How can I get the real size from SourceReader

I use SourceReader to decode H264 video to NV12. The actual size of output video is 1920x1088 with crop 1920x1080 When I call MFGetAttributeSize with MF_MT_FRAME_SIZE attribute for input IMFMediaType it returns height 1080. Is there any way to get the real size?

The same issue with other output formats.