Android and MJPEG

99封情书 提交于 2019-11-25 20:51:35
Carlos Portes

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

MjpegSample Class

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

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

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.

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

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.

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

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.

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

If using Kotlin:

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

If using Java:

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

And then, on button click:

To start:

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

To Stop:

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

Hope this helps.

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