package com.androsz.flatnote.soundrecorder;
import java.io.File;
import java.io.IOException;
import java.io.RandomAccessFile;
import android.media.AudioFormat;
import android.media.AudioRecord;
import android.media.MediaRecorder;
import android.util.Log;
public class RehearsalAudioRecorder {
/**
* INITIALIZING : recorder is initializing; READY : recorder has been
* initialized, recorder not yet started RECORDING : recording ERROR :
* reconstruction needed STOPPED: reset needed
*/
public enum State {
INITIALIZING, READY, RECORDING, ERROR, STOPPED
};
public static final boolean RECORDING_UNCOMPRESSED = true;
public static final boolean RECORDING_COMPRESSED = false;
// The interval in which the recorded samples are output to the file
// Used only in uncompressed mode
private static final int TIMER_INTERVAL = 120;
// Toggles uncompressed recording on/off; RECORDING_UNCOMPRESSED /
// RECORDING_COMPRESSED
private boolean rUncompressed;
// Recorder used for uncompressed recording
private AudioRecord aRecorder = null;
// Recorder used for compressed recording
private MediaRecorder mRecorder = null;
// Stores current amplitude (only in uncompressed mode)
private int cAmplitude = 0;
// Output file path
private String fPath = null;
// Recorder state; see State
private State state;
// File writer (only in uncompressed mode)
private RandomAccessFile fWriter;
// Number of channels, sample rate, sample size(size in bits), buffer size,
// audio source, sample size(see AudioFormat)
private short nChannels;
private int sRate;
private short bSamples;
private int bufferSize;
private int aSource;
private int aFormat;
// Number of frames written to file on each output(only in uncompressed
// mode)
private int framePeriod;
// Buffer for output(only in uncompressed mode)
private byte[] buffer;
// Number of bytes written to file after header(only in uncompressed mode)
// after stop() is called, this size is written to the header/data chunk in
// the wave file
private int payloadSize;
/*
*
* Method used for recording.
*/
private final AudioRecord.OnRecordPositionUpdateListener updateListener = new AudioRecord.OnRecordPositionUpdateListener() {
@Override
public void onMarkerReached(AudioRecord recorder) {
// NOT USED
}
@Override
public void onPeriodicNotification(AudioRecord recorder) {
aRecorder.read(buffer, 0, buffer.length); // Fill buffer
try {
fWriter.write(buffer); // Write buffer to file
payloadSize += buffer.length;
if (bSamples == 16) {
for (int i = 0; i < buffer.length / 2; i++) { // 16bit
// sample
// size
final short curSample = getShort(buffer[i * 2],
buffer[i * 2 + 1]);
if (curSample > cAmplitude) { // Check amplitude
cAmplitude = curSample;
}
}
} else { // 8bit sample size
for (int i = 0; i < buffer.length; i++) {
if (buffer[i] > cAmplitude) { // Check amplitude
cAmplitude = buffer[i];
}
}
}
} catch (final IOException e) {
Log.e(RehearsalAudioRecorder.class.getName(),
"Error occured in updateListener, recording is aborted");
stop();
}
}
};
/**
*
*
* Default constructor
*
* Instantiates a new recorder, in case of compressed recording the
* parameters can be left as 0. In case of errors, no exception is thrown,
* but the state is set to ERROR
*
*/
public RehearsalAudioRecorder(boolean uncompressed, int audioSource,
int sampleRate, int channelConfig, int audioFormat) {
try {
rUncompressed = uncompressed;
if (rUncompressed) { // RECORDING_UNCOMPRESSED
if (audioFormat == AudioFormat.ENCODING_PCM_16BIT) {
bSamples = 16;
} else {
bSamples = 8;
}
if (channelConfig == AudioFormat.CHANNEL_CONFIGURATION_MONO) {
nChannels = 1;
} else {
nChannels = 2;
}
aSource = audioSource;
sRate = sampleRate;
aFormat = audioFormat;
framePeriod = sampleRate * TIMER_INTERVAL / 1000;
bufferSize = framePeriod * 2 * bSamples * nChannels / 8;
if (bufferSize < AudioRecord.getMinBufferSize(sampleRate,
channelConfig, audioFormat)) { // Check to make sure
// buffer size is not
// smaller than the
// smallest allowed one
bufferSize = AudioRecord.getMinBufferSize(sampleRate,
channelConfig, audioFormat);
// Set frame period and timer interval accordingly
framePeriod = bufferSize / (2 * bSamples * nChannels / 8);
Log.w(RehearsalAudioRecorder.class.getName(),
"Increasing buffer size to "
+ Integer.toString(bufferSize));
}
aRecorder = new AudioRecord(audioSource, sampleRate,
channelConfig, audioFormat, bufferSize);
if (aRecorder.getState() != AudioRecord.STATE_INITIALIZED)
throw new Exception("AudioRecord initialization failed");
aRecorder.setRecordPositionUpdateListener(updateListener);
aRecorder.setPositionNotificationPeriod(framePeriod);
} else { // RECORDING_COMPRESSED
mRecorder = new MediaRecorder();
mRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
mRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
mRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
}
cAmplitude = 0;
fPath = null;
state = State.INITIALIZING;
} catch (final Exception e) {
if (e.getMessage() != null) {
Log.e(RehearsalAudioRecorder.class.getName(), e.getMessage());
} else {
Log.e(RehearsalAudioRecorder.class.getName(),
"Unknown error occured while initializing recording");
}
state = State.ERROR;
}
}
/**
*
* Returns the largest amplitude sampled since the last call to this method.
*
* @return returns the largest amplitude since the last call, or 0 when not
* in recording state.
*
*/
public int getMaxAmplitude() {
if (state == State.RECORDING) {
if (rUncompressed) {
final int result = cAmplitude;
cAmplitude = 0;
return result;
} else {
try {
return mRecorder.getMaxAmplitude();
} catch (final IllegalStateException e) {
return 0;
}
}
} else
return 0;
}
/*
*
* Converts a byte[2] to a short, in LITTLE_ENDIAN format
*/
private short getShort(byte argB1, byte argB2) {
return (short) (argB1 | (argB2 << 8));
}
/**
*
* Returns the state of the recorder in a RehearsalAudioRecord.State typed
* object. Useful, as no exceptions are thrown.
*
* @return recorder state
*/
public State getState() {
return state;
}
/**
*
* Prepares the recorder for recording, in case the recorder is not in the
* INITIALIZING state and the file path was not set the recorder is set to
* the ERROR state, which makes a reconstruction necessary. In case
* uncompressed recording is toggled, the header of the wave file is
* written. In case of an exception, the state is changed to ERROR
*
*/
public void prepare() {
try {
if (state == State.INITIALIZING) {
if (rUncompressed) {
if ((aRecorder.getState() == AudioRecord.STATE_INITIALIZED)
& (fPath != null)) {
// write file header
fWriter = new RandomAccessFile(fPath, "rw");
fWriter.setLength(0); // Set file length to 0, to
// prevent unexpected behavior
// in case the file already
// existed
fWriter.writeBytes("RIFF");
fWriter.writeInt(0); // Final file size not known yet,
// write 0
fWriter.writeBytes("WAVE");
fWriter.writeBytes("fmt ");
fWriter.writeInt(Integer.reverseBytes(16)); // Sub-chunk
// size, 16
// for PCM
fWriter.writeShort(Short.reverseBytes((short) 1)); // AudioFormat,
// 1
// for
// PCM
fWriter.writeShort(Short.reverseBytes(nChannels));// Number
// of
// channels,
// 1
// for
// mono,
// 2
// for
// stereo
fWriter.writeInt(Integer.reverseBytes(sRate)); // Sample
// rate
fWriter.writeInt(Integer.reverseBytes(sRate * bSamples
* nChannels / 8)); // Byte rate,
// SampleRate*NumberOfChannels*BitsPerSample/8
fWriter.writeShort(Short
.reverseBytes((short) (nChannels * bSamples / 8))); // Block
// align,
// NumberOfChannels*BitsPerSample/8
fWriter.writeShort(Short.reverseBytes(bSamples)); // Bits
// per
// sample
fWriter.writeBytes("data");
fWriter.writeInt(0); // Data chunk size not known yet,
// write 0
buffer = new byte[framePeriod * bSamples / 8
* nChannels];
state = State.READY;
} else {
Log.e(RehearsalAudioRecorder.class.getName(),
"prepare() method called on uninitialized recorder");
state = State.ERROR;
}
} else {
mRecorder.prepare();
state = State.READY;
}
} else {
Log.e(RehearsalAudioRecorder.class.getName(),
"prepare() method called on illegal state");
release();
state = State.ERROR;
}
} catch (final Exception e) {
if (e.getMessage() != null) {
Log.e(RehearsalAudioRecorder.class.getName(), e.getMessage());
} else {
Log.e(RehearsalAudioRecorder.class.getName(),
"Unknown error occured in prepare()");
}
state = State.ERROR;
}
}
/**
*
*
* Releases the resources associated with this class, and removes the
* unnecessary files, when necessary
*
*/
public void release() {
if (state == State.RECORDING) {
stop();
} else {
if ((state == State.READY) & (rUncompressed)) {
try {
fWriter.close(); // Remove prepared file
} catch (final IOException e) {
Log.e(RehearsalAudioRecorder.class.getName(),
"I/O exception occured while closing output file");
}
(new File(fPath)).delete();
}
}
if (rUncompressed) {
if (aRecorder != null) {
aRecorder.release();
}
} else {
if (mRecorder != null) {
mRecorder.release();
}
}
}
/**
*
*
* Resets the recorder to the INITIALIZING state, as if it was just created.
* In case the class was in RECORDING state, the recording is stopped. In
* case of exceptions the class is set to the ERROR state.
*
*/
public void reset() {
try {
if (state != State.ERROR) {
release();
fPath = null; // Reset file path
cAmplitude = 0; // Reset amplitude
if (rUncompressed) {
aRecorder = new AudioRecord(aSource, sRate, nChannels + 1,
aFormat, bufferSize);
} else {
mRecorder = new MediaRecorder();
mRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
mRecorder
.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
mRecorder
.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
}
state = State.INITIALIZING;
}
} catch (final Exception e) {
Log.e(RehearsalAudioRecorder.class.getName(), e.getMessage());
state = State.ERROR;
}
}
/**
* Sets output file path, call directly after construction/reset.
*
* @param output
* file path
*
*/
public void setOutputFile(String argPath) {
try {
if (state == State.INITIALIZING) {
fPath = argPath;
if (!rUncompressed) {
mRecorder.setOutputFile(fPath);
}
}
} catch (final Exception e) {
if (e.getMessage() != null) {
Log.e(RehearsalAudioRecorder.class.getName(), e.getMessage());
} else {
Log.e(RehearsalAudioRecorder.class.getName(),
"Unknown error occured while setting output path");
}
state = State.ERROR;
}
}
/**
*
*
* Starts the recording, and sets the state to RECORDING. Call after
* prepare().
*
*/
public void start() {
if (state == State.READY) {
if (rUncompressed) {
payloadSize = 0;
aRecorder.startRecording();
aRecorder.read(buffer, 0, buffer.length);
} else {
mRecorder.start();
}
state = State.RECORDING;
} else {
Log.e(RehearsalAudioRecorder.class.getName(),
"start() called on illegal state");
state = State.ERROR;
}
}
/**
*
*
* Stops the recording, and sets the state to STOPPED. In case of further
* usage, a reset is needed. Also finalizes the wave file in case of
* uncompressed recording.
*
*/
public void stop() {
if (state == State.RECORDING) {
if (rUncompressed) {
aRecorder.stop();
try {
fWriter.seek(4); // Write size to RIFF header
fWriter.writeInt(Integer.reverseBytes(36 + payloadSize));
fWriter.seek(40); // Write size to Subchunk2Size field
fWriter.writeInt(Integer.reverseBytes(payloadSize));
fWriter.close();
} catch (final IOException e) {
Log.e(RehearsalAudioRecorder.class.getName(),
"I/O exception occured while closing output file");
state = State.ERROR;
}
} else {
mRecorder.stop();
}
state = State.STOPPED;
} else {
Log.e(RehearsalAudioRecorder.class.getName(),
"stop() called on illegal state");
state = State.ERROR;
}
}
}