IAMExtTransport::SetChase 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 It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation.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 SetChase method enables or disables chase mode.

This method is not implemented.

Syntax

HRESULT SetChase(
  [in] long   Enable,
  [in] long   Offset,
  [in] HEVENT hEvent
);

Parameters

[in] Enable

Specifies whether chase is enabled as a long integer.

Value	Description
OATRUE	Enable chase.
OAFALSE	Disable chase.

[in] Offset

Specifies the offset that the transport will maintain from a reference time. The offset is given in the current time format; see IAMExtTransport::SetTransportBasicParameters for more information.

[in] hEvent

Specifies a handle to an event. The device signals the event after it has established the signal offset.

Return value

When this method succeeds, it returns S_OK. Otherwise it returns an HRESULT error code.

Remarks

Use this method when you want an external transport to follow a timecode signal by a fixed offset. For example, if a VCR supports chasing, it can switch to play mode and keep the tape at a fixed offset from a reference timecode.

Chase mode remains in effect until it completes or is canceled. The filter must verify that the transport is maintaining the fixed offset, by periodically reading the transport's timecode.

DV Implementation

MSDV does not support this method. It returns E_NOTIMPL.

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