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Tivo HD Pixelation Troubleshooting

Discussion in 'TiVo Series3 HDTV DVRs' started by Chimpware, Aug 3, 2007.

  1. btwyx

    btwyx Substantive Member

    Jan 16, 2003
    When have they denied its their issue. I don't think Pony could be any clearer
    What sort of world do you live in where you get ETAs for fixes they don't even seem to know the cause of. That really would be something to complain about if they did that.
  2. Ishma

    Ishma New Member

    Sep 8, 2006
    I thought TiVo Pony already admitted the issue. See the following thread. I didn't read it as vague, just seemed like they need more info.

  3. flyacl

    flyacl New Member

    Jan 9, 2005
    I don't post much here. But I figured I would add my experience with this issue as well.

    Picked up the TivoHD a couple of days ago. While waiting for the cable company (Insight) to come install my cable cards I had it connected and updated with the latest software. During this time I messed around with it using the lower end analog channels. No problems to speak of during that time.

    Today the tech came out and installed two Motorola cableCards. Install went fine and everything seems to be working. That is with the exception of the pixelation problem that appeared within the first 5 minutes. I have tried a few random things mentioned around the forums here, but nothing seems to fix it.

    Like everyone else, I love my Tivo but this is to much money to get a worse experience then I got with my box from the cable company. I will hold out for a couple of weeks. But if things are not fixed by then end of my 30 days I will return it and cancel both my Tivos.

    Fingers crossed but not all that hopeful. Take care~
  4. lavinah

    lavinah New Member

    Aug 6, 2007
    My report:

    TiVO HD
    1 Motorola M Card - Comcast Chicago
    100 Signal Strength (go me!)
    Monster Clean Power Stage 3 power conditioner / backup
    Component Video 1080i

    Occassional pixalization (~7-10m) issues on all channels and menus, but less then I saw with the Motorola Comcast HD DVR. Minor annoyance, easily outweighed by the bevy of features and functionality that TiVo offers.

    My guess is it is a glitch in the video card output processing, and that makes me hopeful for a software patch. I saw a similar issue with my Radeon 9600xt video card on video a while back and it was fixed with a driver update. If it's a hardware issue that gets resolved in a version update that doesn't effect my machine, TiVo will get hell from me, and I *will* get my unit replaced.

    Which means dealing with the idiots at Comcast for swaping cable cards, so I'm keeping my fingers crossed that it will be software fixed.
  5. Chimpware

    Chimpware New Member

    Jan 30, 2002
    Never said they denied the issue. The problem is that they have never clearly taken ownership of the issue. When I have spoken to Level 2 Tech. at Tivo they still were recommending I get the cable company to check the line, which I did yesterday. They at no time told me to not spend time troublshooting the issue, nor that they have identified the problem. I even responded to Tivo Pony's post asking whether I should put off further troubleshooting efforts on my side or not, to which I got no response.

    My concern is exactly what you are pointing out. If they do not know the source of the issue, then it still could be many factors and hopes of a fix are just that. If they have identified the issue, then communicate that and give us hope that it can be remedied. In addition if the source of the issue has been identified then an ETA for the solution is possible.

    As part of my current position I have responsibility for global development so issues with product introductions are not foreign to me. I have found the best solution with respect to these issues is to communicate with customers as often as possible with updates on progress toward the solution. So far all we have gotten is vague statements that they are aware of the issue and are working on it. They has been nothing further really.
  6. jmpage2

    jmpage2 New Member

    Jan 20, 2004
    I just got my cable cards installed today, two Motorola Single-Stream cards on Comcast in the Denver suburbs.

    My Tivo HD is connected to my Sony SXRD TV over an HDMI link. I have optical audio output from the Tivo to a Denon receiver.

    I have noticed some weird macroblocking issues on a few channels, but nothing especially obnoxious (the slow menus and slower channel changes are far more irritating at this point) it ercertainly doesn't seem to happen with any set frequency. I have not had the opportunity to see if anything weird is going on with recorded shows.

    I have noticed a weird pixel smearing along the bottom 1/5 of the screen when jumping into the "Now Playing" screen or other menu screens. It looks like some kind of video artifact of the screen changing. Certainly nothing that gets me particularly concerned.

    I do hope that they fix the problem in the near future as, who knows, the probs might get worse for me in the next 30 days after my return/cancellation windows expire.

    My Comcast tech will be coming back out in a week or two to put an M-card in the system to avoid extra charges for the 2nd cable card. Will be interesting to see if that causes any new problems. Fortunately he has put Cable Cards in lots of Tivos so he pretty much knows what he is doing.
  7. lrhorer

    lrhorer New Member

    Aug 31, 2003
    Signal strength (also called carrier level) is only one - usually fairly irrelevant - measure of signal quality, and may not strongly affect S/N. A carrier level which is too low for a receiver (i.e. below the receiver's specification for sensitivity) will cause reception quality issues. On an analog TV receiver, this will be perceived primarily as "snow". The lower the carrier level, the snowier the picture. It may also occasionally cause other artifacts not directly related to the signal level to be more noticeable. In a transmission system, to first order the noise level is fixed by the system topology (number of amplifiers in cascade, ambient temperature of the plant, noise figure of the amplifiers, etc.). In addition to the noise produced by the transmission system, every modulated signal source has some non-infinite C/N ratio. The total C/N of the signal itself is equal to the signal level divided by the sum of the transport noise and the source noise. In most cases, however, the source noise is far lower than the transport system noise, so the overall C/N is just the signal level divided by the transport noise level. The third component to S/N is the noise figure of the receiver itself. Indeed, fundamentally it is this value which determines the receiver sensitivity. A low S/N ratio in an analog signal will result in graininess, color artifacts, or "black snow" in the displayed picture if the input signal level to the receiver is well above its maximum sensitivity.

    So why not just increase the signal levels? Well, first of all, too high a signal will cause problems with the signal just as signals which are too low. What's more, increasing the signal levels in the plant may not have a very large effect on the S/N, which is the real measure of signal quality. Increasing the gain of an amplifier at the end of the cascade (behind the house) by 8 or 10 dB may not increase the S/N by more than 1 dB, or even less. On the other hand, 2nd order distortion increases by 2dB for every 1dB increase in signal levels, and 3rd order distortion increases by 3dB for every 1dB increase in signal levels. Second and especially 3rd order distortion will really do a number on signal quality. 'And that is for an analog AM signal, where there is a direct relationship between carrier/noise and signal/noise.

    OK, that's for analog signals. What about digital signals? Well, there we're really out of the relatively simple S/N world and into the world of distortion and ingress much more than of S/N. A "perfect" analog video signal is anything above 65dB S/N. That is to say, double blind studies have determined that no human subject can tell the difference between a video signal with a 65dB S/N and one with an 80dB S/N. The average consumer cannot tell the difference between a 60dB S/N and a 65dB S/N in pictures displayed side by side. Most consumers can tell a slight difference between a 50dB and 55dB S/N displayed sequentially (not side by side). The analog signal degrades rather gracefully, however, with the picture being poor but still identifiable even with a 15dB S/N. Digital signals do not degrade gracefully. The lowest possible recoverable digital S/N is 6dB, but most systems - especially tuneable broadband systems - require much higher S/N that that to be able to recover a signal. Nonetheless, no matter what the maximum sensitivity, the recovered data will be essentially "perfect" (usually specified as either better than 1 billion or 1 trillion bits per error depending on the system) down to a certain S/N level, at which point decreasing the S/N by even 1dB will produce significant errors. The difference between an essentially perfect data recovery and a complete loss of all data may be as little as 3dB. For signals well in the optimum range of signal levels and S/N, a change of 2 or 3 dB won't make a difference to a digital receiver, but a change of 2 or 3 dB in distortion can make a huge difference.

    The bottom line is this: Once a digital signal is "good", increasing the signal level does nothing whatsoever (except allow the system a little headroom to degrade over time without impacting reception). An analog signal which suffers an error only loses the information on the screen for the duration of the error, which may be exceedingly - perhaps imperceptibly - brief. Without forward error correction (which increases bandwidth significantly for the same amount of information transferred), the loss of a single bit, which may be a mere .01 microseconds in extent in a CATV broadcast video stream, will cause an entre packet of information to be lost. Depending on the encoding and whether it is an I-frame or a B-frame, this single lost bit may produce a very noticeable glitch in the picture. Once the signal level is above the maximum receiver sensitivity and the S/N is above the digital recovery threshold, increasing the signal level only increases the likelihood of lost packets due to distortion or common mode rejection issues due to receiver overload.
  8. lrhorer

    lrhorer New Member

    Aug 31, 2003
    This is clearly not likely to be an issue with the CATV company or the Cable Cards, but it is also extremely unlikely to be related to the 2nd slot issue, isn't it? What's more, it gives us a better handle on what is happening, or at least one of the things that may be happening. Note the tone of your posts strongly suggest you think there is a single problem. I seriously doubt this to be the case, but one never knows. To wit, the CATV plant / HD receiver / CableCard system is not by any means guaranteed to deliver an informationally identical data stream to the hard drive system as that sent from the CATV headend. The extra TiVo content, however, comes over the internet via TCP, and it DOES guarantee delivery of every packet intact to the I/O subsystem.

    On the other hand, if the pixelization is identical in every spot every time you run the video, then either the data somehow got corrupted between the TCP stack and the hard drive write head, or else there is a systemic error in getting the data off the drive and into the video section of the TiVo.

    Another poster, however, is saying he is seeing variability in the errors from a single program, meaning in his case the data must be good on the drive and there is some intermittent problem between the hard drive and the video output system.

    These three scenarios as related are almost certainly mutually excluded from having a single cause. Now either the reports from the people who are experiencing these problems are inaccurate and misleading, or there are at least three different problems running around here. The reports and quantitative analysis of the actual symptoms need to be firmly resolved and communicated or else no one will very likely be able to fix any of them, regardless of whose equipment is at fault.

    This is not aimed at just you. Everyone who is experiencing an issue needs to be far more detailed and exacting in reporting it, or it possibly may never be resolved in a reasonable time. Be explicit, succinct, thorough, and clear. Report the serial number of the box, frequency of the problem's occurrence, duration of the events, and an estimate of how much of the screen area is involved. Is the interval highly regular, somewhat regular, or highly random? Is the audio impacted always, sometimes, or never? Are both analog and digital audio affected? Turn on Closed Captioning. Is it impacted? How? Will rewinding the video and replaying it clear the error? Does rewinding affect the error at all (audio, video, or Closed Captioning)? If you have the ability to try both component and HDMI connections, does it make a difference? Closely examine a single section of video again and again under different conditions to make the determination. Try a downloaded Amazon Unbox video. Does the problem with downloaded video look and feel identical to videos recorded from cable? Does the issue seem to coincide with highly active video (like smoke or swaying fields of grain)? Does the issue happen when specific colors are present (especially large amounts of red)? Is it worse on bright pictures or dark ones? Are pictures either with lots of edges (like a field of flowers or a crowd of people) or with smooth backgrounds (like a tabletop or a blank wall) affected more?

    Carefully observing the issue and answering these questions and similar questions could get at the heart of the issues - or at least define them - very quickly, rather than dragging on with vague post after vague post and eratic calls to TiVo support.

    (BTW, on my Series III I have never had a single pixelization on downloaded content.)
  9. jmpage2

    jmpage2 New Member

    Jan 20, 2004
    Well, I've been seeing more pixelation tonight on several channels. Interestingly (or not) we watched the first half of a movie on the Tivo HD and finished watching it in another room on the Motorola HD Tuner box (non DVR).

    Bottom line is there was no artifacting in this movie on the Motorola box but there was noticeable (distracting) artifacting when watching the movie on the Tivo.

    There are a few basic things that any digital tuner should do, producing a picture without noticeable artifacts (macroblocks, etc) is one of them. While I realize that there will be some encoding macroblocking due to the compression that the digital cable system uses, this appears to be something else entirely. Also, as others have noted, it is happening in the Tivo menus.

    Hopefully there is a fix for this and a few other things (I had a lockup this evening just browsing channels) very soon as I have 30 days from today to cancel my Tivo subscription.
  10. jmpage2

    jmpage2 New Member

    Jan 20, 2004
    One interesting thing I've noticed about this problem is that it always affects only the lower portion of the screen. I've never seen it happen on the upper portion of the screen.

    Definitely seems to be some kind of buffering/video output sort of problem to me. Maybe the drivers for the new video chipset aren't as solid as they ought to be.
  11. Chimpware

    Chimpware New Member

    Jan 30, 2002
    You my friend should be banned from using the word "succinct" when it relates to any posts on this forum :rolleyes:
  12. lrhorer

    lrhorer New Member

    Aug 31, 2003
    I submit my posts are succinct. They are thorough and detailed, and as succinct as thoroughness combined with explicit detail will admit. After nearly 40 years of designing and troubleshooting electronics systems, it's reflexive.
  13. Phantom Gremlin

    Phantom Gremlin New Member

    Jun 20, 2002
    I don't know what planet you're from, but I don't think it's Earth. We do things differently on Earth.

    On Earth we can "report" our problems to a bunch of outsourced script monkeys (who will ask us if our box is plugged in and if we have rebooted it), or we can "report" our problems here.

    Neither of which is likely to contribute much to having these problems fixed. But at least "reporting" them here makes us feel better. This forum is a support group for early adopters.

    Sorry to be so cynical about it, but if TiVo really cared about our "reports", they would be responding in this forum. They would be publicly posting guidelines about what, how, and where to "report". Or they would be emailing us privately asking the same information. I have seen no indication that they have done either.

    So far I think TiVo's attitude is something akin to: Frankly, my dear, I don't give a damn.

    I'm upset because, in all likelihood, in a few weeks I'll have to cart off my TiVo HD to Circuit City and acknowledge to myself that my latest impulse purchase was a mistake. Then I'll be without an HD DVR for another year while I hope that TiVo can fix their problems.
  14. GoHokies!

    GoHokies! O2->CO2 Converter

    Sep 21, 2005
    Which is why Tivo Pony has replied in this forum, Tivo has publicly stated that they are aware of the problem, and have already pushed a software release that fixed the problem for some folks (which has got to be a record, ask an S3 owner how long they had to wait for the "fall" update last year).

    Sounds like a company that is doing everything that they can, to me. I'd much rather they spend their time working on a fix than posting about it on an internet forum.
  15. thewebgal

    thewebgal MacAphile AV geek

    Aug 10, 2007
    Just got the new TivoHD Aug 6. Ordered Cox to come install Cablecards - first trip they installed a pair of SA '06 cards - had problems with few channels on card 2. Second tech came last night - installed a pair of SA '07 cards. Now all the channels we pay for come in - but still has that pixelization problem on many channel. Maybe I'm fussy but I'd call it unwatchable when the picture pixelates or tears once or more a minute.

    tech was very good checking splitters, replaced fittings, etc - finally connected a 100' test line from incoming line for the Tivo (inside the house) and fed it out to his truch a converter box and his test TV - no pixelization, no tearing, nada ...

    COX tech says -6db is a fine level, shows me a good picture on his box with even less (through the 100 test cable etc)

    It looks to me like the TIVO box doesn't handle the signal as well - and its starting to look like my only choice is to ship the TIVO (and wireless adapter) back for a full refund and get a cable DVR -= and i HATE to give COX any more of my money a month ... but I also won't pay for something that flat doesn't work right.

    FIOS says they are a year away from our home ... sigh.

    Any more ideas?
  16. Chimpware

    Chimpware New Member

    Jan 30, 2002
    Couple of points;

    1. While Tivo Pony's response was nice to get it did not address the issue, only vaguely said thay are aware some people are having issues and are working on it. It did not request any detailed troublshooting information, nor offer any real advice.

    2. Amazing people are basically willing to applaud Tivo for fixing an issue quickly. It is ridiculous, the unit did not work as shipped with SA SCard in Slot 2 so they fixed it. Fine, should not have had the issue in the first place IMHO. No kudos for this.

    3. I am tired of reading, "Get in line this has been a probelm for S3 owners for a while" and "ask an S3 owner how long they have had to wait..." If people that bought the S3 at its ridiculous price, have this issue and it was not remedied quickly they got what they deserved and obviously made the choice to keep a product that did not function properly. This will not be my choice, if this is not fixed within the 30 days I have beore I can return it to CC it is going back and I am canceling my subscription. Why, simply because they are not delivering the value proposition I am paying for, simple as that.

    4. They are not communicating consistently, or enough in my opinion. If people have a case open with their engineering department I would like updates that go beyond 1 call back in a 2 week period that simple says "We are working on it". Not everyone in the company is troubleshooting this issue so to say "I woulod rather they work on the fix, than posting on a forum" is ludicrous. Do you think their market communication, or marketing department is working on a fix???

    Ah well, done venting for now...
  17. bkdtv

    bkdtv New Member

    Jan 9, 2003
    Tivo reads this forum and they have beta testers to test fixes.

    The know about the problem and are working to fix it. What else do you expect them to communicate? Nothing is going to help until they fix the software.
  18. Chimpware

    Chimpware New Member

    Jan 30, 2002
    Well here are some possible thoughts:

    1. We can replicate the issue in our lab.
    2. It is software related and not hardware related.
    3. It is a Tivo issue so those having it please do not troubleshoot further with your cable companies regarding cable card or signal issues.
    4. We have a beta of the fix completed and in our lab it does remedy the issue.

    Just some thoughts since you asked. Basically any update on progress as well as some detail about the source of the issue would be helpful.

    As an aside if the problem were with their billing system software / hardware and as many people as have pixelation issues were not being billed monthly for service how quick do people think that would be fixed??? I seriously doubt this would last longer than 1 week.
  19. jmpage2

    jmpage2 New Member

    Jan 20, 2004
    If Tivo is like most "software" companies they have programmers all over the world and it takes a lot of time to investigate issues and provide fixes for them.

    On the other hand I would be surprised if they did not see this in Beta testing. I am getting the feeling that we've ALL seen this to some degree.

    I did not think that the problem was really noticeable until we watched a movie last night and saw the problem happen quite frequently. Interestingly enough sometimes it will show up in the same spot if I rewind the feed, other times it won't be there when replayed from the buffer. Also as previously reported the problem sometimes happens in the Tivo menus which should have nothing to do with the signal at all, unless the menu is superimposed over a "null" image that is still part of the signal feed.

    This would indicate that;

    1. There is more than one source for this problem.

    2. Tivo knew about this problem when they shipped the box and shipped anyways.

    Those of you saying "it's not a big problem" are seriously living in fantasy land. Tivo is the highest priced mass market DVR product that is available today and the core functionality for playing back error free video is a requirement for that market.

    As Chimp says, for those of you saying you've had this problem for months with your S3 and are still awaiting a fix, I'd say that you were foolish to keep a box that obviously doesn't work.

    I will continue to evaluate for the remainder of my 30 day return policy and if Tivo does not fix the issues it is going back. My wife, who was really excited to get the Tivo asked me last night "why doesn't this work as well as our Comcast box?" and "how much did we pay for this again?". Certainly not getting high marks on the Wife Approval Factor won't be helping Tivo sell too many of these.

    Maybe thousands of returned boxes stacking up with retailers will get the executives at Tivo to devote the necessary resources to fix this problem.
  20. TiVoDoughBoy

    TiVoDoughBoy New Member

    Nov 7, 2004
    What is the deal with this sort of response? It's not the first I've seen it with respect to the pixelation issue and I'm certain it won't be the last. But really, how is it living in a "fantasy land" for an individual say that, to them, it's not a big problem? If it's a problem for you and those of you who post these kinds of replies, that's fine, I completely understand how plenty of people have an issue with it.

    At the same time, however, there are many people for whom the issue, while not something they'd choose, is absolutely better than any of the alternatives. My own situation is that I moved to a plasma HD set last winter -- I purposely got one witth CableCard because I hate Comcast's Motorola cable boxes and didn't want/need one. The downside of going to HD, box or not, was that I had a pair of Series2 units and the SD recording just looked really bad on my HD set. So, given that (1) I didn't want a cable box, (2) loved my TiVo's (4 different units back to my original Philips first-generation box), and (3) really wanted my TiVo to be in HD, when the TiVo HD box shipped, I picked one up the day my local Circuit City had them in. And yeah, for me, even with the very intermittent pixelation, it's a better situation -- and I lost MRV and TTG on that unit, too! But, knowing TiVo's track record over the years, when there are issues like this, they are typically fixed. It may be a couple of months, sure, but it's still an improvement. Plus if I have MRV by the end of the year as they say is coming, then so much the better. If I for a second thought that the pixelation problem was permanent, my story might well be different.

    So I'll probably get a nice flame for being some sort of moron who is living in a "fantasy land", but it's my $300 I spent and I'm happy with it. If you're not satisfied with yours, then great, I can respect and understand that. Return it and make your point to TiVo, but leave me and those like me out of it and let's get back to the conversation of what can be done to get to a resolution sooner rather than later and leave the rest of the "fantasy land" comments out of it.


    P.S. My wife, too, asked me, "you spent how much?" on it when I first came home with it, but after a very smooth M-Card installation, she's also very happy with the improvements.

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