yuanfuc / metalresizepixelbuffer

Use MetalKit and MetalPerformanceShaders to resize CVPixelBuffer

PerformancePixelBufferResize

This project is an example: How to Use Metal to resize CVPixelBuffer on the GPU.

Resize detail steps:

• Create MTLTexture from CVPixelBuffer

• MPSImageBilinearScale shaders scale texture for scaleToFill\scaleAspectFit\ scaleAspectFill mode

• Copy MTLTexture to MTLBuffer

• Create CVPixelBuffer from MTLBuffer

metalresizepixelbuffer's Issues

Crash when resizing scaleX=2, scaleY=1 in scaleToFill mode

let oneEyeWidth: CGFloat = 1920
let oneEyeHeight: CGFloat = 2160
let resizedBuffer = filter.resizeFrame(sourcePixelFrame: pixelBuffer,
                                   targetSize: MTLSize.init(width: oneEyeWidth*2, height: oneEyeHeight, depth: 0),
                                   resizeMode: .scaleToFill) {

The original pixelBuffer size is (1920, 2160) and I want to stretch it into (3840, 2160).
And it crashed with error:

-[MTLDebugBlitCommandEncoder validateCopyFromTexture:sourceSlice:sourceLevel:sourceOrigin:sourceSize:toBuffer
:destinationOffset:destinationBytesPerRow:destinationBytesPerImage:options:]
:1015: failed assertion `Copy From Buffer Validation
destinationBytesPerRow(7680) must be >= (15360).
totalBytesUsed(16596480) must be <= [destinationBuffer length](16588800).

Crash Using in Broadcast Extension

When I use the resizer in the Broadcast Upload Extension to compress the Samples Buffers I receive from ReplayKit, the extension crashes because of the Thread 6: EXC_BAD_ACCESS (code=1, address=0x0)

Any idea how to fix it?