我想在Android中制作流式音频记录器。我不确定如何获取音频流以及如何设置音频流的缓冲区大小。
下面是我的媒体记录器课程
public class MyMediaRecorder {
final MediaRecorder recorder = new MediaRecorder();
final File path;
/**
* Creates a new audio recording at the given path (relative to root of SD
* card).
*/
public MyMediaRecorder(File path) {
this.path = path;
}
/**
* Starts a new recording.
*/
public void start() throws IOException {
String state = android.os.Environment.getExternalStorageState();
if (!state.equals(android.os.Environment.MEDIA_MOUNTED)) {
throw new IOException("SD Card is not mounted. It is " + state
+ ".");
}
// make sure the directory we plan to store the recording in exists
recorder.setAudioSource(MediaRecorder.AudioSource.MIC);
recorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
recorder.setOutputFile(path.getAbsolutePath());
recorder.prepare();
recorder.start();
}
/**
* Stops a recording that has been previously started.
*/
public void stop() throws IOException {
recorder.stop();
recorder.release();
}
}
在开始记录时，我需要获取缓冲区大小并将其发送到服务器并行记录音频。我应该使用Media Recorder的音频记录和音频轨道吗？请建议我该怎么办
您应使用AudioRecord。这是一个简单的代码，显示如何使用AudioRecord类。
final int sampleRate = 48000;
final int channelConfig = AudioFormat.CHANNEL_IN_MONO;
final int audioFormat = AudioFormat.ENCODING_PCM_16BIT;
int minBufferSize = AudioRecord.getMinBufferSize(sampleRate, channelConfig, audioFormat);
AudioRecord microphone = new AudioRecord(MediaRecorder.AudioSource.MIC, sampleRate, channelConfig, audioFormat, minBufferSize * 10);
microphone.startRecording();
//Since audioformat is 16 bit, we need to create a 16 bit (short data type) buffer
short[] buffer = new short[1024];
while(!stopped) {
int readSize = microphone.read(buffer, 0, buffer.length);
sendDataToServer(buffer, readSize);
}
microphone.stop();
microphone.release();
如果需要实时音频记录器和流媒体，则应谨慎对待性能，并尽可能快地读取所有数据并进行管理以将其发送到服务器。 Github中有很多项目，您可以重用它们并从他们的想法中学习。我在这里分享其中一些（特别是录音机类），但是您可以搜索并找到更多内容。1.AudioRecorder2.FullDuplexNetworkAudioCallService3. MicRecorder
注意：Android Emulator无法录制音频。确保在可以记录的真实设备上测试您的代码。
尝试使用此代码，您会没事的
package com.android.audiorecordtest;
import android.Manifest;
import android.content.Context;
import android.content.pm.PackageManager;
import android.media.MediaPlayer;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.LinearLayout;
import java.io.IOException;
public class AudioRecordTest extends AppCompatActivity {
private static final String LOG_TAG = "AudioRecordTest";
private static final int REQUEST_RECORD_AUDIO_PERMISSION = 200;
private static String fileName = null;
private RecordButton recordButton = null;
private MediaRecorder recorder = null;
private PlayButton playButton = null;
private MediaPlayer player = null;
// Requesting permission to RECORD_AUDIO
private boolean permissionToRecordAccepted = false;
private String [] permissions = {Manifest.permission.RECORD_AUDIO};
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
switch (requestCode){
case REQUEST_RECORD_AUDIO_PERMISSION:
permissionToRecordAccepted = grantResults[0] == PackageManager.PERMISSION_GRANTED;
break;
}
if (!permissionToRecordAccepted ) finish();
}
private void onRecord(boolean start) {
if (start) {
startRecording();
} else {
stopRecording();
}
}
private void onPlay(boolean start) {
if (start) {
startPlaying();
} else {
stopPlaying();
}
}
private void startPlaying() {
player = new MediaPlayer();
try {
player.setDataSource(fileName);
player.prepare();
player.start();
} catch (IOException e) {
Log.e(LOG_TAG, "prepare() failed");
}
}
private void stopPlaying() {
player.release();
player = null;
}
private void startRecording() {
recorder = new MediaRecorder();
recorder.setAudioSource(MediaRecorder.AudioSource.MIC);
recorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
recorder.setOutputFile(fileName);
recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
try {
recorder.prepare();
} catch (IOException e) {
Log.e(LOG_TAG, "prepare() failed");
}
recorder.start();
}
private void stopRecording() {
recorder.stop();
recorder.release();
recorder = null;
}
class RecordButton extends Button {
boolean mStartRecording = true;
OnClickListener clicker = new OnClickListener() {
public void onClick(View v) {
onRecord(mStartRecording);
if (mStartRecording) {
setText("Stop recording");
} else {
setText("Start recording");
}
mStartRecording = !mStartRecording;
}
};
public RecordButton(Context ctx) {
super(ctx);
setText("Start recording");
setOnClickListener(clicker);
}
}
class PlayButton extends Button {
boolean mStartPlaying = true;
OnClickListener clicker = new OnClickListener() {
public void onClick(View v) {
onPlay(mStartPlaying);
if (mStartPlaying) {
setText("Stop playing");
} else {
setText("Start playing");
}
mStartPlaying = !mStartPlaying;
}
};
public PlayButton(Context ctx) {
super(ctx);
setText("Start playing");
setOnClickListener(clicker);
}
}
@Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
// Record to the external cache directory for visibility
fileName = getExternalCacheDir().getAbsolutePath();
fileName += "/audiorecordtest.3gp";
ActivityCompat.requestPermissions(this, permissions, REQUEST_RECORD_AUDIO_PERMISSION);
LinearLayout ll = new LinearLayout(this);
recordButton = new RecordButton(this);
ll.addView(recordButton,
new LinearLayout.LayoutParams(
ViewGroup.LayoutParams.WRAP_CONTENT,
ViewGroup.LayoutParams.WRAP_CONTENT,
0));
playButton = new PlayButton(this);
ll.addView(playButton,
new LinearLayout.LayoutParams(
ViewGroup.LayoutParams.WRAP_CONTENT,
ViewGroup.LayoutParams.WRAP_CONTENT,
0));
setContentView(ll);
}
@Override
public void onStop() {
super.onStop();
if (recorder != null) {
recorder.release();
recorder = null;
}
if (player != null) {
player.release();
player = null;
}
}
}希望有帮助！