Ex1ReadVideoSequence.scala

/*
 * Copyright (c) 2011-2019 Jarek Sacha. All Rights Reserved.
 *
 * Author's e-mail: jpsacha at gmail.com
 */

package opencv_cookbook.chapter11

import org.bytedeco.javacv.{CanvasFrame, FFmpegFrameGrabber}

import java.io.File
import javax.swing.WindowConstants
import scala.collection.Iterator.continually


/** The example for section "Reading video sequences" in Chapter 10, page 248.
  *
  * This version of the example is implemented using JavaCV `FFmpegFrameGrabber`class.
  *
  */
object Ex1ReadVideoSequence extends App {

  // Use command line path, if provided
  val inputFile = args
    .headOption
    .map(new File(_))
    .getOrElse(new File("data/bike.avi"))

  val grabber = new FFmpegFrameGrabber(inputFile)
  // Open video video file
  grabber.start()

  // Prepare window to display frames
  val canvasFrame = new CanvasFrame("Extracted Frame", 1)
  canvasFrame.setCanvasSize(grabber.getImageWidth, grabber.getImageHeight)
  // Exit the example when the canvas frame is closed
  canvasFrame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE)

  val delay = math.round(1000d / grabber.getFrameRate)

  // Read frame by frame, stop early if the display window is closed
  for (frame <- continually(grabber.grab()).takeWhile(_ != null)
       if canvasFrame.isVisible) {
    // Capture and show the frame
    canvasFrame.showImage(frame)
    // Delay
    Thread.sleep(delay)
  }

  // Close the video file
  grabber.release()
}