Android录屏 MediaRecorder介绍

电玩女神 2023-07-17 14:13 7阅读 0赞

## Android录屏 MediaRecorder介绍 ##

Android录屏的三种方案

1、adb shell命令screenrecord
    2、MediaRecorder, MediaProjection
    3、MediaCodec和MediaMuxer, MediaProjection ,

## 一、screenrecord命令 ##

screenrecord是一个shell命令，支持Android4.4(API level 19)以上，  
录制的视频格式为mp4 ,存放到手机sd卡里，默认录制时间为180s

adb shell screenrecord --size 1280x720 --bit-rate 6000000 --time-limit 30 /sdcard/demo.mp4
     --size 指定视频分辨率，根据手机情况决定
     --bit-rate 指定视频比特率，默认为4M，该值越小，保存的视频文件越小；
     --time-limit 指定录制时长，若设定大于180，命令不会被执行；

并不是所以手机都执行screenrecord命令，部分手机不识别。  
我在几款华为手机就没执行成功报错：  
/system/bin/sh: screenrecord: inaccessible or not found

## 二、 MediaRecorder ##

MediaProjection是Android5.0后才开放的屏幕采集接口，通过系统级服务MediaProjectionManager进行管理。

这里先整体说一下屏幕录制的流程，不然看起来费劲。

1、通过startActivityForResult(Intent intent)判断是否录屏授权的Activity
    其中intent对象就需要MediaProjectionManager.createScreenCaptureIntent();获取
    
    2、在onActivityResult回调方法中做具体录屏工作
    比如：创建MediaRecorder，设置MP4文件路径
    创建VirtualDisplay，设置屏幕相关参数
    如果不在onActivityResult回调中执行会有问题。
    
    3、开始录屏
    MediaRecorder.start()
    
    4、停止录屏
    MediaRecorder.reset();
    MediaRecorder.release();

录屏过程用到录音权限和数据读写权限。

## 三、MediaCodec和MediaMuxer ##

MediaCodec提供对音视频压缩编码和解码功能，MediaMuxer可以将音视频混合生成多媒体文件，生成MP4文件。

这个录屏的方式和MediaRecorder是类似的，只是流程第二部有点不同，这里不做介绍。

详情可以参考：https://www.jianshu.com/p/8b313692ac85

## 四、MediaRecorder项目示例的主要代码 ##

这里只做了录制和停止录制，没有做相关适配，比如横竖屏切换后尺寸变化。

#### 简单效果： ####

![在这里插入图片描述][20200322105653923.gif]

生成的MP4文件会在sdcard目录下，并且以录屏时间为文件名。

### 1、MainActivity ###

package com.liwenzhi.screen;
    
    import android.Manifest;
    import android.app.Activity;
    import android.content.Context;
    import android.content.Intent;
    import android.content.pm.PackageManager;
    import android.media.projection.MediaProjection;
    import android.media.projection.MediaProjectionManager;
    import android.os.Handler;
    import android.os.Message;
    import android.support.v4.app.ActivityCompat;
    import android.support.v4.content.ContextCompat;
    import android.support.v7.app.AppCompatActivity;
    import android.os.Bundle;
    import android.util.Log;
    import android.view.View;
    import android.widget.Button;
    import android.widget.TextView;
    import android.widget.Toast;
    
    import java.io.File;
    
    
    public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    
        String TAG = "MainActivity";
        MediaProjectionManager mProjectionManager;
        MediaRecordService mediaRecord;
        int displayWidth = 1280;
        int displayHeight = 1920;
        Button btn_start_record;
        Button btn_stop_record;
        TextView tv_time;
        int REQUEST_CODE_PERMISSIONS = 99;
        int REQUEST_CODE_SCREEN = 100;
    
        //录音权限和数据读写权限
        String[] permissions = new String[]{Manifest.permission.RECORD_AUDIO, Manifest.permission.READ_EXTERNAL_STORAGE, Manifest.permission.WRITE_EXTERNAL_STORAGE};
        boolean mPassPermissions = true;
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            initView();
            initData();
            initEvent();
        }
    
        private void initView() {
            btn_start_record = findViewById(R.id.btn_start_record);
            btn_stop_record = findViewById(R.id.btn_stop_record);
            tv_time = findViewById(R.id.tv_time);
        }
    
        private void initData() {
            //权限申请
            //逐个判断你要的权限是否已经通过
            judgePermissions();
            if (!mPassPermissions) {
                ActivityCompat.requestPermissions(this, permissions, REQUEST_CODE_PERMISSIONS);
            }
        }
    
        private void initEvent() {
            btn_start_record.setOnClickListener(this);
            btn_stop_record.setOnClickListener(this);
        }
    
        // 申请权限后的回调
        // 1、录音和读写
        // 2、录屏startActivityForResult后的回调
        @Override
        protected void onActivityResult(int requestCode, int resultCode, Intent data) {
            super.onActivityResult(requestCode, resultCode, data);
            //录音和读写权限
            if (requestCode == REQUEST_CODE_PERMISSIONS) {
                if (resultCode != Activity.RESULT_OK) {
                    mPassPermissions = false;
                }
            } else
    
                // 录屏权限
                if (requestCode == REQUEST_CODE_SCREEN) {
                    if (resultCode == Activity.RESULT_OK) {
                        try {
                            // mediaProjection 如果不在权限申请中回调，获取到的对象为空
                            MediaProjection mediaProjection = mProjectionManager.getMediaProjection(resultCode, data);
                            if (mediaProjection == null) {
                                Log.e(TAG, "media projection is null");
                                return;
                            }
                            File file = new File("/sdcard/" + MyTimeUtils.getTimeString("yyyy-MM-dd_HH:mm:ss") + ".mp4");  //录屏生成文件
                            if (!file.exists()) {
                                file.createNewFile();
                            }
                            mediaRecord = new MediaRecordService(displayWidth, displayHeight, 6000000, 1,
                                    mediaProjection, file.getAbsolutePath());
                            mediaRecord.start();
                            second = 0;
                            mHandler.sendEmptyMessageDelayed(10, 1000);
                        } catch (Exception e) {
                            e.printStackTrace();
                        }
                    } else {
                        Toast.makeText(MainActivity.this, "录屏失败", Toast.LENGTH_LONG).show();
                    }
                }
    
        }
    
    
        @Override
        public void onBackPressed() {
            //super.onBackPressed();
        }
    
        @Override
        public void onClick(View v) {
            switch (v.getId()) {
                case R.id.btn_start_record:
                    startRecord();
                    break;
                case R.id.btn_stop_record:
                    stopRecord();
                    break;
            }
        }
    
        // 开始录屏
        private void startRecord() {
            judgePermissions();
            if (!mPassPermissions) {
                Toast.makeText(this, "基础权限没通过！", Toast.LENGTH_LONG).show();
                return;
            }
            mProjectionManager = (MediaProjectionManager) getSystemService(Context.MEDIA_PROJECTION_SERVICE);
            if (mProjectionManager != null) {
                Intent intent = mProjectionManager.createScreenCaptureIntent();
                PackageManager packageManager = getPackageManager();
                if (packageManager.resolveActivity(intent, PackageManager.MATCH_DEFAULT_ONLY) != null) {
                    //存在录屏授权的Activity
                    startActivityForResult(intent, REQUEST_CODE_SCREEN);
                } else {
                    Toast.makeText(this, "没有录屏权限！", Toast.LENGTH_LONG).show();
                }
            }
        }
    
        // 停止录屏
        private void stopRecord() {
            mediaRecord.release();
            mHandler.removeMessages(10);
        }
    
        int second;
        // 计算时间
        Handler mHandler = new Handler() {
            @Override
            public void handleMessage(Message msg) {
                super.handleMessage(msg);
                switch (msg.what) {
                    case 10:
                        second++;
                        tv_time.setText(second + "");
                        mHandler.sendEmptyMessageDelayed(10, 1000);
                        break;
                }
            }
        };
    
        //判断每个权限是否通过
        private void judgePermissions() {
            boolean permission = true;
            for (int i = 0; i < permissions.length; i++) {
                if (ContextCompat.checkSelfPermission(this, permissions[i]) != PackageManager.PERMISSION_GRANTED) {
                    // 未授予的权限
                    permission = false;
                }
            }
            mPassPermissions = permission;
        }
    
    }

### 2、MediaRecordService ###

package com.liwenzhi.screen;
    
    import android.hardware.display.DisplayManager;
    import android.hardware.display.VirtualDisplay;
    import android.media.MediaRecorder;
    import android.media.projection.MediaProjection;
    import android.util.Log;
    
    public class MediaRecordService extends Thread {
    
        private static final String TAG = "MediaRecordService";
    
        private int mWidth;
        private int mHeight;
        private int mBitRate;
        private int mDpi;
        private String mDstPath;
        private MediaRecorder mMediaRecorder;
        private MediaProjection mMediaProjection;
        private static final int FRAME_RATE = 60; // 60 fps
    
        private VirtualDisplay mVirtualDisplay;
    
        public MediaRecordService(int width, int height, int bitrate, int dpi, MediaProjection mp, String dstPath) {
            mWidth = width;
            mHeight = height;
            mBitRate = bitrate;
            mDpi = dpi;
            mMediaProjection = mp;
            mDstPath = dstPath;
        }
    
        @Override
        public void run() {
            try {
                initMediaRecorder();
    
                //在mediarecorder.prepare()方法后调用
                mVirtualDisplay = mMediaProjection.createVirtualDisplay(TAG + "-display", mWidth, mHeight, mDpi,
                        DisplayManager.VIRTUAL_DISPLAY_FLAG_PUBLIC, mMediaRecorder.getSurface(), null, null);
                Log.i(TAG, "created virtual display: " + mVirtualDisplay);
                mMediaRecorder.start();
                Log.i(TAG, "mediarecorder start");
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    
        /**
         * 初始化MediaRecorder
         *
         * @return
         */
        public void initMediaRecorder() {
            mMediaRecorder = new MediaRecorder();
            mMediaRecorder.setVideoSource(MediaRecorder.VideoSource.SURFACE);
            mMediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
            mMediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
            mMediaRecorder.setOutputFile(mDstPath);
            mMediaRecorder.setVideoSize(mWidth, mHeight);
            mMediaRecorder.setVideoFrameRate(FRAME_RATE);
            mMediaRecorder.setVideoEncodingBitRate(mBitRate);
            mMediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H264);
            mMediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AAC);
    
            try {
                mMediaRecorder.prepare();
            } catch (Exception e) {
                e.printStackTrace();
            }
            Log.i(TAG, "media recorder" + mBitRate + "kps");
        }
    
        public void release() {
            if (mVirtualDisplay != null) {
                mVirtualDisplay.release();
                mVirtualDisplay = null;
            }
            if (mMediaRecorder != null) {
                mMediaRecorder.setOnErrorListener(null);
                mMediaProjection.stop();
                mMediaRecorder.reset();
                mMediaRecorder.release();
            }
            if (mMediaProjection != null) {
                mMediaProjection.stop();
                mMediaProjection = null;
            }
            Log.i(TAG, "release");
        }
    }

### 3、MyTimeUtils ###

package com.liwenzhi.screen;
    
    
    import java.text.SimpleDateFormat;
    import java.util.Date;
    
    /**
     * a Utils for time
     * <p>
     * identify the following letter: ："yyyy-MM-dd DD HH:mm:ss SSS"
     * * method1： long getTimeLong()
     * * method2： int getTimeInt(String filter)
     * * method3： String getTimeString()
     * * method4： String getTimeString(long time)
     * * method5： String getTimeString(long time, String filter)
     * * method6： String getTimeString( String filter)
     */
    
    public class MyTimeUtils {
    
    
        public static long getTimeLong() {
            return System.currentTimeMillis();
        }
        
        public static int getTimeInt(String filter) {
            SimpleDateFormat format = new SimpleDateFormat(filter);
            String time = format.format(new Date());
            return Integer.parseInt(time);
        }
    
    
        public static final String getTimeString() {
            SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
            return format.format(new Date(getTimeLong()));
        }
    
        public static final String getTimeString(long time) {
            SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
            return format.format(new Date(time));
        }
    
        public static final String getTimeString(long time, String filter) {
            SimpleDateFormat format = new SimpleDateFormat(filter);
            return format.format(new Date(time));
        }
    
        public static final String getTimeString(String filter) {
            SimpleDateFormat format = new SimpleDateFormat(filter);
            return format.format(new Date(getTimeLong()));
        }
    
        public static Long getTimeLong(String filter, String date) {
            try {
                SimpleDateFormat format = new SimpleDateFormat(filter);
                Date dateTime = format.parse(date);
                return dateTime.getTime();
            } catch (Exception e) {
                e.printStackTrace();
            }
    
            return 0L;
        }
    
    
    }

测试apk和项目源码下载：  
https://download.csdn.net/download/wenzhi20102321/12262262

这个项目只是简单录屏，如果要做得好，  
最好是正在通知栏/悬浮框里面控制停止，  
并且可以按退出键回到主界面，  
要用到服务来控制录屏屏幕的开始和停止。

# 共勉：时间总会过去，多做一下有意义的事情。 #

[20200322105653923.gif]: /images/20230528/45430df4dbac48038014e468ca94fcce.png