Android:照相机（camera）与视频录制(Recorder)的实现

在我们开发app时，会遇到程序中需要摄像的功能，我们最好的选择是跳转到手机自带的摄像程序中，但有时侯也可以在自己的应用程序中实现这个东西。

要用到的控件：SurfaceView显示照相机的画面

• 实现照相机的核心类：camera

  • surfaceView.getHolder().addCallback()接受摄像头界面变化的信息

• 实现视频录制的核心类：MediaRecorder

---

实现照相机

activity_main.xml:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" android:id="@+id/activity_main"
    android:layout_width="match_parent" android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
  android:paddingTop="@dimen/activity_vertical_margin"
    android:orientation="vertical"
    tools:context="com.example.android27_camera.MainActivity">
    <SurfaceView
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:id="@+id/sv_Camera"
        />
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:onClick="takePhoto"
        android:text="拍照"
        />
LinearLayout>

---

MainActivity.java

package com.example.android27_camera;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.PixelFormat;
import android.hardware.Camera;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

public class MainActivity extends AppCompatActivity {

    private SurfaceView sv_camera;
    private Camera camera;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //surfaceView显示容器
        sv_camera = (SurfaceView) findViewById(R.id.sv_Camera);

        sv_camera.getHolder().addCallback(new SurfaceHolder.Callback() {
            @Override
            public void surfaceCreated(SurfaceHolder holder) {
                //打开摄像头(默认为后置摄像头，1为前置)
                camera = Camera.open(1);
                //给摄像设置参数
                Camera.Parameters parameters= camera.getParameters();
                //每秒几栈
//                parameters.setPreviewFrameRate(3);
                //设置照片的输出格式
                parameters.setPictureFormat(PixelFormat.JPEG);
                //设置照片质量
                parameters.set("jpeg-quality",85);
                //给照相机设置参数
                camera.setParameters(parameters);
                try {
                    //将摄像头的画面显示在SurfaceView上
                    camera.setPreviewDisplay(sv_camera.getHolder());
                } catch (IOException e) {
                    e.printStackTrace();
                }
                //开始预览
                camera.startPreview();
            }

            @Override
            public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
            }
            @Override
            public void surfaceDestroyed(SurfaceHolder holder) {
                camera.stopPreview();
                camera.release();
                camera=null;
            }
        });
    }



    //拍照
    public void takePhoto(View view){
        camera.takePicture(null, null, new Camera.PictureCallback() {//拍照回调函数
            @Override
            public void onPictureTaken(byte[] data, Camera camera) {
                Bitmap bitmap= BitmapFactory.decodeByteArray(data,0,data.length);
                try {
                    //写入本地内存卡中
                    FileOutputStream fos=new FileOutputStream("mnt/sdcard/DCIM/camera/myCamera"+System.currentTimeMillis()+".png");
                    //压缩文件
                    bitmap.compress(Bitmap.CompressFormat.PNG,85,fos);
                    //先停止预览
                    camera.stopPreview();
                    //在开启
                    camera.startPreview();
                } catch (FileNotFoundException e) {
                    e.printStackTrace();
                }
            }
        });
    }
}

---

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

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

下面是视频录制

activity_media_recorder.xml:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_media_recorder"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.android27_camera.MediaRecorderActivity">



    <SurfaceView
        android:layout_width="match_parent"
        android:layout_height="350dp"
        android:id="@+id/sv_recorder"
        />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <Button
            android:layout_weight="1"
            android:layout_width="0dp"
            android:text="开始"
            android:onClick="start"
            android:layout_height="wrap_content" />
        <Button
            android:layout_weight="1"
            android:layout_width="0dp"
            android:text="停止"
            android:onClick="stop"
            android:layout_height="wrap_content" />
    LinearLayout>
LinearLayout>

---

MediaRecorderActivity.java:

package com.example.android27_camera;

import android.media.MediaRecorder;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.SurfaceView;
import android.view.View;

import java.io.IOException;

import static android.os.Build.VERSION_CODES.M;

public class MediaRecorderActivity extends AppCompatActivity {

    private SurfaceView sv_recorder;
    private MediaRecorder mediaRecorder;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_media_recorder);

        sv_recorder = (SurfaceView) findViewById(R.id.sv_recorder);

        //实例化媒体录制器
        mediaRecorder = new MediaRecorder();

    }

    public void start(View view){
        //重置媒体录制器
        mediaRecorder.reset();
        //设置音频和视频来源
        //照相机
        mediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
        //麦克风
        mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
        //设置保存格式
        mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
        //设置编码格式
        mediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H263);
        mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
        //设置每秒几帧
        mediaRecorder.setVideoFrameRate(3);
        //设置保存的路径
        mediaRecorder.setOutputFile("mnt/sdcard/MyRecorder"+System.currentTimeMillis()+".mp4");
        //将画面展示到SurfaceView
        mediaRecorder.setPreviewDisplay(sv_recorder.getHolder().getSurface());
        try {
            //准备
            mediaRecorder.prepare();
            //启动
            mediaRecorder.start();
        } catch (IOException e) {
            e.printStackTrace();
        }


    }


    public void stop(View view){
        mediaRecorder.stop();
    }

}

---

最后别忘了加权限

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

源码下载：

http://download.csdn.net/download/james_lang/9761933