Spec accepts audio mime types for video and vice versa, WPT tests for the opposite

[Psychpsyo]

When checking mime type validity, the spec only checks that the mime type is one of audio/video or application. Thus, if the mime type is application, it passes as both a video and an audio mime type.
WPT then tests for this not being the case:
https://github.com/web-platform-tests/wpt/blob/4830edb033cb486fd0cd6f85b5e937cfc718704d/media-capabilities/decodingInfo.any.js#L140-L151

I assume that maybe this should be caught in step 3.2? But that one only checks whether this is a single media codec, not if it is of the correct type.

[markafoltz]

I can try to track down if an older version of the spec was more specific about checking the codecs inside container types. Regardless if the WPT is passing in major browsers, then we should update the spec to match.