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Discussion Starter · #1 ·
I have Digital Cable provided by Cox cable in " Hampton Roads " area (Virginia).

I have a LCD TV capable of 720p and 1080i (native 768 lines). The image on the HD channels is comparable with the one free over the air, but the SD channels is what I am really unsatisfied with. Compression and motion artifacts all over! All the SD channels are this bad quality. Sure, from the distance looks allright, but I know what I see and it is annoying. The cable reps tried to tell me that is the TV - but I don't get those artifacts from a DVD disc.

Obvious all the cable companies will have a level of compression to their channels, the issue is how much. Now my question:


Is there anywhere an independent comparation review between different CATV or satellite providers? In my area I can choose between Cox Cable, Verizon FiOS, DirectTV or DishNetwork and I want to change to the provider with the best PQ (picture quality) on all the channels that I pay for, not just on the HD portion.


I am fed up with this "our cable is digital, therefore is better than analog, it must be your TV" line that I served over and over. I am talking about stuff that looks like the one attached. The artifacts around edges are "moving", "rearranging" when the image content is changing!
 

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Are you using a STB from the cable co?

If so remove it and plug the cable directly into the TV and scan all channels.

Are your results the same as with the box in line.
 

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Discussion Starter · #3 ·
I am using the cable company tunner (Motorola DCX3200). The digital SD channels (that I think are heavely compressed) are not available via my TV tunner.

My tunner gets all the analog channels and, as for the digital, only the HD channels that are FTA in my area - all the digital is either 720p or 1080i. PQ is comparable (maybe a little better via the air), but my beef is with the rest of the channels (SD ones).

So - any takes about what provider does better in this field (SD delivered via digital cable)?


PS: I can see some 480i digital infomercials - but those are really bad (youtube quality).
 

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You are saying that if you bypass the STB you only get the analog and HD using your TV's tuner.

In an effort to troubleshoot the issue you would have either eliminated or pointed to the STB.

There is a good chance that you have a bad STB.


Any other provider you will need to commit to a 2 year contract.

In terms of quality Verizon FIOS is probably the best.
 

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Discussion Starter · #5 ·
Thank you.

I wonder why am just the only one that notice that? Is my box defective or everybody else is happy with that artifacts in the SD channles?

So - you don't see nothing around the hi-contrast counturs in a SD program?
 

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From the pic you posted, that's pretty bad SD quality, even by the "SD looks poor on an HDTV" standard. I mean, I watch some SD on my HDTV with TWC, and while it isn't stellar, it certainly isn't that bad.


If you want to leave Cox for other reasons, that's fine, but I would definitely try to swap boxes first. Cox should do it for free. At least you could eliminate the box as a factor.


Yeah, I think Verizon would have the best SD quality of the choices if you were to switch. AT&T U-Verse's SD is supposed to be really good, but the HD is supposedly not quite as good as the others. Dunno if that's available to you.
 

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Discussion Starter · #7 ·
No, ATT is not an option... I will try to ask for another box if they will do it with no shipping fees. I kind of doubght it is the box, why the HD will be ok then? I think is them trying to cram as many channels as they can in the same bandwidth.


I have a bundle package with Cox... My wife hates Verizon since they put one of their FiOS distribution boxes in our backyard, but I'll see what I can do
 

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Is the Local Cox office nearby?

If so call them and tell them that you have a bad box and you could take it there yourself and pick up a different one.


What type of cable are you using HDMI or component?

Do you have an S or composite cable handy?

If so before you arrange a box swap connect one of those to your set and see what happens.
 

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Here in Olympia Comcast puts out 528 X 480 at 10 per QAM channel, so you do the math...Pretty low bitrate for sure.
 

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Discussion Starter · #10 ·
I had tried with HDMI and component. I have S cables but I didn't hink to try it - my guess is it will reduce the bandwith and mask/blur the artifacts (if they are from cable).

I will try it tommorow thou.


I have a feeling that is like was said - some "unimportant" channels (like children ones) get less bandwidth.
 

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Quote:
Originally Posted by SoNic67 /forum/post/18223974


I kind of doubt it is the box, why the HD will be ok then? I think is them trying to cram as many channels as they can in the same bandwidth.

You are right. I use to have Cox digital cable and had the same problem. The disappointment I had when a few years ago I hooked up my new 50 inch plasma HDTV to Cox and saw how horrible the SD picture quality was. I was thinking it was the TV at first but after watching a few DVDs that looked awesome and seeing how good OTA looked I knew it was the cable. There is no telling how old the cable in the ground that they laid years ago. And with HD they have to take the bandwith from the SD channels to get all the signal to fit through the cable. There is nothing wong with your HDTV. When the cable person tells you its your TV he is lying or doesn't know what he is talking about. Or he is hoping you have a 20 year old CRT TV were you won't know the difference. This and the rising cost of Cox cable that is now $90 a month is why I just have OTA and DVDs these days.
 

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Quote:
Originally Posted by RCbridge /forum/post/18222171


Any other provider you will need to commit to a 2 year contract.

You can choose to get Dish without a commitment. You just don't get the activation fee refunded, and you usually can't get any of the "introductory deals" (used to be able to - I did when I got it 5 years ago - but I don't really ever see that anymore. At least you still have the option, though).


Other than cable (and OTA), the order of SD quality:


FIOS

U-Verse

Dish

Direct


At least try swapping the box out before you go switching to anything else. Also, try using a differently calibrated input for the SD from that which is calibrated for HD. And play with your set's noise control features to see if that helps.
 

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Discussion Starter · #14 ·
Why would be FiOS better that DirectTV? I think that they have the same sat feeds, same signal, don't they?
 

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Quote:
Why would be FiOS better that DirectTV? I think that they have the same sat feeds, same signal, don't they?

Fiber to the home gives you a lot more bandwidth than cable or satellite, so you don't need to compress as much.
 

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Discussion Starter · #16 ·
I know that, but... where is the signal coming from? Not from the compressed satellite feeds of DirectTV?

I will try to find somebody with FiOS to take a look...
 

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Quote:
I know that, but... where is the signal coming from? Not from the compressed satellite feeds of DirectTV?

Each provider will get his own feed from the satellite the quality of that signal is usually very good, what happens from there will vary from provider to provider.


Each provider will typically down convert to base band (still a great signal) from there what happens will vary, the signal will be reprocessed and put onto a carrier that will be delivered to you, some will put 10 channels (or more) per carrier (compression), some will do less.


If the channels are delivered via an analog carrier (noise is a factor).

Digital carriers are typically cleaner but as you are seeing a lot of compression can hurt the signal.


We say FIOS should be the cleanest because of the extra B/W so they don't need to compress the signals as much as anyone else.
 

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From your attached picture, I tend to agree with the technicians that told you there is a problem with your TV. Neither of my two HD DVRs look like that on the SD channels.


Is the TV too large to take to a friends home with a similar working setup and see if your TV looks the same on their box?


Also, have you tried the different setttings in the converter's menu section? I've seen some TVs look better by changing the SD settings to use either 480I or 480P settings. Sometimes one looks better than the other.


If you're not familar with how to do this, press the Menu button twice, then scroll down to the Video Output settings (or something like that), then press the right button until you see the options for 480P or 480I and see which one works best. The one with a dot beside it is what is currently selected. To change, highlight another option and press Select, then press the left button until you see a message asking if you "can see this message".


Hope this helps.
 

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Discussion Starter · #19 ·
The crop is enlarged, but sitting on my couch I can still see those artifacts on some SD channels (100-200 channel range).

If it is the upconvesion in the TV, changing the SD to be shown at 720p (by the cable box) should cancel that. And it doesn't.

Native HD looks OK, nothing like that.


Look at the 101 SC sign in lower right corner (it's just an example). On my TV I can see artifacts surrounding it and those are changing with the image content. That is visible regardless what I select in the receiver's menu 480i, 480p, 720p (I know how to get there and I tried all variants).
 

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Quote:
Originally Posted by olyteddy /forum/post/18232266


Here in Olympia Comcast puts out 528 X 480 at 10 per QAM channel, so you do the math...Pretty low bitrate for sure.

I have seen resolutions as low as 352x480i at bitrates well under 2Mbps and 15+ channels per 6Mhz slot. There are no limits on QAM specs.

Quote:
Originally Posted by SoNic67 /forum/post/18232376


I had tried with HDMI and component. I have S cables but I didn't hink to try it - my guess is it will reduce the bandwith and mask/blur the artifacts (if they are from cable).

I will try it tommorow thou.


I have a feeling that is like was said - some "unimportant" channels (like children ones) get less bandwidth.

Using Composite/S-Video outputs, combined with a TV that has superior video processing would help. Running the video through something like a Faroudja processing chip would improve that picture. This would require a set larger than 42", designed in Japan. The needed processing can generally only be applied to baseband video, not HDMI/DVI/VGA/Component.

Quote:
Originally Posted by olyteddy /forum/post/18233805


FWIW you can get an idea of how many SD per QAM (assuming your basic cable is available in the clear) over at http://www.silicondust.com/hdhomerun/channels_us

Since it appears that all of your channels are encrypted, it will be difficult to determine how many channels are crammed into one slot. You could scan with a Clear QAM tuner and see how many subchannels are found per main channel. You won't be able to view them but you can get an idea. A channel with 2 or 3 subs probably contains 2 HD plus possibly one SD (720x480) channel. If one has 10 - 15, then you may have dramatically reduced resolution/bitrate SD channels. If you see 20+ subs, then that is probably a music block.
 
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