IPin::QueryAccept

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Microsoft DirectShow 9.0

IPin::QueryAccept

The QueryAccept method determines whether the pin accepts a specified media type.

Syntax

  HRESULT QueryAccept(
  const AM_MEDIA_TYPE *pmt
);

Parameters

pmt

[in] Pointer to an AM_MEDIA_TYPE structure that specifies the media type.

Return Value

Returns one of the following values:

Value Description
S_FALSE The pin rejects the media type.
S_OK The pin accepts the media type.

Remarks

A return value of S_OK indicates that the pin will accept the media type, either on the next sample, or after a pin reconnection. The implementation should take into account the current state of the filter, including connections on other pins, and any properties that can be set on the filter.

Any other return value, including S_FALSE, means that the pin rejects the media type. Therefore, test for S_OK explicitly; do not use the SUCCEEDED macro.

If the filter is running, a return value of S_OK is ambiguous. The pin might accept a format change on the next media sample, without reconnecting; or it might need to reconnect. If the pin supports the IPinConnection interface, call the IPinConnection::DynamicQueryAccept method, which specifically tests whether the pin can accept the new type without reconnecting.

Requirements

Header: Declared in Strmif.h; include Dshow.h.

Library: Use Strmiids.lib.

See Also