Why is video today ever shot interlaced?

[rrats]

TV industry is too lazy to update

[Sharc]

... and most people are probably not willing to shop a new TV every couple of months just to jump onto the latest bandwagon of the industry's "improvements, inventions and enhancements" (marketing gimmick). Backward compatibility has always been a critical issue.

[chris319]

... and most people are probably not willing to shop a new TV every couple of months just to jump onto the latest bandwagon of the industry's "improvements, inventions and enhancements" (marketing gimmick). Backward compatibility has always been a critical issue.

The worst thing that can happen is that a broadcaster changes some property of his signal and viewers start complaining that they can't receive programming with the new signal characteristic. If this is reflected in the ratings then it costs the station money and engineering heads roll. This actually happened at one station in my market back in the analog era.

Conventional TV is not like a web browser where the software can be updated to adapt to changes.

[Cornucopia]

@ConsumerDV, No it is not an edge case. Perhaps you are just less sensitive to the differences.

@sm-p, yeah "too lazy" to upgrade billions of dollars worth of equipment that took a decade to put into place, while avoiding service disruptions.


Scott

[Sharc]

Motion is NOT the same, as there is discontinuity when not going between lines (with 1080i).

Um, I did not get this. Can you elaborate? A link will suffice. Thank you!

Related topic is the Kell Factor. In vertical direction the Interlace factor:
http://www.cockam.com/kell.htm

[usually_quiet]

TV industry is too lazy to update

No. However, the changeover will be slow in most countries for economic reasons, as already mentioned. Surely you are aware that there are a number of countries that have a newer digital broadcast system that includes more progressive resolutions operating in parallel with their old one but not every location has stations broadcasting in the new format. Eventually, new TVs and other consumer equipment with the ability to use the new broadcast system will saturate the market and the older system will fade away.

[chris319]

@sm-p, yeah "too lazy" to upgrade billions of dollars worth of equipment that took a decade to put into place, while avoiding service disruptions.

The bigger concern is that the public won't spend the money to upgrade their OTA receivers and content themselves with the likes of Netflix and other non-broadcast services.

How many people reading this own an IBOC receiver?

I thought so. Or an analog AM stereo receiver? ATSC 3.0 could wind up going the way of IBOC and AM stereo.

I owned an IBOC receiver which one day just died. It would power up but no sound came from it. To the landfill with it.

[ConsumerDV]

@ConsumerDV, No it is not an edge case. Perhaps you are just less sensitive to the differences.

Well, I am not go to argue about personal sensitivity. But between 60p, 30i and 30p the first two are much more alike in terms of motion portrayal, especially if the moving objects are not one line high.

[Cornucopia]

@ConsumerDV,
yes, between those 3 options (and similarly between 50p 50i/25i and 25p) there is a bigger distance between the 2nd and 3rd than there is between the 1st & 2nd. That was the whole reasoning behind interlacing in the first place (quasi-"Full" quality at half the bandwidth).
But we also all have the hindsight of knowing how badly interlacing gets mangled during processing, and how much it creates further difficulties. If it were good enough, we would not have moved up to full progressive highframerate formats.

@chris319,
Most people don't know the tech nomenclature, but there are a vast number of auto radios in the US that are IBOC. They're just called "HD radio" or similar, many are built-in manufacturer OEM models, though not all. I own at least 2 and still use them. They are an improvement, when applicable (not often), but not really enough of one to warrant wholesale changeover. I also remember AM stereo, though due to the inherent bandwidth constraints was NEVER going to live up to the intent, much less the hype.

Getting back around to the topic, interlacing SHOULD become passe and fall into disuse. It was a solution to a problem that was important in its time, but since certainly the 2010s is not really a problem anymore. But there are lots of forces of intertia here: long-term compatibility, financial investment, manpower budgeting...
Be patient, it IS starting to die out, and once individuals and companies have plowed through a purchase & service cycle or 2, and back catalogs are converted to progressive masters, and that portion of the infrastructure gets low demand, it will die off on its own. Give it another 10 years or so.


Scott

[ConsumerDV]

But we also all have the hindsight of knowing how badly interlacing gets mangled during processing, and how much it creates further difficulties. If it were good enough, we would not have moved up to full progressive highframerate formats.

You make it sound as if I am promoting interlaced video. Gee, I just said that interlaced looks the same as progressive motion-wise given that field rate of the former matches frame rate of the latter. We don't watch interlaced video anyway now, it is all deinterlaced one way or another because we don't have CRTs. In case of a simple bob it is converted to double frame rate half the lines: 1080i30 -> 540p60. The only flat panel I know of that natively supported interlaced video was Hitachi ALIS. I briefly owned a 42-inch Hitachi plasma TV fifteen years ago, it was not bad.

[Cornucopia]

Don't have CRTs? You must not know many old people. They hang onto their TVs if they are still working, and many CRTs still are. Interlacing is still a factor in many parts of the US, much less the world.
I see you keep trying to slip "same" back in there.


Scott

[ConsumerDV]

Don't have CRTs? You must not know many old people. They hang onto their TVs if they are still working, and many CRTs still are.

IDK many old people indeed. Well... define old. Maybe I would qualify. It must be fun to watch a tiny fully boxed picture on a 20-inch screen... ok, maybe 27-inch screen. Each and every diginet I have in my area is flagged as 16:9 even when it broadcasts 4:3 content. I don't think the converter boxes these old people use are smart enough to strip pillarboxing, or that these old people are smart enough to zoom in manually. Maybe they are, maybe I think too bad of them. I've seen enough disfigured TV programs in bars and hospitals. Moreover, some channels show widescreen ads within 4:3 frame, which itself is within 16:9 frame, so it is fully boxed on widescreen TV.

[usually_quiet]

Don't have CRTs? You must not know many old people. They hang onto their TVs if they are still working, and many CRTs still are. Interlacing is still a factor in many parts of the US, much less the world.
I see you keep trying to slip "same" back in there.


Scott

True. A 2007 CRT TV with a digital tuner and a built-in DVD player graced my parents' guest bedroom until 2018. It was still working well except for the on/off button on the remote when I recycled it so I felt a little guilty about doing that. I might have waited if I wasn't afraid that it wouldn't be accepted for recycling if I did.

[usually_quiet]

Don't have CRTs? You must not know many old people. They hang onto their TVs if they are still working, and many CRTs still are.

IDK many old people indeed. Well... define old. Maybe I would qualify. It must be fun to watch a tiny fully boxed picture on a 20-inch screen... ok, maybe 27-inch screen. Each and every diginet I have in my area is flagged as 16:9 even when it broadcasts 4:3 content. I don't think the converter boxes these old people use are smart enough to strip pillarboxing, or that these old people are smart enough to zoom in manually. Maybe they are, maybe I think too bad of them. I've seen enough disfigured TV programs in bars and hospitals. Moreover, some channels show widescreen ads within 4:3 frame, which itself is within 16:9 frame, so it is fully boxed on widescreen TV.

Don't forget that many older people have to watch what they spend very carefully, often lack the strength to move something heavy, and may live in homes with small rooms. I helped my father find an HDTV in 2008. The 26" widescreen TV he picked out was one of the least expensive ones in the showroom but it still cost $600. The screen height was about the same as the screen height of the CRT it replaced.

[rrats]

Whole a total switch to progressive sounds like a bad idea, they could at least implement it for a few TV channels

[defbiz]

Some TV stations just aren't willing to handle the bandwidth ATSC 3.0 2160p50/60 video standard requires.

[lordsmurf]

Some TV stations just aren't willing

It's not that easy.
Money.
Who pays for it? Ads are already razor thin margins in recent years.
And don't forget streaming, cord cutting.
Why invest in something that isn't really needed to provide the function of free TV?

[rrats]

sometimes the 4k broadcasts do no low pass filters when converting for other hd streams. 2022 eurovision broadcast for example was full of jaggies on my second tv

[azmoth]

All boils down to money as usual!

[ConnorD]

Some TV stations just aren't willing
ConsumerDV:

IDK many old people indeed. Well... define old. Maybe I would qualify. It must be fun to watch a tiny fully boxed picture on a 20-inch screen... ok, maybe 27-inch screen. Each and every diginet I have in my area is flagged as 16:9 even when it broadcasts 4:3 content. I don't think the converter boxes these old people use are smart enough to strip pillarboxing, or that these old people are smart enough to zoom in manually. Maybe they are, maybe I think too bad of them. I've seen enough disfigured TV programs in bars and hospitals, even at the local gun store https://gritrsports.com/ . Moreover, some channels show widescreen ads within 4:3 frame, which itself is within 16:9 frame, so it is fully boxed on widescreen TV.

It's not that easy.
Money.
Who pays for it? Ads are already razor thin margins in recent years.
And don't forget streaming, cord cutting.
Why invest in something that isn't really needed to provide the function of free TV?

With all that revenue decrease I wonder how traditional TV even stays afloat at this point, especially considering how popular streaming is rn.

[Kenny202]

I don’t shoot much video anymore but I have 3 Canons that shoot 60i and 30P, and I
just don’t have the cabbage to go 60P. 4K is out of the question, especially if I need at least 2 cameras.
Maybe economics plays a part in why interlaced is still viable.

Bit late to the party here Barry, and hoping you are still lurking around lol. I also have a Canon Video cam HF10 that shoots 60i, 30p and 24p. I did a bit of a comparison shoot today taking video in all 3 formats and surprising to me the 60i was hands down better than 30p and 24p. I thought the progressive settings would be much better. The 24p was the worst of the lot. I even did some low light shooting that again I thought the progressive would be superior but nope.

By the way my camera produces MTS files. I can play the MTS files directly without converting them on my Windows PC VLC media player, and the video is sharp and clear. When I use handbrake to convert the files to mp4, using fairly high quality settings (slower rendering) and have deinterlacing turned on, the video is ok but not as crisp as the original MTS files. Again I thought deinterlacing (convert to progressive) an MTS file and converting it to MP4 would improve the video if anything.

Any insights? How are you getting around it all

[Bwaak]

I also have a Canon Video cam HF10 that shoots 60i, 30p and 24p. I did a bit of a comparison shoot today taking video in all 3 formats and surprising to me the 60i was hands down better than 30p and 24p. I thought the progressive settings would be much better. The 24p was the worst of the lot. I even did some low light shooting that again I thought the progressive would be superior but nope.

Define "better". Also depends on how do you process the files. Also, 24p should be a bit better in low light because of 1/48 s shutter speed vs 1/60 s.

Feel free to share your source files, as well as your processed files, I wonder what did you do to them. You need to remove pulldown on 24p files to avoid combing and ghosting.

[Kenny202]

I since deleted the clips and cant send them...actually sold the camera yesterday waiting on another one Panasonic HDC-TM750 which I have used before and are an awesome camera, particularly in low light. It is native 60p. TO answer your question define better....the 24 and 30p clips didn't seem any brighter....they were just noisier....like a clip indoors on a cheap camera with a poor sensor. I don't know what you mean by remove pulldown on 24p files? Is that a setting in handbrake?

Anyway thanks for your reply. I am happy to learn as much as I can....still not even close to getting my head around video conversion or how to convert original MTS file to Mp4 retaining the same quality as the original. My idea is to get the best possible quality video then do post, edit etc....then I can compress it / make it smaller it for social media etc should I need to. Is that normally what you would do?

[Bwaak]

TO answer your question define better....the 24 and 30p clips didn't seem any brighter....they were just noisier....like a clip indoors on a cheap camera with a poor sensor.

Maybe it is just a perception caused by lower image rate, so the grain is more visible? IDK. There are no technical reasons for it.

I don't know what you mean by remove pulldown on 24p files? Is that a setting in handbrake?

I don't usually use Handbrake. It has settings both for removing the pulldown (detelecine) and for traditional deinterlacing. You can specify both settings at the same time, or just one, or none. I suppose, depending on the source and the target frame rate and on field structure it decides which one to use if you specify both methods.

Google for "inverse telecine" or "reverse telecine" or "pulldown removal" to find more. See this website for general info, which is still around after all the years: https://www.100fps.com/ The deinterlacing method names are a bit different from the currently used ones, but you'll get the gist.

sold the camera yesterday waiting on another one Panasonic HDC-TM750 which I have used before and are an awesome camera, particularly in low light. It is native 60p.

Sure, with native progressive there is no need to deinterlace. The TM750 is an oldish camcorder but it shoots very detailed and crisp HD video. Use higher-bitrate 35 Mbit/s MP4 format.