org.kurento.demo.CrowdDetectorHandler.java Source code

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Here is the source code for org.kurento.demo.CrowdDetectorHandler.java

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/*
 * (C) Copyright 2014 Kurento (http://kurento.org/)
 *
 * 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 org.kurento.demo;

import java.io.IOException;

import org.kurento.client.EventListener;
import org.kurento.client.IceCandidate;
import org.kurento.client.IceCandidateFoundEvent;
import org.kurento.client.MediaPipeline;
import org.kurento.client.WebRtcEndpoint;
import org.kurento.jsonrpc.JsonUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.socket.TextMessage;
import org.springframework.web.socket.WebSocketSession;
import org.springframework.web.socket.handler.TextWebSocketHandler;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;

/**
 * CrowdDetector with RTSP media source (application and media logic).
 *
 * @author David Fernndez (d.fernandezlop@gmail.com)
 * @since 5.0.4
 */
public class CrowdDetectorHandler extends TextWebSocketHandler {

    private static final Logger log = LoggerFactory.getLogger(CrowdDetectorHandler.class);
    private static final Gson gson = new GsonBuilder().create();

    @Autowired
    private Pipeline pipeline;

    @Override
    public void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception {
        JsonObject jsonMessage = gson.fromJson(message.getPayload(), JsonObject.class);

        log.debug("Incoming message: {}", jsonMessage);

        switch (jsonMessage.get("id").getAsString()) {
        case "start":
            try {
                start(session, jsonMessage);
            } catch (Throwable t) {
                sendError(session, t.getMessage());
            }
            break;

        case "stop":
            this.pipeline.removeWebRtcEndpoint(session.getId());
            break;

        case "updateFeed":
            updateFeed(jsonMessage);
            break;

        case "changeProcessingWidth":
            changeProcessingWidth(jsonMessage.get("width").getAsInt());
            break;

        case "onIceCandidate": {
            JsonObject candidate = jsonMessage.get("candidate").getAsJsonObject();

            IceCandidate cand = new IceCandidate(candidate.get("candidate").getAsString(),
                    candidate.get("sdpMid").getAsString(), candidate.get("sdpMLineIndex").getAsInt());
            this.pipeline.addCandidate(cand, session.getId());
            break;
        }

        default:
            sendError(session, "Invalid message with id " + jsonMessage.get("id").getAsString());
            break;
        }
    }

    private void start(final WebSocketSession session, JsonObject jsonMessage) throws IOException {

        updateFeed(jsonMessage);

        if (this.pipeline.getPlayerEndpoint() == null) {
            try {
                JsonObject response = new JsonObject();
                response.addProperty("id", "noPlayer");
                session.sendMessage(new TextMessage(response.toString()));
            } catch (IOException a) {
                log.error("Exception sending message", a);
            }
            return;
        }

        if (!this.pipeline.isPlaying()) {
            try {
                JsonObject response = new JsonObject();
                response.addProperty("id", "noPlaying");
                session.sendMessage(new TextMessage(response.toString()));
            } catch (IOException a) {
                log.error("Exception sending message", a);
            }
            return;
        }

        MediaPipeline mediaPipeline = this.pipeline.getPipeline();

        WebRtcEndpoint webRtcEndpoint = new WebRtcEndpoint.Builder(mediaPipeline).build();

        webRtcEndpoint.addIceCandidateFoundListener(new EventListener<IceCandidateFoundEvent>() {

            @Override
            public void onEvent(IceCandidateFoundEvent event) {
                JsonObject response = new JsonObject();
                response.addProperty("id", "iceCandidate");
                response.add("candidate", JsonUtils.toJsonObject(event.getCandidate()));
                try {
                    synchronized (session) {
                        session.sendMessage(new TextMessage(response.toString()));
                    }
                } catch (IOException e) {
                    log.debug(e.getMessage());
                }
            }
        });

        this.pipeline.setWebRtcEndpoint(session.getId(), webRtcEndpoint);

        this.pipeline.getCrowdDetectorFilter().connect(webRtcEndpoint);

        // SDP negotiation (offer and answer)
        String sdpOffer = jsonMessage.get("sdpOffer").getAsString();
        String sdpAnswer = webRtcEndpoint.processOffer(sdpOffer);

        // Sending response back to client
        JsonObject response = new JsonObject();
        response.addProperty("id", "startResponse");
        response.addProperty("sdpAnswer", sdpAnswer);
        response.addProperty("feedUrl", this.pipeline.getFeedUrl());
        response.addProperty("rois", gson.toJson(this.pipeline.getRois()));
        synchronized (session) {
            session.sendMessage(new TextMessage(response.toString()));
        }
        webRtcEndpoint.gatherCandidates();
    }

    private static void sendError(WebSocketSession session, String message) {
        try {
            JsonObject response = new JsonObject();
            response.addProperty("id", "error");
            response.addProperty("message", message);
            session.sendMessage(new TextMessage(response.toString()));
        } catch (IOException e) {
            log.error("Exception sending message", e);
        }
    }

    private void updateFeed(JsonObject jsonMessage) {

        JsonElement feedUrlJson = jsonMessage.get("feedUrl");
        if (feedUrlJson == null) {
            log.warn("No feed url defined");
        } else {
            String feedUrl = feedUrlJson.getAsString();
            log.debug("Updating video feed");
            this.pipeline.setFeedUrl(feedUrl);
        }
    }

    private void changeProcessingWidth(int width) {
        this.pipeline.getCrowdDetectorFilter().setProcessingWidth(width);
    }
}