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post #1 of 9 Old 12-09-2018, 09:33 AM - Thread Starter
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Drop in bitrate - recordings are pixelated

I've been using a Hauppauge 2250 HDTV capture card for years to record OTA programming with it hooked up to the antenna in our attic, and using WinTV 8.5 for software. My recordings always looked great up until about 5 or 6 months ago. Then there was a sudden noticeable drop in files sizes, and my recordings now look terrible, regardless of channel recorded.

I've looked all around in the software settings, and there's nothing to adjust bitrate. Believing there might be something wrong with my capture card, I purchased the Hauppauge WinTV-quadHD card, but the result is exactly the same. Any ideas?

A 1 hour recording of NBC in 1080i is 2.87 GB in file size.

I'm located in the Chicago suburbs.

Setup:
Hauppauge 2250 & quadHD
WinTV 8.5 Software
Windows 10 Pro
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post #2 of 9 Old 12-09-2018, 05:56 PM
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The drop in bit rate you've seen on several channels wasn't caused by your equipment. It was caused by the stations. Many stations sold transmitters in the recent spectrum auction and "doubled up" with other stations still on the air:

  • WMAQ (NBC) is now sharing an RF carrier with WSMS (Telemundo).
  • WLS (ABC) is now sharing an RF carrier with WXFT (Unimas).
  • WFLD (Fox) is now sharing an RF carrier with WPWR (My 50?). They actually have three HD stations on a single carrier now!
  • WTTW (PBS) is now sharing an RF carrier with WYCC (MHz). Actually this one shouldn't be too bad, since WYCC is only SD - but WTTW was already dual HD so its bit rate wasn't that great to start with. WYIN is probably a bit better, but it's dual HD too.
  • Even WWTO (TBN) is now sharing an RF carrier with WLPD, although this one shouldn't be too bad either.

WBBM (CBS) should still have a decent bit rate though. Have you checked that one?
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post #3 of 9 Old 12-09-2018, 08:02 PM - Thread Starter
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Originally Posted by JHBrandt View Post
The drop in bit rate you've seen on several channels wasn't caused by your equipment. It was caused by the stations. Many stations sold transmitters in the recent spectrum auction and "doubled up" with other stations still on the air:

  • WMAQ (NBC) is now sharing an RF carrier with WSMS (Telemundo).
  • WLS (ABC) is now sharing an RF carrier with WXFT (Unimas).
  • WFLD (Fox) is now sharing an RF carrier with WPWR (My 50?). They actually have three HD stations on a single carrier now!
  • WTTW (PBS) is now sharing an RF carrier with WYCC (MHz). Actually this one shouldn't be too bad, since WYCC is only SD - but WTTW was already dual HD so its bit rate wasn't that great to start with. WYIN is probably a bit better, but it's dual HD too.
  • Even WWTO (TBN) is now sharing an RF carrier with WLPD, although this one shouldn't be too bad either.

WBBM (CBS) should still have a decent bit rate though. Have you checked that one?
JHBrandt,

Thanks for the reply. That's really unfortunate. It sounds like there's nothing I can do about it. I guess I'll just have to live with it.
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post #4 of 9 Old 12-10-2018, 07:55 AM
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Quote:
Originally Posted by JHBrandt View Post
The drop in bit rate you've seen on several channels wasn't caused by your equipment. It was caused by the stations. Many stations sold transmitters in the recent spectrum auction and "doubled up" with other stations still on the air:

  • WMAQ (NBC) is now sharing an RF carrier with WSMS (Telemundo).
  • WLS (ABC) is now sharing an RF carrier with WXFT (Unimas).
  • WFLD (Fox) is now sharing an RF carrier with WPWR (My 50?). They actually have three HD stations on a single carrier now!
  • WTTW (PBS) is now sharing an RF carrier with WYCC (MHz). Actually this one shouldn't be too bad, since WYCC is only SD - but WTTW was already dual HD so its bit rate wasn't that great to start with. WYIN is probably a bit better, but it's dual HD too.
  • Even WWTO (TBN) is now sharing an RF carrier with WLPD, although this one shouldn't be too bad either.

WBBM (CBS) should still have a decent bit rate though. Have you checked that one?

why happen this? that happen with one station in my area , i mean loss quality.
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post #5 of 9 Old 12-10-2018, 12:44 PM
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why happen this? that happen with one station in my area , i mean loss quality.
A few years ago Congress directed the FCC to hold a double auction so wireless companies could buy the higher RF frequencies in the UHF TV band. Stations could bid to sell their UHF licenses and either:

  1. Go off the air;
  2. Move to VHF; or
  3. Share a transmitter with someone else.

A lot of stations submitted bids, but the FCC only accepted enough bids to allow as much spectrum to be cleared as the wireless companies were willing to buy. But every area was unique. In the Chicago area, a lot of bids to share transmitters were accepted. In the Dallas area where I live, one station went off the air but not much else happened, except for all the low-power stations that were or will be kicked down to VHF when full-power stations move to lower UHF channels.

Eventually ATSC 3.0 is supposed to fix this. It allows a higher total bit rate per RF carrier, and uses much more efficient compression so that good quality HD video can be broadcast with much lower bit rates. But it's not compatible with the current ATSC 1.0; we'll need all new tuners. Also, there's no "transition" scheduled as with analog-to-digital; stations will have to simulcast in both 1.0 and 3.0 - and still make everything fit in the newly-narrowed TV band - until enough folks have new 3.0 tuners and the FCC is comfortable dropping the simulcast mandate. So the next 5-10 years are probably going to be a mess....
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post #6 of 9 Old 12-10-2018, 04:09 PM
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JHBrandt,

Thanks for the reply. That's really unfortunate. It sounds like there's nothing I can do about it. I guess I'll just have to live with it.
It's one reason more and more people are streaming their content. For the most part the picture quality is superior to what you get OTA
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post #7 of 9 Old 12-10-2018, 06:23 PM
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Well it depends on your location. For instance DC is really bad too. I suspect most of the country is probably OK and it's the big markets that are seeing this channel sharing the most, although you may be lucky even in some of the big markets. (As I mentioned, Dallas OTA isn't bad, so I'll be sticking with OTA for my local stations for now.)

Edit: For kicks & grins I looked up Minneapolis on RabbitEars.info. It's actually not bad either, although PBS and Fox 9 "Plus" kinda suck. Seems like a lot of PBS stations really overtake the plumbing, and I really don't understand why Fox 9 Plus feels the need to simulcast Fox 9 in HD, taking bandwidth away from their own "Plus" channel.

Unfortunately streaming is no panacea either, at least for mobile. A recent study by Northeastern University shows that, post net neutrality, virtually all mobile service providers are slowing down video streaming, even when their networks aren't congested.

Hate to say it but in some cases, your best option may be (expensive) cable, at least if your cable co. has direct fiber lines from your local TV stations.

Last edited by JHBrandt; 12-10-2018 at 06:39 PM.
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post #8 of 9 Old 12-11-2018, 03:29 PM
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Edit: For kicks & grins I looked up Minneapolis on RabbitEars.info. It's actually not bad either, although PBS and Fox 9 "Plus" kinda suck. Seems like a lot of PBS stations really overtake the plumbing, and I really don't understand why Fox 9 Plus feels the need to simulcast Fox 9 in HD, taking bandwidth away from their own "Plus" channel.
Yes MSP isn't too bad, ABC is better now that they dropped the basically never used MDTV And your right about FOX, makes little sense other than some people have better luck getting them on UHF(in town, less multipath) and some get their VHF channel better(out in the country). PBS is "OK" not the best but better than other markets I've seen. Overall I'd call MSP pretty good for OTA, it's the reason I only have OTA and only stream for things I can't get OTA
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post #9 of 9 Old 12-11-2018, 06:55 PM
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That's pretty much what I do too: get locals via OTA and stream "cable" channels (along with YouTube, etc., of course). Looks like our friends in Chicago and DC have it tougher, though, and may have to turn to cable or streaming just to get good PQ on locals.

Back when the auction was going on (and also in discussions about ATSC 3.0, which relies heavily on channel sharing to get 3.0 stations on the air in our new itsy-bitsy teeny-weeny TV spectrum), I read a lot of hype about how much better statmuxers have gotten in the last decade, and that stations could now run not only dual HD, but dual HD plus three or four SD subchannels, with little loss of PQ. It may be true that statmuxers have gotten better, but it's increasingly clear that having two HD channels on one ATSC 1.0 carrier is still far from ideal.
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