Since ATSC 1080i/60 broadcasts are going to be with us for a long time, I would like to understand if the production process lends itself to inverse telecine deinterlacing at the TV.
I understand that many TV shows (not film) are originally filmed/edited at 1080p/24 or 1080psf/24. In the conversion from 1080p/24 to 1080i/60 for broadcast do the networks use a teleine or is some other method used? If they use a telecine then I assume that the deinterlacers from lumagen,vantage, dvdo etc. deinterlace them using inverse telecine 3/2 pulldown?

most shows can be IVTC'd to p24 just fine.

I understand that many TV shows (not film) are originally filmed/edited at 1080p/24 or 1080psf/24.Correct, most of the popular series on CBS and NBC are done that way, as are the series on HBO.

If they use a telecine then I assume that the deinterlacers from lumagen,vantage, dvdo etc. deinterlace them using inverse telecine 3/2 pulldown?Yep, some displays do this correctly too, although only a minority (http://www.hometheatermag.com/hookmeup/1106hook/index.html) (more results here (http://hdguru.com/?p=17)).

It's really rather pathetic how few RPTVs, LCDs, and plasmas will correctly perform inverse telecine on 1080i60 signals. You expect that sort of thing from a no-name brand, but major manufacturers like Panasonic, Samsung, Sony, and Toshiba? It almost makes you wonder about the competence of their design engineers.

Noticed that the article refers to 'Silicon Optix's new high-definition 1080i HQV test disc played on the Toshiba HD-XA1 HD DVD player'.

Is this new HQV test disc available to buy on HD DVD?

StooMonster

Noticed that the article refers to 'Silicon Optix's new high-definition 1080i HQV test disc played on the Toshiba HD-XA1 HD DVD player'.

Is this new HQV test disc available to buy on HD DVD?The beta version of the test disk is available to manufacturers and the press. The final release -- and public availability -- is slated for late March, with a Blu-ray version to follow. More information right here (http://www.hqv.com/benchmark.cfm).

Great responses. How are live events such as Pro Football, basketball captured. Do they use interlaced cameras or are they captured at 24p? In other words does 3:2 inverse telecine work on any live sports broadcasts?

Great responses. How are live events such as Pro Football, basketball captured. Do they use interlaced cameras or are they captured at 24p? In other words does 3:2 inverse telecine work on any live sports broadcasts?
Live 1080i, late-night talk shows, and many documentaries/travelogues are captured with TV cameras at 1080/60i, also the broadcast standard. CBS's weekday soap, THe Young and the Restless, is a rare drama taped at 1080/60i. For sports, this capturing of TV fields (540-line half-frames) each 1/60 second ensures adequate smoothness of motion, although 720p's 60 full frames/second is better from a motion point of view--(not a spatial resolution advantage). 24 fps is slow for sports. For movies, 'overcranking'--speeding up the camera--is often used to help capture motion better. CRT displays often display 1080/60i in interlaced form, and fixed-pixel displays require good deinterlacing algorithms to convert 1080/60i internally or with an external V.P. to 1080/60p (or a scaled down resolution). -- John

I find that most primetime dramas have weird cadence breaks due to their editing, titles, overlays, commercial insert points, or whatever else that will frequently screw up conversion to 24 hz. It's generally less annoying to watch at 60hz than to repeatedly pause and restart the program to resync the cadence.

Greetings, Joshua,
Feel like I'm missing out on all those fluctuations. :) Here, I'm still viewing everything HDTV-wise at 1080/60i, interlaced, on my year-2000 RPTV (Philips 64PH9905). Images remain pretty smooth overall, but of course I'm probably suffering more judder than necessary--assuming I switched to a display technique that handled 24 fps vs 1080/60i correctly. -- John

Hello,

My friend watches a lot of HD, he said everything is 1080i60, what is 108024?

Hello,

My friend watches a lot of HD, he said everything is 1080i60, what is 108024?On broadcast and cable, we have two sources of high-definition material on 1080i channels. We have video-sourced content, such as sports, acquired natively in 1080i60. We also have film-sourced content, acquired in 1080p24, but flagged as 1080i60 for broadcast.

In the case of video-sourced material such as sports, we have 60 different fields, all acquired at different points in time (separated by 1/60th of a second). Because the fields were all acquired at different points in time, they don't "match up" when there is any movement on the screen. Attempting to combine every two fields to form a 1080p30 image would result in severe combing. Some older (and many cheaper) TVs simply display 540p resolution, by taking each field and making it a frame without adding any picture new information. That was the old/cheap way of doing things.

The better displays on the market interpolate new information to create a full 1080p image. The remaining information for each 1080p frame is derived by looking at the adjacent fields and taking an average. The better video chips perform processing at the per-pixel level with interpolation based on 4-5 fields, which helps make movement (such as a player running down field) more detailed and fluid. By comparison, cheaper video chips use region-based processing with interpolation based on just 1-2 fields, and tend to exhibit more blurring.

Said a different way, with video, the processor is "guessing" how it should complete every frame, based on the information in surrounding fields. Some video processors "guess" better than others, because they look at more pixels and more adjacent fields to determine what part of the picture is in motion.

In the case of film-sourced (1080p24) content, this interpolation is unnecessary. There is no need to guess anything, because the full progressive information for all twenty-four frames is already there. For Blu-ray and HD-DVD, movies, as well as episodic programs like CSI on CBS, Heroes on NBC, or The Sopranos on HBO, you have:

Frame1, Field1
Frame1, Field2
Frame2, Field1
Frame2, Field2
Frame2, Field1
Frame3, Field1
Frame3, Field2
Frame4, Field1
Frame4, Field2
Frame4, Field1

As you can see, you can't simply pair each two fields. They don't match. Instead, the display must detect the 3/2 cadence and reconstruct the original 24 progressive frames. This process is known as inverse telecine. It produces an image that is identical to the source. Once this is done, pull-down is applied to repeat the full 1920x1080p frames to match the refresh rate of the display (i.e. 60Hz). At that point, depending on your TV, the image is output directly to the screen, [or] digitally scaled to add overscan, or digitally scaled to fit a lower-resolution panel. On a display that correctly performs inverse telecine, there will be no difference between the 1080i and 1080p output from a Blu-ray player.

Most modern displays can detect the 3/2 cadence on 480p24 content flagged as 480i60, but only a minority can do the same with 1080i60 signals. It is more computationally intensive to do this with high-definition, and many display makers skimp on high-def processing to cut costs. On displays that cannot detect the 3/2 cadence necessary to reconstruct the original 1080p frames, they treat the source as video. They either display the signal as 540p (as was the case on older/cheaper displays) without interpolating information to complete the 1080p frame, or they interpolate new information based on adjacent fields to complete the 1080p frame.

Progressive frames created from interlaced content through interpolation will never be as good as material originally acquired in 1080p. The greatest differences are seen when there is a lot of movement on the screen, because all the information for that motion exists in a progressive source, but does not exist in an interlaced source.

If you've ever seen combing, blurring, or excess judder on episodic content or a movie shown on CBS, NBC, TNT, or HBO, chances are it was because your display could not correctly perform inverse-telecine. Unfortunately, most displays do not have quality deinterlace -- of the displays tested by Home Theater Magazine (http://www.hometheatermag.com/hookmeup/1106hook/index.html) (more results here (http://hdguru.com/?p=17)), only seven of the 61 tested would offer the same performance with a 1080i input as they do with a 1080p input.

Things become a bit more complicated when you have content with "bad edits," as you often get when film and video sources are mixed together. Further, while the actual movie or series may be a 1080p24 source, it's common for commercials to be video sourced. Hence, the display's processing has to be able to switch between video and film modes on the fly, based on what it detects as the source content (60i or 24p). Not all video processors and displays are able to do this well. Some display processors can detect and switch between video and film mode relatively fast (within a few seconds), whereas others may take 30-60 seconds.

Wow! Thank you so much for taking the time in breaking it down like this, much appreciated!
I must I admit, I was knowledgeable in some of this information but this really gave me a
"clear picture"! Thank you, TV watching will never be the same again. :)

The question is, why do we want to do inverse telecine i.e. convert 1080i@30 (60i) to 1080p@24?

Reason #1 --- In 24 fps film source converted to video, matching odd and even fields are always present and by doing IVTC we guarantee constructing full frames with matching material. When put on the screen, the frames are still shown 60 (or 48 or 72) per second and material is repeated as needed namely re-imparting 3-2 pulldown in the case of 60 fps. Fine and dandy.

Reason #2 -- The TV only accepts 24 fps insisting on re-imparting the 3-2 pulldown or whatever internally. Should the source not be 24 fps film, it will be butchered when forced into a 1080p@24 format by the previous device just to transit the cable down to the TV. When put on the screen 60 frames per second, it can never be made as good as it was in its 1080i@30 lifetime.

True, as mentioned earlier, few HDTV's even in 2007 do good IVTC.