IMemInputPin::NotifyAllocator method (strmif.h)

Article
07/27/2023

[The feature associated with this page, DirectShow, is a legacy feature. It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation. Those features have been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use MediaPlayer, IMFMediaEngine and Audio/Video Capture in Media Foundation instead of DirectShow, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]

The NotifyAllocator method specifies an allocator for the connection.

Syntax

HRESULT NotifyAllocator(
  [in]  IMemAllocator *pAllocator,
  [out] BOOL          bReadOnly
);

Parameters

[in] pAllocator

Pointer to the allocator's IMemAllocator interface.

[out] bReadOnly

Flag that specifies whether samples from this allocator are read-only. If TRUE, samples are read-only.

Return value

Returns S_OK if successful, or an HRESULT value indicating the cause of the error.

Remarks

During the pin connection, the output pin chooses an allocator and calls this method to notify the input pin. The output pin might use the allocator that the input pin proposed in the IMemInputPin::GetAllocator method, or it might provide its own allocator.

If the bReadOnly parameter is TRUE, all samples in the allocator are read-only. The filter must copy them to modify the data.

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Target Platform	Windows
Header	strmif.h (include Dshow.h)
Library	Strmiids.lib