ios - 如何在 swift 中将 CMSampleBuffer 转换为 CMAttachmentBearer

Question

我是 swift 的新手，我想在 (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection 中调用函数 CMCopyDictionaryOfAttachments 委托(delegate)

我的代码:

// 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!

}

xcode 出现错误:'CMSampleBuffer' 与 'CMattachmentBearer' 不同 那么我如何使用sampleBuffer作为目标，如果用objective-c编写此代码就可以工作

Answer 1

我想您代码中的主要问题是您传递了 CMSampleBuffer 而不是 CVPixelBufferRef。

接下来的问题是 CMCopyDictionaryOfAttachments 返回一个非托管实例，需要使用 takeRetainedValue() 进行转换。

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()

}