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kmj0577 · Last edited by kmj0577 on Tue Jan 17, 2006 11:05 am; edited 1 time in total

Is anyone else experiencing blocks appearing on their video when tuning using QAM? I get excellent OTA reception usually, but I think I'd prefer to use cable since I do have to adjust my antenna for a couple stations and I'd get more stations on cable that I can't get on OTA (such as Discovery and TNT). I've looked for an answer and can't find one. There was a patch on here back in September or so (was at the bottom of the page) which was supposed to help but didn't in my case.

kmj0577

No one here has had this problem or solved it?

I've come down to 3 possible conclusions:
a) The HD-3000 isn't handling the QAM properly, in which case I'd need to get another card such as the MyHD-130 which also has QAM.
b) My computer isn't fast enough (AMD 1700+) to handle QAM decoding, but is fast enough to handle playing OTA HDTV (with XvMC on a FX5200 for 1080i).
c) It's not coming through my cable provider correctly, although I've checked on avsforum.com in the local reception and no one's complained about the cable, just some audio issues with one of the stations.

tony

You're lucky you can still get Discovery & TNT.. I used to get those channels as well in addition to InHD, ESPN, etc.. but no more Sad

Are you seeing the problem on all the channels? For a while, I had similar problem as you in that none of the stations were watchable, so I went back to analog (sigh) for a while. Then a few weeks later, all the local stations worked again except for NBC and PBS which still has occasional 'pixelated' blocks.. I've tried different cables, reducing the splitters, re-installing the drivers, updating video card drivers, but none of them seemed to fix it. Lately, the PBS problems have gone away, so I'm thinking that it's an issue with the Cable provider. Someone also mentioned that changing the power supply made a big difference in their reception..

kmj0577

pridkett

Have you checked to see what happens if you record a stream and watch it back later (instead of watching while playing) or what happens to your signal levels? Initially it sounds like your problem is similar to the problem that I'm experiencing in this thread. I still haven't managed to resolve it either.

kmj0577

Scott Larson

Believe it or not, the signals on some people's cable systems are too strong. Comcast has had to put attenuators on some people's cable boxes in my area just to get them to work. You might try putting one on your line and see if your 20% suddenly becomes 90%.

kmj0577

I may have fixed my problem. I have to use dvbstream and pick out the exact PIDs of the audio and video stream. Seems if I use the whole transport stream it pixelates.

Edit: Yep, even got my TNT working. Now I have to go through and get all the frequencies and PIDs using the diagnostic channel. I do get a lot of "a52: CRC check failed!" messages though.

Scott Larson

Yeah, QAM-256 transport streams deliver something like 4 megabytes a second which is a lot of stuff to parse.

As for the "a52: CRC failed" errors, you might want to look at the long thread on that and see if my "+4" patch gets rid of the errors. At this point the mplayer developers appear to be ignoring the specific a52 problems we sent them a couple of months ago although one of them did notice the Bugzilla report someone from here submitted.

kmj0577

Confirmed, I built another version of mplayer with that patch and it fixed it. I had previously tried it when I had some CRC errors on my OTA reception, but it had no effect then, but it seems to now.

kmj0577

Hmm, no editing of posts?

But anyways, I think the CRC error on my OTA was on the providers end, looking at avsforum.com, I see a new post about them having some hardware trouble with their decoder.

Edit: Now the edit button shows up for some reason Shocked

Scott Larson

That's one advantage cable has -- they have a direct connection to the stations. Usually every couple of months a local station will have a flakey transmitter problem (one is still running at half power) and naturally I assume I've broken something on my end.

kmj0577

Now the only thing to possibly do is to get xine working with this (haven't found a way to get it to work through stdin, it keeps wanting to buffer. Or I possibly have to get a channel.conf working and get it to do only the AV PIDs I need since it may pixelate like MPlayer) so I can use xvmc/xxmc for bob deinterlacing or upgrade my computer and use other deinterlacing (looking to be about $500 to upgrade to a 3GHz P4, new motherboard, and 2 gigs of RAM, although I'll possibly go with 1 gig since 2 might be excessive).

kmj0577

Scott Larson