Export (0) Print
Expand All

Get and Set the Selected Device for a Media Type

This content is no longer actively maintained. It is provided as is, for anyone who may still be using these technologies, with no warranties or claims of accuracy with regard to the most recent product version or service release.

For local machines configured with more than one media device that can provide needed functionality for a given category, media type, and direction, the API provides a method to discover which media device is currently selected for the task. Likewise, you can select one of those devices for that task. Selecting a device is analogous to making the device the default device for the category, type, and direction.

Getting the media device configured for audio or video I/O involves calling the GetSelectedDevice method. The three arguments for this method are required and should be filled using enumerations created for the purpose. To set a selected media device, call SetSelectedDevice.

Bb804244.note(en-us,office.12).gifNote:
Integer values cannot be substituted for the enumerations specified as arguments to these methods.

The method arguments specify the role that a media device plays in a conference session:

  • Device Category
    The device category describes the public nature of the device. For example, a telephone handset has a speaker that can only be heard by the handset user. Likewise, the microphone in the handset typically picks up only the users voice. The telephone handset is then considered a private audio media device. To set or get a handset device, use UCC_AUDIO_VIDEO_DEVICE_CATEGORY.UCCAVDC_AUDIO_VIDEO_CALL_DEVICE for this argument.
    If a webcam device incorporates a microphone that picks up environmental sound in addition to the speakers voice, the webcam device is considered a non-private audio device. Use UCC_AUDIO_VIDEO_DEVICE_CATEGORY.UCCAVDC_AUDIO_VIDEO_CALL_NONPRIVATE_DEVICE to set the device as the selected media device. If you are getting or setting a video device, you can only specify the media direction UCC_MEDIA_DIRECTIONS.UCCMD_SEND. It is assumed that any video received as part of a conference session is displayed on the workstation console.
    Two additional category types are UCCAVDC_NOTIFICATION_DEVICE and UCCAVDC_NONE. The notification device is that audio speaker that is capable of rendering a notification sound. For this reason, you can only use the media direction: UCC_MEDIA_DIRECTIONS.UCCMD_SEND. If a media device is installed on a local workstation that is not to be used by a Unified Communications Client API enabled application, the enumeration UCCAVDC_NONE should be used.
  • Media Type
    The media type argument refers to the type of information the device renders or captures. A camera is capable of video while a microphone is capable of audio. To configure a webcam for video capture, use UCC_MEDIA_TYPES.UCCMT_VIDEO. The microphone component of the device is configured separately. Use UCC_MEDIA_TYPES.UCCMT_AUDIO for this purpose.
  • Media Direction
    Media direction refers to the ability of a media device to capture or render information. For example, a microphone is capable of capturing information while a speaker can render it. To select or get a microphone device, use UCC_MEDIA_DIRECTIONS.UCCMD_SEND. To select a speaker, use UCC_MEDIA_DIRECTIONS.UCCMD_RECEIVE.

Examples

The following example illustrates getting an IUccMediaDevice interface based on the arguments described previously.

IUccMediaDevice sendPublicAudioDevice = dm.GetSelectedDevice(
                                       UCC_AUDIO_VIDEO_DEVICE_CATEGORY.UCCAVDC_AUDIO_VIDEO_CALL_NONPRIVATE_DEVICE,
                                       UCC_MEDIA_TYPES.UCCMT_AUDIO,
                                       UCC_MEDIA_DIRECTIONS.UCCMD_SEND);

To set a selected media device, call SetSelectedDevice. The following example demonstrates setting the non-private video capture device where d is an object implementing the IUccMediaDevice interface and dm is an object implementing the IUccMediaDeviceManager interface.

dm.SetSelectedDevice(
     UCC_AUDIO_VIDEO_DEVICE_CATEGORY.UCCAVDC_AUDIO_VIDEO_CALL_NONPRIVATE_DEVICE,
     UCC_MEDIA_TYPES.UCCMT_VIDEO,
     UCC_MEDIA_DIRECTIONS.UCCMD_SEND,
     d);

Community Additions

ADD
Show:
© 2014 Microsoft