ATSC vs QAM?

[valnar]

I just bought the HDHomeRun tuner and so far I love it. I have yet to integrate it with Sage, but that'll come this weekend.

I have crystal clear local channels available to me on both my Cable/QAM as well as OTA ATSC. My broadcast towers for Cleveland are only 5 miles from my house.

Visually, I can't tell a difference. But I read somewhere once that cable companies tend to compress the "original" (ATSC) stream further so that the quality of QAM may not be as good as ATSC. My cable company is WOW - Wide Open West.

Is there any way I can tell with a stream analyzer or other such free software if there is any additional compression added to my QAM channels? Is there an objective analysis I can perform on whether I should use ATSC or QAM if I want the best quality?

Thanks,
Robert

[stanger89]

Originally Posted by valnar

Is there any way I can tell with a stream analyzer or other such free software if there is any additional compression added to my QAM channels? Is there an objective analysis I can perform on whether I should use ATSC or QAM if I want the best quality?

Yup, get a hold of TSReader (Lite should do) and you can look at the bitrates and various info for the data streams.

[lobosrul]

Visually, I can't tell a difference. But I read somewhere once that cable companies tend to compress the "original" (ATSC) stream further so that the quality of QAM may not be as good as ATSC. My cable company is WOW - Wide Open West.

The sales guy told me this as well when I bought an HDTV. He also told me if I see a lot of blocking im getting a poor signal (thats a lie). I've checked a few times, and so far the streams have been identical. Some of the cable only HD channels (INHD for example) however seem to be HD (lite), they only come in at 8mbps. Lots of "blocking" on those channels.