com.vrs.qrw100s.NetworkReader.java Source code

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Here is the source code for com.vrs.qrw100s.NetworkReader.java

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/*
 * Copyright (C) 2014 Vine Ripe Consulting LLC.
 * http://www.vineripeconsulting.com/
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

package com.vrs.qrw100s;

import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.IOException;
import java.net.URI;

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 org.apache.http.params.HttpConnectionParams;
import org.apache.http.params.HttpParams;

import android.os.Handler;
import android.os.Message;
import android.util.Log;

class NetworkReader extends Thread {
    private boolean _runThread = true;
    private static final String TAG = "NetworkReader";
    private final Handler mainHandler;

    private byte[] curFrame;

    private final String myURL;

    private boolean skipFrame = false;
    private int skipNum = 0;
    private int frameDecrement = 1;

    // this udp server only receives messages. 
    public NetworkReader(Handler myHandler, String url, boolean isGlass) {
        mainHandler = myHandler;
        myURL = url;
        curFrame = new byte[0];
        if (isGlass) {
            frameDecrement = 6;
        }
    }

    // reads mjpeg from the network returning valid frame data to the calling thread
    @Override
    public void run() {
        Thread.currentThread().setName("Network Reader");

        HttpResponse res;
        DefaultHttpClient httpclient = new DefaultHttpClient();
        HttpParams httpParams = httpclient.getParams();
        HttpConnectionParams.setConnectionTimeout(httpParams, 5 * 1000);
        HttpConnectionParams.setSoTimeout(httpParams, 10 * 1000);

        Log.d(TAG, "1. Sending http request");
        try {
            res = httpclient.execute(new HttpGet(URI.create(myURL)));
            Log.d(TAG, "2. Request finished, status = " + res.getStatusLine().getStatusCode());
            if (res.getStatusLine().getStatusCode() == 401) {
                return;
            }

            DataInputStream bis = new DataInputStream(res.getEntity().getContent());
            ByteArrayOutputStream jpgOut = new ByteArrayOutputStream(10000);

            int prev = 0;
            int cur;

            while ((cur = bis.read()) >= 0 && _runThread) {
                if (prev == 0xFF && cur == 0xD8) {
                    // reset the output stream
                    if (!skipFrame) {
                        jpgOut.reset();
                        jpgOut.write((byte) prev);
                    }
                }

                if (!skipFrame) {
                    if (jpgOut != null) {
                        jpgOut.write((byte) cur);
                    }
                }

                if (prev == 0xFF && cur == 0xD9) {
                    if (!skipFrame) {
                        synchronized (curFrame) {
                            curFrame = jpgOut.toByteArray();
                        }

                        skipFrame = true;

                        Message threadMessage = mainHandler.obtainMessage();
                        threadMessage.obj = curFrame;
                        mainHandler.sendMessage(threadMessage);
                    } else {
                        if (skipNum < frameDecrement) {
                            skipNum++;
                        } else {
                            skipNum = 0;
                            skipFrame = false;
                        }
                    }

                }
                prev = cur;
            }
        } catch (ClientProtocolException e) {
            Log.d(TAG, "Request failed-ClientProtocolException", e);
        } catch (IOException e) {
            Log.d(TAG, "Request failed-IOException", e);
        }

    }

    public void ShutDown() {
        _runThread = false;
    }

}