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Windows Media Player 11 SDK Windows Media Device Manager Device Extensions for Metadata Transfer 

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Windows Media Device Manager Device Extensions for Metadata Transfer

To enable accelerated metadata transfer, manufacturers of devices that do not support MTP must do the following in source code:

  • Define WMP_WMDM_DEVICE_SUPPORT.
  • Include wmpdevices.h, which is installed as part of the Windows Media Player SDK.

Wmpdevices.h defines the following structures.

Structure Description
WMP_WMDM_METADATA_ROUND_TRIP_PC2DEVICE Structure used by Windows Media Player to request accelerated metadata synchronization information from portable devices that do not support MTP.
WMP_WMDM_METADATA_ROUND_TRIP_DEVICE2PC Structure used by Windows Media Player to receive accelerated metadata synchronization information from portable devices that do not support MTP.

To request information from the device about metadata that has changed, Windows Media Player 10 or later calls the Windows Media Device Manager method IWMDMDevice3::DeviceIoControl. When making this call, the Player follows specific steps, as follows:

  • The first parameter, dwIoControlCode, contains the constant IOCTL_WMP_METADATA_ROUND_TRIP. This constant is defined in wmpdevices.h.
  • The second parameter, lpInBuffer, points to a WMP_WMDM_METADATA_ROUND_TRIP_PC2DEVICE structure.
  • The third parameter, nInBufferSize, contains the size of the input buffer.
  • The fourth parameter, lpOutBuffer, points to a WMP_WMDM_METADATA_ROUND_TRIP_DEVICE2PC structure. The device must fill in this structure with information about changes.
  • The fifth parameter, pnOutBufferSize, receives the size of the output buffer.

See Also

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