous, once the onset has been found. If |
| onsetThresh < 0.0, simply make the measurememt over the entire pcm |
| signal. In both cases, the mean of the entire signal is returned in |
| mean. */ |
| void measureRms(short* pcm, int numSamples, float sampleRate, |
| float onsetThresh, float* rms, float* stdRms, |
| float* mean, float* duration); |
| |
| |
| #endif /* MEASURE_RMS_H */ |
