HD for dummies

[kylera]

Can someone simplify the whole HD number list madness? A simple explanation and order of from "less" HD to "more" HD would also be nice.

[Elusive]

The numbers refer to your TV's resolution. Bigger number = better picture.

For example, regular old SD-TV - Standard Definition TV - is 420. 'Basic HD' is 720 - and as it has a higher resolution than SD-TV, is has a clearer, sharper image. Nothing intense, but it's like a layer of dust has been rubbed off your screen. 1080 is 'better HD', as it's at an even higher resolution than the others - so it's an even better, cleaner picture.

The letters p and i refer to progressive and interlaced video. They're simply different methods the TV uses to display images.

This image also shows the capabilities of different TV resolutions. (http://en.wikipedia.org/wiki/Image:Common_Video_Resolutions.svg)

That's really the basics. TV sets advertised as 'HD-ready' can be either 720 or 1080 sets. Check the fine print :)

[evildragon]

Ahem, SD is 480 in the NTSC world, 576 in the PAL world.

[j_factor]

Additionally, standard definition is only 480i. 480p is referred to as either "enhanced definition" or simply "progressive scan". They used to sell "EDTVs" that only did 480p (as well as 480i) but I haven't seen them lately.

Your screen is rendered in horizontal lines of pixels, starting at the top and going downward. If interlaced, half of the lines (in an alternating pattern) will refresh every 1/60th of a second. With progressive the entire screen is refreshed every time.

[evildragon]

Additionally, standard definition is only 480i. 480p is referred to as either "enhanced definition" or simply "progressive scan". They used to sell "EDTVs" that only did 480p (as well as 480i) but I haven't seen them lately.

Your screen is rendered in horizontal lines of pixels, starting at the top and going downward. If interlaced, half of the lines (in an alternating pattern) will refresh every 1/60th of a second. With progressive the entire screen is refreshed every time.
I actually have one of these EDTV's. Hidden thing, they can do 960i too.

[kylera]

Is there a difference between progressive and interlaced video? That is, something a viewer can tell?

[evildragon]

Oh yes.

Interlaced: Flickers
Progressive Scan: Doesn't

[j_factor]

The visual difference between 480i and 480p is actually pretty significant.

[Joe Redifer]

I find it fairly significant as well.

[evildragon]

I just watched Room 1408 today, with my PS2 set to 480p, and it was AWESOME.

I usually have it set to 480i and have the TV de-interlace it. NOOOO, have the PS2 read the "progressive" flag and output complete frames is far better.

Though, it seemed horizontally slightly "softer", but that could just be the cables I used.

[Joe Redifer]

There is no "progressive flag" in the context of which you speak. All DVDs can be played in either 480i or progressive. I don't recall the PS2 being able to play 480p which viewing DVDs, but maybe that was the Xbox. Anyway, deinterlacing sucks. It's best to screw with the video signal as few times as possible. If the DVD movie was authored correctly, then it is in progressive format on the disc and would have to be interlaced and then deinterlaced. Ug.

[evildragon]

There is no "progressive flag" in the context of which you speak. All DVDs can be played in either 480i or progressive. I don't recall the PS2 being able to play 480p which viewing DVDs, but maybe that was the Xbox. Anyway, deinterlacing sucks. It's best to screw with the video signal as few times as possible. If the DVD movie was authored correctly, then it is in progressive format on the disc and would have to be interlaced and then deinterlaced. Ug.
Slimline PS2s can play DVDs in 480p.

Btw, your wrong.

DVDs have a "progressive_scan" flag.


MPEG-2 also has a flag to indicate when a frame is progressive (that the two fields come from the same instant in time). For film content, the progressive_frame flag should be true for every frame. See 3.4 for more MPEG-2 details.

http://www.thedigitalbits.com/officialfaq.html

[kylera]

In the case of the PS2, as someone mentioned, in order to use progressive, would component cables be required? Sorry if this sounds so "duh".

[evildragon]

In the case of the PS2, as someone mentioned, in order to use progressive, would component cables be required? Sorry if this sounds so "duh".
Yes, Component video is the only way you can do that.

Matter of fact, if you use RGB SCART, it won't work, the PS2 only outputs a DVD via Component, not RGB (since the PS2s RGB pins also dub as Y Cr Cb..)

[Elusive]

Oh yes.

Interlaced: Flickers
Progressive Scan: Doesn't

Interlaced images give a much smoother moving image though ;)

[evildragon]

Interlaced images give a much smoother moving image though ;)
An illusion however.

[Joe Redifer]

Btw, your wrong.

DVDs have a "progressive_scan" flag.



http://www.thedigitalbits.com/officialfaq.html
That's not the context you were using it in. Obviously what you linked to is true (I author DVDs for a living by the way), but it seemed that you were saying that a DVD can tell a TV to be progressive or not. They can't. All depends on how the player is set up.


Interlaced images give a much smoother moving image though ;)

LOL!

[evildragon]

That's not the context you were using it in. Obviously what you linked to is true (I author DVDs for a living by the way), but it seemed that you were saying that a DVD can tell a TV to be progressive or not. They can't. All depends on how the player is set up.
I used it in the correct context, read it again please.

The PS2, when set in 480p mode, reads this progressive flag, and uses it to output a complete frame, that's what I said.


...have the PS2 read the "progressive" flag and output complete frames is far better.

With this in mind, the way the PS2's DVD 480p mode works, is it shows only frames with the progressive flag, and then you end up with 24fps video.

ANYWAY, lets forget that, it's a silly argument.

Because this is the ONLY way a PS2's 480p works, when you watch video content, it doesn't even TRY to deinterlace it, and you end up with interlacing artifacts. Sucks Sony missed that.

[Joe Redifer]

I think it probably outputs the 24fps at 29.97 by adding drop frames. I don't know if 480p can handle 24fps (or more specifically 23.98) at that rate without drop frames added. I know HDTV is supposed to, but somehow I doubt any sets show 24fps as 24fps.

[evildragon]

I think it probably outputs the 24fps at 29.97 by adding drop frames. I don't know if 480p can handle 24fps (or more specifically 23.98) at that rate without drop frames added. I know HDTV is supposed to, but somehow I doubt any sets show 24fps as 24fps.
Do this, because on a Mac with the Deinterlacer turned off, it does the same thing as the PS2.

Set computer to 60Hz, load a DVD on Apples DVD player, and turn off the Deinterlacer via the option in the menu.

That's how the PS2 does it, it literally relies on the progressive flag, and it does it decently.

There's no dropped frames at all, and it's not sped up or slowed down.

[Joe Redifer]

The PS2 cannot output a pure 24fps signal. It's 29.97. Same goes with most DVD players. You need to learn about drop frames, not "dropped" frames.

Also if video-sourced DVDs playing on the PS2 show interlacing artifacts, it is ignoring any and all flags and just outputting each frame instead of deinterlacing.

[evildragon]

The PS2 cannot output a pure 24fps signal. It's 29.97. Same goes with most DVD players. You need to learn about drop frames, not "dropped" frames.

Also if video-sourced DVDs playing on the PS2 show interlacing artifacts, it is ignoring any and all flags and just outputting each frame instead of deinterlacing.
That's what I said, it has no deinterlacer. It merely looks for a progressive flag if the video seems to be 24fps, and if it's not, it just shows anything.

What's the framerate Apples DVD player does when you play a DVD at 60Hz? It's the same exact that the PS2 does in 480p mode.

Either way, it plays smooth, no skipping sensation, and I don't give a shit about how it works. I already suggested we drop it, because it's stupid.

EDIT: Ok, I don't know about drop frames, so I will need to read about this. Suggest a link?

[Joe Redifer]

I don't give a shit about how it works.
Yes you do. I KNOW you do! Drop frames are added frames to bring 23.98 fps to 29.97fps. Basically every 3rd frame (out of 60 per second) is repeated once. It works the same in interlace mode, only with fields.
This is a good explanation (http://www.doom9.org/index.html?/synch.htm)

On a lot of commercial DVDs I still see quick interlace artifacts every once in awhile at a scene change when viewed in 480p. It is becoming rarer, thankfully. The cause of this is poor authoring/encoding. I have never seen this with 24fps material I have encoded myself, and I've done a bunch. Basically the reason the interlace artifacts would be there is due to the DVD player becoming confused while converting the 24fps to 30 (rounding up a few decimal points on my framerates here). Other players might show more artifacting, others less. The DVD should never try to "deinterlace" true 24fps material. I wish I knew exactly what they were screwing up to accomplish this.