Converting a series of BufferedImages to a video in Java?

Question

How would I convert an an array of BufferedImages into a video? I'm making a screen recorder.

How would I compress the video afterward?

Answer 1

You'll need the JMF (Java Media Framework) API for this. Sun has a code sample on the subject in the JMF documentation: Generating a Movie File from a List of (JPEG) Images.

---

Update since the takeover by Oracle, a lot of links broke, including the JMF ones. Fortunately the JpegImagesToMovie.java code sample has been mirrored here. For the sake of completeness, here's a copypaste:

package org.apollo.jmf.test;

/*
 * @(#)JpegImagesToMovie.java   1.3 01/03/13
 *
 * Copyright (c) 1999-2001 Sun Microsystems, Inc. All Rights Reserved.
 *
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 * modify and redistribute this software in source and binary code form,
 * provided that i) this copyright notice and license appear on all copies of
 * the software; and ii) Licensee does not utilize the software in a manner
 * which is disparaging to Sun.
 *
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY
 * IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
 * NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE
 * LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING
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 * CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF
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 * aircraft, air traffic, aircraft navigation or aircraft communications; or in
 * the design, construction, operation or maintenance of any nuclear
 * facility. Licensee represents and warrants that it will not use or
 * redistribute the Software for such purposes.
 */

import java.io.*;
import java.util.*;
import java.awt.Dimension;

import javax.media.*;
import javax.media.control.*;
import javax.media.protocol.*;
import javax.media.protocol.DataSource;
import javax.media.datasink.*;
import javax.media.format.VideoFormat;


/**
 * This program takes a list of JPEG image files and convert them into
 * a QuickTime movie.
 */
public class JpegImagesToMovie implements ControllerListener, DataSinkListener {

    public boolean doIt(int width, int height, int frameRate, Vector inFiles, MediaLocator outML) {
    ImageDataSource ids = new ImageDataSource(width, height, frameRate, inFiles);

    Processor p;

    try {
        System.err.println("- create processor for the image datasource ...");
        p = Manager.createProcessor(ids);
    } catch (Exception e) {
        System.err.println("Yikes!  Cannot create a processor from the data source.");
        return false;
    }

    p.addControllerListener(this);

    // Put the Processor into configured state so we can set
    // some processing options on the processor.
    p.configure();
    if (!waitForState(p, p.Configured)) {
        System.err.println("Failed to configure the processor.");
        return false;
    }

    // Set the output content descriptor to QuickTime. 
    p.setContentDescriptor(new ContentDescriptor(FileTypeDescriptor.QUICKTIME));

    // Query for the processor for supported formats.
    // Then set it on the processor.
    TrackControl tcs[] = p.getTrackControls();
    Format f[] = tcs[0].getSupportedFormats();
    if (f == null || f.length <= 0) {
        System.err.println("The mux does not support the input format: " + tcs[0].getFormat());
        return false;
    }

    tcs[0].setFormat(f[0]);

    System.err.println("Setting the track format to: " + f[0]);

    // We are done with programming the processor.  Let's just
    // realize it.
    p.realize();
    if (!waitForState(p, p.Realized)) {
        System.err.println("Failed to realize the processor.");
        return false;
    }

    // Now, we'll need to create a DataSink.
    DataSink dsink;
    if ((dsink = createDataSink(p, outML)) == null) {
        System.err.println("Failed to create a DataSink for the given output MediaLocator: " + outML);
        return false;
    }

    dsink.addDataSinkListener(this);
    fileDone = false;

    System.err.println("start processing...");

    // OK, we can now start the actual transcoding.
    try {
        p.start();
        dsink.start();
    } catch (IOException e) {
        System.err.println("IO error during processing");
        return false;
    }

    // Wait for EndOfStream event.
    waitForFileDone();

    // Cleanup.
    try {
        dsink.close();
    } catch (Exception e) {}
    p.removeControllerListener(this);

    System.err.println("...done processing.");

    return true;
    }


    /**
     * Create the DataSink.
     */
    DataSink createDataSink(Processor p, MediaLocator outML) {

    DataSource ds;

    if ((ds = p.getDataOutput()) == null) {
        System.err.println("Something is really wrong: the processor does not have an output DataSource");
        return null;
    }

    DataSink dsink;

    try {
        System.err.println("- create DataSink for: " + outML);
        dsink = Manager.createDataSink(ds, outML);
        dsink.open();
    } catch (Exception e) {
        System.err.println("Cannot create the DataSink: " + e);
        return null;
    }

    return dsink;
    }


    Object waitSync = new Object();
    boolean stateTransitionOK = true;

    /**
     * Block until the processor has transitioned to the given state.
     * Return false if the transition failed.
     */
    boolean waitForState(Processor p, int state) {
    synchronized (waitSync) {
        try {
        while (p.getState() < state && stateTransitionOK)
            waitSync.wait();
        } catch (Exception e) {}
    }
    return stateTransitionOK;
    }


    /**
     * Controller Listener.
     */
    public void controllerUpdate(ControllerEvent evt) {

    if (evt instanceof ConfigureCompleteEvent ||
        evt instanceof RealizeCompleteEvent ||
        evt instanceof PrefetchCompleteEvent) {
        synchronized (waitSync) {
        stateTransitionOK = true;
        waitSync.notifyAll();
        }
    } else if (evt instanceof ResourceUnavailableEvent) {
        synchronized (waitSync) {
        stateTransitionOK = false;
        waitSync.notifyAll();
        }
    } else if (evt instanceof EndOfMediaEvent) {
        evt.getSourceController().stop();
        evt.getSourceController().close();
    }
    }


    Object waitFileSync = new Object();
    boolean fileDone = false;
    boolean fileSuccess = true;

    /**
     * Block until file writing is done. 
     */
    boolean waitForFileDone() {
    synchronized (waitFileSync) {
        try {
        while (!fileDone)
            waitFileSync.wait();
        } catch (Exception e) {}
    }
    return fileSuccess;
    }


    /**
     * Event handler for the file writer.
     */
    public void dataSinkUpdate(DataSinkEvent evt) {

    if (evt instanceof EndOfStreamEvent) {
        synchronized (waitFileSync) {
        fileDone = true;
        waitFileSync.notifyAll();
        }
    } else if (evt instanceof DataSinkErrorEvent) {
        synchronized (waitFileSync) {
        fileDone = true;
        fileSuccess = false;
        waitFileSync.notifyAll();
        }
    }
    }


    public static void main(String args[]) {

    if (args.length == 0)
        prUsage();

    // Parse the arguments.
    int i = 0;
    int width = -1, height = -1, frameRate = 1;
    Vector inputFiles = new Vector();
    String outputURL = null;

    while (i < args.length) {

        if (args[i].equals("-w")) {
        i++;
        if (i >= args.length)
            prUsage();
        width = new Integer(args[i]).intValue();
        } else if (args[i].equals("-h")) {
        i++;
        if (i >= args.length)
            prUsage();
        height = new Integer(args[i]).intValue();
        } else if (args[i].equals("-f")) {
        i++;
        if (i >= args.length)
            prUsage();
        frameRate = new Integer(args[i]).intValue();
        } else if (args[i].equals("-o")) {
        i++;
        if (i >= args.length)
            prUsage();
        outputURL = args[i];
        } else {
            for (int j = 0; j < 120; j++) {
                inputFiles.addElement(args[i]);
            }
        }
        i++;
    }

    if (outputURL == null || inputFiles.size() == 0)
        prUsage();

    // Check for output file extension.
    if (!outputURL.endsWith(".mov") && !outputURL.endsWith(".MOV")) {
        System.err.println("The output file extension should end with a .mov extension");
        prUsage();
    }

    if (width < 0 || height < 0) {
        System.err.println("Please specify the correct image size.");
        prUsage();
    }

    // Check the frame rate.
    if (frameRate < 1)
        frameRate = 1;

    // Generate the output media locators.
    MediaLocator oml;

    if ((oml = createMediaLocator(outputURL)) == null) {
        System.err.println("Cannot build media locator from: " + outputURL);
        System.exit(0);
    }

    JpegImagesToMovie imageToMovie = new JpegImagesToMovie();
    imageToMovie.doIt(width, height, frameRate, inputFiles, oml);

    System.exit(0);
    }

    static void prUsage() {
    System.err.println("Usage: java JpegImagesToMovie -w <width> -h <height> -f <frame rate> -o <output URL> <input JPEG file 1> <input JPEG file 2> ...");
    System.exit(-1);
    }

    /**
     * Create a media locator from the given string.
     */
    static MediaLocator createMediaLocator(String url) {

    MediaLocator ml;

    if (url.indexOf(":") > 0 && (ml = new MediaLocator(url)) != null)
        return ml;

    if (url.startsWith(File.separator)) {
        if ((ml = new MediaLocator("file:" + url)) != null)
        return ml;
    } else {
        String file = "file:" + System.getProperty("user.dir") + File.separator + url;
        if ((ml = new MediaLocator(file)) != null)
        return ml;
    }

    return null;
    }


    ///////////////////////////////////////////////
    //
    // Inner classes.
    ///////////////////////////////////////////////


    /**
     * A DataSource to read from a list of JPEG image files and
     * turn that into a stream of JMF buffers.
     * The DataSource is not seekable or positionable.
     */
    class ImageDataSource extends PullBufferDataSource {

    ImageSourceStream streams[];

    ImageDataSource(int width, int height, int frameRate, Vector images) {
        streams = new ImageSourceStream[1];
        streams[0] = new ImageSourceStream(width, height, frameRate, images);
    }

    public void setLocator(MediaLocator source) {
    }

    public MediaLocator getLocator() {
        return null;
    }

    /**
     * Content type is of RAW since we are sending buffers of video
     * frames without a container format.
     */
    public String getContentType() {
        return ContentDescriptor.RAW;
    }

    public void connect() {
    }

    public void disconnect() {
    }

    public void start() {
    }

    public void stop() {
    }

    /**
     * Return the ImageSourceStreams.
     */
    public PullBufferStream[] getStreams() {
        return streams;
    }

    /**
     * We could have derived the duration from the number of
     * frames and frame rate.  But for the purpose of this program,
     * it's not necessary.
     */
    public Time getDuration() {
        return DURATION_UNKNOWN;
    }

    public Object[] getControls() {
        return new Object[0];
    }

    public Object getControl(String type) {
        return null;
    }
    }


    /**
     * The source stream to go along with ImageDataSource.
     */
    class ImageSourceStream implements PullBufferStream {

    Vector images;
    int width, height;
    VideoFormat format;

    int nextImage = 0;  // index of the next image to be read.
    boolean ended = false;

    public ImageSourceStream(int width, int height, int frameRate, Vector images) {
        this.width = width;
        this.height = height;
        this.images = images;

        format = new VideoFormat(VideoFormat.JPEG,
                new Dimension(width, height),
                Format.NOT_SPECIFIED,
                Format.byteArray,
                (float)frameRate);
    }

    /**
     * We should never need to block assuming data are read from files.
     */
    public boolean willReadBlock() {
        return false;
    }

    /**
     * This is called from the Processor to read a frame worth
     * of video data.
     */
    public void read(Buffer buf) throws IOException {

        // Check if we've finished all the frames.
        if (nextImage >= images.size()) {
        // We are done.  Set EndOfMedia.
        System.err.println("Done reading all images.");
        buf.setEOM(true);
        buf.setOffset(0);
        buf.setLength(0);
        ended = true;
        return;
        }

        String imageFile = (String)images.elementAt(nextImage);
        nextImage++;

        System.err.println("  - reading image file: " + imageFile);

        // Open a random access file for the next image. 
        RandomAccessFile raFile;
        raFile = new RandomAccessFile(imageFile, "r");

        byte data[] = null;

        // Check the input buffer type & size.

        if (buf.getData() instanceof byte[])
        data = (byte[])buf.getData();

        // Check to see the given buffer is big enough for the frame.
        if (data == null || data.length < raFile.length()) {
        data = new byte[(int)raFile.length()];
        buf.setData(data);
        }

        // Read the entire JPEG image from the file.
        raFile.readFully(data, 0, (int)raFile.length());

        System.err.println("    read " + raFile.length() + " bytes.");

        buf.setOffset(0);
        buf.setLength((int)raFile.length());
        buf.setFormat(format);
        buf.setFlags(buf.getFlags() | buf.FLAG_KEY_FRAME);

        // Close the random access file.
        raFile.close();
    }

    /**
     * Return the format of each video frame.  That will be JPEG.
     */
    public Format getFormat() {
        return format;
    }

    public ContentDescriptor getContentDescriptor() {
        return new ContentDescriptor(ContentDescriptor.RAW);
    }

    public long getContentLength() {
        return 0;
    }

    public boolean endOfStream() {
        return ended;
    }

    public Object[] getControls() {
        return new Object[0];
    }

    public Object getControl(String type) {
        return null;
    }
    }
}

Answer 2

You can use Xuggler (on Windows, Mac or Linux) to do this, and the following tutorials will show you exactly how to do it. In particular, see the (I'm not kidding) "How to Grow Some Balls" tutorial for a program that makes a video out of a series of BufferedImages (and some audio).

Answer 3

Werner Randelshofer did some work to create a Quicktime movie. See: http://www.randelshofer.ch/blog/2008/08/writing-avi-videos-in-pure-java/

You could also use Xuggler: http://www.xuggle.com