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[sub]

Great - glad you've got it working.

Having the ClearQAM tuners connected directly to NextPVR would give some additional advantages, like the ability to record more than one digital channel at a time from a single tuner.

[Rich A]

Thanks.

Are you sure of that? The Prime is only a three tuner device. I have tested it while setting up the tuners for a mix of types. ie. 1 for ASTC and 1 for cable clear QAM and 1 for regular cable card encoded QAM. (sorry I should know what they are called (Clear QAM vs. "not' Clear QAM) but my memory is not what it used to be. Anyway, I don't see how NextPVR can get more than one stream out of one tuner?

[bgowland]

Anyway, I don't see how NextPVR can get more than one stream out of one tuner?

Not that I know anything about US broadcast formats but technically speaking, in digital terms, stream can mean various things.

In reality, when you watch live TV or record a programme NextPVR has to extract two elementary streams - one for video and one for audio....so that's more than one already.

A digital tuner doesn't 'tune' to a stream it tunes to the carrier, and if that carrier is carrying multiple channels then watching or recording a channel is a subtractive process. In other words, grab what's needed and ignore the rest. The fact that the rest is still there and available means that software, such as NextPVR, can extract other parts at the same time for simultaneous recordings. The limitation really comes down to hardware resources such as processing power, physical memory, disk speed etc.

Sub will correct me if I'm wrong or fill in the gaps about clear QAM but I think that's basically what he meant.

Cheers,
Brian

[sub]

As Brian says, each digital broadcast frequency contains multiple channels. NextPVR can take advantage of this and allow you to record multiple channels with the single tuner, of course depending on the frequency of those channels.

For example, your cable company my be transmitting ABC and NBC and a couple of other channels on the same frequency, then if the user schedules recordings for ABC and NBC, it only needs to allocate a single tuner to the job, not two.

On our digital system here, I can record our 18 free to air channels simultaneously with just 2 tuners.

[mvallevand]

In North America that is more theoretical then real because of the heavy encryption of cable and satellite broadcasts. For clear QAM many cableco's have opted to only make SD available clear often on one frequency, but that doesn't help if you want HD. Here in Canada there is no clear QAM so no advantage. Before everything was encrypted I was able to record 3 HD channels on one mux. There is also a disadvantage to this since cable co's degrade quality to fit as many channels as they can on on 40 Mbs frequency.

For OTA, the bandwidth is only 20Mbs so only one HD broadcast fits. Typically you will have a station like PBS with their main broadcast and some SD variants. Here one channel has HD and SD flavours of the same channel but I typically wouldn't record both.

The big advantage is when NextPVR logic works and records back-to-back digital on the same tuner (it doesn't always) you get full pre and post padding on both shows. Another lesser advantage is being able to watch the same digital broadcast as live tv in multiple rooms.

Martin