On Jul 29, 09 09:36:46 -0700, Yang Zhao wrote:
2009/7/29 Matthias Hopf
: 4:3 could result of cropped video from 720p source as well. IMHO something like my test above would deal with all known good resolutions, but...
4:3 cropped from 720p would be silly. That defeats the point of the original being in 720p to begin with. I've certainly not seen it done and it doesn't make any sense to me to do such a thing. (Other than for video composition, in which case the final work is re-encoded anyway)
If the source is 4:3 and had just been encoded in 720p or 1080p for transmission it makes a lot of sense, and I've already done this myself with HDTV transmissions of old movies (color, not b&w, where color space discussions are obviously moot). Not encoding black always makes sense as it saves bits.
Eeck, yes. Similar to 1440x1080 streched to 1920x1080, I assume. I have *no* idea how to deal with that, and whether that's a reasonable medium to assume to be recorded with Rec. 709 in mind.
IMO, at this point, rips with weird dimensions are not worth worrying about. There are a few sources of 720p and higher video that we can be
Agreed.
Although, if we want to default media in the poorly-defined zone between EDTV and HD to Rec. 709 instead of Rec. 601, I propose that we use the heuristic:
if (width >= 928) use_Rec709;
This should exclude all DVD sources--including DVD content re-encoded at their intended resolution (720x480 presented in 852x480)--and STDV and EDTV for both NTSC and PAL.
I like this much better.
The only source of confusion would IMHO be PAL DVD 16:9 content encoded
to 1:1 pixel aspect (which creates 1024x576) - but who on earth would
blow up 720x576 anamorph video like that? If somebody does he deserves
to get the wrong color space :-P
Can you update your patch? I'd love to include it then.
Thanks
Matthias
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Matthias Hopf