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CMSampleBufferCreateReadyWithImageBuffer(allocator:imageBuffer:formatDescription:sampleTiming:sampleBufferOut:)

Creates a sample buffer with image data.

Declaration

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

Parameters

  • allocator:

    The allocator to use for allocating the CMSampleBuffer object. Pass kCFAllocatorDefault to use the default allocator.

  • imageBuffer:

    CVImageBuffer already containing the media data. Must not be NULL.

  • formatDescription:

    A description of the media data’s format. See discussion below for constraints. May not be NULL.

  • sampleTiming:

    A CMSampleTimingInfo struct that provides the timing information for the media represented by the CVImageBuffer.

  • sampleBufferOut:

    Returned newly created CMSampleBuffer.

Discussion

Unlike a CMBlockBuffer, which can reference many samples, a CVImageBuffer is defined to reference only one sample; therefore this routine has fewer parameters than CMSampleBufferCreate.

Sample timing information, which is a vector for CMSampleBufferCreate, consists of only one value for this routine.

The concept of sample size doesn’t apply to CVImageBuffers. As such, CMSampleBufferGetSampleSizeArray returns kCMSampleBufferError_BufferHasNoSampleSizes, and CMSampleBufferGetSampleSize returns 0.

Because CVImageBuffers hold visual data, the format description provided is a CMVideoFormatDescription. The format description must be consistent with the attributes and formatting information attached to the CVImageBuffer. The width, height, and codecType must match (for CVPixelBuffers the codec type is given by CVPixelBufferGetPixelFormatType(pixelBuffer); for other CVImageBuffers, the codecType must be 0). The format description extensions must match the image buffer attachments for all the keys in the list returned by CMVideoFormatDescriptionGetExtensionKeysCommonWithImageBuffers (if absent in either they must be absent in both).

CMSampleBufferCreateReadyWithImageBuffer is identical to CMSampleBufferCreateForImageBuffer except that dataReady is always true, and so no makeDataReadyCallback or refcon needs to be passed.

See Also

Creating Sample Buffers