VideoView black flash before and after playing

2019-01-17 16:37发布

I have a VideoView which I want to use to play a movieclip. I use it like this to play it and it works.

VideoView vv = new VideoView(this);
vv.setVideoURI(Uri.parse("android.resource://cortex2.hcbj/raw/intro"));
setContentView(vv);
vv.start();

However I see a black flash just before and after the movie clip. The flash in itself isn't a big problem, but the blackness of it is. The background is white, so if the flash is white, or if it dissapears it will be okay.

14条回答
Fickle 薄情
2楼-- · 2019-01-17 16:56

here is simple trick

check the condition media player.getCurrentPosition == 0 in on prepared listener of video view ,black screen will appear when position is zero so display an image untill the video will load

mycode:

mVideoView.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
        @Override
        public void onPrepared(final MediaPlayer mediaPlayer) {
                mVideoView.start();


                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {

                        while (mediaPlayer.isPlaying()) {
                            Log.d("MainActivity", "position " + mediaPlayer.getCurrentPosition());
                            if (mediaPlayer.getCurrentPosition() == 0) {
                                videoStillImageView.setVisibility(View.VISIBLE);
                            } else {
                                videoStillImageView.setVisibility(View.GONE);


                                break;
                            }
                        }

                    }
                });
            }
        }
    });
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我欲成王,谁敢阻挡
3楼-- · 2019-01-17 16:43

That flash comes from changing the current content view to another one. You could try adding a VideoView to your layout xml file then referencing it with (VideoView) findViewById(R.id.vid); instead of new VideoView(this); and setting the content view to that layout.

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我欲成王,谁敢阻挡
4楼-- · 2019-01-17 16:44

Where are you changing the contentView (in which method did you write the four lines of code above)?

You should only set the contentView in the onCreate() method of an Activity. If you are doing it somewhere else (for exemple in a button’s callback), you should start a new activity instead.

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\"骚年 ilove
5楼-- · 2019-01-17 16:44

Try this line.This worked for me. if(player!=null)player.release();

@Override
 protected void onDestroy() {
     super.onDestroy();
         player.pause();
     if(player!=null)player.release();
     player = null;
     videoSurface = null;
     controller = null;

 }
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ら.Afraid
6楼-- · 2019-01-17 16:49

Today I had the same problem and found a very bad and hacky workaround for this nasty problem: I realized that one can set a background color / drawable onto the VideoView which blends over the video surface and makes it completely hidden. This only works though while the underlying video is still playing, not when it is stopped (neither when it ended normally nor when stopPlayback() was called), otherwise you'd again see a black flicker. The background must also not be set in the beginning, otherwise the video would be completely hidden right from the start.

So the only logical step for me was to post a delayed event just before I start the video - and since I know the video length, I let this event happen just a few milliseconds before it ends normally. I took a screenshot of the last frame in VLC and then blended it like this:

private void startVideo()
{
    introVideo.setBackgroundDrawable(null);
    introVideo.postDelayed(new Runnable() {
        public void run()
        {
            if (!introVideo.isPlaying())
                return;

            introVideo.setBackgroundResource(R.drawable.video_still_image);
            // other stuff here, for example a custom transition to
            // another activity
        }
    }, 7500); // the video is roughly 8000ms long
    introVideo.start();
}

This however was not enough, because when the video actually ended, I still got a short black screen flicker, so I also had to set the still image as background of the container that contained the video (in my case it was the layout of the activity):

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
          android:layout_width="fill_parent"
          android:layout_height="fill_parent"
          android:background="@drawable/video_still_image">

    <VideoView android:id="@+id/introVideo"
              android:layout_width="fill_parent"
              android:layout_height="fill_parent"
              android:layout_alignParentRight="true"
              android:layout_alignParentLeft="true"
              android:layout_alignParentTop="true"
              android:layout_alignParentBottom="true"
              android:layout_marginTop="-10dip" />

</RelativeLayout>

This activity is rendered in fullscreen and the video is (mostly) scaled to the total screen size (screen 1024x600, video 960x640). I say mostly, because for some unknown reason the layout's background image blends through for about 10px on top. This was the last hack I had to apply to make it work - move the video container -10dip into the void on top.

This now looks awesome on my Galaxy Tab, I don't dare to test it on the SGS2 phone, though...

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我只想做你的唯一
7楼-- · 2019-01-17 16:50

I ended up having to do something very similar to @tommyd to avoid the black surfaceView flash at the beginning and end of my videos. However, I found that setting/nulling the background drawable for the videoView was not occurring instantly on many phones. There could be about a half-second delay between my call to set the background and when it was actually displayed.

What I ended up doing was creating a custom SurfaceView that showed a single, solid color, then overlayed this on top of the VideoView and made use of SurfaceView.setZOrderMediaOverlay().

My custom SurfaceView was heavily informed by: http://android-er.blogspot.com/2010/05/android-surfaceview.html

public class SolidSurfaceView extends SurfaceView implements SurfaceHolder.Callback {

    private static final String TAG = SolidSurfaceView.class.getSimpleName();

    private SolidSurfaceThread mThread;
    private boolean mSurfaceIsValid;
    private int mColor;

    public SolidSurfaceView(Context context) {
        super(context);
        init();
    }

    public SolidSurfaceView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public SolidSurfaceView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init();
    }

    private void init() {
        Log.verbose(TAG, "init");

        getHolder().addCallback(this);
        setZOrderMediaOverlay(true);
    }

    public void setColor(int color) {
        mColor = color;
        invalidate();
    }

    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        Log.verbose(TAG, "surfaceCreated");

        mSurfaceIsValid = true;

        mThread = new SolidSurfaceThread(getHolder(), this);
        mThread.setRunning(true);
        mThread.start();
    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        Log.verbose(TAG, "surfaceDestroyed");
        mSurfaceIsValid = false;

        boolean retry = true;
        mThread.setRunning(false);
        while (retry) {
            try {
                mThread.join();
                retry = false;
            }
            catch (InterruptedException e) {
                Log.warning(TAG, "Thread join interrupted");
            }
        }
        mThread = null;
    }

    @Override
    protected void onDraw(Canvas canvas) {
        if ( ! mSurfaceIsValid) {
            return;
        }

        canvas.drawColor(mColor);
    }

    private static class SolidSurfaceThread extends Thread {

        private final SurfaceHolder mSurfaceHolder;
        private final SolidSurfaceView mSurfaceView;
        private boolean mIsRunning;

        public SolidSurfaceThread(SurfaceHolder surfaceHolder, SolidSurfaceView surfaceView) {
            mSurfaceHolder = surfaceHolder;
            mSurfaceView = surfaceView;
        }

        public void setRunning(boolean running) {
            mIsRunning = running;
        }

        @Override
        public void run() {
            while (mIsRunning) {
                Canvas c = null;
                try {
                    c = mSurfaceHolder.lockCanvas(null);
                    synchronized (mSurfaceHolder) {
                        mSurfaceView.onDraw(c);
                    }
                }
                finally {
                    // do this in a finally so that if an exception is thrown
                    // during the above, we don't leave the Surface in an
                    // inconsistent state
                    if (c != null) {
                        mSurfaceHolder.unlockCanvasAndPost(c);
                    }
                }
            }
        }
    }
}

And in the parent activity that hosts the views:

    mVideoView = (VideoView)findViewById(R.id.video_view);
    mVideoMask = (SolidSurfaceView)findViewById(R.id.video_mask);
    mVideoMask.setColor(Color.BLUE);

You can then do things like mVideoMask.setVisibility(View.GONE) to hide the mask or mVideoMask.setVisibility(View.VISIBLE) to show the mask (and hide the black-screened VideoView).

In my experiments on various phones, this method provided very fast showing/hiding of the video mask, as opposed to setting/nulling the background.

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