Analog recordings of digital channels?

[TromboneKenny]

The discussions about whether to record from digital or analog channels (or SD broadcast on HD channels,) led me to poke around at my channel lineup. I was under the impression that all of my digital cable channels were digital, but it doesn't appear to be so. For example, if I use the cable signal strength meter, only some of those channels show up. Those are the same channels that let me record without setting a quality level, and suppress the tivo sounds on the optical audio out, just like the HD channels. But the majority of the digital cable channels function just like analog cable channels. In fact, a lot of them are simulcast on both the analog channel and digital cable channel (two ESPNs, two Comedy Centrals, etc.) When I go to record the digital cable Comedy Central channel (148 vs 30-something in the analog range,) I get the same recording quality settings as a normal tuner.

Can someone explain to me how, then, does digital cable give me versions of channels that don't record any better than my analog ones? I was under the impression that it worked like DirectTV, where everything was sent digitally. I thought I was doing good understanding how QAM and CableCards worked, but I'm confused on these non-digital channels provided by my digital cable.

I did some testing and the quality on the S3 between recordings at the same quality level on both the digital Comedy Central and the analog one are pretty much the same (the digital might have sounded slightly better.) So where's the advantage of doubling up the analog channels in the digital range?

[cableguy763]

It depends on how the cable company tells the card to decrypt the channels. Some cable co's tell cable cards to only get the analog versions and some let them get the digital simulcast version. This is all up to your channel maps in your cable system.

[TromboneKenny]

I guess I'm just confused why I have a digital channel where the content isn't digital. If I'm getting CSI reruns on Spike, I can pick channel 49 or 141 but they both appear the same. Is Spike 141 being tuned with the analog tuner? I thought digital cable had digital channels...

[Royster]

I guess I'm just confused why I have a digital channel where the content isn't digital. If I'm getting CSI reruns on Spike, I can pick channel 49 or 141 but they both appear the same. Is Spike 141 being tuned with the analog tuner? I thought digital cable had digital channels...

You have a digital channel because the cable company decided to offer you one. The content is digital, but it is still 480i material. You could record the analog version in highest quality and the mpeg encoder in your TiVo would convert it to a digital stream for storing on the HD or you can rply on your cable channels mpeg encoder the output of which is squirted through a digital channel and then dropped directly onto your HD. The only difference, given they both start with 480i material, is how does your TiVo's encoder compare to the cableco's.

Or, perhaps your cable company gets Spike originally in a digital format from their satellite and they convert it to analog for channel 49, but pass the digital version directly on to you in 141. Your TiVo then undoes the digital to analog conversion and converts it back to mpeg for storage.

In the long run, the cableco is going to want to convert all their customers to digital so that they can free up the bandwith that the analog channels consume.

[jlib]

The original poster is claiming that the digital version of a channel is analog (not the other way around as with simulcasting the digital channels into the analog channel range) which is indeed odd if correct.When I go to record the digital cable Comedy Central channel (148 vs 30-something in the analog range,) I get the same recording quality settings as a normal tuner.

[vstone]

I recommend everyone start out with the assumption that cable companies train their technical folk just enough to get by, that this amount of training is not suffiencient to properly set up a system, and that most digital cable systems are not properly set up in ways minor and properly major. Throw in channel assignments by folks not technically knowledgeable enough to make reasoinable decisions and you have a recipe for all kinds of strange occurances.

I don't blame the people; they're doing the best they can with the trainig afforded them. I blame the company.

[TromboneKenny]

I can tune to 148 (the Comedy Central channel as a part of my digital cable package,) and go into Diagnostics and confirm that the modulation is analog (frequency 241250 KHz.) If I tune to 27, it also is analog with freq. 241250 ... so I guess that confirms they're the same thing?

If I switch to 512, which is ESPNCL, I see that it's QAM 64. Eyeballing the last time I went through the cable signal level, I'd say less than 25% of my digital tier are being tuned digitally.

Do you think this means the 148 channel has always been analog, even on their STBs? Or is there some difference between what goes out to their cable boxes and what's decoded on the CableCard? Is there anyway to test that?

I would rather get the digital version on the digital channel, but barring that, I'd prefer not to have the same channel twice. How do I even start to explain this to a CSR at Insight?