Lập trình Android: ứng dụng quay Video docx

Quay VideoỞ hầu hết các điện thoại có hệ điều hành Android đều có hỗ trợ Camera.. Và trong bài viết này mình sẽ xây dựng 1 chương trình xử dụng Camera của thiết bị để quay video.. Các bư

Quay Video

Ở hầu hết các điện thoại có hệ điều hành Android đều có hỗ trợ Camera Và trong bài viết này mình sẽ xây dựng 1 chương trình xử dụng Camera của thiết bị để quay video Các bước làm nên chương trình như sau:

1/ Tạo Project :

Project name: RecordVideo

Build Target: Android 2.3.3

Application name: RecordVideo

Package name: com.dac.RecordVideo

Create Activity: MainActivity

2/ Trong file main.xml các bạn thiết kế như sau:

<?xml version="1.0" encoding="utf-8"?>

<! This file is /res/layout-land/main.xml >

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent"

android:orientation="horizontal"

<LinearLayout

android:orientation="vertical" android:layout_width="wrap_content" android:layout_height="wrap_content">

<Button android:id="@+id/initBtn"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="Initialize Recorder" android:onClick="doClick"

android:enabled="false" />

<Button android:id="@+id/beginBtn"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="Begin Recording" android:onClick="doClick"

android:enabled="false" />

<Button android:id="@+id/stopBtn"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="Stop Recording" android:onClick="doClick" />

<Button android:id="@+id/playRecordingBtn"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="Play Recording" android:onClick="doClick" />

<Button android:id="@+id/stopPlayingRecordingBtn"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="Stop Playing" android:onClick="doClick" /> </LinearLayout>

<LinearLayout android:orientation="vertical"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

<TextView android:id="@+id/recording" android:text=" "

android:textColor="#FF0000"

android:layout_width="wrap_content"

android:layout_height="wrap_content" />

<VideoView android:id="@+id/videoView"

android:layout_width="250dip" android:layout_height="200dip" /> </LinearLayout>

</LinearLayout>

3/ Trong file MainActivity.java:

package com.dac.RecordVideo;

import java.io.File;

import java.io.IOException;

import android.app.Activity;

import android.hardware.Camera;

import android.media.MediaRecorder;

import android.media.MediaRecorder.OnErrorListener;

import android.media.MediaRecorder.OnInfoListener;

import android.os.Bundle;

import android.os.Environment;

import android.util.Log;

import android.view.SurfaceHolder;

import android.view.View;

import android.widget.Button;

import android.widget.MediaController;

import android.widget.TextView;

import android.widget.Toast;

import android.widget.VideoView;

public class MainActivity extends Activity implements

SurfaceHolder.Callback, OnInfoListener, OnErrorListener {

private static final String TAG = "RecordVideo";

private MediaRecorder mRecorder = null;

private String mOutputFileName;

private VideoView mVideoView = null;

private SurfaceHolder mHolder = null;

private Button mInitBtn = null;

private Button mStartBtn = null;

private Button mStopBtn = null;

private Button mPlayBtn = null;

private Button mStopPlayBtn = null;

private Camera mCamera = null;

private TextView mRecordingMsg = null;

/** Called when the activity is first created */

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

Log.v(TAG, "in onCreate");

setContentView(R.layout.main);

mInitBtn = (Button) findViewById(R.id.initBtn);

mStartBtn = (Button) findViewById(R.id.beginBtn);

mStopBtn = (Button) findViewById(R.id.stopBtn);

mPlayBtn = (Button) findViewById(R.id.playRecordingBtn);

mStopPlayBtn = (Button) findViewById(R.id.stopPlayingRecordingBtn); mRecordingMsg = (TextView) findViewById(R.id.recording);

mVideoView = (VideoView)this.findViewById(R.id.videoView);

}

private boolean initCamera() {

try {

mCamera = Camera.open();

Camera.Parameters camParams = mCamera.getParameters();

mCamera.lock();

mHolder = mVideoView.getHolder();

mHolder.addCallback(this);

mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

}

catch(RuntimeException re) {

Log.v(TAG, "Could not initialize the Camera");

re.printStackTrace();

return false;

}

return true;

}

private void releaseRecorder() {

if(mRecorder != null) {

mRecorder.release();

mRecorder = null;

}

}

private void releaseCamera() {

if(mCamera != null) {

mCamera.reconnect();

} catch (IOException e) {

e.printStackTrace();

} mCamera.release();

mCamera = null;

}

}

@Override

protected void onResume() {

Log.v(TAG, "in onResume");

super.onResume();

mInitBtn.setEnabled(false);

mStartBtn.setEnabled(false);

mStopBtn.setEnabled(false);

mPlayBtn.setEnabled(false);

mStopPlayBtn.setEnabled(false);

if(!initCamera())

finish();

}

@Override

protected void onPause() {

Log.v(TAG, "in onPause");

super.onPause();

releaseRecorder();

releaseCamera();

}

@Override

protected void onDestroy() {

Log.v(TAG, "in onDestroy");

super.onDestroy();

}

public void doClick(View view) {

switch(view.getId()) {

case R.id.initBtn:

initRecorder();

break;

case R.id.beginBtn:

beginRecording();

break;

case R.id.stopBtn:

stopRecording();

break;

case R.id.playRecordingBtn:

playRecording();

break;

case R.id.stopPlayingRecordingBtn:

stopPlayingRecording();

break;

}

}

@Override

public void surfaceCreated(SurfaceHolder holder) {

Log.v(TAG, "in surfaceCreated");

try {

mCamera.setPreviewDisplay(mHolder);

mCamera.startPreview();

} catch (IOException e) {

Log.v(TAG, "Could not start the preview");

e.printStackTrace();

} mInitBtn.setEnabled(true);

}

@Override

public void surfaceDestroyed(SurfaceHolder holder) {

Log.v(TAG, "in surfaceDestroyed");

}

@Override

public void surfaceChanged(SurfaceHolder holder, int format, int width,

int height) {

Log.v(TAG, "surfaceChanged: Width x Height = " + width + "x" +

height);

}

private void initRecorder() {

if(mRecorder != null) return;

mOutputFileName = Environment.getExternalStorageDirectory() +

"/videooutput.mp4";

File outFile = new File(mOutputFileName);

if(outFile.exists()) {

outFile.delete();

}

try {

mCamera.stopPreview();

mCamera.unlock();

mRecorder = new MediaRecorder();

mRecorder.setCamera(mCamera);

mRecorder.setAudioSource(MediaRecorder.AudioSource.CAMCORDER);

mRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA); mRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4); mRecorder.setVideoSize(176, 144);

mRecorder.setVideoFrameRate(15);

mRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.MPEG_4_SP); mRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB); mRecorder.setMaxDuration(7000); // limit to 7 seconds

mRecorder.setPreviewDisplay(mHolder.getSurface());

mRecorder.setOutputFile(mOutputFileName);

mRecorder.prepare();

Log.v(TAG, "MediaRecorder initialized");

mInitBtn.setEnabled(false);

mStartBtn.setEnabled(true);

}

catch(Exception e) {

Log.v(TAG, "MediaRecorder failed to initialize");

e.printStackTrace();

}

}

private void beginRecording() {

mRecorder.setOnInfoListener(this);

mRecorder.setOnErrorListener(this);

mRecorder.start();

mRecordingMsg.setText("RECORDING");

mStartBtn.setEnabled(false);

mStopBtn.setEnabled(true);

}

private void stopRecording() {

if (mRecorder != null) {

mRecorder.setOnErrorListener(null);

mRecorder.setOnInfoListener(null);

try {

mRecorder.stop();

}

catch(IllegalStateException e) {

Log.e(TAG, "Got IllegalStateException in stopRecording");

}

releaseRecorder();

mRecordingMsg.setText("");

releaseCamera();

mStartBtn.setEnabled(false);

mStopBtn.setEnabled(false);

mPlayBtn.setEnabled(true);

}

}

private void playRecording() {

MediaController mc = new MediaController(this);

mVideoView.setMediaController(mc);

mVideoView.setVideoPath(mOutputFileName);

mVideoView.start();

mStopPlayBtn.setEnabled(true);

}

private void stopPlayingRecording() {

mVideoView.stopPlayback();

}

@Override

public void onInfo(MediaRecorder mr, int what, int extra) {

Log.i(TAG, "got a recording event");

if(what ==

MediaRecorder.MEDIA_RECORDER_INFO_MAX_DURATION_REACHED) {

Log.i(TAG, " max duration reached");

stopRecording();

Toast.makeText(this, "Recording limit has been reached

Stopping the recording",

Toast.LENGTH_SHORT).show();

} }

@Override

public void onError(MediaRecorder mr, int what, int extra) {

Log.e(TAG, "got a recording error");

stopRecording();

Toast.makeText(this, "Recording error has occurred Stopping the

recording",

Toast.LENGTH_SHORT).show();

}

}

Và trong phần AndroidManifest.xml các bạn thêm các Permission vào ứng dụng:

<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

package="com.dac.Recordvideo"

android:versionCode="1"

android:versionName="1.0">

<application android:icon="@drawable/icon"

android:label="@string/app_name">

<activity android:name=".MainActivity"

android:label="@string/app_name"

android:screenOrientation="landscape">

<intent-filter>

<action android:name="android.intent.action.MAIN" />

<category android:name="android.intent.category.LAUNCHER" />

</intent-filter>

</activity>

</application>

<uses-sdk android:minSdkVersion="4" />

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

<uses-permission android:name="android.permission.RECORD_AUDIO"/>

<uses-permission android:name="android.permission.CAMERA"/>

</manifest>

Cuối cùng các bạn debug ứng dụng (lưu ý ứng dụng chỉ chạy video trên máy thật) và các bạn bấm Ctrl+F11 để chuyển qua màn hình ngang :

Mọi ý kiến đóng góp các bạn vui lòng gữi bài viết về forum :

http://forum.laptrinhdidong.vn Rất mong nhận được sự phản hồi của các bạn.