![](https://seccdn.libravatar.org/avatar/129c5b7244f2b7b09a1348ad3d488c57.jpg?s=120&d=mm&r=g)
On Jul 28, 09 09:44:02 -0700, Yang Zhao wrote:
The autodetect is problematic - at least you should check for both width and height, as 4:3 images in 720p will be 960x720. Also note that 480p is a regular HD standard as well.
Or, you check out my suggestion for autodetect: - 640x480 gets Rec. 709 (this is HD 4:3) - Anything wider than 800 gets Rec. 709 (this includes HD 480p 16:9) - Everything else gets Rec. 601 (this includes 720/768x480/576)
My understanding is that Rec.709 only applies to content that is equal to or larger than 720p. 480p falls under something called "EDTV" which isn't technically HD. The definition of what is considered "HD" varies
Ok, still the 4:3 720p is an argument. So probably something like width >= 1200 || height >= 700 would be reasonable (and account for some weird broken overscan possibilities). I also remember that there was a color space that used the full 0..255 range for Y, but I don't know its specification number.
Can anyone cite anything more authoritative?
Nope, sorry.
Matthias
--
Matthias Hopf