Delete android.speech.srec.*

/*---------------------------------------------------------------------------*

 *  MicrophoneInputStream.java                                               *

 *                                                                           *

 *  Copyright 2007 Nuance Communciations, Inc.                               *

 *                                                                           *

 *  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 android.speech.srec;

import java.io.IOException;

import java.io.InputStream;

import java.lang.IllegalStateException;

/**

 * PCM input stream from the microphone, 16 bits per sample.

 */

public final class MicrophoneInputStream extends InputStream {

    static {

        System.loadLibrary("srec_jni");

    }

    private final static String TAG = "MicrophoneInputStream";

    private long mAudioRecord = 0;

    private byte[] mOneByte = new byte[1];

    /**

     * MicrophoneInputStream constructor.

     * @param sampleRate sample rate of the microphone, typically 11025 or 8000.

     * @param fifoDepth depth of the real time fifo, measured in sampleRate clock ticks.

     * This determines how long an application may delay before losing data.

     */

    public MicrophoneInputStream(int sampleRate, int fifoDepth) throws IOException {

        mAudioRecord = AudioRecordNew(sampleRate, fifoDepth);

        if (mAudioRecord == 0) throw new IOException("AudioRecord constructor failed - busy?");

        int status = AudioRecordStart(mAudioRecord);

        if (status != 0) {

            close();

            throw new IOException("AudioRecord start failed: " + status);

        }

    }

    @Override

    public int read() throws IOException {

        if (mAudioRecord == 0) throw new IllegalStateException("not open");

        int rtn = AudioRecordRead(mAudioRecord, mOneByte, 0, 1);

        return rtn == 1 ? ((int)mOneByte[0] & 0xff) : -1;

    }

    @Override

    public int read(byte[] b) throws IOException {

        if (mAudioRecord == 0) throw new IllegalStateException("not open");

        return AudioRecordRead(mAudioRecord, b, 0, b.length);

    }

    @Override

    public int read(byte[] b, int offset, int length) throws IOException {

        if (mAudioRecord == 0) throw new IllegalStateException("not open");

        // TODO: should we force all reads to be a multiple of the sample size?

        return AudioRecordRead(mAudioRecord, b, offset, length);

    }

    /**

     * Closes this stream.

     */

    @Override

    public void close() throws IOException {

        if (mAudioRecord != 0) {

            try {

                AudioRecordStop(mAudioRecord);

            } finally {

                try {

                    AudioRecordDelete(mAudioRecord);

                } finally {

                    mAudioRecord = 0;

                }

            }

        }

    }

    @Override

    protected void finalize() throws Throwable {

        if (mAudioRecord != 0) {

            close();

            throw new IOException("someone forgot to close MicrophoneInputStream");

        }

    }

    //

    // AudioRecord JNI interface

    //

    private static native long AudioRecordNew(int sampleRate, int fifoDepth);

    private static native int AudioRecordStart(long audioRecord);

    private static native int AudioRecordRead(long audioRecord, byte[] b, int offset, int length) throws IOException;

    private static native void AudioRecordStop(long audioRecord) throws IOException;

    private static native void AudioRecordDelete(long audioRecord) throws IOException;

}