MediaFoundation: Get supported formats from IMFMediaType

[anguzo]

Hi!

I want to contribute to project that is using Vortice - Flyleaf, by adding enumeration of capture device supported formats. Since it is already using Vortice.MediaFoundation for device enumeration(MFEnumDeviceSources), I thought that adding this feature using Media Foundation would be most logical. I started getting into Media Foundation documentation and found https://github.com/OfItselfSo/Tanta samples very useful but I found that some methods needed for that are missing from Vortice.MediaFoundation.
These methods are:

1. MFGetAttributeSize
2. MFGetAttributeRatio

There are also other GetAttribute methods.

I actually managed to replace both these methods and get needed format information using bit manipulation like so:

var frameRateUlong = mediaTypeObj.Get<ulong>(MediaTypeAttributeKeys.FrameRate);

frameRate = (int)(frameRateUlong >> 32);
frameRateDenominator = (int)(frameRateUlong & 0xFFFFFFFF);

But it would be nice if I could do it similar to how Media Foundation documentation suggests:

MediaFactory.MFGetAttributeRatio(mediaTypeObj, MediaTypeAttributeKeys.FrameRate, out frameRate, out frameRateDenominator)

Thank you!

[amerkoleci]

Thanks for tips, just added those helpers:
b621090