![](https://seccdn.libravatar.org/avatar/129c5b7244f2b7b09a1348ad3d488c57.jpg?s=120&d=mm&r=g)
On Jul 27, 09 23:25:51 -0700, Yang Zhao wrote:
The attached patch adds functionality to select between Rec.601 and Rec.709 constants using a Xv attribute. Additionally, an 'auto-detect' setting is provided, where video with width 1280px (720p) or higher uses Rec.709, and Rec.601 is used otherwise. Auto-detection is the default.
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)
The only problematic thing will be 640x480 XVids that had originated
from DVDs - too bad, you cannot detect those. On the other hand, we
could just ignore 480p as a HD standard, as it's only a semi-HD
standard.
Comments?
Matthias
--
Matthias Hopf