使用GVRSDK创建IOSurface镜像(纹理)失败
使用GVRSDK创建IOSurface镜像(纹理)失败
提问于 2016-07-06 11:34:52
我用SKVideoNode创建了一个SKScene，然后应用到一个球体几何体上。
以下是关键代码：
// 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，它将中断为
[_renderer renderAtTime:0]输出结果为：
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。
回答 2
Stack Overflow用户
发布于 2016-07-15 23:25:04
更新：这适用于低质量的视频，但高质量的视频不能很好地复制这么多字节。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。
-
我不知道你是否还在寻找解决方案，但我有幸在6s和iOS 8SIM的iOS 9.3上找到了一个可以与SceneKit / GVR兼容的视频球。不过，我不能保证所有平台都适用！
我完全放弃了SpriteKit，转而使用一个CALayer，它的内容被我从CVPixelBuffer设置为CGImage。
视频编码：(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)
}
纸板拉丝框准备：
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);
}
}
我最初实现的GVR和SceneKit就是基于这个boilerplate的。
帧速率对我来说似乎仍然足够高-它还没有优化，但我会在更新时更新这个答案。
备注：
- CALayer的界限似乎需要是2的幂-或者在这两者之间递增，当我在1960年之间取值时，它不显示任何视频。
- 它在模拟器中运行非常慢，但在我的设备上以60fps运行
Stack Overflow用户
发布于 2016-09-19 11:02:45
我认为原因是软件开发工具包将SCNView的渲染接口设置为OpenGLES，只需将该接口设置为默认(金属)即可解决此问题。
检查是否有类似如下的代码：
[[SVNView alloc] initWithFrame:CGRect() options:@{SCNPreferredRenderingAPIKey: [NSNumber numberWithInt:SCNRenderingAPIOpenGLES2]}]将其更改为：
[[SVNView alloc] initWithFrame:CGRect() options:nil] or [[SVNView alloc] initWithFrame:CGRect()]页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/38215970
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