Showing posts with label 1080p. Show all posts
Showing posts with label 1080p. Show all posts

Saturday, August 16, 2008

Online Class - Conversion to Digital Television - Part 3 - High Definition

In order for a TV station to broadcast high definition (HD) programming they must first be broadcasting in digital. HD is an extension of digital television. Just because a TV station is broadcasting in digital does not mean it is broadcasting HD. And further, just because you have a High Definition TV set doesn't mean that all programming you watch will actually be in high definition.

Two things must be true in order for you to watch high definition television. The TV station (or cable network, which I will get into later) must be sending an HD signal out over the airwaves AND you must have a TV that is displaying high definition receiving that signal.

What is High Definition? A super clear, superior picture with more dots of color to comprise that TV picture than was ever available with analog. There are really 2 types of high definiton. "P" for progressive and "I" for interlaced. You don't need to understand the difference other than "P" puts the image on the screen all at once and "I" put the image on the screen line by line. Television shows are not broadcast in 1080p, really only video games are capable of diplaying this high end of high definition. Television highest dots per inch is 1080i. The other type of high definition picture of TVs is 720p. As an example, the ABC network broadcasts its HD programming in 720p. The CBS network broadcast its HD programming in 1080i. The human eye, under normal circumstances would have an impossible time telling the difference between these two different type of HD. Both are very high quality.

The step-child of 1080i and 720p is "480". 480 is really the lowest number of dots per inch on the screen that you can have and still call it digital. 480i and/or 480p are not high definition, just regular digital TV.

The moral of this story: There are a lot of different kinds of digital TV

Stay tuned for more.

Thursday, December 27, 2007

Ask the Forum about HDTV - Questions and Answers

Do you have questions about High Definition TV?

If you’ve looked through our site and can’t find your answer, or don’t feel like searching, simply send your question to mainehdtv@gmail.com. We’ll do our best to answer you question as quickly as possible. We’ll send you the answer directly if you provide your email address and post your answer on the blog to help others.

Sunday, December 16, 2007

Why do satellite and cable companies say they have 100 HD channels?

This, to me, is the big lie about High Definition TV. There are now, and have been for a while, some very specialized channels that are in HD all the time. There is a network called HDNET which is a good example of this and HDMovies (I believe owned by the same people). You get these channels when you subscribe to the upper end HD package from you cable or satellite provider. There are a few other channels specializing in HD like the National Geographic Channel, Discovery HD, and so forth but this number is very limited.

Other nationwide cable channels like A&E, TBS, the Food Network, etc, claim to be HD channels. However they are still airing lots and lots of programming that is not really in HD but rather reformatted in a stretched out version of the original. Let me state an example.

TBS claims that all it’s programming is in HD. However, all of the re-run, syndicated shows of the past like Seinfeld, Home Improvement, Friends, etc, etc. were never filmed in HD when they were created so they aren’t in HD now and never will be. They may fill up your entire screen if you have an HDTV (16:9 ratio) but the picture will never be in 1080i or 1080p quality. They will simply stretch the picture to fit your HD wide screen but it will still be just as grainy as it ever was when it was produced. Even if the original tapes or digital format still exist, can you imaging how much it would cost to go back and re-engineer 200 episodes for Seinfeld and then redistribute them to every local affiliate that bought the rights to air it?

My advice: WAIT. If you really want an HD TV, get one, but get a UHF/VHF Antenna and pick up as many local programs in HD as you can that way. That’s what I do. When HDTV really comes into its own, then spend the money paying the cable company to receive more programming. In my opinion, it’s not worth it now. I had it all and got rid of it all because all of this supposed HD programming available is, right now, a big Hoax.

Why do I need special equipment to receive High Definition TV?

This is a question I recently posed to Doug Finck from WPME, WPXT.

I have a High Def television (tuner). I use a VHF/UHF antenna to receive over the air HD signals. I don’t have cable TV or satellite. A cable company essentially uses a big antenna to receive signals from satellites and send those signals down the wire to a cable subscriber. If that signal being picked up via the satellite is in HD, what stops it from being in HD when it gets to my house over the cable wire. In other words, if there was no cable box in between the signal and my TV, why would I not receive the signal in HD. Or better yet, does the cable box prevent me from receiving HD or is there something going on in that box that is doing the upconverstion. If the cable box is doing the upconversion, why does the signal need to be upconverted if it originated in HD to begin with. Is the cable company stopping the HD signal from showing up in HD format at your house over the wire so that they can charge you money to upconvert it?

Here is his response. (Warning: Contains some technical information but worth the read)

Good question! Our signal is modulated using an 8VSB modulation system. That is the only approved modulation system for digital TV broadcasting in the US. This modulation system is completely different than the old analog system of NTSC (regular old TV signals) which is why the two systems are completely incompatible. But cable does not send their signals to your house using the 8VSB (or NTSC) modulation system. Instead, cable receives an 8VSB digital signal and converts it to a QAM modulated signal. QAM compresses the 8 VSB signal and makes it smaller. Smaller signals use less bandwidth. The less bandwidth cable uses for each signal they send, the more signals they can send. Your set top box converts the QAM signal back to either an 8VSB for your digital TV or an NTSC signal for your analog TV.

This isn’t the only thing cable does to reduce the bandwidth. They also strip out the sub-channels from digital TV broadcasts. By stripping the digital broadcast signal of its sub-channels and then using QAM modulation to compress the remaining signal, cable is able to squeeze out additional bandwidth in the cable/fiber which can be used for more video channels, telephony, internet, etc. At this point the government has endorsed the practice of stripping and compressing signals as long as the primary signal is delivered and is not “materially degraded” in transit. Satellite uses some sort of compression algorithm as well as a different modulation system but I don’t know which ones. Again, they want to compress all signals and increase the number of signals they can offer. The result to the end user is that a pristine signal coming from a broadcaster is compressed or reduced in size to fit through the cable, then expanded to be recognizable by the TV. These two steps do not improve the quality of the signal and can degrade the quality. For the best picture, use an antenna and watch over-the-air HD. You’ll get the entire signal, uncompressed and just the way it was sent out!

What’s the difference between 1080i and 1080p? Should I buy 1080p or 1080i HD TV?

Some text is quoted from Doug Finck, General Manager of WPXT, Station Manager of WPME.

A more important question is what’s the difference between 1080i and 720p.

That’s because right now and in the foreseeable future, no television shows or movies will be recorded in 1080p. Broadcast, cable and satellite are not capable of delivering 1080p signals (and won’t be in the near future…if ever), the good shows are not going to be created in a format that can’t be appreciated via mass media distribution.

As for the broadcast networks, ABC, Fox, and My Network use 720p, while CBS, NBC, The CW and PBS use 1080i. You would be hard pressed to see a difference between the two.

1080p means 1080 pixels per inch in a “progressive” scan format. 1080i means the same pixels in “interlaced” format. Progressive scan broadcasting offers a higher quality picture so a 720p broadcast is similar to a 1080i broadcast. I’m not going to get into the technical aspect of this but I can tell you that unless you have better than 20/20 vision and you are sitting within 2 feet of your television screen, you don’t even have the chance of noticing the difference between 1080i versus 1080p, or 1080i versus 720p.

There are video snobs out there who call 1080p the only true HD, or Full HD. But does it matter if there is not any programming out there in 1080p and as I said won’t be in the foreseeable future. Broadcasters, cable, and satellite providers aren’t even up to speed on HD in general, let alone full 1080i programming which is the standard and what they are striving for.
Right now, 1080p is only being used for high-end web site video being downloaded (not streaming). The technology, and the need, just isn’t there. And 1080p uses up so much bandwidth over the wires and airwaves that it just isn’t viable in the near future for mass distribution.

Blu Ray and DVD-HD are viable for 1080p but Hollywood isn’t really willing yet to spend the money to get to 1080p.

If you really want to know some details, here’s a formula for determining the optimum screen size and pixel ratio:

The distance you sit from your TV screen determines whether or not you can
see the differences between 720p and 1080i. Specifically, beyond a certain
distance, the human eye and brain cannot see the differences. The formula
for determining that distance is surprising. Take the diagonal
measurement of your HD TV 16:9 screen (let’s use a 37 inch set for example
because that is very common) and multiply that number by 137% (in the case of
our example, that would give you the number 50.69, or just under 51
inches. So, if you are sitting more than 51 inches (or 4 feet, 4 inches)
away from your 37 inch diagonal HD TV, your eye and brain will not be able to
see any difference between the 720p and 1080i image. Most people sit more
than four feet from their TV screen. While a larger screen changes the number (a
50″ screen is “good” only up to 68.5 inches, 5.5 feet) you’re still talking
about distances that are far smaller than the typical living room set up.

I’m getting black bars on my HD TV. What DPI is non-HD?

Even broadcast networks (i.e. NBC, CBS, ABC) that have HD capabilities are not always sending out an HD signal.

Also, most local programming or re-broadcasted programming that originates from your local affiliate (like reruns of ”Friends”) is most likely not in HD either. When not broadcasting in HD (1080i or 720p depending on what network you are watching) stations operate in what is referred to as Standard Definition (SD) mode. That is only 480i. This results in black bars on the side of the picture. The official term for the black bars on the sides of an SD image, is “pillars.”

An SD broadcast (4:3) on a 16:9 display in the “normal” mode will have pillars on the left and right sides. Otherwise the user, or the broadcaster, has the option to “stretch” the picture from 4:3 to 16:9 on their HD TV resulting in fat, wide people. If you see black bars on the sides, top, and bottom of a picture, that means you may be watching an HD program in non-HD mode. So if you have an HD TV, you need to make sure you have set up your TV properly if you know that you have the availability to watch that station in HD. There are situation where, for example Fox Movie Channel, program is shown in letterbox format but the channel is not in HD. This will cause the pillars on the side and on the top and bottom.

Need help setting your HD TV to receive over the air HD broadcasts?

I’ve got a lot of information on this site to help. But if you need some more individualized assistance, I’d be happy to help. Send me an email at mainehdtv@gmail.com .

HD Basics - HD for Dummies - Old TV Sets and Digital HD TV

As of February 17 2009, all broadcasts will be digital. Digital channels have the ability to broadcast High Definition programming. However, if the program is not broadcast in High Def (it’s still digital, just not High Definition), you won’t receive it in High Def even if you have a High Def TV.

TO ME, IT IS ALL WORTH IT; YOU WILL BE AMAZED AT THE HIGH DEFINITION EXPERIENCE.

Viewers who currently get their signals “over the air,” using a rooftop antenna or rabbit ears, will have to make some adjustments. Either they will have to buy digital television sets, or they will have to obtain converter boxes to change the digital signals to analog.If you are a cable or satellite customer, you may need a set-top converter box to receive DTV signals and convert them into the format of your current analog television, even after the DTV transition is complete. A DTV set-top converter box may also receive multicast channels** and high definition programming and display them in analog picture quality. Check with your cable or satellite provider to determine if and when you will need a set-top converter box.

Ask what connectors you need to make sure your new DTV set works with your other electronic equipment (DVD player, digital video recorder (DVR), camcorder, VCR, computer, video games, and other equipment). The electronic equipment you have now should work with your new DTV, but you may need new connectors. Make a list of what you have now and ask your retailer what you need to connect the components.Why are we converting the U.S. television infrastructure? Digital technology delivers a much improved television picture and sound. Less obvious, but just as important, is that converting to DTV will free up parts (bands) of the scarce and valuable broadcast spectrum. The Analog spectrum will be returned to the government (FCC) by television stations. This spectrum will go to public safety services so our police, fire and first responders can communicate more efficiently; and to companies offering advanced wireless services.

The spectrum going to advanced wireless services will be auctioned, with the proceeds going to the U.S. Treasury.** Multicast channels - each digital TV channel is actually made up of four sub channels so you may see them referenced in a few different ways. For example if you receive channel 8, you may see it referred to a 8.1 or 8-1 meaning the first sub channel. The second would be 8.2 or 8-2. However, if a broadcast is in full High Definition (including wide-screen) there is less room left for other programming since HD uses up a lot of the available “room”. DTV comes in several levels of picture quality. The most common are:High Definition Television (HDTV) - this uses up the most amount of space on a 4-sub channel signalEnhanced Definition Television (EDTV) - This is bit lower quality than full HD and uses up less space on a 4-sub channel signalStandard Definition Television (SDTV). This is the basic display and will probably look like what you are watching right now on regular cable TV.If a broadcaster user SDTV they can probably broadcast 4 separate programs at the same time. With EDTV probably 3, and with HDTV probably 1 or 2 at most.Overall -Your current TV will work once the DTV transition is complete but you must have a digital set-top converter box to receive broadcast signals or be connected to a cable or satellite service. This converter box, much like your cable box, will allow you to receive a picture, but it won’t be able to show high-definition pictures or give you access to other digital services. To experience the full benefits of digital television, you will need a digital (preferably HDTV) television set.

Saturday, December 15, 2007

High Definition TV without paying Cable or Satellite companies

Click here for more detail about configuring your HDTV:
http://mainehdtv.blogspot.com/2007/12/high-definition-hd-digital-channels-in.html

I am now receiving 6 high definition channels without the need for cable TV. I live is Southern Maine and right now I receive the following:

CBS - Channel 13 WGME - see posting above regarding Digital/HD/UHF equivalents
NBC - Channel 6 WCSH
ABC - Channel 8 WMTW
PBS - Both the National Feed and Maine Public Broadcasting Network
CW - The new CW Network - Channel 51 - WPXT
MyNetwork Portland - The new MYTV network - Channel 35

As for FOX, we do have a Fox station in Maine called Fox 23. They only broadcast in HD to one cable TV company called Time Warner. I’m not sure that’s fair. If you don’t have Time Warner cable, which I don’t in my area, you can’t get FOX in High Def until February 2009 when they won’t have a choice.

That brings me to the fact that all of the details of HDTV - how to get it, what’s REALLY available in high definition, and questions of this type are the details that most of the general public don’t have a clue about.

I actually had to call WGME channel 13 to let them know that they were not transmitting their over-the-air signal in HD format. The gentlmen I spoke to told me that due to vacations and lack of staffing education, someone forget to “switch it over” to full high def at the proper time. The problem was fixed about 15 minutes later. This got me wondering about the kind of manual intervention involved at television stations in order to broadcast in HD. I was also told that broadcasting in HD is more expensive so I have a lot more question about what that really means in terms of the broadcast tower and what is really going on there, but I will need to investigate that separately.

What the station manager really meant was that most television stations have been converted to digital broadcast towers. However, just because their tower is digital, does not mean it transmits in high defition 100% of the time. Also, they get a feed from the network with has to be in HD format before they can even think about transmitting it locally to HD. Even if HD is available and the station decides to transmit it in HD, someone still has to flip the switch at the local TV station. This affects both cable/satellite views and over-the-air views like me.
Doesn’t this all sound confusing? I know, it really is and so few out there know how all of these pieces work together. People think that if they go out and buy a High Definition TV, they’re all set. Well, I’m here to tell you that they are not.

To get HD, I originally went through the my cable company to:
1) upgrade to digitial cable2) pay for the upgrade to a high definition cable box3) buy a high definition television

After all was said and done I had a monthly cable bill that totalled about $118 dollars a month and only received about 12 high definition (capable) channels.

There are only about 6 non-local broadcast channels that broadcast in HD all of the time and they include:
1) HD net2) Wealth TV3) Discovery HD4) National Geographic HD
and a few others I can’t remember right now.

Addtionally you will get one HBO, one Showtime, one Cinemax, and one Movie Channel HD channel IF YOU SPEND EVEN MORE TO SUBSCRIBE TO THESE PAY CHANNELS.

I must admit I got sick and tired of all the money spent and my misunderstanding of the technology and what I am getting for my money. I found out that HDTV signals must, by federal law, send their Digital/HD signals over the air just like conventional television stations signals effective 2/19/09 but most have done this already. Once I found this out, and bought the right antenna for a one time charge of $65, I received the 6 HD channels I first metioned in this post.

I do believe that the cable companies and satellilte companies are intentinalloy leaving consumers in the dark about what HDTV is all about and what’s going on behind the scenes with the technology and what is truly available in HD. One program director from one of my local stations said “we’ve done a terrible job of educating the public on digital/HD programming”. As a result, a lot of consumers are spending money and are not getting what they think they are supposed to be getting.

I’d be happy to talk about this in much more detail with anyone who is interested, please let me know.