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Old 03-27-2015, 10:13 AM   #1
abdemaio
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Video quality degradation: cable or TiVo?

Sorry if this is a dopey question but my knowledge of video processing and decoding is virtually non-existent. So:

I am a Cablevision (Optimum) customer in the NY area. I currently have a TiVo Premier, with which I have had no problems (except for the occasional v52 error but that's another thread) and a 2013 Panasonic plasma TV. When watching both live and recorded shows, I occasionally notice some flaws in the picture: blocks of blurred pixels, color banding (not sure how else to describe it: for example, the sun is on the screen and instead of a smooth transition of colors moving outward there are distinct bands of color).

I am considering moving from CV to FIOS because I keep hearing about the vastly superior picture quality, which would (I hope) eliminate or reduce the picture flaws. My question, though is: are these flaws likely being introduced by the TiVo or is it more likely that the TV picture is coming in with the flaws already there? Is the TiVo doing some kind of compression and decompression that is degrading the picture? It's my understanding that even when watching live TV the TiVo is writing to disk and then reading from the disk to pass it along to the TV so I'm not surprised that I see the flaws in both live and recorded video.

I recognize that I am probably using bad terminology here and that it is impossible to diagnose picture issues based on my description. But I'm hoping that someone here has seen the same behavior or understands enough about how TiVo processes the video signals to tell me if it is even possible that the TiVo is the sources of the degradation.

Thanks, in advance!

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Old 03-27-2015, 10:23 AM   #2
sangs
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Can't say with any authority what your issue is, but as a FiOS customer I can say that the PQ on my Roamios - and Minis - looks slightly better than it did when I was using the FiOS DVR. For my money, only DirecTV comes close to FiOS PQ.

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Old 03-27-2015, 10:50 AM   #3
BigJimOutlaw
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The Tivo is saving the video bit-for-bit as it is received, so it's not doing anything funky at that level.

I've never heard of a Tivo causing that kind of video output issue. Sometimes people might either have their TV's settings unoptimized or perhaps the Tivo is set to the wrong video output quality (SD instead of HD) but nothing quite like that. You can check those things, but they're probably fine.

The low hanging fruit is to try a different cable between the Tivo and TV. Perhaps the cable is faulty. (You don't need a $50 Monster cable, a $5 MonoPrice cable works just as well.)

Or try a different video source like an HD Netflix or Youtube video to eliminate (or verify) Cablevision as the problem.

A more complicated answer could be signal strength. If you go into Settings > System Info > Diagnostics, what kind of signal strength % and SNR's are you seeing on your affected channel(s)?

Fios picture quality is pretty darn good. It doesn't have the compression artifacts and other issues a lot of other outlets have.


Last edited by BigJimOutlaw; 03-27-2015 at 11:09 AM.
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Old 03-27-2015, 11:19 AM   #4
JoeKustra
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Quote:
Originally Posted by abdemaio View Post
I am considering moving from CV to FIOS because I keep hearing about the vastly superior picture quality, which would (I hope) eliminate or reduce the picture flaws. My question, though is: are these flaws likely being introduced by the TiVo or is it more likely that the TV picture is coming in with the flaws already there? Is the TiVo doing some kind of compression and decompression that is degrading the picture? It's my understanding that even when watching live TV the TiVo is writing to disk and then reading from the disk to pass it along to the TV so I'm not surprised that I see the flaws in both live and recorded video.

Thanks, in advance!
In addition to the great post by BigJim, your description does sound more like a problem with the settings on your television. There are so many things to set anymore it's possible to make money calibrating televisions. Your make and model probably have a thread on AVS Forum which normally has setting advice.

As for the switch of providers, check the content first. By that I mean you need to see if the program you are viewing is being "bit-starved". Examples would be, from my feed, going from bad to good: Castle & Forever need 3.09/3.17GB for the program. Bones needs 5.21GB and NCIS & L&O:SVU use 7.46/7.39GB for their programs. The non-broadcast networks will vary and usually seem to be between 6-7GB per hour. Again, this is my feed and yours may be better or worse. It's no secret that OTA has less compression, and I know my feed combines channels, some more than others. Programs like kmttg can show the exact bit rate, but the TiVo "Info" feature is enough for me. I don't know about satellite. Good luck.

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Old 03-27-2015, 12:38 PM   #5
HarperVision
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Quote:
Originally Posted by abdemaio View Post
Sorry if this is a dopey question but my knowledge of video processing and decoding is virtually non-existent. So: I am a Cablevision (Optimum) customer in the NY area. I currently have a TiVo Premier, with which I have had no problems (except for the occasional v52 error but that's another thread) and a 2013 Panasonic plasma TV. When watching both live and recorded shows, I occasionally notice some flaws in the picture: blocks of blurred pixels, color banding (not sure how else to describe it: for example, the sun is on the screen and instead of a smooth transition of colors moving outward there are distinct bands of color). I am considering moving from CV to FIOS because I keep hearing about the vastly superior picture quality, which would (I hope) eliminate or reduce the picture flaws. My question, though is: are these flaws likely being introduced by the TiVo or is it more likely that the TV picture is coming in with the flaws already there? Is the TiVo doing some kind of compression and decompression that is degrading the picture? It's my understanding that even when watching live TV the TiVo is writing to disk and then reading from the disk to pass it along to the TV so I'm not surprised that I see the flaws in both live and recorded video. I recognize that I am probably using bad terminology here and that it is impossible to diagnose picture issues based on my description. But I'm hoping that someone here has seen the same behavior or understands enough about how TiVo processes the video signals to tell me if it is even possible that the TiVo is the sources of the degradation. Thanks, in advance!
Does Optimum have clear QAM channels that you could hook your cable coax directly to your tv and compare the images? Or do you have another tv you can try your TiVo on to see if the picture is the same? Do you have a tuning adapter with them because they use SDV? I've noticed a lot of my SDV channels are more compressed and appear similar to what you're describing. I even called TWC about it and all they said was "yeah, we know, sorry".

What you describe sounds like MPEG artifacts, especially the blocking. The banding usually occurs with things like 8-bit processing. To me it sounds like Optimum just over processes the signal way too much to cram as much crap onto their system as they can. FiOS sounds like it may be worth the switch. Do any of your neighbors have fios that you could go check and compare your channel images? It won't be exact if they're using a Motorola box but as stated the TiVo shouldn't be processing any of the signal so what comes in and gets buffered on the hard drive is what comes out, so it should be a similar image and good for comparison.

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Old 03-27-2015, 02:10 PM   #6
NiteCourt
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Quote:
Originally Posted by HarperVision View Post
What you describe sounds like MPEG artifacts, especially the blocking. The banding usually occurs with things like 8-bit processing. To me it sounds like Optimum just over processes the signal way too much to cram as much crap onto their system as they can.
It sounds like this to me also. I know Time Warner Cable in NW PA does this on most of their SDV channels here and the HD quality is terrible. Streaming HD video from Netflix of the Walking Dead is much better quality than actually watching it AMC.

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Old 03-27-2015, 07:40 PM   #7
unitron
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Quote:
Originally Posted by abdemaio View Post
Sorry if this is a dopey question but my knowledge of video processing and decoding is virtually non-existent. So:

I am a Cablevision (Optimum) customer in the NY area. I currently have a TiVo Premier, with which I have had no problems (except for the occasional v52 error but that's another thread) and a 2013 Panasonic plasma TV. When watching both live and recorded shows, I occasionally notice some flaws in the picture: blocks of blurred pixels, color banding (not sure how else to describe it: for example, the sun is on the screen and instead of a smooth transition of colors moving outward there are distinct bands of color).

I am considering moving from CV to FIOS because I keep hearing about the vastly superior picture quality, which would (I hope) eliminate or reduce the picture flaws. My question, though is: are these flaws likely being introduced by the TiVo or is it more likely that the TV picture is coming in with the flaws already there? Is the TiVo doing some kind of compression and decompression that is degrading the picture? It's my understanding that even when watching live TV the TiVo is writing to disk and then reading from the disk to pass it along to the TV so I'm not surprised that I see the flaws in both live and recorded video.

I recognize that I am probably using bad terminology here and that it is impossible to diagnose picture issues based on my description. But I'm hoping that someone here has seen the same behavior or understands enough about how TiVo processes the video signals to tell me if it is even possible that the TiVo is the sources of the degradation.

Thanks, in advance!
Are you unable to receive any over the air channels at all?


I'd compare a local broadcaster taken off of an antenna against the cable company's feed of the same channel at the same time and see if there were serious differences. If the OTA looks good and the cable feed of the same thing at the same time (give or take 0.5 seconds) looks decidedly worse, then that lets the TiVo off the hook.

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Old 03-29-2015, 07:19 PM   #8
telemark
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Another way to confirm the over-compression theory, is to transfer a program with the artifacts to a PC. Then check the bitrate of the file you received.

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Old 04-04-2015, 06:15 PM   #9
nycaudioman
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To the original poster ...

By coincidence, a few days ago I posted a similar thread (as a Cablevision/Optimum customer also just outside NYC) in the Roamio thread.

At first I thought it was my signal strength or a TV setting, but after talking with others on that thread and comparing file sizes, it is becoming apparent that the problem is with the compressed Cablevision feed. Maybe you can join us on that thread and post some of your file sizes for comparison?

http://www.tivocommunity.com/tivo-vb...ht=cablevision

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Old 04-16-2015, 10:49 AM   #10
nycaudioman
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Just wanted to point everyone to a continuing thread here on this topic:

http://www.tivocommunity.com/tivo-vb...d.php?t=527140

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