780i vs. 1080i HD

[nitrogen_widget]

I was recently read on another forum:

the quality jump from 720p to 1080i is extremely misleading considering most of the time 720p looks better than 1080i, and 1080p is not worth it currently. You might consider 1080i or 1080p true hd content, but there are millions of avid fans (especially avsforums) who consider 720p true HD content also. Saying 1080p is TRUE HD content is a push by marketing departments considering it does very little over 720p.

I don't have any HDTV sets or tuners so I really don't know if the person who said this knows what he's talking about.

Any input?

[sixgun]

I have a HDTV that is native 1920x1080, but only takes 1080i and i do find the best quality programme that i download is Lost, which is in 720p. I watch a few shows that are in 1080i (The Unit and Friday Night Lights) and they both seem "gritty". But i don't know if that's how they're supposed to look. To be sure i think i'd need to see the same programme in both 720p and 1080i.

[Ted the Penguin]

yes, he knows what he is talking about for the most part... currently 1080p is not being leveraged to its full potential so the improvement over 720p is marginal. also, the current technology (ATSC) does not allow for transmission of a 1080p signal (I think) due to the amount of bandwidth it consumes.

as for 720p vs 1080i, there is not a huge difference. most people think 720p looks sharper because it is a progressive signal (whole frame updates at once) and produces 60 full frames per second. whereas 1080i is interlaced, which requires de-interlacing, resulting in 30 frames per second, and the standard de-interlacing issues which are already well known to HTPC users.
this is really a matter of personal preference.

my personal opinion, is that you should provide video to a display at its native resolution... so if you have a 1080p TV, give it a 1080p signal. and same goes for "720p" LCDs, which are actually 768p, and should be driven at 768x1360(6)

but that is just my $.02

[nitrogen_widget]

I thought originally also that 1080i would look better on a 1080i native TV & the same with 780i.
It does make sense though that 1080i would loose some quality because of bandwidth issues in sending that much bigger of a picture.

the discussion was mainly on the subject of blu-ray / HD-DVD resolution & quality vs what you get over the air & through cable.

Thanks.

[Ted the Penguin]

blu-ray/HD-DVD give you better quality, but it depends on the movie. there is a site out there that rates a movies use of HD...


oh, and please! be consistent/accurate with your use of 'i' and 'p' they stand for interlaced and progressive, and there is a major difference between them.
I am assuming that you want to be using 'p' because there is no such thing as 720i, or 720i/1080i native TVs

[pastro]

1080i and 720p use the same bandwidth. There is no quality loss due to bandwidth. 1080p can be transmitted but only at 30hz. I don't think anyone does this though. 1080p at 60hz could be transmitted over cable since cable tuners can handle double the bitrate.

[Ted the Penguin]

1080i and 720p use the same bandwidth. There is no quality loss due to bandwidth. 1080p can be transmitted but only at 30hz. I don't think anyone does this though. 1080p at 60hz could be transmitted over cable since cable tuners can handle double the bitrate.

agreed

the only way increased bandwidth could reduce quality would be inducing a higher probability of error due to the larger area of the spectrum covered, and therefore more places for things to go wrong.

[-stattik-]

If you wants to see a clean 1080i show, watch Everyone Hates Chris. I agree, other 1080i shows like Friday Night Lights are "gritter" which may be due to the way its filmed and compressed. A 1080i frame has 2073600 pixels while 720P has 921600 pixels. Even if you take into account 60fps, 1080i has more potential for better quality. I agree with comments above that it's not always being taken advantage of. Fast motion will always look better at 60fps though.

Most shows HD shows downloaded from the internet are compressed with x264 and use 720P at 24FPS (Lost is originally 1080i) This size was chosen to fit the desired filesize (1.1GIG per 42min show) while keeping a high quality. The 1.1 gig size was chosen so you could fit 4 shows per DVD for archival.

[sixgun]

If you wants to see a clean 1080i show, watch Everyone Hates Chris. I agree, other 1080i shows like Friday Night Lights are "gritter" which may be due to the way its filmed and compressed. A 1080i frame has 2073600 pixels while 720P has 921600 pixels. Even if you take into account 60fps, 1080i has more potential for better quality. I agree with comments above that it's not always being taken advantage of. Fast motion will always look better at 60fps though.

Most shows HD shows downloaded from the internet are compressed with x264 and use 720P at 24FPS (Lost is originally 1080i) This size was chosen to fit the desired filesize (1.1GIG per 42min show) while keeping a high quality. The 1.1 gig size was chosen so you could fit 4 shows per DVD for archival.

Didn't know that i just assumed some channels in the states put stuff out in 720p and others in 1080i. As for the codec the ones i download are the MPEG2 TS variety. My HTPC struggles with h264 so until i can squeeze more speed out of it, or NVidia get their act together and write some faster drivers, i'm a bit stuck.

[pastro]

. A 1080i frame has 2073600 pixels while 720P has 921600 pixels. Even if you take into account 60fps, 1080i has more potential for better quality. I agree with comments above that it's not always being taken advantage of. Fast motion will always look better at 60fps though.

True, but deinterlacing causes blurring, and color artifacts that just don't happen with progresive frames, which lowers the resolution. In addition, sets that have anti flicker lower the resolution as well.

Never really thought about this, but if you had a progressive 1080p source and interlaced it, then deinterlaced it, that would look good except for the flicker blurrer. hmm except for the fact that you have to drop frames... ah well that's not going to look good either.