IAMExtTransport interface (strmif.h)
[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 It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation.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 IAMExtTransport interface controls the transport on a video tape recporder (VTR) or camcorder. Applications can use this interface to play, record, or stop the transport; determine whether the transport contains media; and other transport-related functions. The implementation of this interface can vary, depending on the device. Some methods might return E_NOTIMPL if the device does not support them.
This interface also contains methods for non-linear editing through edit events and edit property sets. Currently, DirectShow does not provide any filters or drivers that implement this part of the interface.
Inheritance
The IAMExtTransport interface inherits from the IUnknown interface. IAMExtTransport also has these types of members:
Methods
The IAMExtTransport interface has these methods.
| IAMExtTransport::get_AntiClogControl The get_AntiClogControl method determines whether the anti-headclog control is enabled or disabled. |
| IAMExtTransport::get_EditStart The get_EditStart method determines whether the external transport's edit control is active. |
| IAMExtTransport::get_LocalControl The get_LocalControl method determines whether the transport is under local control or remote control. |
| IAMExtTransport::get_MediaState The get_MediaState method retrieves the current state of the media. |
| IAMExtTransport::get_Mode The get_Mode method retrieves the current transport mode, such as play, stop, or record. |
| IAMExtTransport::get_Rate The get_Rate method retrieves the playback rate for variable-speed external devices. |
| IAMExtTransport::GetBump The GetBump method retrieves the status of bump mode. |
| IAMExtTransport::GetCapability The GetCapability method retrieves the general capabilities of the transport. |
| IAMExtTransport::GetChase The GetChase method retrieves the status of chase mode. |
| IAMExtTransport::GetEditProperty The GetEditProperty method retrieves parameters and values associated with an edit event. |
| IAMExtTransport::GetEditPropertySet The GetEditPropertySet method retrieves the state of an edit event. |
| IAMExtTransport::GetStatus The GetStatus method returns information about the transport's status. |
| IAMExtTransport::GetTransportAudioParameters The GetTransportAudioParameters method retrieves audio parameter setting for external transport. |
| IAMExtTransport::GetTransportBasicParameters The GetTransportBasicParameters method retrieves general properties of the external transport. |
| IAMExtTransport::GetTransportVideoParameters The GetTransportVideoParameters retrieves video parameter settings for external transport. |
| IAMExtTransport::put_AntiClogControl The put_AntiClogControl method enables or disables anti-headclog control on the transport. |
| IAMExtTransport::put_EditStart The put_EditStart method activates the edit control on a capable transport. |
| IAMExtTransport::put_LocalControl The put_LocalControl method switches the device between local and remote control. |
| IAMExtTransport::put_MediaState The put_MediaState method sets the current state of the media. |
| IAMExtTransport::put_Mode The put_Mode method sets the transport mode; for example, play, stop, or record. |
| IAMExtTransport::put_Rate The put_Rate method sets the playback rate for variable-speed external devices. |
| IAMExtTransport::SetBump The SetBump method temporarily changes the playback, for synchronization of multiple external devices. |
| IAMExtTransport::SetChase The SetChase method enables or disables chase mode. |
| IAMExtTransport::SetEditProperty The SetEditProperty method defines parameters and values associated with an edit event. |
| IAMExtTransport::SetEditPropertySet The SetEditPropertySet method registers an edit property set that describes a group of edit properties. |
| IAMExtTransport::SetTransportAudioParameters The SetTransportAudioParameters assigns audio parameter settings for external transport. |
| IAMExtTransport::SetTransportBasicParameters The SetTransportBasicParameters method sets general properties of the transport. |
| IAMExtTransport::SetTransportVideoParameters The SetTransportVideoParameters method assigns video parameters for external transport. |
Remarks
The DV device drivers require some additional constants that are defined in the header file Xprtdefs.h.
For Windows Driver Model (WDM) devices, the WDM Video Capture Filter automatically exposes this interface if the WDM driver supports the PROPSETID_EXT_TRANSPORT property set. For more information, see the Windows Driver Kit (WDK) documentation.
Hardware Requirements
To control an external VCR, certain hardware requirements are recommended. VCRs with an RS-422 serial interface require a special serial port card or an external RS-232-to-RS-422 adapter. In addition, for best performance, your computer should have a serial port card built with a 16550 high-performance UART to sustain higher baud rates, such as 38.4 baud.Filter Developers
Implement this interface if you are writing a filter that controls an external device with a transport, such as a VTR. If you implement this interface, you should implement the IAMExtDevice interface as well.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) |