我打从SD卡一个加密的mp4视频文件。为此我做什么.....

第1步我复制文件从SD卡内部存储器和我写在世界可读和可写的世界格式文件，这样，我可以播放

第2步。我解密了temprary文件夹中的文件

第3步。现在我玩这个，文件播放没有问题

但问题是这个过程需要时间，因为文件很大大约25 MB，而这个过程（复制和解密）大约需要2分钟时间

在一些阅读，我发现这个问题的解决办法，我可以通过使用时间缩短 libmedia库，但我面临着一些问题  当我玩这个使用libmedia库 错误出现在日志中的猫

  6月10日至10号：33：42.908：E / MediaPlayer的（9249）：错误（1，-2147483648）
 

在活动屏幕我得到了在对话框的消息 无法播放视频

libmedia库链接 http://libeasy.alwaysdata.net/

感谢您的宝贵建议和帮助。

我的活动code是

 包com.example.playvideo2;

进口java.io.IOException异常;
进口java.security.InvalidKeyException;
进口java.security.NoSuchAlgorithmException;

进口javax.crypto.Cipher中;
进口javax.crypto.KeyGenerator;
进口javax.crypto.NoSuchPaddingException;
进口javax.crypto.SecretKey;

进口fr.maxcom.http.LocalSingleHttpServer;
进口fr.maxcom.libmedia.Licensing;
进口android.media.MediaPlayer;
进口android.media.MediaPlayer.OnCompletionListener;
进口android.os.Bundle;
进口android.os.Environment;
进口android.app.Activity;
进口android.view.Menu;
进口android.widget.MediaController;
进口android.widget.VideoView;


公共类MainActivity扩展活动实现OnCompletionListener
{
    LocalSingleHttpServer mServer上;
    VideoView mVideoView;

    @覆盖
    保护无效的onCreate（包savedInstanceState）{
        super.onCreate（savedInstanceState）;
        的setContentView（R.layout.video_view）;

        Licensing.allow（本）;
        playENCVideo（Environment.getExternalStorageDirectory（）
                +/encVideo.mp4）;
    }

@覆盖
公共布尔onCreateOptionsMenu（功能菜单）{
    //充气菜单;这增加了项目操作栏，如果它是present。
    。getMenuInflater（）膨胀（R.menu.main，菜单）;
    返回true;
}

公共无效playENCVideo（字符串路径）{

    尝试 {
        密码破译= NULL;

        的KeyGenerator kgen = KeyGenerator.getInstance（AES）;
        SecretKey的SKEY = kgen.generateKey（）;

        解密= Cipher.getInstance（AES）;

        decipher.init（Cipher.DECRYPT_MODE，SKEY）;

        mServer上=新LocalSingleHttpServer（）;

        mServer.setCipher（解码）;
        mServer.start（）;

        PATH = mServer.getURL（路径）;

        mVideoView =（VideoView）findViewById（R.id.videoView1）;
        mVideoView.setVideoPath（路径）;

        // mVideoView.setMediaController（新的MediaController（本））;
        // mVideoView.requestFocus（）;
        mVideoView.start（）;
    }赶上（InvalidKeyException将E）{
        // TODO自动生成的catch块
        e.printStackTrace（）;
    }赶上（抛出：NoSuchAlgorithmException E）{
        // TODO自动生成的catch块
        e.printStackTrace（）;
    }赶上（NoSuchPaddingException E）{
        // TODO自动生成的catch块
        e.printStackTrace（）;
    }赶上（IOException异常E）{
        // TODO自动生成的catch块
        e.printStackTrace（）;
    }
}

@覆盖
公共无效onCompletion（MediaPlayer的MP）{
    // MediaPlayer.OnCompletionListener接口
    mServer.stop（）;

}

}
 

我的清单文件

 ＆LT;舱单的xmlns：机器人=htt​​p://schemas.android.com/apk/res/android
    包=com.example.playvideo2
    安卓版code =1
    机器人：VERSIONNAME =1.0
    ＆GT;

＆LT;用途-SDK
    安卓的minSdkVersion =8
    机器人：targetSdkVersion =18/＆GT;

＆LT;使用-权限的Andr​​oid：名称=android.permission.INTERNET对/＆GT;

＆lt;应用
    机器人：allowBackup =真
    机器人：图标=@可绘制/ ic_launcher
    机器人：标签=@字符串/ APP_NAME
    机器人：主题=@风格/ AppTheme＆GT;
    ＆LT;活动
        机器人：名称=com.example.playvideo2.MainActivity
        机器人：标签=@字符串/ APP_NAME＆GT;
        ＆LT;意向滤光器＆gt;
            ＆lt;作用机器人：名称=android.intent.action.MAIN/＆GT;

            ＆LT;类机器人：名称=android.intent.category.LAUNCHER/＆GT;
        ＆所述; /意图滤光器＆gt;
    ＆LT; /活性GT;

    ＆所述;元数据
        机器人：名称=fr.maxcom.libmedia.apiKey
        android:value="qV1T3Zf+IyCpb1jomsomS3NUXBk7LdDaV31DcwmVIoMpvWWK8xAQIl1RUVWQegSt2jJbwH+cleik7YCH2/chP1JWdhpSfgMaNRl3fDMOez8mGn98Jhp7KyAffjc5RA==" /＆GT;
＆LT; /用途＆gt;

＆LT; /舱单＆GT;
 

这是我用于加密和解密

 的FileInputStream FIS =新的FileInputStream（新文件（D：/QLurnVideo/inputVideo.mp4））;
        文件OUTFILE =新的文件（D：/QLurnVideo/encVideo.mp4）;
        INT读取;
        如果（！outfile.exists（））
            outfile.createNewFile（）;
        文件decfile =新的文件（D：/QLurnVideo/decVideo.mp4）;
        如果（！decfile.exists（））
            decfile.createNewFile（）;
        FileOutputStream中FOS =新的FileOutputStream（OUTFILE）;
        的FileInputStream encfis =新的FileInputStream（OUTFILE）;
        FileOutputStream中decfos =新的FileOutputStream（decfile）;
        密码加密器= Cipher.getInstance（AES）;
        密码译码= Cipher.getInstance（AES）;
        的KeyGenerator kgen = KeyGenerator.getInstance（AES）;

        SecretKey的SKEY = kgen.generateKey（）;
        // LGO
        encipher.init（Cipher.ENCRYPT_MODE，SKEY）;
        CipherInputStream顺=新CipherInputStream（FIS，加密器）;
        decipher.init（Cipher.DECRYPT_MODE，SKEY）;
        CipherOutputStream COS =新CipherOutputStream（decfos，破译）;
        而（（读= cis.read（））！=  -  1）
                {
                    fos.write（（char）的读取）;
                    fos.flush（）;
                }
        fos.close（）;
        而（（读= encfis.read（））！=  -  1）
        {
            cos.write（读）;
            cos.flush（）;
        }
cos.close（）;
 

解决方案

您是通过加密文字图象，这要花费很多时间去更好地与逐行通过使用缓冲区这样的..

 字节[] BUFF =新的字节[1024];
而（（读= cis.read（BUFF））！=  -  1）
            {
                fos.write（BUFF，0，读）;
                fos.flush（）;
            }
    fos.close（）;
    而（（读= encfis.read（BUFF））！=  -  1）
    {
        cos.write（BUFF，0，读）;
        cos.flush（）;
    }
cos.close（）;
 

I am playing a encrypted mp4 video file from sdcard. for this what i do .....

STEP 1. i copy file from sdcard in internal memory and i write that file in world readable and world writeable format so that that i could Play

STEP 2. I decrypt that file in a temprary folder

STEP 3. now i play this , file plays no problem

Problem is this process takes time , because file is large about 25 mb , and this process ( copying and decryption ) takes about 2 minutes time

after some reading i found a solution of this problem i could reduce time by using libmedia library , but i am facing some problem when i play this by using libmedia library error comes in log cat

10-10 06:33:42.908: E/MediaPlayer(9249): error (1, -2147483648)

on Activity screen i got a message in dialog "can't play video"

libmedia library link is http://libeasy.alwaysdata.net/

thanks for your valuable suggestion and help

my activity code is

package com.example.playvideo2;

import java.io.IOException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;

import fr.maxcom.http.LocalSingleHttpServer;
import fr.maxcom.libmedia.Licensing;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnCompletionListener;
import android.os.Bundle;
import android.os.Environment;
import android.app.Activity;
import android.view.Menu;
import android.widget.MediaController;
import android.widget.VideoView;


public class MainActivity extends Activity implements OnCompletionListener 
{
    LocalSingleHttpServer mServer;
    VideoView mVideoView;

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

        Licensing.allow(this);
        playENCVideo(Environment.getExternalStorageDirectory()
                + "/encVideo.mp4");
    }

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

public void playENCVideo(String path) {

    try {
        Cipher decipher = null;

        KeyGenerator kgen = KeyGenerator.getInstance("AES");
        SecretKey skey = kgen.generateKey();

        decipher = Cipher.getInstance("AES");

        decipher.init(Cipher.DECRYPT_MODE, skey);

        mServer = new LocalSingleHttpServer();

        mServer.setCipher(decipher);
        mServer.start();

        path = mServer.getURL(path);

        mVideoView = (VideoView) findViewById(R.id.videoView1);
        mVideoView.setVideoPath(path);

        // mVideoView.setMediaController(new MediaController(this));
        // mVideoView.requestFocus();
        mVideoView.start();
    } catch (InvalidKeyException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (NoSuchAlgorithmException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (NoSuchPaddingException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

@Override
public void onCompletion(MediaPlayer mp) {
    // MediaPlayer.OnCompletionListener interface
    mServer.stop();

}

}

my manifest file is

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.playvideo2"
    android:versionCode="1"
    android:versionName="1.0" 
    >

<uses-sdk
    android:minSdkVersion="8"
    android:targetSdkVersion="18" />

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

<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name="com.example.playvideo2.MainActivity"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

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

    <meta-data
        android:name="fr.maxcom.libmedia.apiKey"
        android:value="qV1T3Zf+IyCpb1jomsomS3NUXBk7LdDaV31DcwmVIoMpvWWK8xAQIl1RUVWQegSt2jJbwH+cleik7YCH2/chP1JWdhpSfgMaNRl3fDMOez8mGn98Jhp7KyAffjc5RA==" />
</application>

</manifest>

This is that code which i used for encryption and decryption

        FileInputStream fis = new FileInputStream(new File("D:/QLurnVideo/inputVideo.mp4"));
        File outfile = new File("D:/QLurnVideo/encVideo.mp4");
        int read;
        if(!outfile.exists())
            outfile.createNewFile();
        File decfile = new File("D:/QLurnVideo/decVideo.mp4");
        if(!decfile.exists())
            decfile.createNewFile();
        FileOutputStream fos = new FileOutputStream(outfile);
        FileInputStream encfis = new FileInputStream(outfile);
        FileOutputStream decfos = new FileOutputStream(decfile);
        Cipher encipher = Cipher.getInstance("AES");
        Cipher decipher = Cipher.getInstance("AES");
        KeyGenerator kgen = KeyGenerator.getInstance("AES");

        SecretKey skey = kgen.generateKey();
        //Lgo
        encipher.init(Cipher.ENCRYPT_MODE, skey);
        CipherInputStream cis = new CipherInputStream(fis, encipher);
        decipher.init(Cipher.DECRYPT_MODE, skey);
        CipherOutputStream cos = new CipherOutputStream(decfos,decipher);
        while((read = cis.read())!=-1)
                {
                    fos.write((char)read);
                    fos.flush();
                }   
        fos.close();
        while((read=encfis.read())!=-1)
        {
            cos.write(read);
            cos.flush();
        }
cos.close();

You are encrypting video by character, this take much time better go with line by line by using buffer like this..

byte[] buff=new byte[1024];
while((read = cis.read(buff))!=-1)
            {
                fos.write(buff,0,read);
                fos.flush();
            }   
    fos.close();
    while((read=encfis.read(buff))!=-1)
    {
        cos.write(buff,0,read);
        cos.flush();
    }
cos.close();