IltmmCaptureInputs Interface

Sets and retrieves properties on ltmmCaptureInputs objects. This interface is obtained through the parent object's get_VideoInputs member function.

Some video capture devices, like TV Tuners, have audio inputs also. For these devices, the IltmmCaptureInputs interface controls both video and audio input selection. When a video device is selected, a matching list, which contains a video input and its matching audio input, is built, and held internally. For those video devices that do not have audio inputs coupled with video inputs, there is no need to be concerned about matching video and audio inputs.

For more control over video and audio inputs, see the IAMCrossbar Interface .

To gain access to the video cross bar object, call IltmmCapture::GetSubObject with ltmmCapture_Object_VideoCrossbar set for the ObjType parameter. The video cross bar property page can also be used to change the video and audio inputs.To display the property page, call IltmmCapture::ShowDialog with either ltmmCapture_Dlg_VideoCrossbar or ltmmCapture_Dlg_Capture set in the Dialog parameter.

Changing the video and audio inputs using the cross bar property page may create an unmatched Video-Audio inputs pair. For example, if the video is set to come in from the 'TV Tuner', and the audio from the 'Audio Line-In', the video will not match the audio. This is a non-matching pair. To make sure the correct pair of inputs are matched after setting the property page, call IltmmCaptureInputs::get_NearestSelection to retrieve the closest valid pair of video and audio inputs. Then, pass the index obtained from the get_NearestSelection function to the IltmmCaptureInputs::put_Selection function to fix the potential problem. To determine whether the audio and video inputs match after using the cross bar property page, retrieve the current selection using IltmmCaptureInputs::get_Selection. The index obtained using this function will be -1 (provided get_Count returns non-zero) if the selected pair  is not matching.

However, if a video input is selected programmatically using IltmmCaptureInputs::put_Selection, there should be no problem with a non-matching pair of video and audio inputs; the right audio input will be selected automatically.

In addition to the methods inherited from IDispatch, the IltmmCaptureInputs Interface exposes the following functions:

Functions

IltmmCaptureInputs::Find

IltmmCaptureInputs::get_Count

IltmmCaptureInputs::get_NearestSelection

IltmmCaptureInputs::get_Selection

IltmmCaptureInputs::Item

IltmmCaptureInputs::put_Selection

Platforms

Win32, x64

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