Channel Changing Methods on Comcast STB

[Greg]

I understand that I could use Firewire or IR blaster methods to change channels on my Comcast DCT-6200 HDTV STB.

What are the pros and cons of each method?

I read somewhere on this forum that for consistent channel changes with Firewire that certain delay settings had to be used, but it took 8 seconds to change the channel. Is this still the case?

Can 2 STB's be controlled with Firewire?

Thanks,
Greg

[reggie14]

For the record, I have my firewire channel changing delay set at 1.5 seconds, though it seems to work fine even lower.

On my system I'm using firewire to change channels (and record) on my Comcast 6200 box. It works pretty well, but occasionally strange things are crashing on my system, and I'm not entirely sure why. It might be my firewire card drivers, or it might be sgraphrecorder, or it might be the 6200 box drivers. It's been a couple days since it has happened, so maybe I have it under control now.

I also use a Hauppauge IR blaster to change channels on an older standard-definition cable box. It's actually never tuned to the wrong channel over the 6 months of using it. Channel changing isn't terribly fast, though its not terribly slow either. I find it a little annoying that I end up seeing the previous channel for a little while on screen before the blaster changes channels on the box. I also find it a little annoying that I can't suppress the guide data from showing up on screen during channel changes, but neither is that bad.

Setting up the IR blaster was surprisingly easy. Firewire channel changing wasn't too bad, although I think the setup for it is a little different when you're also doing firewire recording (I assume you're trying to set up an HD-PVR). I'm not sure, but it wouldn't surprise me if its easier to set up firewire channeling changing on multiple boxes than trying to hack together multi-zone USB-UIRT.

[ace007]

I just got my USB-UIRT which I'm using to change the channel on my Comcast 6200 box which is connecting to the Sage server through a HD-PVR. I just got it working last night but so far it seems to be pretty reliable and was not too difficult to setup.

There is a few second lag as the channels change but since this is only use to capture channels I can't get from other means like the HDHR or the analog tuners on my 1600s I don't mind the delay.

Rob

[Greg]

Thanks for the responses. Yes, I would be setting up an HD-PVR. Not sure if I would want to record via Firwire or not......heard some horror stories during the set-up. What's the quality like?

There is a couple second delay changing the Comcast box, as it is right now.......using the remote.

Thanks,
Greg

[reggie14]

Originally Posted by Greg

Thanks for the responses. Yes, I would be setting up an HD-PVR. Not sure if I would want to record via Firwire or not......heard some horror stories during the set-up. What's the quality like?

Firewire recording quality is great. When you're recording over firewire you're basically just dumping the raw mpeg2 stream on to your hard drive without any processing- sort of like what you do when you record OTA signals, or unencrypted QAM channels using an HD Homerun or one of Hauppauge's digital cards.

Setup isn't terribly pleasant... It took me some tinkering to get things working. It wasn't at all trivial, though it wasn't quite as hard as I expected. My first couple attempts were not successful, however.

It's certainly not a perfect solution. Firewire tuners record files as transport streams, as opposed to program streams for pretty much everything else. I'm not really sure what the difference is, but it definitely seems like Sage has more problems playing back transport streams. I can't get playback working directly on my server at all (which isn't a big deal, because I don't use the server for playback purposes). Playback occasionally works on my Vista client box, which I find very strange. Playback on the HD100 is almost always fine, except it seems a little goofy when I'm watching nearly live TV. Playback itself is usually fine then, but rewinding and fast forwarding can screw things up.

I've also had a few problems with crashes. I'm crossing my fingers that updated a few things on my computer will fix that, but I don't know yet. It's been a couple days since I've seen a crash.

There is a couple second delay changing the Comcast box, as it is right now.......using the remote.

You know, I've never used the STB by itself- it's always been as a tuner in Sage. That sort of helps explain why there's about a 4 second delay when I start watching a live show using the firewire tuner. That's really not so bad.

[mayamaniac]

Having used IR Blasters (Actisys IR-200, USB-UIRT) before, I recommend serial or firewire for channel changing when possible. Channel changing is 100% accurate in my experience. And it is at least 5 times faster than IR blasters.