Could it be? 4k broadcasts [Archive] - Audio & Video Forums

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Mr Peabody
04-15-2014, 04:24 PM
This really don't give much info but apparently LG of all companies has devised some way of 4k broadcasts. What I want to know is if it's true 4k or 4k upscaling of some sort.
4K Broadcasts On The Way (http://hometheaterreview.com/bring-on-the-4k-broadcasts/)

Sir Terrence the Terrible
04-16-2014, 06:40 PM
Sorry, but this is not going to happen anytime soon. I was just reading in Broadcast Magazine that a poll of station owners and technicians say 1080p will come long before 4K. As a matter of fact, the poll stated that 33% are already setting up infrastructure for 1080p, and only 8% are even interested in looking at 4K broadcast.

Keep in mind. You have to have a lot of content to make 4K feasible(this was 3D's problem as well). You also have to have the station infrastructure to go along with the broadcast, and you must increase the power of your antenna to get all of that resolution into the airwaves. A 4K workflow is simply out of the budgets of most stations these days, and broadcast television is IMO a dying proposition at this point. The broadcast field is shedding jobs, and losing them to cable - it is not a growing industry that can support UHD broadcast.

Smokey
04-17-2014, 01:32 PM
I was just reading in Broadcast Magazine that a poll of station owners and technicians say 1080p will come long before 4K. As a matter of fact, the poll stated that 33% are already setting up infrastructure for 1080p, and only 8% are even interested in looking at 4K broadcast.

Keep in mind. You have to have a lot of content to make 4K feasible(this was 3D's problem as well). You also have to have the station infrastructure to go along with the broadcast, and you must increase the power of your antenna to get all of that resolution into the airwave.

I hope the last part did not come from Broadcast Magazine since technically that is not correct :)

Antenna power output is indepedent of its content and resolution. Type of antenna, transmission frequency, antenna height, physical coverage area and terrain determine the antenna power output.

Sir Terrence the Terrible
04-17-2014, 05:49 PM
I hope the last part did not come from Broadcast Magazine since technically that is not correct :)

Antenna power output is indepedent of its content and resolution. Type of antenna, transmission frequency, antenna height, physical coverage area and terrain determine the antenna power output.

So are you telling me that transmitting a 720p signal has the same bandwidth as transmitting a 1080p signal? Rediculous. Are you saying that you can broadcast signal with widely different bandwidths with the same power and get the same result? That is physically impossible. More bandwidth requires more power to transmit the signal over the same coverage area. There is four times the resolution in 4K than there is in 1080p. Do you really think that both resolution can be transmitted at the same power level, and there would not be visual artifacts?

Smokey
04-17-2014, 08:36 PM
So are you telling me that transmitting a 720p signal has the same bandwidth as transmitting a 1080p signal? Rediculous.

Bandwidth is different from transmitting power. You could have same transmission power with different bandwidth. Like when you could have different bit rate on bluray disc films. The bit rate is diffrent, but it is same medium.


Are you saying that you can broadcast signal with widely different bandwidths with the same power and get the same result? That is physically impossible. More bandwidth requires more power to transmit the signal over the same coverage area. There is four times the resolution in 4K than there is in 1080p. Do you really think that both resolution can be transmitted at the same power level, and there would not be visual artifacts?

It is not the main video signal that is transmitted. The video signal with different bandwidth is modulated into transmsision frequency (either in VHF or UHF band), and then modulated transmsision frequency is broadcast over the antenna into airwaves.

That is the reason signal strenght from antenna will remain constant whether the same channel is transmitting 480i, 720p or 1080i programs :)

Sir Terrence the Terrible
04-19-2014, 04:50 PM
Bandwidth is different from transmitting power. You could have same transmission power with different bandwidth. Like when you could have different bit rate on bluray disc films. The bit rate is diffrent, but it is same medium.

Unfortunately Smoke, power is not infinite. You have limitations enforced by the FCC. The only way to increase resolution without increasing power is to accept the fact that your coverage area will shrink. You cannot get something(increased resolution) without giving or giving up something.




It is not the main video signal that is transmitted. The video signal with different bandwidth is modulated into transmsision frequency (either in VHF or UHF band), and then modulated transmsision frequency is broadcast over the antenna into airwaves.

That is the reason signal strenght from antenna will remain constant whether the same channel is transmitting 480i, 720p or 1080i programs :)

You are making the assumption that all things power wise are going to be equal, and that is not the way it is in real life. I can accept the concept of the power being equal for all resolutions, however you have to compress your signal more aggressively as the resolution of that signal increases. Unless you want your signal artifact laden, you have to increase power when you up the resolution.

Smokey
04-20-2014, 09:38 PM
The only way to increase resolution without increasing power is to accept the fact that your coverage area will shrink.Sir TT, you still have to distinguish between resolution (bandwidth) and power output as they are not related. Antanna power output signal is a just merly a carrier embedded with video signal. The video signal can be low resolution or high resolution (higher bandwidth). It does not effect the power output.


You cannot get something(increased resolution) without giving or giving up something.

That is very much true. In electronics, its called "there is no free lunch" :)

What we are giving up when increasing resloution is signal's bandwidth. Each TV station have only 6 mhz of bandwidth to work which translate to roughly 19.4 MBits/sec of bit rate. And station can do whever they want with bitrate as long as it does not exceed it.

A station can have one full bandwidth HD 1080i channel at 19.4 Mbits/sec bite rate. Or less bandwidth HD channel at 12 Mbit/sec, and rest of bit rate is used for sub non HD channels with bit rate of 2 or 3 Mbits/sec.

Since maximum bit rate a station can have is 19.4 mbit/sec, if station decide to transmit higher resolution signal such as 4K which will have higher bit rate than 19.4 m/s, then they have no choice but to decrease bandwidth of 4 k signal (more compression) as not to exceed 19.4 m/s.


I can accept the concept of the power being equal for all resolutions, however you have to compress your signal more aggressively as the resolution of that signal increases.

That is excatly what is going to happen. There is no way around it. Station's 6 mhz bandwith is set in stone and can not be changed. Take a look at this chart which show Tv stations channel number and its associate carrier frequency:

Television Frequency Table (http://www.csgnetwork.com/tvfreqtable.html)

As you can see, each channel have 6 mhz of separation and unless FCC re-arranged the channel line up to have more than 6 mhz of separation, TV stations are stuck with that bandwidth which mean digitally they can have maximum of 19.4 mbits/sec.


Unless you want your signal artifact laden, you have to increase power when you up the resolution.

Only signal's bandwidth detemine the amount of artifacts and compression in the [video] signal. By the time it is ready to be modulated into transmission signal, its bandwidth and resolution has been pre-determined :)