Jump to content


Welcome to DBSTalk


Sign In 

Create Account
Welcome to DBSTalk. Our community covers all aspects of video delivery solutions including: Direct Broadcast Satellite (DBS), Cable Television, and Internet Protocol Television (IPTV). We also have forums to discuss popular television programs, home theater equipment, and internet streaming service providers. Members of our community include experts who can help you solve technical problems, industry professionals, company representatives, and novices who are here to learn.

Like most online communities you must register to view or post in our community. Sign-up is a free and simple process that requires minimal information. Be a part of our community by signing in or creating an account. The Digital Bit Stream starts here!
  • Reply to existing topics or start a discussion of your own
  • Subscribe to topics and forums and get email updates
  • Send private personal messages (PM) to other forum members
  • Customize your profile page and make new friends
 
Guest Message by DevFuse

Photo
- - - - -

Pixelation Problems


  • Please log in to reply
8 replies to this topic

#1 OFFLINE   Carey

Carey

    New Member

  • Registered
  • 2 posts
Joined: Nov 17, 2009

Posted 11 December 2011 - 08:19 PM

I have a 722k with HD feeds. I am having pixelation problems on sporting shows, is this normal? Sunday football seems to be getting worse each week. I am not having problems on any other shows or dvd's. My Tv is about a year old LED, 1080p. Any ideas?

...Ads Help To Support This SIte...

#2 OFFLINE   gtal98

gtal98

    Godfather

  • Registered
  • 363 posts
Joined: Jan 30, 2011

Posted 11 December 2011 - 10:02 PM

Does this happen on just the local channels, or other sports channels like ESPN too?

If it's only happening on your local channels, then it's probably the quality of the uplink from the TV station to Dish. OTA broadcasts can look horrible for football games because the stations will cheat the bitrate down so they can have room to fit multiple subchannels in their bandwidth. Some channels have a higher bandwidth dedicated uplink to Dish, some send the same as the OTA feed.

#3 OFFLINE   FarmerBob

FarmerBob

    Godfather

  • Registered
  • 569 posts
Joined: Nov 27, 2002

Posted 12 December 2011 - 12:54 AM

I have been seeing more motion blur on all channels on my DLP, which is immuned to motion blur that is prevalent on LCD's. The mirrors move 1000 times faster than the LCD doors. I'm seeing it not only with sports, but things with cars driving by or fast motion. If I watch OTA direct and not through the SBT, I don't see it and matter of fact the picture is crisper, clearer and more dynamic. I noticed that the first moment I got my HD box a week after I had been watching OTA exclusively. So that tells me that it's a DISH compression/quality issue. If anyone has reason to "cheat" the quality, it'd be DISH to save bandwidth. I have also noticed that VOD programs DL'd via the Internet are considerably better compared to their broadcast counterparts. I watched Spartacus season 1 via VOD and it blew my mind. Season 2 was not as impressive via sat broadcast. Via VOD, great.

#4 OFFLINE   esl1885

esl1885

    New Member

  • Registered
  • 10 posts
Joined: Nov 16, 2011

Posted 12 December 2011 - 12:04 PM

I have noticed the same thing. I have watched the Dish local network feeds and the OTA feeds and they both are the same. NBC is the worst, with CBS a close second. But on Fox and ESPN I get no pixelation at all. And, some games on CBS have no problems. This suggests to me that it is the networks themselves creating the problem.

Sam

#5 OFFLINE   FarmerBob

FarmerBob

    Godfather

  • Registered
  • 569 posts
Joined: Nov 27, 2002

Posted 12 December 2011 - 12:27 PM

I have noticed the same thing. I have watched the Dish local network feeds and the OTA feeds and they both are the same. NBC is the worst, with CBS a close second. But on Fox and ESPN I get no pixelation at all. And, some games on CBS have no problems. This suggests to me that it is the networks themselves creating the problem.

Sam

The networks do broadcast at different resolutions, which is where the issue begins. But DISH reprocesses the signal for their transmission that only takes whatever signal and makes it worse. That's the point of this discussion. It's not the networks that are completely to blame, but a comedy of errors. As I said before when I watch OTA direct I see none of these problems and the picture is better than through DISH rebroadcasts or the STB OTA. This suggests to me that the "reprocessing" is only making, at times, a marginal situation worse. And thus this discussion.

The kicker is that VOD DL and 1080p PPV programming is beautiful. When the initial source is good. This tells me that DISH is capable of a really great picture. We just don't get it with regular Sat broadcasting and OTA through the box.

#6 OFFLINE   gtal98

gtal98

    Godfather

  • Registered
  • 363 posts
Joined: Jan 30, 2011

Posted 12 December 2011 - 07:48 PM

If I watch OTA direct and not through the SBT, I don't see it and matter of fact the picture is crisper, clearer and more dynamic. I noticed that the first moment I got my HD box a week after I had been watching OTA exclusively. So that tells me that it's a DISH compression/quality issue.


Are you comparing OTA to TV vs OTA to Receiver, or OTA to TV vs Dish feed?? Because the receiver does not compress an OTA feed at all, it just records/buffers it directly. There could be differences in OTA hardware though.

If anyone has reason to "cheat" the quality, it'd be DISH to save bandwidth.


Correct, but Dish cheats the resolution (this is well documented) not the bitrate of the compression. So the picture seems slightly softer, but you don't end up with any fast-motion blocking.


I know the OTA channels have to lower the bitrate to fit in subchannels because I was told this by a station engineer. (I was installing a Dish system for them to monitor their own channel's feed as it was rebroadcast by Dish). He found it odd that Dish was only rebroadcasting a direct OTA broadcast (receiving the station feed by antenna at the uplink center) where as with DirecTV the station provided them a full fiber link and sent them a full bitrate version of the shows. Now I'm sure Dish does this to save $$, but it doesn't seem like the best way to go IMO.

#7 OFFLINE   gtal98

gtal98

    Godfather

  • Registered
  • 363 posts
Joined: Jan 30, 2011

Posted 12 December 2011 - 07:56 PM

I have noticed the same thing. I have watched the Dish local network feeds and the OTA feeds and they both are the same. NBC is the worst, with CBS a close second. But on Fox and ESPN I get no pixelation at all. And, some games on CBS have no problems. This suggests to me that it is the networks themselves creating the problem.

Sam


This is because Fox, ESPN and ABC all broadcast in 720p which gives you 60 full frame images per second. NBC and CBS broadcast in 1080i - which is 60 half frame images per second - but at a higher resolution.

Some people say 1080i is crap for sports because you end up with a lot of fast motion blocking, but it depends on the bitrate of the broadcast. Where I am I pick up two different CBS stations OTA from different markets (only way I get to watch my Texans play in Dallas). One of the stations has no sub channels, and the other has 2 sub channels. When the same game is on both channels I've switched back and forth and there is a drastic difference. On the channel with no sub channels there is little to no fast motion blocking. On the channel with subs, the fast motion blocking is highly evident and very annoying.

#8 OFFLINE   FarmerBob

FarmerBob

    Godfather

  • Registered
  • 569 posts
Joined: Nov 27, 2002

Posted 12 December 2011 - 08:45 PM

Are you comparing OTA to TV vs OTA to Receiver, or OTA to TV vs Dish feed?? Because the receiver does not compress an OTA feed at all, it just records/buffers it directly. There could be differences in OTA hardware though.


Yes. An OTA to TV picture is far better than either Sat RB and OTA through the STB. Like I said I notice the difference from watching OTA direct for a week before getting an HD STB. And with it, even now, when I switch back and forth you can see the difference. Even had a Field Supervisor, who has since left DISH, spent some time flipping back and forth saying that he never knew it was so dynamic and that he was grateful for the opportunity to see what I and many others were saying.

Correct, but Dish cheats the resolution (this is well documented) not the bitrate of the compression. So the picture seems slightly softer, but you don't end up with any fast-motion blocking.

Oh Yeh. I see much more fast-motion blur and just plain picture blocking when watching through a STB compared to a direct OTA feed or the same movie off DVD or BD compared to upper channel bcasts.
Only because it was brought to my attention due to as much as it happens through the STB - you just can't avoid it. It's that glaring. So yes, as far as I have seen, the STB introduces PQ issues as verified by a DISH FS that sat here and watched it on my set.

I know the OTA channels have to lower the bitrate to fit in subchannels because I was told this by a station engineer. (I was installing a Dish system for them to monitor their own channel's feed as it was rebroadcast by Dish). He found it odd that Dish was only rebroadcasting a direct OTA broadcast (receiving the station feed by antenna at the uplink center) where as with DirecTV the station provided them a full fiber link and sent them a full bitrate version of the shows. Now I'm sure Dish does this to save $$, but it doesn't seem like the best way to go IMO.


Yeh, and I have been told by several local station Chief Engineers that they don't "dink" with their signals when I have watched them do it. So that conversation carries no weight with me. And as far as DISH rebroadcasting via an OTA antenna is another shortcut on DISH's part which seems to be SOP with them. And the DTV incident that you cite only goes to prove that DISH saving $$ is more important than quality that has far more reaching to the bottom line with retaining customers or this throwing hardware at software issues to try to appease subs.


#9 OFFLINE   gtal98

gtal98

    Godfather

  • Registered
  • 363 posts
Joined: Jan 30, 2011

Posted 13 December 2011 - 08:24 AM



Yes. An OTA to TV picture is far better than either Sat RB and OTA through the STB. Like I said I notice the difference from watching OTA direct for a week before getting an HD STB. And with it, even now, when I switch back and forth you can see the difference. Even had a Field Supervisor, who has since left DISH, spent some time flipping back and forth saying that he never knew it was so dynamic and that he was grateful for the opportunity to see what I and many others were saying.

Oh Yeh. I see much more fast-motion blur and just plain picture blocking when watching through a STB compared to a direct OTA feed or the same movie off DVD or BD compared to upper channel bcasts.
Only because it was brought to my attention due to as much as it happens through the STB - you just can't avoid it. It's that glaring.[FONT=Arial] So yes, as far as I have seen, the STB introduces PQ issues as verified by a DISH FS that sat here and watched it on my set.


Strange, all I can say is your experiences are pretty much the exact opposite of mine. I never get fast-motion blocking artifacts when watching the SAT feed. It's much more prevalent on the OTA channels.




Protected By... spam firewall...And...