Merge "Crash in SurfaceTextureTarget filter open" into jb-dev

    @Override

    public synchronized void open(FilterContext context) {

        // Set up SurfaceTexture internals

        if (mSurfaceTexture == null) {

            Log.e(TAG, "SurfaceTexture is null!!");

            throw new RuntimeException("Could not register SurfaceTexture: " + mSurfaceTexture);

        }

        mSurfaceId = context.getGLEnvironment().registerSurfaceTexture(

            mSurfaceTexture, mScreenWidth, mScreenHeight);

        if (mSurfaceId <= 0) {

    }

    // Once the surface is unregistered, we still need the surfacetexture reference.

    // That is because when the the filter graph stops and starts again, the app

    // may not set the mSurfaceTexture again on the filter. In some cases, the app

    // may not even know that the graph has re-started. So it is difficult to enforce

    // that condition on an app using this filter. The only case where we need

    // to let go of the mSurfaceTexure reference is when the app wants to shut

    // down the graph on purpose, such as in the disconnect call.

    @Override

    public synchronized void close(FilterContext context) {

        if (mSurfaceId > 0) {

            context.getGLEnvironment().unregisterSurfaceId(mSurfaceId);

            mSurfaceId = -1;

            // Once the surface is unregistered, remove the surfacetexture reference.

            // The surfaceId could not have been valid without a valid surfacetexture.

            mSurfaceTexture = null;

        }

    }

    // This should be called from the client side when the surfacetexture is no longer

    // valid. e.g. from onPause() in the application using the filter graph.

    // In this case, we need to let go of our surfacetexture reference.

    public synchronized void disconnect(FilterContext context) {

        if (mLogVerbose) Log.v(TAG, "disconnect");

        if (mSurfaceTexture == null) {