我想为我的录音机实现暂停和恢复功能。我知道我不能使用MediaRecorder来做到这一点。 所以请给我一个可以加入两个AAC音频文件的类的源代码。
答案 0 :(得分：1)
MediaRecorder在API级别24添加了暂停功能。如果你的minSdkVersion小于24，你可以使用下面的代码。它是从 this page 中提取的。在录制停止后，它会以给定的名称生成一个wave文件。
import android.media.AudioFormat;
import android.media.AudioRecord;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.os.Environment;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.RandomAccessFile;
public class RecordAudio extends AppCompatActivity {
private static final int RECORDER_BPP = 16;
private static final int RECORDER_SAMPLE_RATE = 8000;
private static final int RECORDER_CHANNELS = AudioFormat.CHANNEL_IN_STEREO;
private static final int RECORDER_AUDIO_ENCODING = AudioFormat.ENCODING_PCM_16BIT;
private Button recordButton, stopButton, pauseButton, resumeButton;
private EditText recordingName;
private AudioRecord recorder = null;
private int bufferSize = 0;
private Thread recordingThread = null;
private boolean isRecording = false;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_record_audio);
bufferSize = AudioRecord.getMinBufferSize(RECORDER_SAMPLE_RATE, RECORDER_CHANNELS, RECORDER_AUDIO_ENCODING);
recordButton = (Button) findViewById(R.id.record_button);
stopButton = (Button) findViewById(R.id.stop_button);
pauseButton = (Button) findViewById(R.id.pause_button);
resumeButton = (Button) findViewById(R.id.resume_button);
recordingName = (EditText) findViewById(R.id.recording_name);
recordButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
startRecording(false);
}
});
pauseButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
stopRecording(false);
}
});
resumeButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
startRecording(true);
}
});
stopButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
stopRecording(true);
}
});
}
private void startRecording(final boolean b) {
recorder = new AudioRecord(MediaRecorder.AudioSource.MIC, RECORDER_SAMPLE_RATE, RECORDER_CHANNELS, RECORDER_AUDIO_ENCODING, bufferSize);
recorder.startRecording();
isRecording = true;
recordingThread = new Thread(new Runnable() {
@Override
public void run() {
writeAudioDataToFile(b);
}
}, "AudioRecorder Thread");
recordingThread.start();
}
private void writeAudioDataToFile(boolean b) {
byte data[] = new byte[bufferSize];
String filename = getTempFilename();
FileOutputStream os = null;
try {
os = new FileOutputStream(filename, b);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
int read = 0;
if (os != null) {
while (isRecording) {
read = recorder.read(data, 0, bufferSize);
if (AudioRecord.ERROR_INVALID_OPERATION != read) {
try {
os.write(data);
} catch (IOException e) {
e.printStackTrace();
}
}
}
try {
os.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
private String getTempFilename() {
String filepath = Environment.getExternalStorageDirectory().getPath();
File file = new File(filepath + "/recording_temp.raw");
try {
file.createNewFile();
} catch (IOException e) {
e.printStackTrace();
}
return (file.getAbsolutePath());
}
private void stopRecording(boolean b) {
if (recorder != null) {
isRecording = false;
recorder.stop();
recorder.release();
recorder = null;
recordingThread = null;
}
if (b == true) {
copyWaveFile(getTempFilename(), getFilename());
deleteTempFile();
}
}
private void copyWaveFile(String inFilename, String outFilename) {
FileInputStream in = null;
FileOutputStream out = null;
long totalAudioLen = 0;
long totalDataLen = totalAudioLen + 44;
long longSampleRate = RECORDER_SAMPLE_RATE;
int channels = 2;
long byteRate = RECORDER_BPP * RECORDER_SAMPLE_RATE * channels / 8;
byte[] data = new byte[bufferSize];
try {
in = new FileInputStream(inFilename);
out = new FileOutputStream(outFilename, true);
totalAudioLen = in.getChannel().size() + out.getChannel().size();
totalDataLen = totalAudioLen + 44;
WriteWaveFileHeader(out, totalAudioLen, totalDataLen,
longSampleRate, channels, byteRate, outFilename);
while (in.read(data) != -1) {
out.write(data);
}
in.close();
out.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
private void WriteWaveFileHeader(
FileOutputStream out, long totalAudioLen,
long totalDataLen, long longSampleRate, int channels,
long byteRate, String outFileName) throws IOException {
byte[] header = new byte[44];
header[0] = 'R'; // RIFF/WAVE header
header[1] = 'I';
header[2] = 'F';
header[3] = 'F';
header[4] = (byte) (totalDataLen & 0xff);
header[5] = (byte) ((totalDataLen >> 8) & 0xff);
header[6] = (byte) ((totalDataLen >> 16) & 0xff);
header[7] = (byte) ((totalDataLen >> 24) & 0xff);
header[8] = 'W';
header[9] = 'A';
header[10] = 'V';
header[11] = 'E';
header[12] = 'f'; // 'fmt ' chunk
header[13] = 'm';
header[14] = 't';
header[15] = ' ';
header[16] = 16; // 4 bytes: size of 'fmt ' chunk
header[17] = 0;
header[18] = 0;
header[19] = 0;
header[20] = 1; // format = 1
header[21] = 0;
header[22] = (byte) channels;
header[23] = 0;
header[24] = (byte) (longSampleRate & 0xff);
header[25] = (byte) ((longSampleRate >> 8) & 0xff);
header[26] = (byte) ((longSampleRate >> 16) & 0xff);
header[27] = (byte) ((longSampleRate >> 24) & 0xff);
header[28] = (byte) (byteRate & 0xff);
header[29] = (byte) ((byteRate >> 8) & 0xff);
header[30] = (byte) ((byteRate >> 16) & 0xff);
header[31] = (byte) ((byteRate >> 24) & 0xff);
header[32] = (byte) (2 * 16 / 8); // block align
header[33] = 0;
header[34] = RECORDER_BPP; // bits per sample
header[35] = 0;
header[36] = 'd';
header[37] = 'a';
header[38] = 't';
header[39] = 'a';
header[40] = (byte) (totalAudioLen & 0xff);
header[41] = (byte) ((totalAudioLen >> 8) & 0xff);
header[42] = (byte) ((totalAudioLen >> 16) & 0xff);
header[43] = (byte) ((totalAudioLen >> 24) & 0xff);
RandomAccessFile rFile = new RandomAccessFile(outFileName, "rw");
rFile.seek(0);
rFile.write(header, 0, 44);
rFile.close();
}
private String getFilename() {
String filepath = Environment.getExternalStorageDirectory().getPath();
File file = new File(filepath + "/record_" + recordingName.getText() + ".wav");
try {
file.createNewFile();
} catch (IOException e) {
e.printStackTrace();
}
return (file.getAbsolutePath());
}
private void deleteTempFile() {
File file = new File(getTempFilename());
file.delete();
}
}