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 It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation.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

The QueueSample method queues a sample.

Syntax

void QueueSample(
   IMediaSample *pSample
);

Parameters

pSample: Pointer to the sample's IMediaSample interface.

Return value

This method does not return a value.

Remarks

This method adds a sample to the tail of the queue. Hold the critical section before calling this method, and call it only when the object is using a thread to deliver samples. To determine if the object is using a thread, call the COutputQueue::IsQueued method.

This method can also be used to put control messages onto the queue. A control message is a defined constant (cast to a LONG_PTR type) that instructs the thread to perform some action. The COutputQueue class defines the control messages shown in the following table.

Label	Value
Message	Action
EOS_PACKET	Deliver an end-of-stream notification.
NEW_SEGMENT	Deliver a new segment.
RESET_PACKET	Reset the state of the queue.
SEND_PACKET	Send a partial batch of samples.

This is a protected method, which the COutputQueue class uses internally.

Requirements

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