justalurker said:They are transmitting the same number of full frames. The three highest HDTV levels are:
1080/24p (x1920, Square or 16:9)
1080/30p (x1920, Square or 16:9)
1080/30i (x1920, Square or 16:9) = 1080i HDTV
These three are 2,073,600 pixels per frame (24p would be slighly lower bandwidth with the same compression due to less frames)
The next highest HDTV levels are (921,600 pixels):
720/24p (x1280, Square or 16:9)
720/30p (x1280, Square or 16:9)
720/60p (x1280, Square or 16:9)
24p would have the lowest bandwidth requirement moving up to 60p (60 full frames per second compared to 30 full frames in 30p or 30i formats).
The remainder of the 18 ATSC formats are not HD. ALL ATSC tuners MUST be able to tune ALL 18 formats. No ATSC TV is required to display *in* HD.
Monitors must be able to display 810i or 540p in the 16:9 viewable area to be defined as HD. Monitors less than 480p or NTSC are defined as SD. The middle ground is ED.
I'd like to see movies move to 1080/24p or 720/24p - primary movie channels in 1080 and additional channels in 720/24p or 480/24p. The 20% savings in frames can go toward decreasing the compression needed.
Voom has a 25% reduction by using 1440 width and DirecTV has 33% by using 1280. Going to 24p is a good way of saving 20% without losing a pixel.
JL
It is not one of the 18 that the FCC has accepted for ATSC, and therefore cannot be considered one of their 6 HD formats.T2k said:Ahem.
Apparently everybody forgot that 1440x1080 is a standard MPEG2 profile - read on: http://videosystems.com/mag/video_profiles_levels/index.html
justalurker said:It is not one of the 18 that the FCC has accepted for ATSC, and therefore cannot be considered one of their 6 HD formats.
I suppose one could accept it as HD outside of the FCC accepted ATSC context. Just like we accept 480x480 scanned images as standard "SD" channels on satellite. But it is still HDLite, just with more calories than DirecTV.
(And beyond the downrezzing on width there is still the level of compression that can ruin the picture. Voom's 1440HD could be worse than DirecTV's 1280HD if they choked the pipe. E*'s 1920HD could be choked down enough to lose the benefit of having the full pixel width.)
JL
justalurker said:They are transmitting the same number of full frames. The three highest HDTV levels are:
1080/24p (x1920, Square or 16:9)
1080/30p (x1920, Square or 16:9)
1080/30i (x1920, Square or 16:9) = 1080i HDTV
These three are 2,073,600 pixels per frame (24p would be slighly lower bandwidth with the same compression due to less frames)
JL
There are six HD formats:justalurker said:The industry has a spec, only 720p or 1080i are HD formats JL
searswd said:I call E* to cancel my dish service when I was transferred to retention. The person on the other side stated that Voom's HD channels were not really HD but down rezzed. Basically stated that since no one else has those channels that they can not be real HD. Also accused me of not doing research on the matter...
Anyway, Is it true that Voom's HD channels are not really HD? I personally think the channels are excellent looking, but I would like some verification for the technical side of me .
Thanks!
30i is thirty full frames per second sent as 60 half frames (similar to NTSC TV). 30p is thirty full frames per second sent as 30 full frames.zombie said:By definition doesnt an interlaced scan only send half the frame at a time vs progressive that sends a combined even/odd twice as often (or a little more in the case of dvd's that use 24 frames per second)?
Not quite - HDrvsixer said:There are six HD formats:
1280x720 (60p, 30p, 24p)
1920x1080 (60i, 30p, 24p)