Contents

VTCompressionSessionBeginPass(_:flags:_:)

Marks the start of a specific compression pass.

Declaration

func VTCompressionSessionBeginPass(_ session: VTCompressionSession, flags beginPassFlags: VTCompressionSessionOptionFlags, _ reserved: UnsafeMutablePointer<UInt32>?) -> OSStatus

Parameters

  • session:

    A compression session.

  • beginPassFlags:

    Pass Beginfinalpass to inform the encoder that the pass must be the final pass.

  • reserved:

    A reserved value.

Discussion

During multipass encoding, this function must be called before VTCompressionSessionEncodeFrame(_:imageBuffer:presentationTimeStamp:duration:frameProperties:sourceFrameRefcon:infoFlagsOut:).

It’s an error to call this function when multipass encoding is not enabled by setting kVTCompressionPropertyKey_MultiPassStorage.

Topics

Option Flags

See Also

Performing Multiple Passes