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   1 /**
   2  * Copyright (c) 2010-2024 Contributors to the openHAB project
   3  *
   4  * See the NOTICE file(s) distributed with this work for additional
   5  * information.
   6  *
   7  * This program and the accompanying materials are made available under the
   8  * terms of the Eclipse Public License 2.0 which is available at
   9  * http://www.eclipse.org/legal/epl-2.0
  10  *
  11  * SPDX-License-Identifier: EPL-2.0
  12  */
  13 package org.openhab.binding.ipcamera.internal.servlet;
  14
  15 import java.io.IOException;
  16 import java.util.concurrent.ArrayBlockingQueue;
  17 import java.util.concurrent.BlockingQueue;
  18
  19 import javax.servlet.ServletOutputStream;
  20 import javax.servlet.http.HttpServletResponse;
  21
  22 import org.eclipse.jdt.annotation.NonNullByDefault;
  23 import org.slf4j.Logger;
  24 import org.slf4j.LoggerFactory;
  25
  26 /**
  27  * The {@link StreamOutput} Streams mjpeg out to a client
  28  *
  29  * @author Matthew Skinner - Initial contribution
  30  */
  31 @NonNullByDefault
  32 public class StreamOutput {
  33     public final Logger logger = LoggerFactory.getLogger(getClass());
  34     private final HttpServletResponse response;
  35     private final String boundary;
  36     private String contentType;
  37     private final ServletOutputStream output;
  38     private BlockingQueue<byte[]> fifo = new ArrayBlockingQueue<byte[]>(50);
  39     private boolean connected = false;
  40     public boolean isSnapshotBased = false;
  41
  42     public StreamOutput(HttpServletResponse response) throws IOException {
  43         boundary = "thisMjpegStream";
  44         contentType = "multipart/x-mixed-replace; boundary=" + boundary;
  45         this.response = response;
  46         output = response.getOutputStream();
  47         isSnapshotBased = true;
  48     }
  49
  50     public StreamOutput(HttpServletResponse response, String contentType) throws IOException {
  51         boundary = "";
  52         this.contentType = contentType;
  53         this.response = response;
  54         output = response.getOutputStream();
  55         if (!contentType.isEmpty()) {
  56             sendInitialHeaders();
  57             connected = true;
  58         }
  59     }
  60
  61     public void sendSnapshotBasedFrame(byte[] currentSnapshot) throws IOException {
  62         String header = "--" + boundary + "\r\n" + "Content-Type: image/jpeg" + "\r\n" + "Content-Length: "
  63                 + currentSnapshot.length + "\r\n\r\n";
  64         if (!connected) {
  65             sendInitialHeaders();
  66             // iOS needs to have two jpgs sent for the picture to appear instantly.
  67             output.write(header.getBytes());
  68             output.write(currentSnapshot);
  69             output.write("\r\n".getBytes());
  70             connected = true;
  71         }
  72         output.write(header.getBytes());
  73         output.write(currentSnapshot);
  74         output.write("\r\n".getBytes());
  75     }
  76
  77     public void queueFrame(byte[] frame) {
  78         try {
  79             fifo.add(frame);
  80         } catch (IllegalStateException e) {
  81             logger.debug("FIFO buffer has run out of space: {}", e.getMessage());
  82             fifo.remove();
  83             fifo.add(frame);
  84         }
  85     }
  86
  87     public void updateContentType(String contentType) {
  88         this.contentType = contentType;
  89         if (!connected) {
  90             sendInitialHeaders();
  91             connected = true;
  92         }
  93     }
  94
  95     public void sendFrame() throws IOException, InterruptedException {
  96         if (isSnapshotBased) {
  97             sendSnapshotBasedFrame(fifo.take());
  98         } else if (connected) {
  99             output.write(fifo.take());
 100         }
 101     }
 102
 103     private void sendInitialHeaders() {
 104         response.setContentType(contentType);
 105         response.setHeader("Access-Control-Allow-Origin", "*");
 106         response.setHeader("Access-Control-Expose-Headers", "*");
 107     }
 108
 109     public void close() {
 110         try {
 111             output.close();
 112         } catch (IOException e) {
 113         }
 114     }
 115 }