[trbarry]

An interesting read about 1080p plans and (maybe) a future HDNet, courtesy of the Digital Television-HDTV Forum news. See the CED article .


Though I personally believe that once the displays are here the 1080p will likely (and happily) first come on HD-DVD, and then on frame rate converted HD-DVD players that can display 24p movies properly at 60 (or 72?) FPS.


- Tom

 

[hmurchison]

Put me in the necessity group. Good article. Most of the broadcasters are looking at this somewhat myopically. They are focused on the needs of Broadcast. Consumers who just spent $5k on a TV are looking to get the best quality obtainable.


Me personally I wouldn't have a problem watching 1080i but I want a 1080P capable TV because broadcasting won't be the only way I watch my TV. In fact broadcasting is still MPEG2 based but 1080P on WM9 or AVC eventually is going to easily come in under 19.4Mpbs.


1080P to me is the Holy Grail of HD. All my buddies on the pro cam boards want to record progressive with as high a resolution as they can. Which refutes the statement below

Quote:

Still, others in the industry doubt 1080p will ever make a splash in HD. Harmonic Inc., a supplier of video encoders, isn’t exploring development of 1080p, nor do its encoders support the format “and it is not supported because we do not see really a reason to support it,†says Yaron Simler, president of Harmonic’s convergent systems division.

Just silly.

 

[oxothuk]

Quote:

Originally posted by trbarry Though I personally believe that once the displays are here the 1080p will likely (and happily) first come on HD-DVD, and then on frame rate converted HD-DVD players that can display 24p movies properly at 60 (or 72?) FPS.

This is where the discussion needs to be centered. We need to ensure that the interlacing kludge is not perpetuated in HD-DVD.


IMHO the case for overhauling the broadcast infrastructure to support 1080p60 is pretty weak. There would be a marginal improvement for live sports, but hardly anything else. Most dramas/sitcoms are already recorded as 1080p24 or 1080p30. So long as they are properly flagged, a progressive display should be able to deinterlace them perfectly.

 

[John Mason]

Tom,

Believe you've often pointed out that 720p is easier to compress because the frames, while at a higher rate, are more similar to each other, simplifying encoding. The article points out that 1080p is ~3 Gbps (1080/60p?[1]) versus 1080i's ~1.5 Gbps. Wonder how much of that "frame similarity" advantage would apply to reducing 1080/60p's ~3 Gbps to 'feasible' levels without newer transmission algorithms? Agree it's a nice summary article, and was planning to post a reference until a search uncovered this thread. Glad HDNet sees an advantage; perhaps their eventual adoption will push others into the camp. - John

Edit: [1] I see from a reference text that 1080/60p is 148 MHz sampling, while the other lower 1080p rates require only ~74 MHz.

 

[TheFerret]

I do not think 1080p is a luxury when you are asking not to introduce [de]interlacing artifacts.

 

[trbarry]

Quote:

Wonder how much of that "frame similarity" advantage would apply to reducing 1080/60p's ~3 Gbps to 'feasible' levels without newer transmission algorithms?

Some very sloppy experiments I did with Xvid/MPEG-4 awhile back made me think that doubling the frame rate would increase the bit rate by only about 75%, though I'd hoped for more efficiency than that. And, on top of this we'd also save a bit by encoding progressive, plus the slightly increased chroma fidelity that progressive has in the 4:2:0 color format used by almost all modern codecs.


Anyway, 1080p @ 60 is probably not a broadcast format but should fit easily on HD-DVD. And if anyone could actually display it I could also see it used for special PPV sporting events on cable or satellite. For instance you could imagine ESPN sending 720p on cable but using 1080p cameras and having a special sports bar premium satellite service.


- Tom

 

[Erik Garci]

Has anyone actually done an A/B comparison of the following?


A) a camera shooting native 1080p60, displayed at full 1080p60 resolution, and viewed from a typical distance of 3 screen-heights.


B) a camera shooting native 1080p60, downconverted to 1080i60 (by discarding every other line), then upconverted back to 1080p60 using high-quality motion-compensated deinterlacing, displayed at full 1080p60 resolution, and viewed from a typical distance of 3 screen-heights.

 

[paintit77]

Yaron Simler is just silly. My beef with the whole issue is that Fox, ESPN-HD and ABC have maintained all along that their decision to use the 720P format was that it offered a better picture for sports. What many of us AVs Forum subscribers have maintained is that it is thier way of saving on bandwidth and money. It was never about the quality to us, the customers. I just got through an upgrade on my PC to a system that can play back WMV-9 disks. Microsoft offers two qualities, 720P and 1080P. Let me make this clear, THERE IS NO COMPARISON!!!! The 1080P format is much, much better in terms of clarity, detail and color. The 720P formats are much grainier. I don't know why it is, but it is.

 

[Glimmie]

Quote:

Originally posted by paintit77 Yaron Simler is just silly. My beef with the whole issue is that Fox, ESPN-HD and ABC have maintained all along that their decision to use the 720P format was that it offered a better picture for sports. What many of us AVs Forum subscribers have maintained is that it is thier way of saving on bandwidth and money. It was never about the quality to us, the customers.

This is totally untrue!


720p equipment is just as expensive as 1080i. In fact a good portion of professional HDTV equipment is tri-standard 1080/30i, 1080/24p, and 1280/720p. So much for your money argument.


1280/720p is the SAME uncompressed bandwidth as 1920/1080i. Half the horizontal pixels but twice the frames. 1080i fields are only 540 lines each. Now 720p does compress a bit more efficiently but it's not a significant amount. So much for the bandwidth argument.


Going 720p while NBC and CBS went 1080i may have some political motovations behind but savig money or bandwidth was not either of them.

 

[R11]

I clearly remember reading direct quotes from one of the Head Honchos at ABC saying that one of their primary reasons for going 720p was the bandwidth savings that would allow their broadcasters to multicast a HD and a SD feed (or two) side by side without artifacting (as opposed to the implied bandwidth hog 1080i alternative). Perhaps their entire decision making process was based on flawed logic but they did state it publicly none the less.


ron

 

[Erik Garci]

Quote:

Originally posted by R11 I clearly remember reading direct quotes from one of the Head Honchos at ABC saying that one of their primary reasons for going 720p was the bandwidth savings that would allow their broadcasters to multicast a HD and a SD feed (or two) side by side without artifacting (as opposed to the implied bandwidth hog 1080i alternative).

Here is a bandwidth comparison, in terms of active pixels per second.


1. 720p24 = 22,118,400

2. 720p60 with 2-3 pulldown flags = 22,118,400

3. 720p30 = 27,648,000

4. 720p60 with 2-2 pulldown flags = 27,648,000

5. 1080i with 2-3 pulldown flags = 49,766,400

6. 720p60 native = 55,296,000

7. 1080i with 2-2 pulldown flags = 62,208,000

8. 1080i native = 62,208,000


It is obvious that 720p24, 720p30, and 720p60 w/pulldown flags offer significant bandwidth savings over 1080i. It is also obvious that native 720p60 offers little bandwidth savings over 1080i.