interactivespaces.service.image.vision.opencv.OpenCvVideoLoop.java Source code

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Here is the source code for interactivespaces.service.image.vision.opencv.OpenCvVideoLoop.java

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/*
 * Copyright (C) 2013 Google Inc.
 *
 * 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 interactivespaces.service.image.vision.opencv;

import interactivespaces.service.image.video.VideoLoop;
import interactivespaces.util.InteractiveSpacesUtilities;

import org.apache.commons.logging.Log;
import org.opencv.core.Mat;
import org.opencv.highgui.VideoCapture;

/**
 * A {@link VideoLoop} which grabs video frames using OpenCV and processes them.
 *
 * @author Keith M. Hughes
 */
public class OpenCvVideoLoop extends VideoLoop<Mat> {

    /**
     * Time for the camera to initialize, in milliseconds.
     */
    public static final long CAMERA_INITIALIZATION_TIME = 1000;

    /**
     * The IS of the camera to use.
     */
    private final int cameraId;

    /**
     * The video capture device.
     */
    private VideoCapture capture;

    /**
     * Logger for the loop.
     */
    private final Log log;

    /**
     * Construct a video loop.
     *
     * @param cameraId
     *          ID for the camera to use
     * @param log
     *          logger for the loop
     */
    public OpenCvVideoLoop(int cameraId, Log log) {
        this.cameraId = cameraId;
        this.log = log;
    }

    @Override
    protected void setup() {
        capture = new VideoCapture(cameraId);

        // OpenCV sometimes needs a bit of time for the camera to fully initialize.
        InteractiveSpacesUtilities.delay(CAMERA_INITIALIZATION_TIME);
    }

    @Override
    protected void loop() throws InterruptedException {
        Mat frame = new Mat();
        capture.grab();
        capture.retrieve(frame);
        if (frame.empty()) {
            log.warn("No image");
            return;
        }

        notifyListenersNewVideoFrame(frame);
    }

    @Override
    protected void cleanup() {
        capture.release();
    }

    @Override
    protected void handleException(Exception e) {
        log.error("Error during video loop", e);
    }
}