ltmmCaptureInputs Object
The ltmmCaptureInputs Object contains a collection of the capture device inputs. The ltmmCaptureCtrl object uses the collection to enumerate and select audio and video capture inputs. An ltmmCaptureInputs object is not externally creatable and is only obtained through the parent object�s VideoInputs property.
Some video capture devices, like TV Tuners, have audio inputs also. For these devices, the IltmmCaptureInputs object 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 don�t 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 ltmmCaptureCtrl.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 IltmmCaptureCtrl.ShowDialog method 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, retrieve the closest valid pair of video and audio inputs from the ltmmCaptureInputs.NearestSelection property. Then, set the ltmmCaptureInputs.Selection property to the index obtained from the NearestSelection property 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 from the ltmmCaptureInputs.Selection. The index obtained will be -1 (provided the Count property is non-zero) if the selected pair is not matching.
However, if a video input is selected programmatically by setting the ltmmCaptureInputs.Selection property, there should be no problem with a non-matching pair of video and audio inputs; the right audio input will be selected automatically.
The ltmmCaptureInputs Object contains the following properties and methods:
Properties
ltmmCaptureInputs.NearestSelection Property
Methods
Win32, x64
See Also