CBasePin.TryMediaTypes method

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 It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation.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.]

Given a list of media types, the TryMediaTypes method tries to complete a connection using one of those types.

Syntax

virtual HRESULT TryMediaTypes(
         IPin            *pReceivePin,
   const CMediaType      *pmt,
         IEnumMediaTypes *pEnum
);

Parameters

pReceivePin: Pointer to the receiving pin's IPin interface.
pmt: Pointer to a CMediaType object that limits the possible media types, or NULL.
pEnum: Pointer to an IEnumMediaTypes interface, used to enumerate the list of media types.

Return value

Returns an HRESULT value. Possible values include those in the following table.

Return code	Description
S_OK	Success.
VFW_E_NO_ACCEPTABLE_TYPES	Did not find an acceptable media type.

Remarks

For each media type returned by the IEnumMediaTypes interface, this method attempts a connection by calling the CBasePin::AttemptConnection method.

If the pmt parameter is non-NULL, the pin skips media types that do not match this type. The pmt parameter can specify a partial media type. A partial media type has a value of GUID_NULL for either the major type, the subtype, or the format. The GUID_NULL value matches any type, similar to a "wildcard" value.

Requirements

Requirement	Value
Header	Amfilter.h (include Streams.h)
Library	Strmbase.lib (retail builds); Strmbasd.lib (debug builds)