Do we need this? Maybe it's enough to check the header or some elements of it actually being h264 stream, but full frame, it seems too much. Maybe we could use media foundation itself to check that output file type is detected as h264 when played back.
The frame data must be used when testing `IMFStreamSink_ProcessSample()`, this data is the input for generating the output file.
The header data is set as a media type field. So, to test ProcessSample(), we should have a frame data.