I want to send frames, captured from a webcam, to my android application over UDP Sockets, and display them so that it appears as live-stream. I am able to receive images at the Android App, but I can only display single image. Not a stream. What I have done is following.
public class getImage extends AsyncTask<String, Bitmap, Bitmap> {
protected void onProgressUpdate(Bitmap... values) {
Log.i("onProgressUpdate", "done");
imageDisplay.setImageBitmap(values[0]); //imageDisplay is an ImageView on UI
imageDisplay.invalidate();
}//end of onProgressUpdate
protected Bitmap doInBackground(String... params) {
//receive an image over socket
publishProgress(bitmapimage); //update on UI
return bitmapimage;
}//end of getImage
public void ConnectionButton(View v) {
Connect = (Button) findViewById(R.id.Connect);
//while(true) {
try {
clientsocket = new DatagramSocket(9999);
} catch (IOException e) {
Log.i("Connection", "exception while creating socket");
}
try {
getImage obj = new getImage();
receivedImage = obj.execute("9999").get(); //receive image and over stream
//obj.onProgressUpdate(receivedImage);
}
catch(Exception e){
e.printStackTrace();
}
//}//endof while
}//end of ConnectionButton
If I press, the Connect button repeatedly, I get images as stream. I have tried onProgress update, but it updates images infrequently with quite large delay. How can I make these received images display on application as real-time stream.
An AsyncTask
object can be executed only once, so I was unable to receive a stream. But I achieved it through following mehtod.
I overrode onPostExecute()
to return a single image received from socket. Removed my call to publishProgress()
in doInBackground()
. And, the last step was to re-initialize the class object which extended AsyncTask and execute it in the onPostExecute()
i.e. create a new object and asyncobject.execute().get()
it in the onPostExecute()
. Hope it helps, anyone else facing the same issue.