设置CMSampleBuffer样本附件（Swift）

Question

我试图为kCMSampleAttachmentKey_DisplayImmediately中的每个样本设置CMSampleBuffer。

到目前为止，我已尝试获取字典（Dictionary<NSObject, AnyObject>，NSDictionary，CFDictionary），并在CMSetAttachment及其附件上调用CMSampleBuffer

要检索附件，请使用CMSampleBufferGetSampleAttachmentsArray。

任何想法如何在Swift中设置这些标志？

Answer 1

这里的解决方案（可能远非完美）适用于Swift 4（应该与3一起工作）。

func setSampleBufferAttachments(_ sampleBuffer: CMSampleBuffer) {
    let attachments: CFArray! = CMSampleBufferGetSampleAttachmentsArray(sampleBuffer, true)
    let dictionary = unsafeBitCast(CFArrayGetValueAtIndex(attachments, 0),
        to: CFMutableDictionary.self)
    let key = Unmanaged.passUnretained(kCMSampleAttachmentKey_DisplayImmediately).toOpaque()
    let value = Unmanaged.passUnretained(kCFBooleanTrue).toOpaque()
    CFDictionarySetValue(dictionary, key, value)
}