# Odd new SDV "bug" with Roamio



## LoadStar (Jul 24, 2001)

I'm used to various SDV issues, mostly a failure of my TiVo HD to tune in the channel properly, resulting in nothing but a black screen. Fortunately, I haven't seen that on the Roamio.

Oddly, what I *have* now seen a few times is a new unique situation. Tuning to an SDV channel, I can see the picture and hear audio - for about 1-2 seconds. Then, I get the "channel temporarily unavailable," "press select" message.

I'm not sure why TiVo is displaying the "press select" message in this instance, because clearly the channel is tuned properly, since I can see and hear the channel. I can only assume this is a bug, and a rather annoying one at that.

Has anyone else experienced this?


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## mrizzo80 (Apr 17, 2012)

I've experienced this on my Roamio... rare, but has happened multiple times. Can't remember if I ever saw this on my Elite.


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## Dan203 (Apr 17, 2000)

Has this effected recordings, or only live TV?


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## jwbelcher (Nov 13, 2007)

I've gotten this before, last time Oct 28th, and reported the issue to Margret. One of her engineers said it is a bandwidth issue with the SDV system when the Tivo receives the channel not available messages immediately after tuning. However, I've also had this issue at 12 am when you'd think bandwidth would not be an issue.

I'm not sure since pressing SELECT generally tunes successfully. However, I have had the occasion where I've pressed SELECT repeatedly, each time getting video for 1-2 seconds. 

Hoping that the next Tuning Adapter (Cisco) firmware fixes this. This is another issue I never had on the TivoHD, but now I am pulling more SDV channels with 6 tuners... So I'm not sure what to think.


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## jwbelcher (Nov 13, 2007)

Btw, back in Oct, I wrote down the Tivo diags. For me the diags show that Tivo did get the SDV freq, but the TA later decided to stop providing it. For those on BHN, I've reported this issue to them as well and they replied that they were aware. I didn't expect that, so while surprised, I was happy to hear it.

Tivo DVR diagnostics state of failed channel :

Tuner : 5
Channel : 127
Frequency : 669000 KHz
Modulation : QAM 256
Program Number : 1321
Signal Strength : 100%
Signal Lock : Yes
Program Lock : Yes
Search Complete : Yes
SNR: 40 dB
Current Tuning status : Tuned : Success
Tune State : In Progress
Time Since Tune Start : 330 secs
Resolution Status : Channel not available
Resolution Time : 10/26/2013 00:16:59

Cisco Tuning Adapter diagnostics :

Session-6
Name Status : LTSID5-Idle
SamSvcid/Type: 61542/Swtched
Source Id: 4321
Act Time: n/a
Retries/Resends : 0/0
Retunes: 0
Tuner Status: Inactive
Tv/Rec Rsrc: 0/0
SDV Freq: 0 MHz
LUA Tx Time: 10/[email protected]:40:34
Last CCP Err: NoErr
Err Time: n/a

Current QAM

Freq: 669.000 MHz
Tuning Mode: QAM-256
Status: Locked
Level: 7 dBmV
S/N: 39 db
Seconds: 1166


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## CoxInPHX (Jan 14, 2011)

LoadStar said:


> Oddly, what I *have* now seen a few times is a new unique situation. Tuning to an SDV channel, I can see the picture and hear audio - for about 1-2 seconds. Then, I get the "channel temporarily unavailable," "press select" message.
> 
> I'm not sure why TiVo is displaying the "press select" message in this instance, because clearly the channel is tuned properly, since I can see and hear the channel. I can only assume this is a bug, and a rather annoying one at that.
> 
> Has anyone else experienced this?


This is not new for me, I have experienced this since day 1 with the Roamio Pro. But it has improved and become less frequent with the SW updates.

I had never experienced this with my Elite, but since the Fall update have seen it a few times on it now also.

When this happens, after pressing Select, each time I enter the menus, and the Video moves to the window, I loose the buffer for that channel, and it resets and will not retain a buffer until I channel up then tune back.

TiVo has been blaming the Cisco TA saying it is a known bug, but since it is now happening on the Elite, I have to suspect the issue is with the current SW 20.3.7.x


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## JosephB (Nov 19, 2010)

It seems odd that anyone would blame it on bandwidth, since you get sound/picture for a second. If there were no available QAMs to stick the channel on, you'd never get the initial picture.


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## Dan203 (Apr 17, 2000)

JosephB said:


> It seems odd that anyone would blame it on bandwidth, since you get sound/picture for a second. If there were no available QAMs to stick the channel on, you'd never get the initial picture.


Unless the initial picture is not from the new channel. It could be from the previous channel or some default QAM the TiVo tunes to when there is an SDV failure.


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## LoadStar (Jul 24, 2001)

Dan203 said:


> Unless the initial picture is not from the new channel. It could be from the previous channel or some default QAM the TiVo tunes to when there is an SDV failure.


No, in the case I describe, it is definitely the new channel.


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## JosephB (Nov 19, 2010)

LoadStar said:


> No, in the case I describe, it is definitely the new channel.


I'm assuming you don't have any kind of box from the cable company in your house, do you? If it were a bandwidth problem then you'd see some kind of problem (maybe not seeing the video, but definitely not able to tune the channel) with one of the cable company's boxes.


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## jwbelcher (Nov 13, 2007)

I personally don't put any weight into this, but I have read people on this forum saying their cable co CSR stated their boxes are prioritized so if they want to be guaranteed an SDV channel / program, they'd need to rent a cable box. I'd argue the TA is a cable co box, but as conspiracy theories go, this may suggest that not all things are equal...


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## Dan203 (Apr 17, 2000)

I doubt that. I don't think the cable company can even tell the difference between a TA and a real box when processing a SDV request.


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## JosephB (Nov 19, 2010)

Dan203 said:


> I doubt that. I don't think the cable company can even tell the difference between a TA and a real box when processing a SDV request.


I'm with you. The whole reason of having a TA is so that you can have proprietary implementations of SDV without having to modify it to work with UDCPs like TiVos. Of course at *some* level they know a TA from a normal STB, but when it comes to the mechanism of tuning channels, it doesn't.

As much as cable companies hate CableCard devices and would rather you pay them $20 a month for their DVR service, we are their customers. And while making CableCard painless may not be a priority, I don't see them actively sabotaging paying customers.

Besides, if they are doing SDV right they should never run out of bandwidth for SDV channels. I doubt there are many nodes on any cable system that have more than 5-10 UDCP/OCUR devices with tuning adapters. If that small of a number of customers can go over some priority threshold, then customers with the cable company's boxes are going to hit the wall too. There should always be enough overhead that you don't bang into the limit.

Theoretically I would assume that eventually the trend will be that the percentage of channels delivered via SDV will approach 100%. That's just the logical progression, and then the next stage beyond that will be moving from MPEG streams in a predefined QAM channel to the entire system dedicated to DOCSIS channels and video broadcast via IP multicast like U-Verse.


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## Dan203 (Apr 17, 2000)

A pure IP system would require changes to the CableCARD laws, so I don't see that happening in the immediate future. However 100% SDV is probably going to happen, especially in areas where they've converted to pure digital.


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## jwbelcher (Nov 13, 2007)

Well, the one caveat is cable operators are also deploying new UDCP devices on a pure digital roll-outs. The digital adapters hit Comcast a few years ago and just begun hitting Brighthouse Networks here in Orlando. Orlando has been used as a test bed for new roll-outs in the past (we were a test bed SDV for BHN / TWC in the past). Given that cable operators are pulling the plug on analog, they're providing cheap UDCP digital adapters for nominal fee (1-2 dollars) to consumers as the alternative. They only provide basic tier cable channels, but I don't expect them to go away anytime soon. People would revolt by having to pay for a full digital cable box for each outlet.


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## tim1724 (Jul 3, 2007)

LoadStar said:


> I'm used to various SDV issues, mostly a failure of my TiVo HD to tune in the channel properly, resulting in nothing but a black screen. Fortunately, I haven't seen that on the Roamio.
> 
> Oddly, what I *have* now seen a few times is a new unique situation. Tuning to an SDV channel, I can see the picture and hear audio - for about 1-2 seconds. Then, I get the "channel temporarily unavailable," "press select" message.
> 
> ...


Yep, I get this too. Cisco tuning adapter on Charter. I see this fairly often when I watch live TV. (Luckily I rarely watch live TV.)


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## Dan203 (Apr 17, 2000)

jwbelcher said:


> Well, the one caveat is cable operators are also deploying new UDCP devices on a pure digital roll-outs. The digital adapters hit Comcast a few years ago and just begun hitting Brighthouse Networks here in Orlando. Orlando has been used as a test bed for new roll-outs in the past (we were a test bed SDV for BHN / TWC in the past). Given that cable operators are pulling the plug on analog, they're providing cheap UDCP digital adapters for nominal fee (1-2 dollars) to consumers as the alternative. They only provide basic tier cable channels, but I don't expect them to go away anytime soon. People would revolt by having to pay for a full digital cable box for each outlet.


I could see them leaving a handful of channels non-SDV. Maybe the same channels offered by the Basic tier. That way simple UDCP boxes can be used for secondary rooms to access the most popular networks. But by moving most of the expanded channels to SDV they could free up a lot of bandwidth for additional services like VOD, cloud based DVRs, and higher speed internet.


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## JosephB (Nov 19, 2010)

I didn't realize the DTAs were one-way devices. Seems kind of odd, but I guess since these are boxes that they're being forced to provide for free or insanely cheap (when compared to their regular STBs) they want them to be as cheap as humanly possible.


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## Dan203 (Apr 17, 2000)

DTAs are two way. That's how they work. They send a request to the cable company for a SDV channel and then cable company assigns that channel a frequency and then replies to the DTA with the frequency so the TiVo knows what to tune.

The UDCP boxes jwbelcher was referring to are small inexpensive tuner boxes that some cable providers are starting to offer for secondary rooms. They do not have any two way capabilities so they can not access SDV channels or VOD. For these to continue to work they need to maintain a core list of channels that are not SDV.


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## jwbelcher (Nov 13, 2007)

When BHN first announced these UDCP devices, they were using the term DTA (digital tuning adapter). As expected, it caused a lot of confusion about them vs the SDV tuning adapters over a dslreports. BHN recently dropped the Tuning part and now they're simply referred to as digital adapters (DA) for the UDCP devices.


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## LoadStar (Jul 24, 2001)

Dan203 said:


> DTAs are two way. That's how they work. They send a request to the cable company for a SDV channel and then cable company assigns that channel a frequency and then replies to the DTA with the frequency so the TiVo knows what to tune.
> 
> The UDCP boxes jwbelcher was referring to are small inexpensive tuner boxes that some cable providers are starting to offer for secondary rooms. They do not have any two way capabilities so they can not access SDV channels or VOD. For these to continue to work they need to maintain a core list of channels that are not SDV.


DTAs (Digital Transport Adapters) are one-way devices. They're the cheap devices you describe in the second paragraph. Time Warner, like it's close cousin Bright House Networks, calls them simply Digital Adapters.

Tuning Adapters are two-way devices. Those are what you describe in the first paragraph, the boxes that work with TiVos.


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## JosephB (Nov 19, 2010)

Dan203 said:


> DTAs are two way. That's how they work. They send a request to the cable company for a SDV channel and then cable company assigns that channel a frequency and then replies to the DTA with the frequency so the TiVo knows what to tune.
> 
> The UDCP boxes jwbelcher was referring to are small inexpensive tuner boxes that some cable providers are starting to offer for secondary rooms. They do not have any two way capabilities so they can not access SDV channels or VOD. For these to continue to work they need to maintain a core list of channels that are not SDV.


DTA = Digital Transport Adapter
TA or TR = Tuning Adapter/Tuning Resolver

No one ever accused CableLabs of good marketing.


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## Dan203 (Apr 17, 2000)

I've seen people refer to Tuning Adapters as DTAs, as in Digital Tuning Adapter, that's what I thought you were doing.


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## crxssi (Apr 5, 2010)

mrizzo80 said:


> I've experienced this on my Roamio... rare, but has happened multiple times. Can't remember if I ever saw this on my Elite.


I have seen this too and it DOES affect recordings. I can have a complete recording of nothing but blank. Very annoying. I really hate [Cox] SDV.

When it starts acting up, I can't tune any of the SDV channels and end up having to power cycle the [Motorola] tuning adapter and things will return to "normal" again for several days to a few weeks.


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## jwbelcher (Nov 13, 2007)

crxssi said:


> I have seen this too and it DOES affect recordings. I can have a complete recording of nothing but blank. Very annoying. I really hate [Cox] SDV.
> 
> When it starts acting up, I can't tune any of the SDV channels and end up having to power cycle the [Motorola] tuning adapter and things will return to "normal" again for several days to a few weeks.


Do you have a 1-2 seconds of video at the beginning of the recordings? I'm inclined to think this issue is different since your using Motorola rather than the Cisco TA discussed in this thread. Maybe they both have a similar bug, but would be surprised.


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## crxssi (Apr 5, 2010)

jwbelcher said:


> Do you have a 1-2 seconds of video at the beginning of the recordings? I'm inclined to think this issue is different since your using Motorola rather than the Cisco TA discussed in this thread. Maybe they both have a similar bug, but would be surprised.


You know, I am just not sure. I could have sworn I have seen a little video before, but it might have been left over from another function or channel. My memory of the events is not that good, so I don't want to commit either way at this time.

It probably is a different situation.


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## jwbelcher (Nov 13, 2007)

I'd be curious, if it happens again. This issue for me didn't honk up the TA to the point where it required power cycling. Your issue seems to be a lot worse since it doesn't recover on its own.


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## JosephB (Nov 19, 2010)

So I wanted to chime in on the bug, specifically. I swapped one of my TiVos out for an HDHomeRun Prime and Windows Media Center in my office. I am seeing this exact behavior on the HDHR. I first noticed that I was missing some recordings, and then I further noticed that it was only happening when I had two other recordings happening (IE: the failed recording was attempting to use the last available tuner)

Checking the logs, almost every time I tune an SDV channel, I get a "tuning resolver timeout" error in the log, but the channel will still tune properly. However, sometimes the cablecard (or tuning adapter..the logs aren't 100% clear) will report to the tuner "Channel temporarily unavailable". 

I decided to do a little experiment. I loaded up two of the tuners with recordings and started watching live TV with the remaining tuner. I just kept switching channels until I had a problem. Lo and behold I hit one channel, get about half a second of video, and then get a "no signal" error from Windows Media Center. 

If I immediately change to another channel and BACK to the one I got the error on, it tunes, which leads me to believe it is not entirely a bandwidth problem. The logs say the cable card reported "channel temporarily unavailable". 

I didn't check this but plan to, and that is to open up the HDHR config utility and see what that tuner is actually doing. Did it stay on that QAM and program ID? And if so, what is the video coming out of it.

For the record, I'm on Charter with Cisco equipment. I also have occasional tuning failures when watching TV on at least one of my TiVos as well, but of course a couple of presses of select and the TiVo will finally successfully tune the channel.


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## LoadStar (Jul 24, 2001)

I believe the suggestion of bandwidth issues is not bandwidth for the channel itself, it is latency caused by insufficient bandwidth on the OOB channel, i.e. the TiVo makes the request for the channel, but the response from the head end lags long enough for the TiVo to give up and assume the channel failed to tune in.

This seems as reasonable an answer as any. The better question, then, is why this problem only seems to affect some equipment, but not others, and doesn't seem to affect MSO-provided converters.


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## JosephB (Nov 19, 2010)

I wonder how MSO converters handle a failed tune? I'm curious if they "retry" over and over until it succeeds. 

The cablecard actually reports "channel not available" so it's not the TiVo (or other UDCP/OCUR) giving up, the cablecard has actively told the UDCP that the channel will not be tuned.


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## JosephB (Nov 19, 2010)

Additionally, I did these tests today around 2PM at home. If bandwidth is a problem at that point in time, the system should be unusable when everyone is at home, but the problem seems to be the same (which is to say, it isn't terrible and is fairly intermittent) regardless of the time of day.

I think maybe the servers in the headend are just slow to get everything situated and get the control messages out on the network and the TA/Cablecard give up before they get confirmation from the SDV servers. Not bandwidth on the network, but bandwidth in terms of the servers' responsiveness.


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## HarperVision (May 14, 2007)

JosephB said:


> So I wanted to chime in on the bug, specifically. I swapped one of my TiVos out for an HDHomeRun Prime and Windows Media Center in my office. I am seeing this exact behavior on the HDHR. I first noticed that I was missing some recordings, and then I further noticed that it was only happening when I had two other recordings happening (IE: the failed recording was attempting to use the last available tuner) Checking the logs, almost every time I tune an SDV channel, I get a "tuning resolver timeout" error in the log, but the channel will still tune properly. However, sometimes the cablecard (or tuning adapter..the logs aren't 100% clear) will report to the tuner "Channel temporarily unavailable". I decided to do a little experiment. I loaded up two of the tuners with recordings and started watching live TV with the remaining tuner. I just kept switching channels until I had a problem. Lo and behold I hit one channel, get about half a second of video, and then get a "no signal" error from Windows Media Center. If I immediately change to another channel and BACK to the one I got the error on, it tunes, which leads me to believe it is not entirely a bandwidth problem. The logs say the cable card reported "channel temporarily unavailable". I didn't check this but plan to, and that is to open up the HDHR config utility and see what that tuner is actually doing. Did it stay on that QAM and program ID? And if so, what is the video coming out of it. For the record, I'm on Charter with Cisco equipment. I also have occasional tuning failures when watching TV on at least one of my TiVos as well, but of course a couple of presses of select and the TiVo will finally successfully tune the channel.


 I reported this same thing after I tested a ceton infinitv 6 pcie card and got the same results. I opened a ticket with them and it was resolved within 24 hours. They indicated exactly what you're all saying as far as the tuner giving up so they wrote it in their firmware to do the continuous tune attempts and it worked like a champ! The most reliable tuning I have ever had with newer digital cable systems. I have used a LOT of devices like the various versions of Cetons (ITV4 and 6 in both PCIe and USB), all tivos, SD HDHomerun and HDHR Prime, the old Sony DHGs and sxrd Cablecard TVs.

Moral of the story is it CAN be done and I don't know why TiVo is taking so long to implement it.


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## JosephB (Nov 19, 2010)

HarperVision said:


> I reported this same thing after I tested a ceton infinitv 6 pcie card and got the same results. I opened a ticket with them and it was resolved within 24 hours. They indicated exactly what you're all saying as far as the tuner giving up so they wrote it in their firmware to do the continuous tune attempts and it worked like a champ! The most reliable tuning I have ever had with newer digital cable systems. I have used a LOT of devices like the various versions of Cetons (ITV4 and 6 in both PCIe and USB), all tivos, SD HDHomerun and HDHR Prime, the old Sony DHGs and sxrd Cablecard TVs.
> 
> Moral of the story is it CAN be done and I don't know why TiVo is taking so long to implement it.


Awesome. I hope SiliconDust will do this as well. Seems like TiVo should be doing it, especially on recordings when no one is there to hit select when you get the error.


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