HDTV broadcasting question (1 Viewer)

[Doug Smith]

Just purchased a new digital cable box for my HDTV ready Toshiba. So I can now watch the pitifully few programs out there on my local cable carrier (Shaw). Last night I was watching CSI on High Def - with Dolby surround - how is this being broadcast in 1080i, 480p, or what? And is there any way to tell? One thing positive to say about the local cable company is that they have taken all High Def programming and no matter which network it is coming from , put it on one of three channels (and then fill up the remaining time with High Def films).

 

[Patrick Sun]

CSI is HD 1080i.

If your HDTV tuner/receiver displays a programs with black or grey bars on the sides, it was an upconverted 4:3 aspect ratio show, but it's just SDTV in terms of resolution. More likely, if you get the full 16x9 aspect ratio on new shows in HDTV, then they are true HDTV programs with 1080i resolution.

There's a lot of SDTV shows being broadcasted on the HDTV channels (the sidebars are the tell-tale signs).

 

[Michael St. Clair]

I have a Scientific Atlanta 3200HD box.

In December, SciAtl announced a new 4200HD box that should be out really soon (if it hasn't snuck out already). It will give you full control as far as 480i/480p/720p/1080i goes. It also lets you stretch things around. This will give us greater control over how standard-def material looks on our sets.

 

[Chris_HD]

Charter has said that they will have new HD settops available in the spring that will provide scaling. I am waiting for one.

 

[Doug Smith]

Yeah, mine is a new Motorola 5100 - apparently they've only been out a few months. It allows you to make the changes in both screen size and 480i, 480p, 780p, and 1080i. Underneath these items in the menu it then asks a default question (back to 480i or p) which I have switched off. Are these the correct settings (my screen is 16x9)? I'm rather new at this! Also is 1080i the best resolution (of the above mentioned) that I can receive? If a program appears with grey or black lines down the side does this mean it is NOT in high def? Thanks in advance for the info.

 

[Steve Schaffer]

Doug,

Use 1080i for HD stuff. 720p and 1080i are the 2 scanrates classified as HD, but your set won't display 720p natively. It converts incoming 720p to 1080i. The fewer conversions the better. 720p is the native scanrate for a lot of plasma sets, and the format used for ABC network HD and the upcoming ESPN HD.

For regular 480i brodcasts, try both 480i and 480p and see which looks best on your set.

 

[Doug Smith]

Thanks - but what about the grey (black) lines on the side? Am I not getting high def?

 

[BruceSpielbauer]

The truth is that anything which is truly high definition is in widescreen 16 X 9 format. This is actually one part of the definition of high definition.

A technicality, perhaps, but one to keep in mind, if we hope to avoid cases similar to Fox (which uses its Faux enhanced definition in widescreen, and hopes that the general public will never understand anyway). By definition, true HDTV must be in a 16 X 9 format. This is a part of the ATSC standard.

Now, that said, a good general rule is as follows: IF you see those bars or bands at the side of the screen, you are most probably viewing standard definition programming. In some cases, it is standard definition which is being "upconverted" and sent out as one of the high definition formats in terms of scan lines (1080i or 720p, for example). However, it is still really a standard definition upconvert. I have seen only very, very rare exceptions, and these two both happened to be older films which had actually been mastered in high definition, but the aspect ratio of the films was very close to 4 X 3 (since they were much, much older films). A Citizen Kane or a King King or similar films from the 1930s and 1940s might end up in the rare instance as a high defintion transfer, but with those bands at the side (in a 4 X 3 format). These exceptions are so rare that you can almost ignore them, though. That is because the original (older) film actually was in 1.33:1 or 1.35:1 aspect ratio, which is basically a perfect match for 4 X 3, and is not at all "widescreen."

And, the converse is not true. There are some stations showing widescreen all day, even though they are broadcasting mostly standard def. They are doing their own form of stretching and cropping. My ABC local affiliate does this. So, on that digital local station, I see all of the standard def stuff in 16 X 9, even though they might be broadcasting a standard def show at the moment. This is similar in a way to HBO, which will take very, very widescreen films on HBO-H (their HDTV network), and show it at exactly 16 X 9, even though it should not be. The station is doing their own form of "stretching" or "cropping" or "zooming."

Now, to those bands... there has been some misleading information already regarding those. One post above mentions a set top box which can control the aspect ratio by allowing various stretch and zoom and cropping modes. Many set top boxes have these. Mine has five of these, for standard definition. BUT... be aware: sometimes those masking bars are actually being broadcast by the statsion or the networks. A very common example is a high defintion showing of a major motion picture on NBC. It is presented in 16 X 9. Then, a commerical comes on. It was a standard definition commercial, so it has bands at the side. Sometimes, these bands are actually coming from the broadcaster. Your set top box will not let you "zoom" or "stretch" or "crop" because you are watching something which is in 1080i. The movie ends, and a reality based show comes on the same statsion. It is standard def. It has the same bands at the left and right. Again, you are still watching a 1080i feed, from the local station, so you cannot "zoom" or "stretch." You could change to the non-digital station, in many cases, and you see no bands. Or, you can change to a lesser format with the box, sometimes from the remote, and then stretch the picture. This is a common occurrence, with many of the digital stations today. Many of them send the signal in 1080i, and upconver the standard def stuff, and add their own bars to the standard def stuff. (And, the bands added by most of my 9 locals are black, not gray, which increases risk of uneven phosphor wear -- grrr.)

Now, are you thoroughly confused?

There is not a lot of consistency out there, yet. Obviously.

Just thought I would mention it...

-Bruce in Chi-Town

 

[Doug Smith]

Thanks that helps a lot. On final question - in my digital boxes setup mode it asks you three basic questions:
1.) screeen size - easy in this case 16x9
2.) output - now easy thanks to above info.
3.) 4:3 override - this has three options 480i, 480p, and off - I have presently set this to off. But what the heck is this setting for?
Thanks again.
(By the way none of my smart remotes has Motorola in its choices for cable boxes - are they THAT new?)

 

[Doug Smith]

Forgot to mention one more thing. I have a Toshiba 57" HDX - this T.V. has 4 theatrewide settings. With the new digital box, I cannot now access the full setting. Also theatrewide 1 which is the recommended stretch setting for 4:3 sources (and works well in the lower analog channels) now really makes the digital pictures looked abnormally stretched - I've had to switch to theatrewide 3 (which loses part of the picture). Is this normal?