MediaRecorder类介绍：
MediaRecorder类是Android sdk提供的一个专门用于音视频录制，一般利用手机麦克风采集音频，摄像头采集图片信息。
MediaRecorder主要函数：
setAudioChannels(int numChannels) 设置录制的音频通道数
setAudioEncoder(int audio_encoder) 设置audio的编码格式
setAudioEncodingBitRate(int bitRate) 设置录制的音频编码比特率
setAudioSamplingRate(int samplingRate) 设置录制的音频采样率
setAudioSource(int audio_source) 设置用于录制的音源
MediaRecorder主要配置参数：
1.）视频编码格式MediaRecorder.VideoEncoder
default，H263，H264，MPEG_4_SP，VP8
2.）音频编码格式MediaRecorder.AudioEncoder
default，AAC，HE_AAC，AAC_ELD，AMR_NB，AMR_WB，VORBIS
3.）视频资源获取方式MediaRecorder.VideoSource
default，CAMERA，SURFACE
4.）音频资源获取方式MediaRecorder.AudioSource
defalut，camcorder，mic，voice_call，voice_communication,voice_downlink,voice_recognition, voice_uplink
5.）资源输出格式MediaRecorder.OutputFormat
amr_nb，amr_wb,default,mpeg_4,raw_amr,three_gpp，aac_adif， aac_adts， output_format_rtp_avp， output_format_mpeg2ts ，webm
MediaRecorder录制视频简单实现：
1.）需要添加权限
<uses-permission android:name\="android.permission.CAMERA" />
<uses-permission android:name\="android.permission.RECORD\_AUDIO" />
<uses-permission android:name\="android.permission.WRITE\_EXTERNAL\_STORAGE" />
2.）简单实现录制视频
public class MediaRecorderActivity extends Activity implements SurfaceHolder.Callback {
private SurfaceView mSurfaceView;
private SurfaceHolder mSurfaceHolder;
private Button btnStartStop;
private boolean isRecording = false;//标记是否已经在录制
private MediaRecorder mRecorder;//音视频录制类
private Camera mCamera = null;//相机
private Camera.Size mSize = null;//相机的尺寸
private int mCameraFacing = Camera.CameraInfo.CAMERA\_FACING\_BACK;//默认后置摄像头
private static final SparseIntArray orientations = new SparseIntArray();//手机旋转对应的调整角度
static {
orientations.append(Surface.ROTATION\_0, 90);
orientations.append(Surface.ROTATION\_90, 0);
orientations.append(Surface.ROTATION\_180, 270);
orientations.append(Surface.ROTATION\_270, 180);
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setWindow();
setContentView(R.layout.activity\_media\_recorder);
initViews();
}
private void setWindow() {
requestWindowFeature(Window.FEATURE\_NO\_TITLE);// 去掉标题栏
getWindow().setFlags(WindowManager.LayoutParams.FLAG\_FULLSCREEN,
WindowManager.LayoutParams.FLAG\_FULLSCREEN);// 设置全屏
// 设置竖屏显示
setRequestedOrientation(ActivityInfo.SCREEN\_ORIENTATION\_PORTRAIT);
// 选择支持半透明模式,在有surfaceview的activity中使用。
getWindow().setFormat(PixelFormat.TRANSLUCENT);
}
private void initViews() {
mSurfaceView \= (SurfaceView) findViewById(R.id.surfaceview);
btnStartStop \= (Button) findViewById(R.id.btnStartStop);
btnStartStop.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (!isRecording) {
startRecord();
} else {
stopRecord();
}
}
});
SurfaceHolder holder \= mSurfaceView.getHolder();// 取得holder
holder.setFormat(PixelFormat.TRANSPARENT);
holder.setKeepScreenOn(true);
holder.addCallback(this); // holder加入回调接口
}
/\*\*
\* 初始化相机
\*/
private void initCamera() {
if (Camera.getNumberOfCameras() == 2) {
mCamera \= Camera.open(mCameraFacing);
} else {
mCamera \= Camera.open();
}
CameraSizeComparator sizeComparator \= new CameraSizeComparator();
Camera.Parameters parameters \= mCamera.getParameters();
if (mSize == null) {
List<Camera.Size> vSizeList = parameters.getSupportedPreviewSizes();
Collections.sort(vSizeList, sizeComparator);
for (int num = 0; num < vSizeList.size(); num++) {
Camera.Size size \= vSizeList.get(num);
if (size.width >= 800 && size.height >= 480) {
this.mSize = size;
break;
}
}
mSize \= vSizeList.get(0);
List<String> focusModesList = parameters.getSupportedFocusModes();
//增加对聚焦模式的判断
if (focusModesList.contains(Camera.Parameters.FOCUS\_MODE\_CONTINUOUS\_VIDEO)) {
parameters.setFocusMode(Camera.Parameters.FOCUS\_MODE\_CONTINUOUS\_VIDEO);
} else if (focusModesList.contains(Camera.Parameters.FOCUS\_MODE\_AUTO)) {
parameters.setFocusMode(Camera.Parameters.FOCUS\_MODE\_AUTO);
}
mCamera.setParameters(parameters);
}
int rotation = getWindowManager().getDefaultDisplay().getRotation();
int orientation = orientations.get(rotation);
mCamera.setDisplayOrientation(orientation);
}
@Override
protected void onResume() {
super.onResume();
initCamera();
}
@Override
public void onPause() {
releaseCamera();
super.onPause();
}
/\*\*
\* 开始录制
\*/
private void startRecord() {
if (mRecorder == null) {
mRecorder \= new MediaRecorder(); // 创建MediaRecorder
}
if (mCamera != null) {
mCamera.stopPreview();
mCamera.unlock();
mRecorder.setCamera(mCamera);
}
try {
// 设置音频采集方式
mRecorder.setAudioSource(MediaRecorder.AudioSource.CAMCORDER);
//设置视频的采集方式
mRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
//设置文件的输出格式
mRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG\_4);//aac\_adif， aac\_adts， output\_format\_rtp\_avp， output\_format\_mpeg2ts ，webm
//设置audio的编码格式
mRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR\_NB);
//设置video的编码格式
mRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H264);
//设置录制的视频编码比特率
mRecorder.setVideoEncodingBitRate(1024 \* 1024);
//设置录制的视频帧率,注意文档的说明:
mRecorder.setVideoFrameRate(30);
//设置要捕获的视频的宽度和高度
mSurfaceHolder.setFixedSize(320, 240);//最高只能设置640x480
mRecorder.setVideoSize(320, 240);//最高只能设置640x480
//设置记录会话的最大持续时间（毫秒）
mRecorder.setMaxDuration(60 \* 1000);
mRecorder.setPreviewDisplay(mSurfaceHolder.getSurface());
String path \= getExternalCacheDir().getPath();
if (path != null) {
File dir \= new File(path + "/videos");
if (!dir.exists()) {
dir.mkdir();
}
path \= dir + "/" + System.currentTimeMillis() + ".mp4";
//设置输出文件的路径
mRecorder.setOutputFile(path);
//准备录制
mRecorder.prepare();
//开始录制
mRecorder.start();
isRecording \= true;
btnStartStop.setText("停止");
}
} catch (Exception e) {
e.printStackTrace();
}
}
/\*\*
\* 停止录制
\*/
private void stopRecord() {
try {
//停止录制
mRecorder.stop();
//重置
mRecorder.reset();
btnStartStop.setText("开始");
} catch (Exception e) {
e.printStackTrace();
}
isRecording \= false;
}
/\*\*
\* 释放MediaRecorder
\*/
private void releaseMediaRecorder() {
if (mRecorder != null) {
mRecorder.release();
mRecorder \= null;
}
}
/\*\*
\* 释放相机资源
\*/
private void releaseCamera() {
try {
if (mCamera != null) {
mCamera.stopPreview();
mCamera.setPreviewCallback(null);
mCamera.unlock();
mCamera.release();
}
} catch (RuntimeException e) {
} finally {
mCamera \= null;
}
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
// 将holder，这个holder为开始在onCreate里面取得的holder，将它赋给mSurfaceHolder
mSurfaceHolder = holder;
if (mCamera == null) {
return;
}
try {
//设置显示
mCamera.setPreviewDisplay(holder);
mCamera.startPreview();
} catch (Exception e) {
e.printStackTrace();
releaseCamera();
finish();
}
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
// 将holder，这个holder为开始在onCreate里面取得的holder，将它赋给mSurfaceHolder
mSurfaceHolder = holder;
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
// surfaceDestroyed的时候同时对象设置为null
if (isRecording && mCamera != null) {
mCamera.lock();
}
mSurfaceView \= null;
mSurfaceHolder \= null;
releaseMediaRecorder();
releaseCamera();
}
private class CameraSizeComparator implements Comparator<Camera.Size> {
public int compare(Camera.Size lhs, Camera.Size rhs) {
if (lhs.width == rhs.width) {
return 0;
} else if (lhs.width > rhs.width) {
return 1;
} else {
return -1;
}
}
}
}
3.）布局文件
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android\="http://schemas.android.com/apk/res/android"
xmlns:tools\="http://schemas.android.com/tools"
android:layout\_width\="match\_parent"
android:layout\_height\="match\_parent"
android:orientation\="vertical"\>
<SurfaceView
android:id\="@+id/surfaceview"
android:layout\_width\="match\_parent"
android:layout\_height\="0dp"
android:layout\_weight\="1" />
<Button
android:id\="@+id/btnStartStop"
android:layout\_width\="wrap\_content"
android:layout\_height\="55dip"
android:layout\_gravity\="center"
android:text\="开始"
tools:context\=".MainActivity" />
</LinearLayout\>
