当尝试调试为什么某些CoreImage渲染显着增加了CPU使用率时，我可以在示例跟踪中看到，当我以某些方式裁剪和合成图像时，CoreImage正在执行memcpys。当我取出作物过滤器时，它消失了。我正在将其用于实时2D视频管道，所以这不好。
我所有的图像都在GPU上，所以我对其在CPU上复制的内容感到困惑。
任何人都知道这可能在做什么吗？
+ ! 457 -[CIContext render:toCVPixelBuffer:bounds:colorSpace:] (in CoreImage) + 1296 [0x7fff8db01111]
+ ! 457 -[CIContext render:toIOSurface:bounds:colorSpace:] (in CoreImage) + 1907 [0x7fff8db030e5]
+ ! 455 CI::image_render_to_surface(CI::Context*, CI::Image*, CGRect, CGColorSpace*, __IOSurface*, CGPoint, CI::PixelFormat) (in CoreImage) + 1862 [0x7fff8db1d8a9]
+ ! : 451 CI::_image_render(char const*, CI::Context*, CI::Image*, CGRect, CGColorSpace*, CI::PixelFormat, unsigned long, CGPoint const&, CI::swizzle_info const&) (in CoreImage) + 869 [0x7fff8db1cdda]
+ ! : | 443 CI::tile_node_graph(CI::Context*, char const*, CI::Node*, CGRect const&, CI::PixelFormat, CI::swizzle_info const&, void (CI::Node*, CGRect) block_pointer) (in CoreImage) + 834 [0x7fff8db1ffe1]
+ ! : | + 416 ___ZN2CIL13_image_renderEPKcPNS_7ContextEPNS_5ImageE6CGRectP12CGColorSpaceNS_11PixelFormatEmRK7CGPointRKNS_12swizzle_infoE_block_invoke (in CoreImage) + 22 [0x7fff8db22d54]
+ ! : | + ! 416 CI::Context::render(CI::Node*, CGRect const&) (in CoreImage) + 75 [0x7fff8db0efb1]
+ ! : | + ! 413 CI::Context::recursive_render(CI::Node*, CGRect const&, CI::Node*) (in CoreImage) + 1285 [0x7fff8db0ee95]
+ ! : | + ! : 277 CI::MetalContext::render_root_node(CI::ProgramNode*, CGRect const&, void () block_pointer) (in CoreImage) + 105 [0x7fff8dc09549]
+ ! : | + ! : | 273 CI::MetalContext::render_node(CI::ProgramNode*, CGRect const&, void const**, unsigned long, bool) (in CoreImage) + 765 [0x7fff8dc08ddb]
+ ! : | + ! : | + 269 CI::MetalContext::bind_arguments(CI::ProgramNode const*, CGRect const&, CGRect const&) (in CoreImage) + 532 [0x7fff8dc0906a]
+ ! : | + ! : | + ! 252 CI::Context::bind_sampler(CI::TextureSampler const*, CGRect const&, int, CI::KernelArgumentType) (in CoreImage) + 992 [0x7fff8db0f3a6]
+ ! : | + ! : | + ! : 232 CI::SurfaceNode::surfaceForROI(CI::Context const*, CGRect) const (in CoreImage) + 718 [0x7fff8db71dc2]
+ ! : | + ! : | + ! : | 142 SurfaceApplyPlaneReadOnlyBlock (in CoreImage) + 170 [0x7fff8dbdcd39]
+ ! : | + ! : | + ! : | + 142 ___ZNK2CI11SurfaceNode13surfaceForROIEPKNS_7ContextE6CGRect_block_invoke (in CoreImage) + 123 [0x7fff8db71e5c]
+ ! : | + ! : | + ! : | + 139 SurfaceApplyPlaneBlock (in CoreImage) + 196 [0x7fff8dbdcbeb]
+ ! : | + ! : | + ! : | + ! 133 ___ZNK2CI11SurfaceNode13surfaceForROIEPKNS_7ContextE6CGRect_block_invoke_2 (in CoreImage) + 367 [0x7fff8db71fd1]
+ ! : | + ! : | + ! : | + ! : 133 _platform_memmove$VARIANT$Haswell (in libsystem_platform.dylib) + 324,224,... [0x7fffa2a63fe4,0x7fffa2a63f80,...]
更新：
这是包含作物的渲染管道。这与上面的memcpy一起使用了大量的CPU。所有来源均为IOSurfaces。它要拍摄两张图像并创建一个分屏：
<CIImage: 0x618000623e20 extent [infinite]>
colorkernel _sourceOver(src,dst) extent=[infinite]
crop [1280 0 1280 1440] extent=[1280 0 1280 1440]
affine [3.13725 0 0 3.13725 825.098 0] extent=[825.098 0 2189.8 1440]
affine [1 0 0 -1 0 459] extent=[0 0 698 459]
IOSurface 0x610000010300 BGRA8 extent=[0 0 698 459]
colorkernel _sourceOver(src,dst) extent=[infinite]
crop [0 0 1281 1440] extent=[0 0 1281 1440] opaque
affine [-2.00156 -0 0 2 1921.5 0] extent=[-640.5 0 2562 1440] opaque
affine [1 0 0 -1 0 720] extent=[0 0 1280 720] opaque
IOSurface 0x60000000b650 YCC420v 709 alpha_one extent=[0 0 1280 720] opaque
fill [0 0 0 1 "Generic Gray Profile"] extent=[infinite][0 0 1 1] opaque
-
如果我将农作物取出，这是不使用CPU且不会沿着surfaceForROI路径运行的管道：
<CIImage: 0x618000225040 extent [infinite]>
colorkernel _sourceOver(src,dst) extent=[infinite]
affine [3.13725 0 0 3.13725 825.098 0] extent=[825.098 0 2189.8 1440]
affine [1 0 0 -1 0 459] extent=[0 0 698 459]
IOSurface 0x6180000077c0 BGRA8 extent=[0 0 698 459]
colorkernel _sourceOver(src,dst) extent=[infinite]
affine [-2.00156 -0 0 2 1921.5 0] extent=[-640.5 0 2562 1440] opaque
affine [1 0 0 -1 0 720] extent=[0 0 1280 720] opaque
IOSurface 0x61000000c730 YCC420v 709 alpha_one extent=[0 0 1280 720] opaque
fill [0 0 0 1 "Generic Gray Profile"] extent=[infinite][0 0 1 1] opaque