How to create instance of Sample Buffer (CMSampleBufferRef)?

Andrew Kachalin picture Andrew Kachalin · Jun 2, 2016 · Viewed 7.4k times · Source

I try to write ios camera, and I took some part of code from apple:

- (void)captureOutput:(AVCaptureOutput *)captureOutput
         didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
         fromConnection:(AVCaptureConnection *)connection
{
    // Create a UIImage from the sample buffer data
    UIImage *image = [self imageFromSampleBuffer:sampleBuffer];

     < Add your code here that uses the image >

}

I need to call this function, from anywhere in my program. But for it demands to create an object type of (CMSampleBufferRef). How to do it?

I tried to write something like:

buf1 = [[CMSampleBufferRef alloc]init] 

But it's wrong way.

Answer

Rotem Tamir picture Rotem Tamir · Aug 21, 2017

This is a snippet I'm currently using for mocking CMSampleBuffer for unit tests in swift3:

fileprivate func getCMSampleBuffer() -> CMSampleBuffer {
    var pixelBuffer : CVPixelBuffer? = nil
    CVPixelBufferCreate(kCFAllocatorDefault, 100, 100, kCVPixelFormatType_32BGRA, nil, &pixelBuffer)

    var info = CMSampleTimingInfo()
    info.presentationTimeStamp = kCMTimeZero
    info.duration = kCMTimeInvalid
    info.decodeTimeStamp = kCMTimeInvalid


    var formatDesc: CMFormatDescription? = nil
    CMVideoFormatDescriptionCreateForImageBuffer(kCFAllocatorDefault, pixelBuffer!, &formatDesc)

    var sampleBuffer: CMSampleBuffer? = nil

    CMSampleBufferCreateReadyWithImageBuffer(kCFAllocatorDefault,
                                             pixelBuffer!,
                                             formatDesc!,
                                             &info,
                                             &sampleBuffer);

    return sampleBuffer!
}