| /* |
| * Copyright (C) 2006 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. |
| */ |
| |
| package com.android.speechrecorder; |
| |
| import java.io.IOException; |
| import java.io.InputStream; |
| |
| import android.media.AudioRecord; |
| |
| import static android.media.AudioFormat.CHANNEL_IN_MONO; |
| import static android.media.AudioFormat.ENCODING_PCM_16BIT; |
| import static android.media.MediaRecorder.AudioSource.VOICE_RECOGNITION; |
| |
| /** |
| * Provides an InputStream like API over {@code android.media.AudioRecord}. |
| * |
| * <b>Not thread safe.</b> |
| */ |
| public final class MicrophoneInputStream extends InputStream { |
| |
| private final int mSampleRate; |
| private final int mBufferSize; |
| private final AudioRecord mAudioRecord; |
| |
| private boolean mRecording; |
| |
| public MicrophoneInputStream(int sampleRate) throws IOException { |
| mSampleRate = sampleRate; |
| mBufferSize = AudioRecord.getMinBufferSize(sampleRate, |
| CHANNEL_IN_MONO, ENCODING_PCM_16BIT); |
| mAudioRecord = createAudioRecord(); |
| mRecording = false; |
| } |
| |
| private AudioRecord createAudioRecord() throws IOException { |
| AudioRecord ar = new AudioRecord(VOICE_RECOGNITION, |
| mSampleRate, CHANNEL_IN_MONO, ENCODING_PCM_16BIT, mBufferSize); |
| |
| if (ar.getState() != AudioRecord.STATE_INITIALIZED) { |
| ar.release(); |
| throw new IOException("Unable to create AudioRecord"); |
| } |
| |
| return ar; |
| } |
| |
| private void maybeStartRecording() throws IOException { |
| if (mRecording) { |
| return; |
| } |
| |
| mAudioRecord.startRecording(); |
| |
| int recordingState = mAudioRecord.getRecordingState(); |
| if (recordingState != AudioRecord.RECORDSTATE_RECORDING) { |
| throw new IOException("Unexpected recordingState: " + recordingState); |
| } |
| mRecording = true; |
| } |
| |
| @Override |
| public int read() throws IOException { |
| throw new UnsupportedOperationException("Single byte read."); |
| } |
| |
| @Override |
| public int read(byte[] b, int offset, int length) throws IOException { |
| maybeStartRecording(); |
| |
| final int ret = mAudioRecord.read(b, offset, length); |
| if (ret == AudioRecord.ERROR_INVALID_OPERATION || |
| ret == AudioRecord.ERROR_BAD_VALUE) { |
| throw new IOException("AudioRecord.read returned: " + ret); |
| } |
| |
| return ret; |
| } |
| |
| @Override |
| public void close() throws IOException { |
| mAudioRecord.stop(); |
| mAudioRecord.release(); |
| } |
| } |