Android media player - play from network stream

Question

I am trying to make an android media player which should play the media from network stream. I know it can play media that is streamed on RTSP or HTTP but my case is different.

I am not having any media streaming server and if I intend to use one, then I will have to modify it.

What I am trying to do is to stream the video that is being captured from android camera to the server, do little bit of modification in the video (like change color or apply some effect, etc) and stream it back to the phone. So typically my screen is divided in 2 parts, one is for upstreaming and other shows down streamed video.

Now what I am doing is capturing the video on sdcard and at the same time I am reading it and streaming it to the web. On web part, I am capturing the video (saving it in file [I am also able to play the video on the server]) and sending it back to the phone. On phone I am able to receive it but I am not able to figure out how to convert this stream to the proper format so that I can play it in VideoPlayer.

I also found that MediaPlayer provides some method to play the video from FileDescriptor so can I create a FileDescriptor from the socket and pass it to MediaPlayer? Will this method work? Is it possible to do it without RTSP or HTTP?

Answer 1

    package com.pocketjourney.media;

import java.io.BufferedInputStream;

/**
 * MediaPlayer does not yet support streaming from external URLs so this class provides a pseudo-streaming function
 * by downloading the content incrementally & playing as soon as we get enough audio in our temporary storage.
 */
public class StreamingMediaPlayer {

    private static final int INTIAL_KB_BUFFER =  96*10/8;//assume 96kbps*10secs/8bits per byte

    private TextView textStreamed;

    private ImageButton playButton;

    private ProgressBar progressBar;

    //  Track for display by progressBar
    private long mediaLengthInKb, mediaLengthInSeconds;
    private int totalKbRead = 0;

    // Create Handler to call View updates on the main UI thread.
    private final Handler handler = new Handler();

    private MediaPlayer     mediaPlayer;

    private File downloadingMediaFile; 

    private boolean isInterrupted;

    private Context context;

    private int counter = 0;

    public StreamingMediaPlayer(Context  context,TextView textStreamed, ImageButton playButton, Button  streamButton,ProgressBar    progressBar) 
    {
        this.context = context;
        this.textStreamed = textStreamed;
        this.playButton = playButton;
        this.progressBar = progressBar;
    }

    /**  
     * Progressivly download the media to a temporary location and update the MediaPlayer as new content becomes available.
     */  
    public void startStreaming(final String mediaUrl, long  mediaLengthInKb, long   mediaLengthInSeconds) throws IOException {

        this.mediaLengthInKb = mediaLengthInKb;
        this.mediaLengthInSeconds = mediaLengthInSeconds;

        Runnable r = new Runnable() {   
            public void run() {   
                try {   
                    downloadAudioIncrement(mediaUrl);
                } catch (IOException e) {
                    Log.e(getClass().getName(), "Unable to initialize the MediaPlayer for fileUrl=" + mediaUrl, e);
                    return;
                }   
            }   
        };   
        new Thread(r).start();
    }

    /**  
     * Download the url stream to a temporary location and then call the setDataSource  
     * for that local file
     */  
    public void downloadAudioIncrement(String mediaUrl) throws IOException {

        URLConnection cn = new URL(mediaUrl).openConnection();   
        cn.connect();   
        InputStream stream = cn.getInputStream();
        if (stream == null) {
            Log.e(getClass().getName(), "Unable to create InputStream for mediaUrl:" + mediaUrl);
        }

        downloadingMediaFile = new File(context.getCacheDir(),"downloadingMedia.dat");

        // Just in case a prior deletion failed because our code crashed or something, we also delete any previously 
        // downloaded file to ensure we start fresh.  If you use this code, always delete 
        // no longer used downloads else you'll quickly fill up your hard disk memory.  Of course, you can also 
        // store any previously downloaded file in a separate data cache for instant replay if you wanted as well.
        if (downloadingMediaFile.exists()) {
            downloadingMediaFile.delete();
        }

        FileOutputStream out = new FileOutputStream(downloadingMediaFile);   
        byte buf[] = new byte[16384];
        int totalBytesRead = 0, incrementalBytesRead = 0;
        do {
            int numread = stream.read(buf);   
            if (numread <= 0)   
                break;   
            out.write(buf, 0, numread);
            totalBytesRead += numread;
            incrementalBytesRead += numread;
            totalKbRead = totalBytesRead/1000;

            testMediaBuffer();
            fireDataLoadUpdate();
        } while (validateNotInterrupted());   
            stream.close();
        if (validateNotInterrupted()) {
            fireDataFullyLoaded();
        }
    }  

    private boolean validateNotInterrupted() {
        if (isInterrupted) {
            if (mediaPlayer != null) {
                mediaPlayer.pause();
                //mediaPlayer.release();
            }
            return false;
        } else {
            return true;
        }
    }


    /**
     * Test whether we need to transfer buffered data to the MediaPlayer.
     * Interacting with MediaPlayer on non-main UI thread can causes crashes to so perform this using a Handler.
     */  
    private void  testMediaBuffer() {
        Runnable updater = new Runnable() {
            public void run() {
                if (mediaPlayer == null) {
                    //  Only create the MediaPlayer once we have the minimum buffered data
                    if ( totalKbRead >= INTIAL_KB_BUFFER) {
                        try {
                            startMediaPlayer();
                        } catch (Exception e) {
                            Log.e(getClass().getName(), "Error copying buffered conent.", e);               
                        }
                    }
                } else if ( mediaPlayer.getDuration() - mediaPlayer.getCurrentPosition() <= 1000 ){ 
                    //  NOTE:  The media player has stopped at the end so transfer any existing buffered data
                    //  We test for < 1second of data because the media player can stop when there is still
                    //  a few milliseconds of data left to play
                    transferBufferToMediaPlayer();
                }
            }
        };
        handler.post(updater);
    }

    private void startMediaPlayer() {
        try {   
            File bufferedFile = new File(context.getCacheDir(),"playingMedia" + (counter++) + ".dat");

            // We double buffer the data to avoid potential read/write errors that could happen if the 
            // download thread attempted to write at the same time the MediaPlayer was trying to read.
            // For example, we can't guarantee that the MediaPlayer won't open a file for playing and leave it locked while 
            // the media is playing.  This would permanently deadlock the file download.  To avoid such a deadloack, 
            // we move the currently loaded data to a temporary buffer file that we start playing while the remaining 
            // data downloads.  
            moveFile(downloadingMediaFile,bufferedFile);

            Log.e(getClass().getName(),"Buffered File path: " + bufferedFile.getAbsolutePath());
            Log.e(getClass().getName(),"Buffered File length: " + bufferedFile.length()+"");

            mediaPlayer = createMediaPlayer(bufferedFile);

            // We have pre-loaded enough content and started the MediaPlayer so update the buttons & progress meters.
            mediaPlayer.start();
            startPlayProgressUpdater();         
            playButton.setEnabled(true);
        } catch (IOException e) {
            Log.e(getClass().getName(), "Error initializing the MediaPlayer.", e);
            return;
        }   
    }

    private MediaPlayer createMediaPlayer(File mediaFile)
    throws IOException {
        MediaPlayer mPlayer = new MediaPlayer();
        mPlayer.setOnErrorListener(
                new MediaPlayer.OnErrorListener() {
                    public boolean onError(MediaPlayer mp, int what, int extra) {
                        Log.e(getClass().getName(), "Error in MediaPlayer: (" + what +") with extra (" +extra +")" );
                        return false;
                    }
                });

        //  It appears that for security/permission reasons, it is better to pass a FileDescriptor rather than a direct path to the File.
        //  Also I have seen errors such as "PVMFErrNotSupported" and "Prepare failed.: status=0x1" if a file path String is passed to
        //  setDataSource().  So unless otherwise noted, we use a FileDescriptor here.
        FileInputStream fis = new FileInputStream(mediaFile);
        mPlayer.setDataSource(fis.getFD());
        mPlayer.prepare();
        return mPlayer;
    }

    /**
     * Transfer buffered data to the MediaPlayer.
     * NOTE: Interacting with a MediaPlayer on a non-main UI thread can cause thread-lock and crashes so 
     * this method should always be called using a Handler.
     */  
    private void transferBufferToMediaPlayer() {
        try {
            // First determine if we need to restart the player after transferring data...e.g. perhaps the user pressed pause
            boolean wasPlaying = mediaPlayer.isPlaying();
            int curPosition = mediaPlayer.getCurrentPosition();

            // Copy the currently downloaded content to a new buffered File.  Store the old File for deleting later. 
            File oldBufferedFile = new File(context.getCacheDir(),"playingMedia" + counter + ".dat");
            File bufferedFile = new File(context.getCacheDir(),"playingMedia" + (counter++) + ".dat");

            //  This may be the last buffered File so ask that it be delete on exit.  If it's already deleted, then this won't mean anything.  If you want to 
            // keep and track fully downloaded files for later use, write caching code and please send me a copy.
            bufferedFile.deleteOnExit();   
            moveFile(downloadingMediaFile,bufferedFile);

            // Pause the current player now as we are about to create and start a new one.  So far (Android v1.5),
            // this always happens so quickly that the user never realized we've stopped the player and started a new one
            mediaPlayer.pause();

            // Create a new MediaPlayer rather than try to re-prepare the prior one.
            mediaPlayer = createMediaPlayer(bufferedFile);
            mediaPlayer.seekTo(curPosition);

            //  Restart if at end of prior buffered content or mediaPlayer was previously playing.  
            //  NOTE:  We test for < 1second of data because the media player can stop when there is still
            //  a few milliseconds of data left to play
            boolean atEndOfFile = mediaPlayer.getDuration() - mediaPlayer.getCurrentPosition() <= 1000;
            if (wasPlaying || atEndOfFile){
                mediaPlayer.start();
            }

            // Lastly delete the previously playing buffered File as it's no longer needed.
            oldBufferedFile.delete();

        }catch (Exception e) {
            Log.e(getClass().getName(), "Error updating to newly loaded content.", e);                  
        }
    }

    private void fireDataLoadUpdate() {
        Runnable updater = new Runnable() {
            public void run() {
                textStreamed.setText((totalKbRead + " Kb read"));
                float loadProgress = ((float)totalKbRead/(float)mediaLengthInKb);
                progressBar.setSecondaryProgress((int)(loadProgress*100));
            }
        };
        handler.post(updater);
    }

    private void fireDataFullyLoaded() {
        Runnable updater = new Runnable() { 
            public void run() {
                transferBufferToMediaPlayer();

                // Delete the downloaded File as it's now been transferred to the currently playing buffer file.
                downloadingMediaFile.delete();
                textStreamed.setText(("Audio full loaded: " + totalKbRead + " Kb read"));
            }
        };
        handler.post(updater);
    }

    public MediaPlayer getMediaPlayer() {
        return mediaPlayer;
    }

    public void startPlayProgressUpdater() {
        float progress = (((float)mediaPlayer.getCurrentPosition()/1000)/mediaLengthInSeconds);
        progressBar.setProgress((int)(progress*100));

        if (mediaPlayer.isPlaying()) {
            Runnable notification = new Runnable() {
                public void run() {
                    startPlayProgressUpdater();
                }
            };
            handler.postDelayed(notification,1000);
        }
    }    

    public void interrupt() {
        playButton.setEnabled(false);
        isInterrupted = true;
        validateNotInterrupted();
    }

    /**
     *  Move the file in oldLocation to newLocation.
     */
    public void moveFile(File   oldLocation, File   newLocation)
    throws IOException {

        if ( oldLocation.exists( )) {
            BufferedInputStream  reader = new BufferedInputStream( new FileInputStream(oldLocation) );
            BufferedOutputStream  writer = new BufferedOutputStream( new FileOutputStream(newLocation, false));
            try {
                byte[]  buff = new byte[8192];
                int numChars;
                while ( (numChars = reader.read(  buff, 0, buff.length ) ) != -1) {
                    writer.write( buff, 0, numChars );
                }
            } catch( IOException ex ) {
                throw new IOException("IOException when transferring " + oldLocation.getPath() + " to " + newLocation.getPath());
            } finally {
                try {
                    if ( reader != null ){                      
                        writer.close();
                        reader.close();
                    }
                } catch( IOException ex ){
                    Log.e(getClass().getName(),"Error closing files when transferring " + oldLocation.getPath() + " to " + newLocation.getPath() ); 
                }
            }
        } else {
            throw new IOException("Old location does not exist when transferring " + oldLocation.getPath() + " to " + newLocation.getPath() );
        }
    }
}

try to use this