Is over-the-air HDTV signal better than cable or satellilte?

Question

I was listening to a popular radio consumer advocate. He said that you will actually get a better picture using an antenna to get your HDTV vs. cable or satellite. The reason given was that cable and satellite have to compress the signal, but free over-the-air does not.

In the computer world, there's lossy compression, like JPEG, where some clarity is lost. Then there's ZIP where no data is lost and you receive a perfect reproduction.

So I guess their are 3 questions:

1. Is an over-the-air signal compressed or not?
2. Do cable and sattellite companies use a "lossy" compression scheme for the HDTV signals.
3. Is it true that the HDTV picture is superior if received from over-the-air transmission.

To Pancakes - HDTV has resolutions of 1080i and 720p, both superior to progressive DVD which is 480p.

Answer 1

The ATSC standard for HDTV transmission is MPEG-2 compression and 19mbit data rate. OTA and cable both use MPEG-2, as does most satellite transmission. Some recent satellite local stations are compressed with MPEG-4. All HDTV is compressed. However, the MPEG specs allow for different amounts of compression and different qualities. When OTA utilizes the full bandwidth for a single HDTV channel at 19mbs, you will get the best quality obtainable from HDTV. However, many OTA stations will broadcast several programs on sub-channels simultaneously with their HD channel. That steals bandwidth and bitrate from their HD channel, and if that is done too much, the HD picture quality will suffer (the subchannels are usually not HD). So you cannot lump all OTA into one category for picture quality.

The same is true for cable channels; they have the option of retransmitting the exact signal broadcast, in which case the cable will have the same quality as the broadcast. However, some cable systems will decompress and recompress the signal so they can use a lower bitrate and less bandwidth. If they do that, the cable's picture will be poorer than OTA. It is also possible for the cable to receive a higher-quality signal from the station (less strongly compressed) that the networks use to distribute their HD content. If the cable system then compresses that signal to a high bitrate, but the broadcaster limits its bandwidth, the cable signal would be better. i do not know if this latter approach is being used by any cable companies at this time, but it is a possibility.

Finally, satellite compression is often more severe than OTA or cable, and my experience with satellite HD is that for the major networks, it is not as good as OTA or cable. However, special HD channels on satellite (HDnet, Discovery HD) are excellent.

In summary, the answer to our question is: it depends.

Finally, all MPEG compression schemes are "lossy". It would be impossible to get the HD picture in the allotted bandwidth with lossless compression. But the degree of "loss" is flexible and up to the party doing the enccoding.

Answer 2

Over Air Hdtv

Answer 3

HDTV pictures are superior to analog, period, unless the HDTV station is reproducing an analog picture.

HDTV is either there or it isn't. If an HDTV signal is strong enough for you to receive, then it will be of maximum quality.

Yes, HDTV signals are compressed while analog over the air signals are not, but the HDTV picture is still superior to analog. Cable or Satellite analog signals may be compressed, but that doesn't matter much, since analog quality is far inferior to start with.

As far as satellite or cable companies compressing HDTV signals, I don't know much about that. In my area, my cable company does not provide any HDTV content, so I must use over the air stations to get any HDTV at all.

Answer 4

I believe that the compressed signals are verified in packets before sending to the processor, even if it slows the reception down (by a few milliseconds), so picture quality should not suffer. I have not heard that over-air transmissions are not compressed. I believe they would have to be to be compatible. But, I'm not a popular radio consumer advocate.
HDTV cable, satellite, and over-air should be the same quality as a progressive scan DVD.

Answer 5

on-the-air is not compressed but cable does compress and lost resolution is lost but most people can't tell and Satellite company's generally use the latest compress tech i think they are going to switch over to MPEG 4 which is a very good compression standard. and cable must compress because they do not have nearly enough bandwidth to support that many HD channels and soon when the telephone companys upgrade their copper networks to super high speed fiber optic cabling they will be able to sent uncompressed HD channels i think the first one to do that will be at&t since sbc bought out AT&T and changed their name and then bought Bell South and yes technically over the air is better

Answer 6

Over the air is not compressed. yes cable n satelite companies do compress there media. and yes hdtv looks a tad better over the air.

Answer 7

How far away (maximum) can I expect my antenna to pick up an HDTV signal?

Answer 8

so as that they are cable waiting? Does your son room desire a sign amplification/develop? Is the cable container in the front room bypass into the LR television? the place does the cable run from for you son?