Comcast Digital Adaptors!!!!

[rob11252]

Can someone explain wht the purpose of the adaptor is

Does it convert a digital signal back to analog? I am so confused.

Yes that's exactly what it is. The analog TV in USA understands only one signal- NTSC, so these converters (or 'adaptors') take available digital signal and convert it to NTSC for our analog TV consumption. First users of those converters were DirectTV and Dishnet users. Their Set-Top-Boxes (STB's) were converting satellite digital low resolution signal and converting to NTSC. Then digital cable customers joined them. Soon over-the-air (OTA) or antenna crowd will join them. The rest of cable customers are nor far behind.
Soon everybody will be on digital. Then the only difference will be that High Definition (HDTV) customers will be watching in 720x1280 or 1080x1920 resolution vs 480xiii (iii depends on the quality of the converter box and quality of your analog TV).

[sub]

The digital adapters that comcast lets you use for free are not STB's. It is mearly a QAM to analog convertor with an RF modulator (I have 2 of them). There is no analog video out. It re-modulates the converted digital signal to channel 3 or 4 so your analog TV can receive the channels.

That sounds like a set top box to me. ie, its a box with a tuner inside, which is can be tuned to digital channel, and you can switch channels using a remote. Like a lot of set top boxes, it has a modulator for outputting an analog NTSC on CH3/4. HighDef channels are downscaled to regular NTSC for this analog output.

[wtg]

What type of file does the digital tuner create for an SD digital TV signal (I'm not interested in HDTV, yet)? My PVR150 and Avermedia M150 create mpg files. I typically watch these in my MVP upstairs. Will the files created by a digital tuner be viewable on the MVP?

Using a digital capture device like the HDHomeRun or some of the newer Hauppauge cards that can record clear QAM channels, gbpvr records the program in the format defined by the BDA mux selected in config. Only the Cyberlink and ATI muxes will record to mpg format. The TS mux records in .ts format and the Microsoft DVR-MS mux, in .dvr-ms format.

I personally haven't had good luck with either the ATI or Cyberlink muxes but others have, so your mileage may vary. If you don't or can't use them, TS is your next best choice for the MVPs because the gbpvr server will try to convert the files to mpg format in realtime and serve it to your MVP. Unfortunately it does put a bigger load on your server, and it eliminates the ability to jump forward very far in the video or resume, since the file is being transcoded to mpg on the fly and the server may not be too far ahead of you while viewing.

On the plus side, if you do use a digital capture device and you have a good cable signal, the captured picture and sound is fantastic. It's perfect actually, because the digital stream as sent by the cable co. is simply saved to a file. There's no analog to digital conversion taking place - the picture is pristine - and anything broadcast in surround sound will be recorded that way too.

If you use the digital converter boxes as others have pointed out, you'll be able to continue to use your PVR-150 but it will require a means to change the channel on the stb they give you. Whether you can do this with the pvr-150's blaster or not is hard to say. If you can find out what specific box they'll be supplying, you'll probably be able to search the web for info. There are a number of ways to control the stb if the blaster won't work - Hauppauge can be slow to add new device codes - but you'll have to find out what your dealing with first.

Good luck!

[khaver]

That sounds like a set top box to me. ie, its a box with a tuner inside, which is can be tuned to digital channel, and you can switch channels using a remote. Like a lot of set top boxes, it has a modulator for outputting an analog NTSC on CH3/4. HighDef channels are downscaled to regular NTSC for this analog output.

Technically you're right. But Comcast differenciates between them. Their normal cable converter box they charge rent for they call their Set Top Box that can also do Video on Demand. The converters they let you use for free are about the size of a paperback book and only convert the QAM channels to analog on channel 3 or 4. No HighDef channels. Just uses the SD channel that Comcast also sends.

Yes, you could use this with your analog tuner by setting it to always use channel 3 or 4 and have a blaster change the channels on it, but Comcast only lets you have 2 free ones and I used those on my 2 analog TVs in our kitchen and bedroom. My HVR-2250 works great for QAM channels.

[sub]

Yes, you could use this with your analog tuner by setting it to always use channel 3 or 4 and have a blaster change the channels on it, but Comcast only lets you have 2 free ones and I used those on my 2 analog TVs in our kitchen and bedroom. My HVR-2250 works great for QAM channels.

Yep, I'd definitely being recommending using QAM tuner cards rather than a converter box. Lets hope all these channels that are being made digital, end up being clear QAM.

[wtg]

If you don't or can't use them, TS is your next best choice for the MVPs because the gbpvr server will try to convert the files to mpg format in realtime and serve it to your MVP. Unfortunately it does put a bigger load on your server, and it eliminates the ability to jump forward very far in the video or resume, since the file is being transcoded to mpg on the fly and the server may not be too far ahead of you while viewing.

I should have pointed out that you can have gbpvr automatically convert .ts recordings to .mpg format after the recording is complete. If most of your viewing is via MVPs this option might work best for you, instead of having gbpvr convert on-the-fly and on-demand. Converted once and saved, all the normal features of gbpvr should be available to you on the MVP.

[khaver]

Lets hope all these channels that are being made digital, end up being clear QAM.

So far all of Comcast's Expanded Basic lineup in the Salem, Oregon area are clearQAM plus a few extras plus all the local HD channels. The Comcast folks here seem to have gotten it right. Let's just hope it stays that way. This is like when TV manufactures first started putting tuners in TVs that could receive unencrypted cable broadcasts. It really helped cable TV to become almost a staple in American households. Wow, you didn't need a cable STB to get cable!!! Now we're at the same point with digital TV. We have QAM tuners in our TV's so we don't have to have a STB. Now, if the cable companies would realise that more people would use cable if all they had to do was attach their QAM ready TV to get their 70 or so channels like before. But most cable companies want to make it so you have to rent thier STB so they can sell you Video on Demand and charge you for having a DVR, etc. Even Comcast doesn't have 1 marketing plan used throughout the US. Like I said, here in Oregon they seem to have it right, but I've read in these forums that in other places, almost all of Comcasts QAM channels are encrypted.

[donschjr]

"So far all of Comcast's Expanded Basic lineup in the Salem, Oregon area are clearQAM plus a few extras plus all the local HD channels. The Comcast folks here seem to have gotten it right"

I wish Comcast was doing this in my area. The only clear Qam channels here are Over the Air, news, shopping and TCM. When they make the switch to all digital in my area I'm going to have to decide what to do. To feed the tv's and tuner cards in my house would take 8 stb's and I don't think I want to pay the price or deal with it. I can watch everything but sports over the internet for free so I'm considering dropping all tv service.

[SLR_65]

It's not just the cable compnies wanting to rent equipment - it's also the programmers. They don't want you to be able to make hd recording, have the ability to skip commercials, etc..

[khaver]

They don't want you to be able to make hd recording, have the ability to skip commercials, etc..

If that were the case, they wouldn't allow the cable companies to offer DVR's and Tivo would be forced out of business.