Add sublayer over CALayer - ios

Question

I've been developing with Vuforia SDK where I want to put video over a layer.
When the Augmented image is recognize its caling method to show targetOverlayView (UIView) layer.
[booksDelegate setOverlayLayer:self.targetOverlayView.layer];
While the method for setOverlayLayer is this:
- (void)setOverlayLayer:(CALayer *)overlayLayer {
UIImage* image = nil;
UIGraphicsBeginImageContext(overlayLayer.frame.size);
{
[overlayLayer renderInContext: UIGraphicsGetCurrentContext()];
image = UIGraphicsGetImageFromCurrentImageContext();
}
UIGraphicsEndImageContext();
// Get the inner CGImage from the UIImage wrapper
CGImageRef cgImage = image.CGImage;
// Get the image size
NSInteger width = CGImageGetWidth(cgImage);
NSInteger height = CGImageGetHeight(cgImage);
// Record the number of channels
NSInteger channels = CGImageGetBitsPerPixel(cgImage)/CGImageGetBitsPerComponent(cgImage);
// Generate a CFData object from the CGImage object (a CFData object represents an area of memory)
CFDataRef imageData = CGDataProviderCopyData(CGImageGetDataProvider(cgImage));
unsigned char* pngData = new unsigned char[width * height * channels];
const int rowSize = width * channels;
const unsigned char* pixels = (unsigned char*)CFDataGetBytePtr(imageData);
// Copy the row data from bottom to top
for (int i = 0; i < height; ++i) {
memcpy(pngData + rowSize * i, pixels + rowSize * (height - 1 - i), width * channels);
}
glClearColor(0.0f, 0.0f, 0.0f, QCAR::requiresAlpha() ? 0.0f : 1.0f);
if (!trackingTIDSet) {
glGenTextures(1, &tID);
}
glBindTexture(GL_TEXTURE_2D, tID);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_BGRA_EXT, GL_UNSIGNED_BYTE, (GLvoid*)pngData);
trackingTIDSet = YES;
trackingTextureAvailable = YES;
delete[] pngData;
CFRelease(imageData);
renderState = RS_OVERLAY;
}
It will show a blank screen, even i change the background colour for targetOverlayView, it still only black screen.
targetOverlayView.m :
self.layer.backgroundColor = [UIColor orangeColor].CGColor;
and this is when i want to put the avplayer layer on the layer, but still no luck,it blanks.
AVURLAsset *avasset = [[AVURLAsset alloc] initWithURL:URL1 options:nil];
AVPlayerItem *item = [[AVPlayerItem alloc] initWithAsset:avasset];
player = [[[AVPlayer alloc] initWithPlayerItem:item]retain];
playerLayer = [AVPlayerLayer playerLayerWithPlayer:player];
CGSize size = self.layer.bounds.size;
float x = size.width/2.0-187.0;
float y = size.height/2.0 - 125.0;
playerLayer.frame = CGRectMake(x, y, 374, 250);
[self.layer insertSublayer:playerLayer atIndex:0];
[player play]
How can i present a video over the layer?FYI, the video is played because i can hear the sound.
Thanks..