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  #1  
Old 06-03-2017, 04:44 PM
Adlershof Adlershof is offline
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1080i vs. 720p

Any opinions about the pros and cons of these two formats?

I would like to read some in particular from the US, because here in Europe this is almost a matter of religious belief. When introducing HD engineers of German public broadcasters resolutely said that interlaced formats must finally be a thing of the past, defending their decision to use 720p against demands for "full HD", i.e. 1080i.

The point is that all ARD studio outputs and internal feeds are 1080i. Only in the last stage they convert their video to 720p, thus combining the disadvantages of both formats.
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Old 06-03-2017, 06:02 PM
Chip Chester Chip Chester is offline
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Stateside, the mantra is 720p for sports, apparently for its better motion characteristics. Since most content is squeezed down DirecTV/Dish Network satellite, and cable systems, few viewers see anything close to full fidelity of either format. The only real way to get it is by antenna. Or thru streaming video, sometimes. They can do 4K, but various compression artifacts sometimes dilute the experience. Sometimes.

Chip
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Old 06-03-2017, 09:24 PM
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The comparison was more distinct when using a CRT display that scanned in the native format of the capture. It was quite true that sports looked better in 720p (viewers particularly mentioned the difference on basketball games). Mostly-still images, on the other hand, had noticeably better horizontal resolution upon close examination.

Since flat panel displays all are longer persistence than CRTs, and native 1920x1080 flat panels require interlace to progressive conversion of some type, the comparison is muddied these days.
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Old 06-03-2017, 10:58 PM
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Quote:
Originally Posted by Chip Chester View Post
Stateside, the mantra is 720p for sports, apparently for its better motion characteristics. Since most content is squeezed down DirecTV/Dish Network satellite, and cable systems, few viewers see anything close to full fidelity of either format. The only real way to get it is by antenna. Or thru streaming video, sometimes. They can do 4K, but various compression artifacts sometimes dilute the experience. Sometimes.

Chip
I'm sitting here watching SNL at 1080i on my "analog cable." No silly box. Just plug the cable into the back of my flat screen TV and auto scan the channels. When I press "info" on the remote, it says 1080i for the local NBC and CBS stations. Other stations say 720p and the regular cable channels 2 through 76 say 480p. So everything isn't digital. My cable provider puts the digital versions of the local stations, and their sub-channels, on a separate tier and the signal is gorgeous and dropout-free. So am I one of the lucky ones?

I dropped Time-Warner after 20+ years when they discontinued analog and went with the local telco's cable TV and have never regretted it for a second. TWC, now Spectrum, still wastes their money sending me something almost every week and I've had two visits from someone trying to get me back. I told him I wouldn't have it even if it were free and slammed the door in his face the first time. The second time I wasn't home, but the sheet he left said I got a free "motem" with their service.

I think I'll keep what I have for as long as I can.
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Old 06-03-2017, 11:48 PM
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There is no analog transmission of 1080i or 720p (high definition) on any media or service anywhere, and never was. You must be watching a digital signal for these.
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Old 06-04-2017, 10:21 AM
Chip Chester Chip Chester is offline
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All of those display formats are possible in ATSC. And for the tuner to receive 1080i, and moreover say it's 1080i, it has to be an ATSC tuner. 480p confirms it, as NTSC is 480i. (Actually 525i, only 483 of which are visible... but who's counting?) If you're in PAL country, your lineage may be different, but the concept is the same.

But comparison of that show via cable vs. the same show at the same time via antenna will reveal the compression and general monkey business taking place at the cable company front-end that allows enough space on the system to present 82 PPV wrestling and on-demand movie choices and 142 shopping and sports channels in addition to the normal broadcast and cable-box-only offerings. Even though you're not watching them, or ordering them, they still take up room on the cable spectrum that shows up at your house. I call shenanigans. (On BigCable, not you.)

Chip
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Old 06-23-2017, 07:41 AM
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Robert Grant Robert Grant is offline
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Quote:
Originally Posted by old_tv_nut View Post
There is no analog transmission of 1080i or 720p (high definition) on any media or service anywhere, and never was. You must be watching a digital signal for these.
Technically, Japan did offer analog HDTV service many years ago, using an 1125-line raster to deliver a 1080i image.

jsowers is apparently one of the lucky few in America that still gets open digital cable (unencrypted QAM, or, even more unlikely, ATSC).

The vast majority of CATV systems in the USA encrypt EVERYTHING on their system (with perhaps the sole exception of an analog channel 3 with a slide showing the telephone number to the company's new subscription office). This allows the CATV company to shut a customer off without actually sending a person to unplug a cable on a utility pole, meaning they can layoff several employees who did so.
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Old 06-23-2017, 10:48 AM
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Here last summer they switched off ~70 analog channels, and replaced it with this encrypted QAM BS. The get a box analog lasted till winter. Now all that is left is encrypted QAM, a FEW locals on ATSC or clear QAM (I forget which) And 1-2 garbage unencrypted QAM channels.

I had at least 4 DVR/DVD-recorders/S-VHS decks hooked to analog cable and could tune, watch and or record 4-10 shows at once on the rig in my room, and I could have my time shifts change channel to grab various shows (important, especially on long vacations)....Now I've got 1 maybe 2-3 channels (if I heist boxes from other rooms) at once, at best, with the same gear (and no way for the timers to change channels) unless I engineer some super complex IR remote based automation project. I would not mind half as much If the basterds did not encrypt their service...I was prepared to get plenty of clear QAM decoder boxes and 'make my own analog cable', and or get some more QAM tuner sticks for my PC and use those as tuner/DVRs....If that ain't enough to burn my ass already the jerks at scrotum cable think in under 1 year they are gunna get away with charging $6 a month a head rent on those 5 "free" hockey phuck boxes....I think I'll we'll end up switching to playstationVue or some combination of that Hulu, Roku, streaming....Their shyte is expensive enough as it is, and they have the gall to change up the hardware to serve me worse, and charge me more for it?...They might do better to simply ask us nicely to leave.

I'm smarter than every scrotum employee whom I've met or who's decisions have affected my service.....Literally I had to explain to the first tech how to run the damn coax he was installing through the walls/vents, that clown did not install an amp as I was sure we needed, and the next installer who came to fix internet/phone dropouts realized the amp was needed to fix that....Two weeks back I had to climb the damn pole....All the little phuck boxes were not getting signal and the big box was lousy (phone &net somehow were okay), with no analog relative signal strength was hard to judge....I first checked the 'splices' on the underground cable that mom's gardening brought back to the surface to find they were fine...checking the amp etc proved things so I went up to try to bypass the line before the splice....When I went up there I found our fitting at the spliter* during a recent replacement of the splitter had been over tightened till the threaded collar on the F connector cracked off the connector...Leaving ONLY the center lead of the coax just barely coupling signal between us and the cable co... :grr: It was not too hard to change the fitting, and I did it safely (a 2 phase 120V + cable pole ain't too dangerous), but having to do it at all ticks me off (once the problem was discovered it was either miss my shows and let them do it or DIY fix and watch my shows).
*There are 2 taps on the proper outdoor cable co hardware on my pole and 3 homes using it...So some enterprising cable guy added a second consumer grade spliter in series with the telco grade one on the pole to add an extra tap....Yeesh!
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  #9  
Old 06-30-2017, 07:38 PM
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Add to this the cable companies compressing their feeds which means you don't get real HD either. Satellite from DirecTV and Dish also compress theirs.
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