如何快速將CMSampleBuffer轉換為CMAttachmentBearer

Question

我是新手，我想在(void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection委托中調用函數CMCopyDictionaryOfAttachments

我的代碼：

// MARK: Delegates

func captureOutput(captureOutput: AVCaptureOutput!, didOutputSampleBuffer sampleBuffer: CMSampleBuffer!, fromConnection connection: AVCaptureConnection!) {
    // got an image
    let pixelBuffer : CVPixelBufferRef = CMSampleBufferGetImageBuffer(sampleBuffer)
    let attachments : CFDictionaryRef = CMCopyDictionaryOfAttachments(kCFAllocatorDefault, sampleBuffer, CMAttachmentMode( kCMAttachmentMode_ShouldPropagate)) as CFDictionaryRef!

}

這是xcode的錯誤： 'CMSampleBuffer' is not identical to 'CMAttachmentBearer'所以我如何使用sampleBuffer作為目標，如果用Objective-C編寫，此代碼就可以工作

Answer 1

我猜代碼中的主要問題是您傳遞了CMSampleBuffer而不是CVPixelBufferRef 。

接下來的問題是CMCopyDictionaryOfAttachments返回一個非托管實例，需要使用takeRetainedValue()對其進行轉換。

func captureOutput(captureOutput: AVCaptureOutput!, didOutputSampleBuffer sampleBuffer: CMSampleBuffer!, fromConnection connection: AVCaptureConnection!) {
    // got an image
    let pixelBuffer : CVPixelBufferRef = CMSampleBufferGetImageBuffer(sampleBuffer)
    let attachments : [NSObject : AnyObject] = CMCopyDictionaryOfAttachments(kCFAllocatorDefault, pixelBuffer, CMAttachmentMode( kCMAttachmentMode_ShouldPropagate)).takeRetainedValue()

}