Android自定義錄影（一）之錄影功能實現(附demo原始碼)
阿新 • • 發佈：2019-02-05
引言
最近在做一個專案，是有關用手機攝像頭做影象實時識別的。所以裡面需要自定義一個錄影功能。該demo實現了錄影和錄影後文件的儲存檢視，錄影會實時自動對焦（AutoFocus）。根據功能分兩篇講述。這第一篇講述錄影基本實現思路和需要注意的點。後面附有github的demo原始碼下載連結。
思路
*Android實現錄影主要依靠MediaRecorder和SurfaceView這兩個類。另外，因為需要對攝像頭引數做一些設定，所以也需要Camera類。它們的作用分別是：MediaRecorder通過控制錄影音視訊源和輸出編碼等；surfaceview則是作為View的存在提供使用者介面，在surfaceview的不同生命週期實現不同的操作；camera類則用於對攝像頭引數做一些設定，再呼叫MediaRecorder的setCamera()
程式碼
1.佈局
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:baselineAligned="false"
xmlns:android="http://schemas.android.com/apk/res/android">
<SurfaceView
2.佈局截圖：
3.核心程式碼及註釋：
package com.alanjet.videorecordertest;
import android.annotation.TargetApi;
import android.app.Activity;
import android.content.Intent;
import android.content.pm.ActivityInfo;
import android.graphics.PixelFormat;
import android.hardware.Camera;
import android.media.CamcorderProfile;
import android.media.MediaRecorder;
import android.os.Build;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import android.widget.ImageButton;
import android.widget.Toast;
import java.io.File;
import java.util.Calendar;
public class MainActivity extends Activity implements SurfaceHolder.Callback {
private static final String TAG = "MainActivity";
private SurfaceView mSurfaceview;
private ImageButton mBtnStartStop;
private ImageButton mBtnSet;
private ImageButton mBtnShowFile;
private boolean mStartedFlg = false;
private MediaRecorder mRecorder;
private SurfaceHolder mSurfaceHolder;
private Camera myCamera;
private Camera.Parameters myParameters;
private Camera.AutoFocusCallback mAutoFocusCallback=null;
private boolean isView = false;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//重寫AutoFocusCallback介面
mAutoFocusCallback=new Camera.AutoFocusCallback() {
@Override
public void onAutoFocus(boolean success, Camera camera) {
if(success){
Log.i(TAG, "AutoFocus: success...");
}else {
Log.i(TAG, "AutoFocus: failure...");
}
}
};
initScreen();
setContentView(R.layout.activity_main);
mSurfaceview = (SurfaceView)findViewById(R.id.capture_surfaceview);
mBtnStartStop = (ImageButton) findViewById(R.id.ib_stop);
mBtnSet= (ImageButton) findViewById(R.id.capture_imagebutton_setting);
mBtnShowFile= (ImageButton) findViewById(R.id.capture_imagebutton_showfiles);
mBtnShowFile.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent=new Intent(MainActivity.this,ShowVideoActivity.class);
startActivity(intent);
finish();
}
});
mBtnSet.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(MainActivity.this,"相機設定待開發~",Toast.LENGTH_SHORT).show();
}
});
SurfaceHolder holder = mSurfaceview.getHolder();// 取得holder
holder.addCallback(this); // holder加入回撥介面
holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
/**
* 獲取系統時間，儲存檔案以系統時間戳命名
*/
public static String getDate(){
Calendar ca = Calendar.getInstance();
int year = ca.get(Calendar.YEAR);
int month = ca.get(Calendar.MONTH);
int day = ca.get(Calendar.DATE);
int minute = ca.get(Calendar.MINUTE);
int hour = ca.get(Calendar.HOUR);
int second = ca.get(Calendar.SECOND);
String date = "" + year + (month + 1 )+ day + hour + minute + second;
Log.d(TAG, "date:" + date);
return date;
}
/**
* 獲取SD path
*/
public String getSDPath(){
File sdDir = null;
boolean sdCardExist = Environment.getExternalStorageState()
.equals(android.os.Environment.MEDIA_MOUNTED); // 判斷sd卡是否存在
if (sdCardExist)
{
sdDir = Environment.getExternalStorageDirectory();// 獲取跟目錄
return sdDir.toString();
}
return null;
}
//初始化螢幕設定
public void initScreen(){
requestWindowFeature(Window.FEATURE_NO_TITLE);// 去掉標題欄
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);// 設定全屏
// 設定橫屏顯示
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
// 選擇支援半透明模式,在有surfaceview的activity中使用。
getWindow().setFormat(PixelFormat.TRANSLUCENT);
}
//初始化Camera設定
public void initCamera()
{
if(myCamera == null && !isView)
{
myCamera = Camera.open();
Log.i(TAG, "camera.open");
}
if(myCamera != null && !isView) {
try {
myParameters = myCamera.getParameters();
myParameters.setPreviewSize(1920, 1080);
myParameters.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_VIDEO);
myCamera.setParameters(myParameters);
myCamera.setPreviewDisplay(mSurfaceHolder);
myCamera.startPreview();
isView = true;
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
Toast.makeText(MainActivity.this, "初始化相機錯誤",
Toast.LENGTH_SHORT).show();
}
}
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
// TODO Auto-generated method stub
mSurfaceHolder = holder;
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
// TODO Auto-generated method stub
mSurfaceHolder = holder;
initCamera();
mBtnStartStop.setOnClickListener(new View.OnClickListener() {
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if (!mStartedFlg) {
// Start
if (mRecorder == null) {
mRecorder = new MediaRecorder(); // Create MediaRecorder
}
try {
myCamera.unlock();
mRecorder.setCamera(myCamera);
// Set audio and video source and encoder
// 這兩項需要放在setOutputFormat之前
mRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
mRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
mRecorder.setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_720P));
mRecorder.setPreviewDisplay(mSurfaceHolder.getSurface());
// Set output file path
String path = getSDPath();
if (path != null) {
File dir = new File(path + "/VideoRecorderTest");
if (!dir.exists()) {
dir.mkdir();
}
path = dir + "/" + getDate() + ".mp4";
mRecorder.setOutputFile(path);
Log.d(TAG, "bf mRecorder.prepare()");
mRecorder.prepare();
Log.d(TAG, "af mRecorder.prepare()");
Log.d(TAG, "bf mRecorder.start()");
mRecorder.start(); // Recording is now started
Log.d(TAG, "af mRecorder.start()");
mStartedFlg = true;
mBtnStartStop.setBackground(getDrawable(R.drawable.rec_stop));
}
} catch (Exception e) {
e.printStackTrace();
}
} else {
// stop
if (mStartedFlg) {
try {
mRecorder.stop();
mRecorder.reset();
mBtnStartStop.setBackground(getDrawable(R.drawable.rec_start));
} catch (Exception e) {
e.printStackTrace();
}
}
mStartedFlg = false;
}
}
});
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
// TODO Auto-generated method stub
// surfaceDestroyed的時候同時物件設定為null
mSurfaceview = null;
mSurfaceHolder = null;
if (mRecorder != null) {
mRecorder.release();
mRecorder = null;
}
}
@Override
protected void onRestart() {
super.onRestart();
}
@Override
protected void onResume() {
super.onResume();
}
@Override
protected void onStart() {
super.onStart();
}
}4.manifest許可權配置：
<uses-permission android:name="android.permission.RECORD_AUDIO" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />5.注意點：
Surfaceview主要是通過
SurfaceHolder holder = mSurfaceview.getHolder();中的SurfaceHolder來做控制的，SurfaceHolder加入回撥介面holder.addCallback(this)來重寫介面中的三個生命週期方法：public void surfaceChanged(), public void surfaceCreated(), public void surfaceDestroyed().實現自動對焦的關鍵在於重寫
Camera.AutoFocusCallback()介面。並且需要將camera的parameters設定對焦模式為myParameters.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_VIDEO)。
6.執行截圖：
7.demo原始碼下載連結:
後言
還有一篇部落格《Android自定義錄影（二）之錄影檔案儲存檢視實現(附demo原始碼)》將在近期推出！
在實踐中求真知，在技術中尋快樂。這是自己在做專案中的一點小積累，希望能幫到有需要的Android開發小夥伴。這也是自己第一次寫csdn部落格。可能表達得並不是很到位，一些地方寫的也比較稚嫩，歡迎大家在評論中多指點多交流，在技術之路上不斷前進。