How to develop screen capture to video application
- To get a screenshot, use
Robot.createScreenCapture(Rectangle). - To get many screenshots, call that in a loop invoked by a (Swing)
Timer. Add them to an expandable collection such as anArrayList. - Convert the
BufferedImageobjects to JPEG format usingImageIO.write(). - To form those screenshots into a .MOV, use JpegImagesToMovie of the JMF (yes JMF is obsolete, but the parts that still work, work just fine).
Since I could not find a copy of the JpegImagesToMovie source for love nor searching, here is an old copy that I adapted for my use. I think this version is before any changes had been made.
Note that a Java applet will need to be digitally signed (by you) and trusted (by the end user) before it can get a single screenshot. It will also need trust (or the JNLP API services in a plug-in2 JRE) in order to save a MOV to the client's local file system.
JpegImagesToMovie.java
/*
* @(#)JpegImagesToMovie.java 1.3 01/03/13
*
* Copyright (c) 1999-2001 Sun Microsystems, Inc. All Rights Reserved.
*
* Sun grants you ("Licensee") a non-exclusive, royalty free, license to use,
* 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
* OR DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS
* LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT,
* INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
* CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF
* OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGES.
*
* This software is not designed or intended for use in on-line control of
* 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 {
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;
}
}
}
java screen recorder library:
https://code.google.com/p/java-screen-recorder/
You need to include all the .jar from the java-screen-recorder lib and also the jmf lib (can be downloaded here http://www.oracle.com/technetwork/java/javase/download-142937.html) to ensure the RecordingConverter is working.
Example
try {
//Temp file for the Recorder
File file = new File("D:\\Users\\USER\\Desktop", "screen.cap");
OutputStream out = new FileOutputStream(file);
ScreenRecorder screenRecorder = new DesktopScreenRecorder(out,this);
screenRecorder.startRecording();
try {
Thread.sleep(5000);
screenRecorder.stopRecording();
//We reformat the video to .mov file
RecordingConverter.main(new String[]{file.getAbsolutePath()});
} catch(InterruptedException e) {
e.printStackTrace();
}
out.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
}