Interlaced source picture to progressive output picture.

I'm a complete noob to MF, please help me out.

I am capturing some legacy interlaced video (using Firewire), and encoding it using the H.264 encoder, into an MP4 file, using the sample project MFCaptureToFile. I would like to configure the MF so that the output H.264 picture is progressive. Can it be done?

As I understand, I must set the AVEncVideoOutputScanType property of the ICodecAPI to eAVEncVideoOutputScan_Progressive. How do I obtain the ICodecAPI from the IMFSinkWriter? Do I use the GetServiceForStream method? I tried, but I don't know what GUID to use for the second parameter.