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IAMTimecodeGenerator Interface

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Microsoft DirectShow 9.0

IAMTimecodeGenerator Interface

The IAMTimecodeGenerator interface controls how an external SMPTE/MIDI timecode generator supplies data to the filter graph.

DirectShow currently does not provide any filters that implement this interface. Third parties should implement this interface on any filter that controls an external timecode generator. Timecode generators can be built into a VCR or can be separate external devices. The device must be able to read timecode and send it to the computer over its control interface. If not, the user must have a timecode reader card in the computer, or you can write a software decoder that converts VITC embedded in captured video frames or LTC captured as an audio signal into DirectShow timecode samples.

SMPTE timecode is a frame addressing system that identifies video and audio sources, makes automatic track synchronization possible, and provides a container for additional data related to the production. SMPTE timecode's main purpose is to provide a machine-readable address for video and audio. It is displayed in hh:mm:ss:ff format and is thoroughly defined in ANSI/SMPTE 12-1986.

Optionally, you can enable applications to convert timecode to  reference time by supporting the IMediaSeeking::ConvertTimeFormat method on the filter.

Hardware Requirements

For hardware requirements, see the IAMExtTransport interface.

In addition to the methods inherited from IUnknown, the IAMTimecodeGenerator interface exposes the following methods.

Method Description
GetTCGMode Retrieves the SMPTE timecode generator properties.
SetTCGMode Sets the SMPTE timecode generator properties.
put_VITCLine Specifies which line(s) to insert the vertical interval timecode information into.
get_VITCLine Retrieves which line(s) the vertical interval timecode information has been inserted into.
SetTimecode Sets the timecode, userbit value, or both.
GetTimecode Retrieves the most recent timecode and/or userbit value available in the stream.

Requirements

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

Library: Use Strmiids.lib.

See Also