2.5.55 IDeckLinkVideoBufferAllocator Interface

The IDeckLinkVideoBufferAllocator interface is requested by the DeckLinkAPI via IDeckLinkVideoBufferAllocatorProvider::GetVideoBufferAllocator(). During capture, calls will be made to this interface to manage memory for storing video buffers of the same parameters provided by IDeckLinkVideoBufferAllocatorProvider::GetVideoBufferAllocator(). When the DeckLinkAPI no longer wants these buffers, it will release this interface, so it is suggested that all allocated buffers also AddRef on this allocator until all buffer retainers have released them.

Related Interfaces

Interface

Interface ID

Description

IDeckLinkVideoBuffer

IID_IDeckLinkVideoBuffer

IDeckLinkVideoBufferAllocator::AllocateVideoBuffer() outputs an IDeckLinkVideoBuffer object interface

IDeckLinkVideoBufferAllocatorProvider

IID_IDeckLinkVideoBufferAllocatorProvider

IDeckLinkVideoBufferAllocatorProvider::GetVideoBufferAllocator() outputs an IDeckLinkVideoBufferAllocator object interface

2.5.55.1 IDeckLinkVideoBufferAllocator::AllocateVideoBuffer method

HRESULT IDeckLinkVideoBufferAllocator::AllocateVideoBuffer(IDeckLinkVideoBuffer **allocatedBuffer);

The AllocateVideoBuffer method allocates an IDeckLinkVideoBuffer for internal use by a video frame. This method is abstract in the base interface and must be implemented by the application developer if using IDeckLinkInput::EnableVideoInputWithAllocatorProvider().

Note

The internal address, available via IDeckLinkVideoBuffer::GetBytes() must be aligned on a 16-byte boundary.

Note

These buffers become internal to a video frame and thus a QueryInterface on the frame for an IDeckLinkVideoBuffer will return an interface that is not the same as provided by AllocateVideoBuffer. If the developer wishes to access their custom implementation of a particular IDeckLinkVideoBuffer then it is suggested that the QueryInterface function on a buffer provided by this AllocateVideoBuffer supports a custom IID.

Parameters:

allocatedBuffer – Address of newly allocated IDeckLinkVideoBufferbuffer provided by the implementation of the allocator

Return values:

  • E_OUTOFMEMORY – There is insufficient memory to allocate a buffer.

  • S_OK – Success