Why is there blocking on my OTA signal?

[EmpireState]

Hey, I'm sorry if this has been addressed before but I just wanted to send a quick question out. Why is there blocking during fast action shots on my OTA shows? NBC, ABC, CBS, etc...

I'm picking up these shows with my rabbit ears and I still see some blocking. I thought blocking was all Dish Networks fault. Turn's out I see it in OTA broadcasts as well when the action flies too fast for the picture to keep up with.

-thanks.

 

[ussexplroer]

don't know about you

I don't know about you. But I use two older tv's. A 19" from 1999 and a old sony 3 tube CRT projector from 1983. The reason I have not upgraded to a new lcd tv is mostly because of price. But also the tv's can't keep up with the shots. Though every year they get better and better. I'm sure many of us can remeber when LCD tv's first came out. How they was even worse.

Later,

Josh

 

[Jim5506]

It should be more obvious on NBC and CBS because they use 1080i whereas ABC uses 720p.

Do these stations have subchannels? If they do the loss of bandwidth to that subchannel is partially responsible for the blocking.

I was just watching the synchronized diving on NBC's Olympics coverage and relatively close shots of the divers spinning and moving around on the screen cause major blockiness problems with the NBC OTA signal here partially because NBC has an SD subchannel that robs some of the bandwidth from the HD channel.

Fortunately both my CBS and ABC affiliates have no subchannels so I do not see this on them.

 

[ozzy1028]

It should be more obvious on NBC and CBS because they use 1080i whereas ABC uses 720p.

Do these stations have subchannels? If they do the loss of bandwidth to that subchannel is partially responsible for the blocking.

I was just watching the synchronized diving on NBC's Olympics coverage and relatively close shots of the divers spinning and moving around on the screen cause major blockiness problems with the NBC OTA signal here partially because NBC has an SD subchannel that robs some of the bandwidth from the HD channel.

Fortunately both my CBS and ABC affiliates have no subchannels so I do not see this on them.

Yes, I read interlaced signals are more apparent in macro blocking. I notice it on my dlp also. I believe its just something we have to live with for the time being. The tv companies are bandwidth starved.

 

[Tron]

Compressed digital streams, regardless of their method of delivery (satellite, cable, or OTA), may suffer from macroblocking artifacts. This is evident when the bitrate of the stream is too low to handle the onslaught of data required to depict rapid movement, fine detail such as leaves or water, etc. It is not as visible (although it is present to some extent) on higher bitrate compressed video such as DVDs and Blu-Ray discs.