如何将MTLTexture转换为CVpixelBuffer以写入AVAssetWriter？

// 创建CVPixelBuffer
var pixelBuffer: CVPixelBuffer?
let width = texture.width
let height = texture.height
let pixelFormat = kCVPixelFormatType_32BGRA
let attributes = [
    kCVPixelBufferMetalCompatibilityKey: true,
    kCVPixelBufferCGImageCompatibilityKey: true,
    kCVPixelBufferCGBitmapContextCompatibilityKey: true
] as CFDictionary
CVPixelBufferCreate(kCFAllocatorDefault, width, height, pixelFormat, attributes, &pixelBuffer)

// 锁定CVPixelBuffer的基地址
CVPixelBufferLockBaseAddress(pixelBuffer!, CVPixelBufferLockFlags(rawValue: 0))

// 从MTLTexture中读取图像数据
let bytesPerRow = texture.width * 4
let region = MTLRegionMake2D(0, 0, texture.width, texture.height)
texture.getBytes(pixelBuffer!.baseAddress!, bytesPerRow: bytesPerRow, from: region, mipmapLevel: 0)

// 解锁CVPixelBuffer的基地址
CVPixelBufferUnlockBaseAddress(pixelBuffer!, CVPixelBufferLockFlags(rawValue: 0))

// 现在可以将pixelBuffer传递给AVAssetWriter进行视频编码了