ios - 使用GVRSDK创建IOSurface图像(纹理)失败

Question

我用 SKVideoNode 创建了一个 SKScene，然后应用到一个球体几何体。

关键代码如下:

// Create a SKScene to play video
NSString* filePath = [[NSBundle mainBundle] pathForResource:@"2222" ofType:@"mp4"];
NSURL* sourceMovieURL = [NSURL fileURLWithPath:filePath];
AVPlayer* player = [AVPlayer playerWithURL:sourceMovieURL];
SKVideoNode* videoNode = [SKVideoNode videoNodeWithAVPlayer:player];

//CGSize size = CGSizeMake(512, 512);
CGSize size = [UIScreen mainScreen].bounds.size;
videoNode.size = size;
videoNode.position = CGPointMake(size.width/2.0, size.height/2.0);
SKScene* spriteScene = [SKScene sceneWithSize:size];
[spriteScene addChild:videoNode];


// create a material with SKScene
SCNMaterial* material = [SCNMaterial material];
material.doubleSided = true;
material.diffuse.contents = spriteScene;


[sphereNode.geometry replaceMaterialAtIndex:0 withMaterial:material];

[videoNode play];

[_scnScene.rootNode addChildNode:sphereNode];

// create SCNRenderer to render the scene
_renderer = [SCNRenderer rendererWithContext:cardboardView.context options:nil];
_renderer.scene = _scnScene;
_renderer.pointOfView = _scnCameraNode;

在drawEye函数中:

- (void)cardboardView:(GVRCardboardView *)cardboardView drawEye:(GVREye)eye withHeadTransform:(GVRHeadTransform *)headTransform
{
//CGRect viewport = [headTransform viewportForEye:eye];

// Get the head matrix.
const GLKMatrix4 head_from_start_matrix = [headTransform headPoseInStartSpace];

// Get this eye's matrices.
GLKMatrix4 projection_matrix = [headTransform projectionMatrixForEye:eye near:_scnCamera.zNear far:_scnCamera.zFar];


GLKMatrix4 eye_from_head_matrix = [headTransform eyeFromHeadMatrix:eye];

// Compute the model view projection matrix.
GLKMatrix4 view_projection_matrix = GLKMatrix4Multiply(
                                                       projection_matrix, GLKMatrix4Multiply(eye_from_head_matrix, head_from_start_matrix));
// Set the projection matrix to camera
[_scnCamera setProjectionTransform:SCNMatrix4FromGLKMatrix4(view_projection_matrix)];


// Render the scene
[_renderer renderAtTime:0];

}

当运行代码时，它会中断

[_renderer renderAtTime:0]

输出是:

Failed to create IOSurface image (texture)
Assertion failed: (result), function create_texture_from_IOSurface, file /BuildRoot/Library/Caches/com.apple.xbs/Sources/Jet/Jet-2.6.1/Jet/jet_context_OpenGL.mm, line 570.

当我从 SKScene 中删除 SKVideoNode 时，一切正常。

有什么帮助吗？谢谢。

Answer 1

更新:这适用于低质量视频，但高质量视频在复制这么多字节时表现不佳。我还没有尝试过，但我的下一个方法是使用带有 CVPixelBuffer 的 OpenGL 纹理以获得更好的性能。

-

我不知道您是否仍在寻找解决方案，但我已经幸运地在 iOS 9.3 6s 和 iOS 8 sim 上获得了一个使用 SceneKit/GVR 的视频球体。不过，我不能保证所有平台都适用!

我已经完全放弃了 SpriteKit，转而使用 CALayer，我将其内容设置为来自 CVPixelBuffer 的 CGImage。

视频代码:(最初基于this OpenGL 360 video tutorial)

init(url: NSURL)
{
    self.videoURL = url
    super.init()
    self.configureVideoPlayback()
}

private override init()
{
    self.videoURL = nil
    super.init()
}

deinit
{
    self.playerItem.removeOutput(self.videoOutput)
}

private func configureVideoPlayback()
{
    let pixelBufferAttributes = [
        kCVPixelBufferPixelFormatTypeKey as String : NSNumber(unsignedInt: kCVPixelFormatType_32ARGB),
        kCVPixelBufferCGImageCompatibilityKey as String: true,
        kCVPixelBufferOpenGLESCompatibilityKey as String: true
    ]
    self.videoOutput = AVPlayerItemVideoOutput(pixelBufferAttributes: pixelBufferAttributes)
    
    self.playerItem = AVPlayerItem(URL: self.videoURL)
    self.playerItem.addOutput(self.videoOutput)
    NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(VideoReader.playerItemDidPlayToEndTime(_:)), name: AVPlayerItemDidPlayToEndTimeNotification, object: self.playerItem)

    self.player = AVPlayer(playerItem: self.playerItem)
    self.player.play()
}   

func currentPixelBuffer() - > CVPixelBuffer ? {
    guard self.playerItem ? .status == .ReadyToPlay
    else {
        return nil
    }
    
    let currentTime = self.playerItem.currentTime()
    return self.videoOutput.copyPixelBufferForItemTime(currentTime, itemTimeForDisplay: nil)
}

func playerItemDidPlayToEndTime(notification: NSNotification)
{
    self.player.seekToTime(kCMTimeZero)
    self.player.play()
}

场景:

func setupScene() {
  self.scene = SCNScene()

  self.imageLayer = CALayer()
  self.imageLayer.frame = CGRectMake(0, 0, 2048, 2048) //Doesn't work if not power of 2 or incremenets inbetween - need to investigate

  let material = SCNMaterial()
  material.doubleSided = true
  material.diffuse.contents = self.imageLayer

  let geometry = SCNSphere(radius: 10)

  let sphere = SCNNode(geometry: geometry)
  sphere.geometry ? .replaceMaterialAtIndex(0, withMaterial: material)
  sphere.position = SCNVector3(0, 0, 0)
  sphere.scale.y = 1
  sphere.scale.z = -1

  self.scene!.rootNode.addChildNode(sphere)
}

纸板并条机准备:

func cardboardView(cardboardView: GVRCardboardView!, prepareDrawFrame headTransform: GVRHeadTransform!) {
  
  // .. boilerplate code

  if let pixelBuffer = self.videoReader.currentPixelBuffer() {
    CVPixelBufferLockBaseAddress(pixelBuffer, 0);

    let width = CVPixelBufferGetWidth(pixelBuffer)
    let height = CVPixelBufferGetHeight(pixelBuffer)
    let pixels = CVPixelBufferGetBaseAddress(pixelBuffer);

    let pixelWrapper = CGDataProviderCreateWithData(nil, pixels, CVPixelBufferGetDataSize(pixelBuffer), nil);

    // Get a color-space ref... can't this be done only once?
    let colorSpaceRef = CGColorSpaceCreateDeviceRGB();

    // Get a CGImage from the data (the CGImage is used in the drawLayer: delegate method above)

    let bitmapInfo = CGBitmapInfo(rawValue: CGImageAlphaInfo.NoneSkipFirst.rawValue)
    if let currentCGImage = CGImageCreate(width,
      height,
      8,
      32,
      4 * width,
      colorSpaceRef, [.ByteOrder32Big, bitmapInfo],
      pixelWrapper,
      nil,
      false,
      .RenderingIntentDefault) {
      self.imageLayer.contents = currentCGImage
    }

    // Clean up
    CVPixelBufferUnlockBaseAddress(pixelBuffer, 0);

  }
}

我最初对 GVR 和 SceneKit 的实现是基于这个 boilerplate

帧速率对我来说似乎仍然足够高 - 它尚未优化，但我会在优化时更新此答案。

注意:

• CALayer 边界似乎需要是 2 的幂 - 或者递增中间，当我寻找介于两者之间的值时，它不会显示任何视频就像 1960 年一样。
• 它在模拟器中运行速度非常慢，但在我的设备上运行速度为 60fps