Android 安卓和 MJPEG

Android and MJPEG

提问by bl4d3

I need to get the mjpeg stream from an IP camera, anyone know the right way do it? I googled a bit and I find this example

我需要从 IP 摄像机获取 mjpeg 流，有人知道正确的方法吗？我用谷歌搜索了一下，我找到了这个例子

http://www.anddev.org/mjpeg_on_android_anyone-t1871.html

http://www.anddev.org/mjpeg_on_android_anyone-t1871.html

but I've been stucked when I tried to get the stream from another activity called by the main activity. Here the code:

但是当我试图从主要活动调用的另一个活动中获取流时，我被卡住了。这里的代码：

Main acitivity

主要活动

package com.test;


public class IntentTest extends Activity {
    /** Called when the activity is first created. */
    ListView myListView = null;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        myListView = (ListView)findViewById(R.id.listView);
        final ArrayList<String> items = new ArrayList<String>();
        items.add("00408C944B9A");
        final ArrayAdapter<String> aa;
        aa = new ArrayAdapter<String>(this,
                android.R.layout.simple_list_item_1,
                items);

        myListView.setAdapter(aa);
        myListView.setOnItemClickListener(listClicked);

    }


    private OnItemClickListener listClicked = new OnItemClickListener() {
        public void onItemClick(AdapterView<?> arg0, View arg1, int position, long id) {
            // TODO Auto-generated method stub
            Intent i = new Intent(IntentTest.this, OtherActivity.class);
            i.putExtra("MAC", myListView.getItemAtPosition(position).toString());
            startActivity(i);         
        }
    };
}

Second activity

第二个活动

package com.test;

import com.test.mjpeg.mjpegsample.MjpegView.*;
import com.test.parser.JSONParse;


public class OtherActivity extends Activity {
    /** Called when the activity is first created. */
    private MjpegView mv;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        Bundle extras = getIntent().getExtras();
        if (extras != null){
            String mac = (String)extras.get("MAC");
            Log.i("Other", "---->" + mac);
            TextView tv = (TextView)findViewById(R.id.textView);
            tv.setText(mac);


            String URL = "myurl";

            requestWindowFeature(Window.FEATURE_NO_TITLE);
            getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, 
                    WindowManager.LayoutParams.FLAG_FULLSCREEN);

            mv = new MjpegView(this);
            setContentView(mv);        

            mv.setSource(MjpegInputStream.read(URL));
            mv.setDisplayMode(MjpegView.SIZE_BEST_FIT);
            mv.showFps(true);      

        }
    }

    public void onPause() {
        super.onPause();
        mv.stopPlayback();
    }


}

回答by Carlos Portes

I found this code over the internet some time ago, maybe it will be of some help to you.

这段代码是前段时间在网上找到的，也许对你有帮助。

MjpegSample Class

MjpegSample 类

package de.mjpegsample;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.Window;
import android.view.WindowManager;
import de.mjpegsample.MjpegView.MjpegInputStream;
import de.mjpegsample.MjpegView.MjpegView;

public class MjpegSample extends Activity {

    private MjpegView mv;
    private static final int MENU_QUIT = 1;

    /* Creates the menu items */
    public boolean onCreateOptionsMenu(Menu menu) {    
    menu.add(0, MENU_QUIT, 0, "Quit");
    return true;
    }

    /* Handles item selections */
    public boolean onOptionsItemSelected(MenuItem item) {    
        switch (item.getItemId()) {
            case MENU_QUIT:
                finish();
                return true;    
            }    
        return false;
    }

    public void onCreate(Bundle icicle) {
        super.onCreate(icicle);
        //sample public cam
        String URL = "http://gamic.dnsalias.net:7001/img/video.mjpeg";

        requestWindowFeature(Window.FEATURE_NO_TITLE);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FORCE_NOT_FULLSCREEN, WindowManager.LayoutParams.FLAG_FORCE_NOT_FULLSCREEN);
        mv = new MjpegView(this);
        setContentView(mv);        
        mv.setSource(MjpegInputStream.read(URL));
        mv.setDisplayMode(MjpegView.SIZE_BEST_FIT);
        mv.showFps(false);
    }

    public void onPause() {
        super.onPause();
        mv.stopPlayback();
    }
}

MjpegView Class

MjpegView 类

package de.mjpegsample.MjpegView;

import java.io.IOException;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.Typeface;
import android.util.AttributeSet;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

public class MjpegView extends SurfaceView implements SurfaceHolder.Callback {
    public final static int POSITION_UPPER_LEFT  = 9;
    public final static int POSITION_UPPER_RIGHT = 3;
    public final static int POSITION_LOWER_LEFT  = 12;
    public final static int POSITION_LOWER_RIGHT = 6;

    public final static int SIZE_STANDARD   = 1; 
    public final static int SIZE_BEST_FIT   = 4;
    public final static int SIZE_FULLSCREEN = 8;

    private MjpegViewThread thread;
    private MjpegInputStream mIn = null;    
    private boolean showFps = false;
    private boolean mRun = false;
    private boolean surfaceDone = false;    
    private Paint overlayPaint;
    private int overlayTextColor;
    private int overlayBackgroundColor;
    private int ovlPos;
    private int dispWidth;
    private int dispHeight;
    private int displayMode;

    public class MjpegViewThread extends Thread {
        private SurfaceHolder mSurfaceHolder;
        private int frameCounter = 0;
        private long start;
        private Bitmap ovl;

        public MjpegViewThread(SurfaceHolder surfaceHolder, Context context) { mSurfaceHolder = surfaceHolder; }

        private Rect destRect(int bmw, int bmh) {
            int tempx;
            int tempy;
            if (displayMode == MjpegView.SIZE_STANDARD) {
                tempx = (dispWidth / 2) - (bmw / 2);
                tempy = (dispHeight / 2) - (bmh / 2);
                return new Rect(tempx, tempy, bmw + tempx, bmh + tempy);
            }
            if (displayMode == MjpegView.SIZE_BEST_FIT) {
                float bmasp = (float) bmw / (float) bmh;
                bmw = dispWidth;
                bmh = (int) (dispWidth / bmasp);
                if (bmh > dispHeight) {
                    bmh = dispHeight;
                    bmw = (int) (dispHeight * bmasp);
                }
                tempx = (dispWidth / 2) - (bmw / 2);
                tempy = (dispHeight / 2) - (bmh / 2);
                return new Rect(tempx, tempy, bmw + tempx, bmh + tempy);
            }
            if (displayMode == MjpegView.SIZE_FULLSCREEN) return new Rect(0, 0, dispWidth, dispHeight);
            return null;
        }

        public void setSurfaceSize(int width, int height) {
            synchronized(mSurfaceHolder) {
                dispWidth = width;
                dispHeight = height;
            }
        }

        private Bitmap makeFpsOverlay(Paint p, String text) {
            Rect b = new Rect();
            p.getTextBounds(text, 0, text.length(), b);
            int bwidth  = b.width()+2;
            int bheight = b.height()+2;
            Bitmap bm = Bitmap.createBitmap(bwidth, bheight, Bitmap.Config.ARGB_8888);
            Canvas c = new Canvas(bm);
            p.setColor(overlayBackgroundColor);
            c.drawRect(0, 0, bwidth, bheight, p);
            p.setColor(overlayTextColor);
            c.drawText(text, -b.left+1, (bheight/2)-((p.ascent()+p.descent())/2)+1, p);
            return bm;           
        }

        public void run() {
            start = System.currentTimeMillis();
            PorterDuffXfermode mode = new PorterDuffXfermode(PorterDuff.Mode.DST_OVER);
            Bitmap bm;
            int width;
            int height;
            Rect destRect;
            Canvas c = null;
            Paint p = new Paint();
            String fps = "";
            while (mRun) {
                if(surfaceDone) {
                    try {
                        c = mSurfaceHolder.lockCanvas();
                        synchronized (mSurfaceHolder) {
                            try {
                                bm = mIn.readMjpegFrame();
                                destRect = destRect(bm.getWidth(),bm.getHeight());
                                c.drawColor(Color.BLACK);
                                c.drawBitmap(bm, null, destRect, p);
                                if(showFps) {
                                    p.setXfermode(mode);
                                    if(ovl != null) {
                                        height = ((ovlPos & 1) == 1) ? destRect.top : destRect.bottom-ovl.getHeight();
                                        width  = ((ovlPos & 8) == 8) ? destRect.left : destRect.right -ovl.getWidth();
                                        c.drawBitmap(ovl, width, height, null);
                                    }
                                    p.setXfermode(null);
                                    frameCounter++;
                                    if((System.currentTimeMillis() - start) >= 1000) {
                                        fps = String.valueOf(frameCounter)+"fps";
                                        frameCounter = 0; 
                                        start = System.currentTimeMillis();
                                        ovl = makeFpsOverlay(overlayPaint, fps);
                                    }
                                }
                            } catch (IOException e) {}
                        }
                    } finally { if (c != null) mSurfaceHolder.unlockCanvasAndPost(c); }
                }
            }
        }
    }

    private void init(Context context) {
        SurfaceHolder holder = getHolder();
        holder.addCallback(this);
        thread = new MjpegViewThread(holder, context);
        setFocusable(true);
        overlayPaint = new Paint();
        overlayPaint.setTextAlign(Paint.Align.LEFT);
        overlayPaint.setTextSize(12);
        overlayPaint.setTypeface(Typeface.DEFAULT);
        overlayTextColor = Color.WHITE;
        overlayBackgroundColor = Color.BLACK;
        ovlPos = MjpegView.POSITION_LOWER_RIGHT;
        displayMode = MjpegView.SIZE_STANDARD;
        dispWidth = getWidth();
        dispHeight = getHeight();
    }

    public void startPlayback() { 
        if(mIn != null) {
            mRun = true;
            thread.start();         
        }
    }

    public void stopPlayback() { 
        mRun = false;
        boolean retry = true;
        while(retry) {
            try {
                thread.join();
                retry = false;
            } catch (InterruptedException e) {}
        }
    }

    public MjpegView(Context context, AttributeSet attrs) { super(context, attrs); init(context); }
    public void surfaceChanged(SurfaceHolder holder, int f, int w, int h) { thread.setSurfaceSize(w, h); }

    public void surfaceDestroyed(SurfaceHolder holder) { 
        surfaceDone = false; 
        stopPlayback(); 
    }

    public MjpegView(Context context) { 
        super(context); 
        init(context); 
        }    
    public void surfaceCreated(SurfaceHolder holder) { 
        surfaceDone = true; 
        }
    public void showFps(boolean b) { 
        showFps = b; 
        }
    public void setSource(MjpegInputStream source) { 
        mIn = source; 
        startPlayback();
        }
    public void setOverlayPaint(Paint p) { 
        overlayPaint = p; 
        }
    public void setOverlayTextColor(int c) { 
        overlayTextColor = c; 
        }
    public void setOverlayBackgroundColor(int c) { 
        overlayBackgroundColor = c; 
        }
    public void setOverlayPosition(int p) { 
        ovlPos = p; 
        }
    public void setDisplayMode(int s) { 
        displayMode = s; 
        }
}

MjpegInputStream Class

MjpegInputStream 类

package de.mjpegsample.MjpegView;

import java.io.BufferedInputStream;
import java.io.ByteArrayInputStream;
import java.io.DataInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URI;
import java.util.Properties;

import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;

public class MjpegInputStream extends DataInputStream {
    private final byte[] SOI_MARKER = { (byte) 0xFF, (byte) 0xD8 };
    private final byte[] EOF_MARKER = { (byte) 0xFF, (byte) 0xD9 };
    private final String CONTENT_LENGTH = "Content-Length";
    private final static int HEADER_MAX_LENGTH = 100;
    private final static int FRAME_MAX_LENGTH = 40000 + HEADER_MAX_LENGTH;
    private int mContentLength = -1;

    public static MjpegInputStream read(String url) {
        HttpResponse res;
        DefaultHttpClient httpclient = new DefaultHttpClient();     
        try {
            res = httpclient.execute(new HttpGet(URI.create(url)));
            return new MjpegInputStream(res.getEntity().getContent());              
        } catch (ClientProtocolException e) {
        } catch (IOException e) {}
        return null;
    }

    public MjpegInputStream(InputStream in) { super(new BufferedInputStream(in, FRAME_MAX_LENGTH)); }

    private int getEndOfSeqeunce(DataInputStream in, byte[] sequence) throws IOException {
        int seqIndex = 0;
        byte c;
        for(int i=0; i < FRAME_MAX_LENGTH; i++) {
            c = (byte) in.readUnsignedByte();
            if(c == sequence[seqIndex]) {
                seqIndex++;
                if(seqIndex == sequence.length) return i + 1;
            } else seqIndex = 0;
        }
        return -1;
    }

    private int getStartOfSequence(DataInputStream in, byte[] sequence) throws IOException {
        int end = getEndOfSeqeunce(in, sequence);
        return (end < 0) ? (-1) : (end - sequence.length);
    }

    private int parseContentLength(byte[] headerBytes) throws IOException, NumberFormatException {
        ByteArrayInputStream headerIn = new ByteArrayInputStream(headerBytes);
        Properties props = new Properties();
        props.load(headerIn);
        return Integer.parseInt(props.getProperty(CONTENT_LENGTH));
    }   

    public Bitmap readMjpegFrame() throws IOException {
        mark(FRAME_MAX_LENGTH);
        int headerLen = getStartOfSequence(this, SOI_MARKER);
        reset();
        byte[] header = new byte[headerLen];
        readFully(header);
        try {
            mContentLength = parseContentLength(header);
        } catch (NumberFormatException nfe) { 
            mContentLength = getEndOfSeqeunce(this, EOF_MARKER); 
        }
        reset();
        byte[] frameData = new byte[mContentLength];
        skipBytes(headerLen);
        readFully(frameData);
        return BitmapFactory.decodeStream(new ByteArrayInputStream(frameData));
    }
}

If you need any more info, let me know, I'll help in any way I can.

如果您需要更多信息，请告诉我，我会尽我所能提供帮助。

FYI: I did not write SimpleMjpegView, you can find more up to date code here

仅供参考：我没有写 SimpleMjpegView，你可以在这里找到更多最新的代码

回答by bbodenmiller

For those looking to get this working with AsyncTask (and thus working on Ice Cream Sandwich (ICS), 4.0.4) see Android ICS and MJPEG using AsyncTask.

对于那些希望与 AsyncTask 一起工作的人（从而在 Ice Cream Sandwich (ICS), 4.0.4 上工作），请参阅Android ICS 和 MJPEG using AsyncTask。

回答by Anirudh Gangwal

I had the same problem and tried using custom Mjpeg viewers. While they worked, they proved unstable and clumsy for me.

我遇到了同样的问题并尝试使用自定义 Mjpeg 查看器。当它们工作时，它们对我来说是不稳定和笨拙的。

I am simply using a WebView. On Android Studio, simply drag and drop a WebView. My WebView is not covering the entire screen, but half of it.

我只是在使用 WebView。在 Android Studio 上，只需拖放一个 WebView。我的 WebView 没有覆盖整个屏幕，而是它的一半。

Then, to fit the video best, in your onCreate:

然后，为了最适合视频，在您的 onCreate 中：

If using Kotlin:

如果使用 Kotlin：

webView.settings.loadWithOverviewMode = true;
webView.settings.useWideViewPort = true;

If using Java:

如果使用 Java：

webView.getSettings().setLoadWithOverviewMode(true);
webView.getSettings().setUseWideViewPort(true);

And then, on button click:

然后，在按钮上单击：

To start:

开始：

webView.loadUrl("http://$id:8081/cam.mjpeg") // start

To Stop:

停止：

webView.stopLoading()
webView.loadUrl("about:blank")

Hope this helps.

希望这可以帮助。