2.5.53 IDeckLinkVideoBuffer Interface

The IDeckLinkVideoBuffer interface represents a video frame buffer.

Note

macOS sandboxed apps communicate via XPC and require special handling of buffer memory. If this interface is caller-implemented, to enable sandboxing IDeckLinkMacVideoBuffer should be implemented too.

Note

The final release of this interface should resolve all outstanding calls to EndAccess.

Related Interfaces

Interface

Interface ID

Description

IDeckLinkVideoBufferAllocator

IID_IDeckLinkVideoBufferAllocator

IDeckLinkVideoBufferAllocator::AllocateVideoBuffer() outputs an IDeckLinkVideoBuffer object interface

IDeckLinkOutput

IID_IDeckLinkOutput

An IDeckLinkVideoBuffer object interface is added to the newly created video frame with IDeckLinkOutput::CreateVideoFrameWithBuffer()

IDeckLinkVideoFrame

IID_IDeckLinkVideoFrame

An IDeckLinkVideoBuffer object interface may be obtained from IDeckLinkVideoFrame using QueryInterface

IDeckLinkVideoConversion

IID_IDeckLinkVideoConversion

An IDeckLinkVideoBuffer object interface is an optional destination video buffer for IDeckLinkVideoConversion::ConvertNewFrame()

2.5.53.1 IDeckLinkVideoBuffer::GetBytes method

HRESULT IDeckLinkVideoBuffer::GetBytes(void **buffer);

The GetBytes method allows a CPU to directly access to the image data buffer of a video frame.

Parameters:

buffer – Pointer to raw frame buffer - only valid while object remains valid.

Return values:

  • E_ACCESSDENIED – StartAccess must be used first

  • E_FAIL – Failure

  • S_OK – Success

2.5.53.2 IDeckLinkVideoBuffer::StartAccess method

HRESULT IDeckLinkVideoBuffer::StartAccess(BMDBufferAccessFlags flags);

If not already, prepare the buffer to be directly accessible by a CPU-bound program that calls GetBytes.

The number of calls to this function and flagged intent of access should match the number of times EndAccess has been called with the same access flags.

Tip

BMDBufferAccessFlags signals intent of use of the buffer access. Implementers of this class can use it to make access more efficient or secure.

Parameters:

flags – Buffer access flags

Return values:

  • E_FAIL – Failure

  • S_OK – Success

2.5.53.3 IDeckLinkVideoBuffer::EndAccess method

HRESULT IDeckLinkVideoBuffer::EndAccess(BMDBufferAccessFlags flags);

Releases access to the buffer.

The number of calls to this function and flagged intent of access should match the number of times StartAccess has been called with the same access flags.

Parameters:

flags – Form of access that is no longer required

Return values:

  • E_INVALIDARG – StartAccess has not been called prior with the same access flags

  • E_FAIL – Failure

  • S_OK – Success