avfoundationarkitcore-videocore-media

Create a CMSampleBuffer from a CVPixelBuffer

I get a CVPixelBuffer from ARSessionDelegate:

func session(_ session: ARSession, didUpdate frame: ARFrame) {
    frame.capturedImage // CVPixelBufferRef
}

But another part of my app (that I can't change) uses a CMSampleBuffer.

CMSampleBuffer is a container of CVPixelBuffer.

In order to create a CMSampleBuffer I can use this function:

func CMSampleBufferCreateReadyWithImageBuffer(_ allocator: CFAllocator?, 
                                            _ imageBuffer: CVImageBuffer, 
                                            _ formatDescription: CMVideoFormatDescription, 
                                            _ sampleTiming: UnsafePointer<CMSampleTimingInfo>, 
                                            _ sBufOut: UnsafeMutablePointer<CMSampleBuffer?>) -> OSStatus

The only missing parameter for me is sampleTiming - how can I extract that from CVPixelBuffer?

Solution

  • The sampleTiming mainly contains the presentationTimeStamp, You can easy create it by following codes:

    let scale = CMTimeScale(NSEC_PER_SEC)
let pts = CMTime(value: CMTimeValue(frame.timestamp * Double(scale)),
                 timescale: scale)
var timingInfo = CMSampleTimingInfo(duration: kCMTimeInvalid,
                                    presentationTimeStamp: pts,
                                    decodeTimeStamp: kCMTimeInvalid)