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Is there a way to create a player specific countdown, that stops when the player leaves in Java?

I'm looking for a way to create a player-specific countdown for my BankSystem Plugin in Java.
Currently everybody gets their interest at the same time, because I'm using a Bukkit scheduler.
Bukkit.getScheduler().scheduleSyncRepeatingTask(Main.getPlugin(), new Runnable() {
#Override
public void run() {
try {
Statement stmt = DatabaseManager.getCon().createStatement();
String sql = ("SELECT uuid, money FROM Accounts");
stmt.executeUpdate("USE " + ConfigManager.getConf().getString("Database.DBName"));
ResultSet rs = stmt.executeQuery(sql);
while (rs.next()) {
uids.add(rs.getString(1));
money.put(rs.getString(1), rs.getInt(2));
}
if (!ConfigManager.getConf().getBoolean("Settings.PayInterestOffline")) {
try {
for (String uid : uids) {
Player pl = Bukkit.getPlayer(UUID.fromString(uid));
if (pl == null) {
uids.remove(IndexIdentifier.getIndex(uid, uids));
money.remove(uid);
}
}
} catch (Exception e) {
}
}
for (int i = 0; i < uids.size(); i++) {
try {
String puid = uids.get(i);
double doubleMoney = money.get(puid);
if (doubleMoney > ConfigManager.getConf().getInt("Settings.MaximumMoney")) {
continue;
} else {
doubleMoney = (((doubleMoney / 100) * percent) + doubleMoney);
int intMoney = (int) Math.ceil(doubleMoney);
stmt.executeUpdate("UPDATE Accounts SET money = " + intMoney + " WHERE uuid = '" + puid + "';");
Player p = Bukkit.getPlayer(UUID.fromString(puid));
if (p.isOnline() && p != null) {
p.sendMessage(
"§aYou've credited an interest of §6" + (int) Math.ceil((intMoney / 100) * percent)
+ ".0 " + ConfigManager.getConf().getString("Settings.currency"));
}
}
money.remove(puid);
uids.remove(i);
} catch (NullPointerException e) {
}
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}, 0, period);
Is there a way, to create a countdown for every online player. That means that the countdown stops, when the player leaves the server and resumes after rejoining.

You can associate an integer with a player in a hashmap:
HashMap<UUID, Integer> playersAndTimes = new HashMap<>();
To add players to the HashMap when you want to start the countdown:
playersAndTimes.put(player.getUniqueId(), time)
Now you just need to run this function when the plugin enables which loops through every player online, if they are in the HashMap (have a countdown on them) it will remove 1 every second from their value:
Bukkit.getScheduler().scheduleSyncRepeatingTask(Main.getPlugin(Main.class), new Runnable() {
#Override
public void run() {
for (Player player : Bukkit.getOnlinePlayers()) {
if (playersAndTimes.containsKey(player.getUniqueId())) {
if (playersAndTimes.get(player.getUniqueId()) >= 1) {
playersAndTimes.put(player.getUniqueId(), playersAndTimes.get(player.getUniqueId()) - 1);
} else {
//The Player's Time Has Expired As The Number Associated With Their UUID In The Hashmap Is Now Equal To 0.
//DO SOMETHING
}
}
}
}
}, 0, 20);

Tapping android screen solves media skipping, how to fix?

I wrote an Android app that plays multi-track audio files and it works completely in the simulator. On the device, it plays for a few seconds and then starts skipping and popping every few seconds. If I continuously tap the screen in the dead space of the app, the skipping doesn't occur and then recurs about 5 seconds after screen tapping ceases. I presume that this has something to do with thread priority, but I log the thread priority in the play loop and it never changes.
I'm hoping that somebody can tell me either:
a hack where I can simulate a screen tap every second so that I can run a beta test without the app skipping
explain a way to debug activity/thread/etc priority when it seems that my thread priority isn't changing when it seems like it is.
Here is how the player code is executed:
private class DecodeOperation extends AsyncTask<Void, Void, Void> {
#Override
protected Void doInBackground(Void... values) {
AudioTrackPlayer.this.decodeLoop();
return null;
}
#Override
protected void onPreExecute() {
}
#Override
protected void onProgressUpdate(Void... values) {
}
}
Here is the relevant player code:
private void decodeLoop()
{
ByteBuffer[] codecInputBuffers;
ByteBuffer[] codecOutputBuffers;
// extractor gets information about the stream
extractor = new MediaExtractor();
try {
extractor.setDataSource(this.mUrlString);
} catch (Exception e) {
mDelegateHandler.onRadioPlayerError(AudioTrackPlayer.this);
return;
}
MediaFormat format = extractor.getTrackFormat(0);
String mime = format.getString(MediaFormat.KEY_MIME);
// the actual decoder
codec = MediaCodec.createDecoderByType(mime);
codec.configure(format, null /* surface */, null /* crypto */, 0 /* flags */);
codec.start();
codecInputBuffers = codec.getInputBuffers();
codecOutputBuffers = codec.getOutputBuffers();
// get the sample rate to configure AudioTrack
int sampleRate = format.getInteger(MediaFormat.KEY_SAMPLE_RATE);
Log.i(LOG_TAG,"mime "+mime);
Log.i(LOG_TAG,"sampleRate "+sampleRate);
// create our AudioTrack instance
audioTrack = new AudioTrack(
AudioManager.STREAM_MUSIC,
sampleRate,
AudioFormat.CHANNEL_OUT_5POINT1,
AudioFormat.ENCODING_PCM_16BIT,
AudioTrack.getMinBufferSize (
sampleRate,
AudioFormat.CHANNEL_OUT_5POINT1,
AudioFormat.ENCODING_PCM_16BIT
),
AudioTrack.MODE_STREAM
);
// start playing, we will feed you later
audioTrack.play();
extractor.selectTrack(0);
// start decoding
final long kTimeOutUs = 10000;
MediaCodec.BufferInfo info = new MediaCodec.BufferInfo();
boolean sawInputEOS = false;
boolean sawOutputEOS = false;
int noOutputCounter = 0;
int noOutputCounterLimit = 50;
while (!sawOutputEOS && noOutputCounter < noOutputCounterLimit && !doStop) {
//Log.i(LOG_TAG, "loop ");
noOutputCounter++;
if (!sawInputEOS) {
inputBufIndex = codec.dequeueInputBuffer(kTimeOutUs);
bufIndexCheck++;
// Log.d(LOG_TAG, " bufIndexCheck " + bufIndexCheck);
if (inputBufIndex >= 0) {
ByteBuffer dstBuf = codecInputBuffers[inputBufIndex];
int sampleSize =
extractor.readSampleData(dstBuf, 0 /* offset */);
//Log.d(LOG_TAG, "SampleLength = " + String.valueOf(sampleSize));
long presentationTimeUs = 0;
if (sampleSize < 0) {
Log.d(LOG_TAG, "saw input EOS.");
sawInputEOS = true;
sampleSize = 0;
} else {
presentationTimeUs = extractor.getSampleTime();
}
// can throw illegal state exception (???)
codec.queueInputBuffer(
inputBufIndex,
0 /* offset */,
sampleSize,
presentationTimeUs,
sawInputEOS ? MediaCodec.BUFFER_FLAG_END_OF_STREAM : 0);
if (!sawInputEOS) {
extractor.advance();
}
}
else
{
Log.e(LOG_TAG, "inputBufIndex " +inputBufIndex);
}
}
int res = codec.dequeueOutputBuffer(info, kTimeOutUs);
if (res >= 0) {
//Log.d(LOG_TAG, "got frame, size " + info.size + "/" + info.presentationTimeUs);
if (info.size > 0) {
noOutputCounter = 0;
}
int outputBufIndex = res;
ByteBuffer buf = codecOutputBuffers[outputBufIndex];
final byte[] chunk = new byte[info.size];
buf.get(chunk);
buf.clear();
audioTrack.write(chunk,0,chunk.length);
if(this.mState != State.Playing)
{
mDelegateHandler.onRadioPlayerPlaybackStarted(AudioTrackPlayer.this);
}
this.mState = State.Playing;
}
codec.releaseOutputBuffer(outputBufIndex, false /* render */);
if ((info.flags & MediaCodec.BUFFER_FLAG_END_OF_STREAM) != 0) {
Log.d(LOG_TAG, "saw output EOS.");
sawOutputEOS = true;
}
} else if (res == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED) {
codecOutputBuffers = codec.getOutputBuffers();
Log.d(LOG_TAG, "output buffers have changed.");
} else if (res == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
MediaFormat oformat = codec.getOutputFormat();
Log.d(LOG_TAG, "output format has changed to " + oformat);
} else {
Log.d(LOG_TAG, "dequeueOutputBuffer returned " + res);
}
}
Log.d(LOG_TAG, "stopping...");
relaxResources(true);
this.mState = State.Stopped;
doStop = true;
// attempt reconnect
if(sawOutputEOS)
{
try {
AudioTrackPlayer.this.play();
return;
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if(noOutputCounter >= noOutputCounterLimit)
{
mDelegateHandler.onRadioPlayerError(AudioTrackPlayer.this);
}
else
{
mDelegateHandler.onRadioPlayerStopped(AudioTrackPlayer.this);
}
}

Have you monitored the CPU frequency while your application is running? The CPU governor is probably scaling the CPU up on touch and scaling back down on a timer. Increasing the priority on your background thread to THREAD_PRIORITY_DEFAULT will probably fix the issue, the default priority for AsyncTask is quite low and not appropriate for Audio.
You could also increase the size of the AudioTrack's buffer to some multiple of the value returned by getMinBufferSize, that method only returns the minimum possible buffer for the Class to operate, it does not guarantee smooth playback.

Reuse threads to download next segment of file

I am looking for possible methods that can increase download speed and improve cpu, memory performance. Currently I am downloading file in segments and transferring data using java nio transferFrom function.
public void startDownload() {
threadService.execute(() -> {
double currentBytes = bytesDone.doubleValue();
//Download each segment independently.
for (int i = 0; i < segments; i++) {
if (intialState[i] != -1) {
threadService.execute(new Segment((i * sizeOfEachSegment)
+ intialState[i], (i + 1) * sizeOfEachSegment, i));
}
}
if (intialState[segments] != -1) {
threadService.execute(new Segment((segments * sizeOfEachSegment)
+ intialState[segments], sizeofFile, segments));
}
// Keep saving states of threads. And updating speed.
while (bytesDone.get() < sizeofFile) {
for (int i = 0; i < 1; i++) {
try {
Thread.sleep(5000);
} catch (InterruptedException ex) {
System.out.println("thread interupted while sleeping");
}
System.out.println(speed
= (int) ((bytesDone.doubleValue() - currentBytes) / 5120));
currentBytes = bytesDone.doubleValue();
avgSpeed[0] += speed;
avgSpeed[1]++;
}
states.saveState(stateArray, currentState);
}
// Download Complete.
try {
fileChannel.close();
file.close();
} catch (IOException ex) {
System.out.println("failed to close file");
}
currentState.set(2);
states.saveState(stateArray, currentState);
System.out.println("Alhamdullilah Done :)");
System.out.println("Average Speed : " + avgSpeed[0] / avgSpeed[1]);
});
}
public class Segment implements Runnable {
long start;
long end;
long delta;
int name;
public Segment(long start, long end, int name) {
this.start = start;
this.end = end;
this.name = name;
}
#Override
public void run() {
try {
HttpGet get = new HttpGet(uri);
// Range header for defining which segment of file we want to receive.
String byteRange = start + "-" + end;
get.setHeader("Range", "bytes=" + byteRange);
try (CloseableHttpResponse response = client.execute(get)) {
ReadableByteChannel inputChannel = Channels.newChannel(
response.getEntity().getContent());
while (start < end && currentState.get() == 1) {
delta = fileChannel.transferFrom(inputChannel, start, 8192);
start += delta;
bytesDone.addAndGet(delta);
stateArray.set(name, start);
}
stateArray.set(name, -1);
}
System.out.println("Thread done: " + name);
} catch (IOException ex) {
System.out.println("thread " + name + " failed to download");
}
}
}
This implementation gives 400+ kb/s but Internet Download Manager downloads same file at 500+ kb/s.
Are there any resources I can reuse(I noticed every connection initially takes time to reach its maximum speed so is there any way i can reuse the same thread to download the next portion of file as soon as it complete downloading previous)?

timer in java using threads

I am developing an exam software in core java where I am conducting various tests for students.I am stuck at a piece of code where timer with countdown is set.
My problem is when I display minutes its working fine but when I try to display seconds with the minutes in mm:ss format its not working.
Code is:
// for below int ti=20,si=60;
// test is for 20 minutes
public void run() {
while (true) {
try {
Thread.currentThread().sleep(60000);
for (int i = 0; i <= 60; i++) {
etime.setText("Remaining Time:-" + ti + ":" + si);
System.out.println("Remaining Time:-" + ti + ":" + si);
Thread.currentThread().sleep(1000);
si--;
}
ti--;
if (ti == 0) {
close();
}
} catch (InterruptedException ex) {
Logger.getLogger(Exam.class.getName()).log(Level.SEVERE, null, ex);
}
}
}

Once si has counted down to 0, you need to reset it to 59.
Also, the i variable is completely unnecessary, and there is an off-by-one error in your loop.

Capture only one thumbnail image from a video

i am working to generate thumbnail images from a video. I am able to do it but i need only one thumbnail image from a video , but what i get is more than one images at different times of the video. I have used the following code to generate the thumbnails . Please suggest me what should i modify in the following code to get only one thumbnail from the middle portion of the video . The code i used is as follows ( I have used Xuggler ):
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import com.xuggle.mediatool.IMediaReader;
import com.xuggle.mediatool.MediaListenerAdapter;
import com.xuggle.mediatool.ToolFactory;
import com.xuggle.mediatool.event.IVideoPictureEvent;
import com.xuggle.xuggler.Global;
public class Main {
public static final double SECONDS_BETWEEN_FRAMES = 10;
private static final String inputFilename = "D:\\k\\Knock On Wood Lesson.flv";
private static final String outputFilePrefix = "D:\\pix\\";
// The video stream index, used to ensure we display frames from one and
// only one video stream from the media container.
private static int mVideoStreamIndex = -1;
// Time of last frame write
private static long mLastPtsWrite = Global.NO_PTS;
public static final long MICRO_SECONDS_BETWEEN_FRAMES =
(long) (Global.DEFAULT_PTS_PER_SECOND * SECONDS_BETWEEN_FRAMES);
public static void main(String[] args) {
IMediaReader mediaReader = ToolFactory.makeReader(inputFilename);
// stipulate that we want BufferedImages created in BGR 24bit color space
mediaReader.setBufferedImageTypeToGenerate(BufferedImage.TYPE_3BYTE_BGR);
mediaReader.addListener(new ImageSnapListener());
// read out the contents of the media file and
// dispatch events to the attached listener
while (mediaReader.readPacket() == null);
}
private static class ImageSnapListener extends MediaListenerAdapter {
public void onVideoPicture(IVideoPictureEvent event) {
if (event.getStreamIndex() != mVideoStreamIndex) {
// if the selected video stream id is not yet set, go ahead an
// select this lucky video stream
if (mVideoStreamIndex == -1) {
mVideoStreamIndex = event.getStreamIndex();
} // no need to show frames from this video stream
else {
return;
}
}
// if uninitialized, back date mLastPtsWrite to get the very first frame
if (mLastPtsWrite == Global.NO_PTS) {
mLastPtsWrite = event.getTimeStamp() - MICRO_SECONDS_BETWEEN_FRAMES;
}
// if it's time to write the next frame
if (event.getTimeStamp() - mLastPtsWrite
>= MICRO_SECONDS_BETWEEN_FRAMES) {
String outputFilename = dumpImageToFile(event.getImage());
// indicate file written
double seconds = ((double) event.getTimeStamp())
/ Global.DEFAULT_PTS_PER_SECOND;
System.out.printf("at elapsed time of %6.3f seconds wrote: %s\n",
seconds, outputFilename);
// update last write time
mLastPtsWrite += MICRO_SECONDS_BETWEEN_FRAMES;
}
}
private String dumpImageToFile(BufferedImage image) {
try {
String outputFilename = outputFilePrefix
+ System.currentTimeMillis() + ".png";
ImageIO.write(image, "png", new File(outputFilename));
return outputFilename;
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
}
}

This is how you can.
public class ThumbsGenerator {
private static void processFrame(IVideoPicture picture, BufferedImage image) {
try {
File file=new File("C:\\snapshot\thimbnailpic.png");//name of pic
ImageIO.write(image, "png", file);
} catch (Exception e) {
e.printStackTrace();
}
}
#SuppressWarnings("deprecation")
public static void main(String[] args) throws NumberFormatException,IOException {
String filename = "your_video.mp4";
if (!IVideoResampler.isSupported(IVideoResampler.Feature.FEATURE_COLORSPACECONVERSION))
throw new RuntimeException("you must install the GPL version of Xuggler (with IVideoResampler support) for this demo to work");
IContainer container = IContainer.make();
if (container.open(filename, IContainer.Type.READ, null) < 0)
throw new IllegalArgumentException("could not open file: "
+ filename);
String seconds=container.getDuration()/(1000000*2)+""; // time of thumbnail
int numStreams = container.getNumStreams();
// and iterate through the streams to find the first video stream
int videoStreamId = -1;
IStreamCoder videoCoder = null;
for (int i = 0; i < numStreams; i++) {
// find the stream object
IStream stream = container.getStream(i);
// get the pre-configured decoder that can decode this stream;
IStreamCoder coder = stream.getStreamCoder();
if (coder.getCodecType() == ICodec.Type.CODEC_TYPE_VIDEO) {
videoStreamId = i;
videoCoder = coder;
break;
}
}
if (videoStreamId == -1)
throw new RuntimeException(
"could not find video stream in container: " + filename);
if (videoCoder.open() < 0)
throw new RuntimeException(
"could not open video decoder for container: " + filename);
IVideoResampler resampler = null;
if (videoCoder.getPixelType() != IPixelFormat.Type.BGR24) {
resampler = IVideoResampler.make(videoCoder.getWidth(), videoCoder
.getHeight(), IPixelFormat.Type.BGR24, videoCoder
.getWidth(), videoCoder.getHeight(), videoCoder
.getPixelType());
if (resampler == null)
throw new RuntimeException(
"could not create color space resampler for: "
+ filename);
}
IPacket packet = IPacket.make();
IRational timeBase = container.getStream(videoStreamId).getTimeBase();
System.out.println("Timebase " + timeBase.toString());
long timeStampOffset = (timeBase.getDenominator() / timeBase.getNumerator())
* Integer.parseInt(seconds);
System.out.println("TimeStampOffset " + timeStampOffset);
long target = container.getStartTime() + timeStampOffset;
container.seekKeyFrame(videoStreamId, target, 0);
boolean isFinished = false;
while(container.readNextPacket(packet) >= 0 && !isFinished ) {
if (packet.getStreamIndex() == videoStreamId) {
IVideoPicture picture = IVideoPicture.make(videoCoder
.getPixelType(), videoCoder.getWidth(), videoCoder
.getHeight());
int offset = 0;
while (offset < packet.getSize()) {
int bytesDecoded = videoCoder.decodeVideo(picture, packet,
offset);
if (bytesDecoded < 0) {
System.err.println("WARNING!!! got no data decoding " +
"video in one packet");
}
offset += bytesDecoded;
picture from
if (picture.isComplete()) {
IVideoPicture newPic = picture;
if (resampler != null) {
newPic = IVideoPicture.make(resampler
.getOutputPixelFormat(), picture.getWidth(),
picture.getHeight());
if (resampler.resample(newPic, picture) < 0)
throw new RuntimeException(
"could not resample video from: "
+ filename);
}
if (newPic.getPixelType() != IPixelFormat.Type.BGR24)
throw new RuntimeException(
"could not decode video as BGR 24 bit data in: "
+ filename);
BufferedImage javaImage = Utils.videoPictureToImage(newPic);
processFrame(newPic, javaImage);
isFinished = true;
}
}
}
}
if (videoCoder != null) {
videoCoder.close();
videoCoder = null;
}
if (container != null) {
container.close();
container = null;
}
} }

I know this is an old question but I found the same piece of tutorial code while playing with Xuggler today. The reason you are getting multiple thumbnails is due to the following line:
public static final double SECONDS_BETWEEN_FRAMES = 10;
This variable specifies the number of seconds between calls to dumpImageToFile. So a frame thumbnail will be written at 0.00 seconds, at 10.00 seconds, at 20.00 seconds, and so on:
if (event.getTimeStamp() - mLastPtsWrite >= MICRO_SECONDS_BETWEEN_FRAMES)
To get a frame thumbnail from the middle of the video you can calculate the duration of the video using more Xuggler capability which I found in a tutorial at JavaCodeGeeks. Then change your code in the ImageSnapListener to only write a single frame once the IVideoPictureEvent event timestamp exceeds the calculated mid point.
I hope that helps anyone who stumbles across this question.