Buying into High Definition

MediaManMediaMan Powered by loose parts.
edited June 2006 in Science & Tech
The lure of high definition Television is strong but is an HDTV right for you? Learn now about formats, sales jargon and steps towards a better purchase.

Read it here

Comments

  • edited June 2004
    Lots of incomplete, incorrect, or misleading information here.
    Progressive modes are at 60 FRAMES per second, not fields, and 1080i is actually 1080 lines of resolution - more than 720p, but at 60 fields per second. This is very important information.

    A picture really IS upconverted frpm 720p to 1080i, however at a slower total framerate. Listing 1080i as "1920x540" is just plain wrong, mathematically you can account for the total pixel bandwidth this way, but it is still wrong. Imagine if I called a 10'x10' square a 20'x5' square because it has the same area. Upconvert and Downconvert actually do mean something when you understand what is really going on.

    Running a game at 720p on a 1080i native resolution set will not cause problems as long as the image scaler isn't crap.


  • MediaManMediaMan Powered by loose parts.
    edited June 2004
    And here we see the great argument begin. This is the trap people fall into with regards to 720p and 1080i.

    First and foremost. TV is 30 frames per second. NTSC signals are divided into two interlaced fields: A and B. A and B make up one frame as I had explained.

    Progressive scanning is the presentation of a complete picture. Our unregistered guest sort of correctly assumes that if a complete picture was presented on field A and B then math dictates 2 fields to a frame and 30 frames per second then you'd get 60 frames per second. I can see how this happens but he's wrong.

    The progressive frame is repeated from field A to B so it counts as one frame since it is the same image. TV stays at 30 fps....not the 60 the guest wrongly assumed. (But let me check the standards committee at ATSC just to make sure. Also I'm speaking of NTSC TV and not film of 24fps or with the 3:2 pulldown.)


    Now as to the 720 vs 1080i aspect. This again is the great debate. BUT...yes 1080i is 1080 lines of resolution but of an INTERLACED image. The image is present field A and B and each field contains only 540 lines of resolution.

    NOT 1080. For that to occur it would have to be 1080p which is a format not supported. It can be argued that 720p is a progressive image therefore a complete image all at once of 720 lines of resolution vs. the 540 of the interlaced image in 1080i. It's a six of one half dozen of the other. Yes it is 1080 lines of image BUT some argue that the interlacing degrades the image and so on and so forth.

    Again...as I said in the article not one or the other is better. I didn't say that 720p was higher resolution than 1080i or vice versa. I just presented what the confusion is...just like our guest...people making the incorrect assumptions.
  • edited June 2004
    It makes sense to you to broadcast the same frame twice for progressive?
    Look:
    480i -> 480 lines of resolution drawn odd lines and then even lines at 60Hz, which is 60 fields per second, totalling 30 frames per second of data (not actual frames)
    480p -> 480 lines of resolution drawn one frame at a time at 60Hz, totalling 60 frames per second of data.

    Of course the mpeg-2 compression allows for a variety of different formats, but as a general rule if your HD station is progressive, it's at 60 frames per second.

    See below for ATSC's standards. (AKA the horse's mouth)

    http://www.atsc.org/standards/a_53c.pdf

    Page 29 -> 36. You'll find of interest Tables A1, A3, and A10. You'll notice there are only three different line resolution for input formats, and also that 59.94/60Hz frame rate. I assure you all 720p stations in my reach _are_ broadcasting at 60Hz progressive which is 60 frames per second. Also you see that interlaced and progressive video formats reference the same line count SMPTE standard.

    Less engineering oriented here:
    http://www.atsc.org/standards/a_54a.pdf

    Pages 24 and 25, Tables 5.1, 5.2 and section 5.2.1.2 Those picture rates should be a clue. As you can see the subject is much more complex, however in reality stations are broadcasting at 60I or 60P.

    A still picture at 1080i and 1080p should be identical, if not, you've been ripped of by your set manufacturer/salesmen/etc. Even a set capable of drawing 1080 lines it may not actually be able to display it because the beam size is too large to allow for 1080 distinct lines. Try writing a letter by hand with a super-magic-marker.

    http://electronics.howstuffworks.com/hdtv1.htm
    "Progressive scanning shows the whole picture, every line in one showing, every sixtieth of a second. This provides for a much smoother picture, but uses slightly more bandwidth."

    As for one being better than the other, the both are - for their respective uses which becomes clear when you understand the formats.
  • TexTex Dallas/Ft. Worth
    edited June 2004
    One area I wish you had touched on perhaps is the new influx of PC tuner cards that are claiming HDTV capabilities perhaps.

    Tex
  • MediaManMediaMan Powered by loose parts.
    edited June 2004
    Tex.

    Yes...would be interesting.


    Unregistered Guest.

    You've opened up a can of worms with respect to 720p and 1080i and variable frame rates. (24, 30 and 60 fps). It's going to make life shooting behind the camera - to going to editing - to broadcast and definite challenge for engineers. Now throw the 3:2 pulldown into the equation and it becomes even more of a challenge.

    The point of my discussion is that hi-def is in its early stages for the home consumer. Many are confused as to what to buy or which TV. The big players in the industry continue to duke it out as to which format is the "best".

    It will be interesting for the rest of the broadcast industry. Reminds me of the betacam vs. vhs bandwagon.



    UPDATE:

    For those who are reading this our guest has brought up an interesting point. I will delve into it further.

    720p and 1080i frame rates can be 24, 30 or 60. Higher frame rate doesn't mean more data information in the picture per say but a higher frame rate means that you can "freeze" an image at a given point with greater detail. Example: If you are shooting a car race and the race car zooms buy you in one second. The camera is stationary and isn't following the car.

    At 24 FPS it the car would be captured over 24 frames. (24 frames of image over 1 second.)

    And so on for 30 and 60. At 60 the same 1 second of motion is captured over 60 frames therefore the motion is "chopped up" into smaller timeslices. You'll be able to isolate the motion with greater detail.

    Now this isn't a discussion of which format, 720p or 1080i, has greater detail in the image but one of frame frate for the moment.

    The "oh crap" for broadcasters is which format to jump on and how to broadcast it. Here is where I must extend an apology to our guest as he/she pointed out very good information. The three most discussed frame rates for broadcast are 24, 30 and 60 FPS be it 720 or 1080 or even 480.

    The real pain in the arse for broadcasters is conversion depending on which way they leap for equipment. DTV networks who are moving to broadcasting in HD (ABC, FOX, CBS, NBC) are tossing about a mixture of frame rates but not necessarily a mixture of formats. ABC and FOX look as though they are leaning towards 720 and an all progressive network. NBC is dabbling in 1080i.

    Now here is where I went astray. Say if the superbowl is shot in hi-def with 1080 cameras at 60 FPS. If you had a TV and hooked it straight into the broadcast truck and the TV could display 60 FPS 1080i then you'd be watching a 60 FPS 1080i signal.

    BUT...the variable is how that signal bounces around before it finally gets to you. It may not be a direct line. It may pass through up/down convertors at the source, cable or satellite provider or even the affiliate station. Your TV itself may do some sort of conversion too. The HD purists are going to have a field day with this and "videophiles" will debate till we fall over. Marketers will love this...in a way. Can you see the ads now? "The ONLY PURE 1080 HD set or the ONLY pure 720 TV".

    The ability to display variable frame rates isn't glaringly obvious in specifications of an HD set. To be honest...I cannot actually say for certain if it is an issue to be concerned about. Will the HD set of choice automatically adapt itself to 24, 30 or 60 FPS in either of the 3 formats (480, 720 and 1080) depending on the signal its fed? Will you notice? Or is there some internal conversion inside the TV depending on brand, make and model?

    The mind-splitting discussion goes much further than how to buy an HD set. Get deeper into it and there are many things out of the consumer's control or what they really should be concerned about at this moment. It's going to take years to settle down the formats and frame rates into some sort of "norm". It's also going to take LOTS of money on the broadcaster's side to re-tool. Remember there are 100s if not 1000s of TV stations, cable and satellite providers in North America and each is getting a signal from somewhere and re-broadcasting it. It depends on how that signal is treated from source to end consumer.

    It can make your head spin.

    Thanks to our guest for bringing new aspects to the discussion. I'll see if I can tap some of my sources higher up in the larger networks to get further into this plus if any manufacturers are willing to divulge their own conversion practices.

    For now...an 16:9 HD-ready TV is a wise choice for your next upgrade. :)
  • edited June 2004
    An emphasis on signal source as affecting the advisability of buying HDTV is in order. HDTV over the air signals are prone to break up and become unuseable when the same antennna and the same channel is fine with an analog (regular) signal. This can be caused by rain/snow, upper air storm, or even wind blowing trees near the antenna.

    Satelite HDTV signals are available for only 10-15% of the channels and none of the local TV channels yet.

    I had to spend $1500 on antennas, rotors, dishes and wiring. No that didn't include converter boxes or TVs. And I get excellent reception only about 50% of the time. Yes I've had the antenna people out repeatedly.

    If you live in an area with beautiful sight lines to transmission towers or a cable system that provides a high number of Hi-Def channels, it is a different story.

    But if there is any doubt, get the antenna installers out to measure your signals and get an antenna quote before buying.
  • MediaManMediaMan Powered by loose parts.
    edited June 2004
    Good advice (I wish these people would register so I could use names. :) )

    The other great debate is satellite vs. cable for PQ (picture quality). Pros and cons of both.

    What is known at this time for certain.

    1) Buying a Hi-Def TV will provide a better picture quality becasue you're getting new electronics vs. your old 27" that you've had for years and years. This is based in my own experience on CRT direct view tube comparisons. I temper this by advising that when you do go to larger screens (40 inch plus) that normal TV risks becoming degraded because the picture is blown up too large for some tastes. Best advice? Go look and compare at two stores at least.

    2) DVD content will look better with component video (those 3 cables). How good depends on the type of TV (CRT RPTV, direct view, DLP and so on). Again...take your favorite DVD because you know what it looks like and go to a store and have a looksy.
  • TexTex Dallas/Ft. Worth
    edited June 2004
    Crap now you got my interest peaked and I spent houring searching for options on the friggin hdtv PC tuner cards dad gum you MediaDude !!

    Like I didn't have enough to do without opening this can of worms. I wasted half my day I usually have set aside for porno site surfing, looking for hdtv tuner cards...... You think the HDTV consumer TV market is immature and confusing, try the HDTV PC tuner cards.

    Ahhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh

    Get your reviewer hat back on and start asking for samples NOW ! (grin) with your TV broadcasting background you should be able to get samples of HDTV cards easy dude.

    Save me from myself before its too late.

    Tex
  • GobblesGobbles Ventura California
    edited June 2004
    there is hype and sales jargon but have you actually watched an HD broadcast on and HDtv, its friggin beautiful compared to a crappy standard cable feed. My folks have an HDtv 42"" samsung and they have several hd channels and the picture is perfect for those channels as is the sound and in the end, thats whats gonna matter.

    You can spit technical facts at people all day long on a sales floor and your at best gonna get a deer in the headlights look from most people, but when they see a HD broadcast on and HDtv they will be sold.

    Gobbles
  • MediaManMediaMan Powered by loose parts.
    edited June 2004
    Now I don't know what it's like in the US but here in Canuckland there is a trap for HD broadcasts. Well...not really a trap but a "I didn't think of that".

    Regardless of an HD-ready set or an HD-tuner card for the PC you still have to subscribe to a service and get their decoder at a cost. For example and these prices are just plucked out of thin air for example purposes.

    Step 1) Regular cable. You pay for that and it comes out of your wall.

    Step 2) Digital Television (remember DTV has HD and SDTV but for now the providers are refering to the SDTV channels as Digital Television) You pay for the regular cable and now you have to buy/rent a decoder STB. Be it Satellite or cable.

    Step 3) Teh full meal deal. Bigger big bucks for the HD decoder STB. Be it satellite or Cable. That can set you back 100's of dollars for the 6-10 available HD channels.

    Definitely falls into the luxury spending budget.

    So you might get an HD card for the PC but don't expect to plug it into the cable in the wall and immediately get HD channels. :(
  • TexTex Dallas/Ft. Worth
    edited June 2004
    Comcast claims many HDTV channels are available for the normal subscription price in many areas. You need a hdtv and comcasts cable box. You pay extra for extra premium channels and some of the all hdtv channels but they offer the major networks (ABC, CBS, etc... and espn etc...) included in a regular cable subscription price.

    Tex

    p.s. here is the blurb from comcasts site om hdtv from them

    There was a time when you thought your old TV looked just fine. Then you saw HDTV. The clarity. The vivid color. The wide-screen format. And your only question was, how do I get it? If you have an "HD-capable" or an "HD-ready" TV set, a Comcast HD box is the only additional equipment you need (available for a small monthly fee). So there's no need to buy a separate HD receiver, decoder or antenna. And no long term contracts.

    A broad selection of HD content. Unlike satellite, with Comcast you can watch local broadcast channels (like ABC, NBC, CBS, and PBS*) in HD without an antenna. So you can see the prime-time and sports programs that you wanted to watch when you bought an HDTV set. In addition to our HD programming, in many cities Comcast offers the enhanced viewing experience of FOX Widescreen.

    Plus, you get great HD networks like ESPN HD which offers over 100 high definition games a year and selected ESPN original programming. Also, the INHD and INHD2 channels offer an exceptional variety of sports, movies, travel, and nature programming - all in high definition.

    Finally, at no extra cost, premium subscribers can catch their favorite hit movies and many ground breaking original series from HBO HD and SHOWTIME HD. And for HD movie lovers, STARZ HD and CINEMAX HD are coming soon.
  • gtghmgtghm New
    edited June 2004
    In all of my research unforutniately Comcast has the most HD channels to choose form.
    I have been looking to dump Comcrap but I just can't now that I've gone HD.
    And for the record I've been watching HD for about a year now and yea its the snitz... :)

    Comcast boradcasts channels INHD 1 and 2 and even though they are a little slow to update their programing content these 2 channels are broadcast in the best HD signal Comcast can send and you can see it... Realy amazing stuff...
    They run a lot of stuff that was shot in IMAX and all I can say is wow.
    They are also broadcasting our Mariners in HD like they did last year and if you had watched last years games you can see that they are playing with the depth of field on these cameras. Last year you could plainly see the crowd. I mean so clear that you could see what a guy was eating and stuff.... This year I noticed that in certian shots the crowd is being blured out especially on the close ups which quite frankly is too close... I really don't need to see the hanger in the pitcher or batters nose... LOL
    Definately a big difference in pic quality....

    Oh a word of warnig to perspective HD buyers....
    Regular cable signals look like crap on all HD sets.
    In all of the sets I demo'ed before I got mine the regular 480 sig looked realy crappy. If you are not going to get an HD reciever or OTA antenna with a box that can pump the HD sigs to your new HD then wait.
    You will not be happy watching regular TV on a 1080i HDTV.
    There are certian models that look better with the regular cable signal, but none of them, even the highend Mits and Pioneers, looks as good as a regular old 480 4:3 set when viewing the regular cable signal, so if basic cable is what your going to watch then I would wait.

    DVDs are great too but the DVD player does make a difference along with componet cables.
    I had an older Tosh DVD player that was progressive scan and I replaced it with the Panasonic XP30, before they discontinued them, the difference between the two pics on my HDTV is quite noticeable.

    Just as this forum is here for us comp/tech geeks there are lots of forums and info out there on HDTV's and DVD players.

    I found the hometheaterspot.com was a great source of info and they have a lot of techs that frequent that site, but thats only one of many out there...

    Hope this helps someone good luck,
    "g"
  • MediaManMediaMan Powered by loose parts.
    edited June 2004
    gtghm wrote:
    Oh a word of warnig to perspective HD buyers....
    Regular cable signals look like crap on all HD sets.
    In all of the sets I demo'ed before I got mine the regular 480 sig looked realy crappy. If you are not going to get an HD reciever or OTA antenna with a box that can pump the HD sigs to your new HD then wait.
    You will not be happy watching regular TV on a 1080i HDTV.
    "g"

    I'd like to disclaimer that if I may. Regular cable looks like crap on any 40 inch plus TV because the standard 4:3 tv picture is blown up beyond it's comfortable broadcast size.

    Regular cable on my 34" Toshiba HD looks better than my old 27". Simply because this is a CRT direct view tube and they do the best job at the middle ground between large size and pq.


    BTW G?

    May I ask what you are paying for monthly bill and what the STB cost?
  • TexTex Dallas/Ft. Worth
    edited June 2004
    mediadude I updated my post with comcasts blurb on their hdtv offerrings

    As usual I think you canucks get screwed on pricing again. It seems everything from computer parts to hdtv costs you guys more up there.

    Tex
  • MediaManMediaMan Powered by loose parts.
    edited June 2004
    Tex wrote:
    As usual I think you canucks get screwed on pricing again.

    ;D Ya...sometimes we feel like 2 dollar hookers down at the Navy docks.
  • Geeky1Geeky1 University of the Pacific (Stockton, CA, USA)
    edited June 2004
    Are those Canadian dollars? :D
  • gtghmgtghm New
    edited June 2004
    Basicaly I have the whole comcast cable tv package except for The Movie channel and Cinemax. I don't subscribe to any sport packs either but I still pay like 80 bucks a month.

    I have done the research and while satalite might be cheaper or I could go with the tax payer cable network from the city of Tacoma called "Click" but they are all within 10 to 20 bucks a month for simular channel packages but when it comes to channel line up comcast does have the most and right now they have the most HD channels as compaired to the others includeing the new Voom.

    I do not have or use a STB but they run about $250 and the antenna runs between 40 and 70 bucks US.

    Thanks Media dude, your right about the 4:3 being blown up and looking bad on the 40"'ers and above... I should have been more clear about that but even still when regular programs are broadcast in the larger format like they do for some movies on the non-HD HBO you can still see a huge difference between the 480 and 1080i pics...

    Later,
    "g"
  • edited January 2005
    Enjoyed the article. Understand a little more about HDTV. Nice work.
  • rykoryko new york
    edited June 2006
    good read...lots of info to digest, but the bottom line for me is that there just aren't enough HD channels available to justify me dropping 1k+ on an HDTV (not to mention cable/satellite costs per month).

    really, you get like 20 HD channels if you are lucky. untill all channels are broadcast in HD sometime in 2009, i don't think i am going to bother.

    also, my friend has a 27" LCD 1080i HDTV, and regular cable looks like crap on it. so i don't believe that it is only 40" or greater sets that screws up regular SD broadcasts. it is not from the strecthing of 4:3 to 16:9, but the fact that the resolution of SD broadcasts is so low compared to the native res of an HDTV. I know this is the case, b/c i have a standard tv tuner on my pc with a 17" LCD and regular cable also looks like crap here.

    and tv tuner cards is another story. we are still waitting for CableCard ready tv tuners and it now looks like they may never come b/c cable/satellite providers are slow to adpot the standard. not to mention the numerous revisions of the CableCard spec. CableCard was suppose to remove the cable box from our lives so that your new shiny 50" plasma didn't have an ugly box attached to it. but cable/satellite providers want to push their new do-everything-and-more boxes on us so no CableCard, and no HDTV tv tuner cards compatible with cable/satellite boxes.

    yeah...consumers get screwed again!
Sign In or Register to comment.