Question about 720p HDTV networks

[jd594]

I've used this site for years and it's great. I've been familiar with digital video for at least the last decade, and I've also been doing HD capturing for the last year or two.


I know certain TV shows or networks are broadcast only in 720p, such as ABC. I receive and capture Fox in 720p, but not ABC. I've always received and captured ABC in 1080i, which like I said has been for at least over a year or two. For instance, google "jimmy kimmel 720p april", and around the 5th result should be an article that mentions the Jimmy Kimmel Live program starting in 720p in April 2009, and also notes that 720p is ABC's HDTV format. At this time I was capturing it in 1080i, along with all other ABC shows. I've wondered why this is and it's been bugging me for a while.

I could post a sample of an ABC show in 1080i, which I probably would if it was really necessary, but I guess that's not really the point. Does anyone else also get ABC in this manner? Is it just that certain ABC stations broadcast in 1080i? The specific question is how or why does this happen? Is there any chance ABC really does use 1080i, just not in all markets, or am I just getting an upscaled resolution? It doesn't really look any worse than NBC or CBS so I wouldn't have guessed it, but I really don't know the answer.

[Robert Simandl]

ABC uses 720p to broadcast to its affiliates. Sounds like your local affiliate is converting to 1080i for some reason before sending the signal on to you.

It's just the opposite with PBS in my area (among many other areas). PBS broadcasts in 1080i, and MANY affiliates convert to 720p because 720p makes it easier to cram in 3 or 4 subchannels.

What the advantage is for your ABC affiliate converting its incoming 720p into 1080i, I have no idea.

[[_chef_]]

The ZDF here in Germany does it the other way, recording in 1080i as the EBU suggests, then downconverting to 720p because they started in 720p...

Illogical but the truth.

[jman98]

Where I live, all ABC owned HD channels (includes ESPN, etc.) are in 720p.

ABC and Fox broadcast in 720p.
CBS and NBC broadcast in 1080i.

I agree that either your local affiliate or your TV provider is doing something they aren't supposed to in converting this to 1080i.