Hi! The HLS Authoring Specification for Apple Devices mentions in several places "HD resolutions", but there's no explanation of what the term HD means. Is it explained somewhere else, or maybe someone could clarify it here? I'm looking for specific numbers. Something like "HD is 720p only; 721p is not HD", for example.
The problem is that terms like SD, HD, UHD, and so forth, are not strictly defined anywhere. Because of that, different people think about the same things differently. Some people think that HD is 720p only, other people think that HD is 720p and 1080p only, and others think it's everything between 720p and 1440p. The same is related to SD and UHD. This problem makes it difficult to follow guidelines and verify whether they were followed.
Specifically, I'm interested in the interpretation of content protection requirements described in 13.5 (content with HD resolutions SHOULD use HDCP-LEVEL of TYPE-0) and 13.6 (content with greater than HD resolutions SHOULD use HDCP-LEVEL of TYPE-1), but it would be nice to clarify other terms as well.
Perhaps the specification could be extended with the strict definition of such terms as SD, HD, UHD, etc.? This would be very helpful for content creators and developers of media tools.
