Can someone help with OTA and Avermedia A180?

[wazkaren]

I new to OTA and I'm having trouble trying to receive digital TV with my Avermedia A180. I can get a signal but it studders very frequently, like it's missing frames, and is unwatchable. Some channels are worse than others. This weekend I put a Channel Master 4221 UHF antenna on the roof but I still get bad studdering. I'm 7 miles from the broadcast towers and I thought the roof antenna would do the trick. I tried adding an amplifier (a Magnavox mast-mounted amplifier) but that made the problem worse. I've also tried several different programs (WatchHDTV, the Avermedia application and GraphEdit as well as Sage) all with the same results. Does anyone have any suggestions on how to debug this problem? Does this sound like a signal problem? (the Avermedia doesn't seem to have a signal strength indicator) Is there anyway to tell if this is a multi-path problem? Or could it be a problem with my system? Any help from the experts here would really be appreciated.

Thanks,
Greg

[chrisc16]

It would probably be helpful if you could record a short clip of HD and upload it to someone else to see if it plays correctly on their machine. Then at least you'll know if your A180 is recording correctly or not. Of course even a very short clip (15 seconds) is pretty big...

-Chris

[wazkaren]

Thats a good thought but I'm not sure how to get a sample small enough to upload anywhere. I did try playing a high def sample I found (from ESPN) that plays fine on my system. And I tried my studdering file on 3 difference PCs with different decoders and video cards, all with the same result. So I'm thinking the problem is most likely on the recording side.

Greg

[evilpenguin]

If you go to Avermedia's website they have a stand alone app for using the A180(you can get it where you download the drivers). It will give you signal strength and tell you what channels it can see. It's not very user friendly or intuative, but it gets the job done.

[DFA]

Check CPU consumption w/ Task Manager while decoding. Most people need to use overlay and DXVA video card decoding assist for HD MPEG in order to avoid over-amping CPU and stop studdering.

DFA

[wazkaren]

Originally Posted by evilpenguin

If you go to Avermedia's website they have a stand alone app for using the A180(you can get it where you download the drivers). It will give you signal strength and tell you what channels it can see. It's not very user friendly or intuative, but it gets the job done.

Thanks Evilpenguin. I had tried the Avermedia app before but didn't think the signal strength indicator was working. I went back and took a closer look at it last night and the indicator does work. I had made a bad assumption that I was having a signal problem and since the indicator showed 100% on all channels I thought it didn't work. It turns out that I actually do have 100% on all channels and signal strength is not my problem (I put a variable attenuator in line and could see the indicator go up and down as I turned the knob on the attenuator). I need to stop working on this late at night when I'm tired I guess.

Tonight I'm going to try the A180 in a different computer to see if that makes a difference.

Does anyone have an Avermedia working correctly without skips and studders? How would I know if I have a multi-path problem? I've tried the recorded files from the Avermedia app on several different PCs and all studder in exactly the same spot so I really think it's a recording problem.

EDIT: Oh, and I did check CPU usage and it was around %40 to %50 while I was recording and watching from the Avermedia app (I still can't get sage to work at all with card, but first things first).

Thanks,
Greg

[wazkaren]

For what it's worth, I finally got my head out of my butt and have it working reasonably well. I moved the A180 to a different computer and it is much improved. Still have some glitches but I think I'm on the right path now. I'm not sure exactly what was the difference in the two systems that made it work but I suspect it's the fact that the first PC did not have a DirectX 9 video card and the second did. I'm using the Avermedia application and it is displaying live while it's recording. I'm guessing that running the stream through the codec without h/w acceleration was causing the problem (even though I never saw anywhere near %100 CPU usage, maybe it spiked and task manager didn't refresh fast enough to show it?). And it just so happens that the channel I was having the most problem with was broadcasting at 1080i (the others were 720p). Don't know if that is a factor but it sure is a coincidence. Another difference is I was using nVidia decoder on the problem PC and Sonic decoder on the working PC.

So now I just need Sage to fix the problems I've run into with the A180 and I'll be all set.

Thanks everybody for the suggestions, it helped me wake up from my bad assumptions and get to the real issue.

Greg