Devin Heitmueller wrote: > <snip> > > If you haven't already, you should install the latest v4l-dvb code. I > did some fixes which significantly improve the signal quality for > ClearQAM tuning. > I'm running your drivers that you announced back on Oct 29, and I downloaded on Nov 1. I never got a decent chance to A-B them against the standard drivers, so I never reported anything. It was only a few weeks ago that I got back into messing with the digital side, again.
>> These are only 2 channels, but everything else is like this - encrypted >> channels get a solid lock, clear ones done. > > It is very common for a cable provider to multiplex *all* the ClearQAM > channels onto two or three frequencies. So you shouldn't expect to > see ten or twelve unencrypted frequencies just because there are ten > or twelve "must-carry" ClearQAM channels. > When I said "only 2 channels", I meant listings and information for 1 clear, 1 encrypted. For the clear stuff, Comcast has generally stuffed 2 HD and 2 SD channels on several frequencies, 7 SH channels on another, etc. The SD and clearQAM counts don't match up because some of our HD channels have an extra SD channel (or 2, for one PBS) attached. >> So to boil this down to a question: How do I interpret the results of >> azap? If I try searching, all I get is people talking about using it >> to look for "FE_HAS_LOCK". I find nothing about how to interpret the >> various fields, for instance "status", "signal", "snr", "ber", "unc". >> It's kind of obvious what "signal" and "snr" mean, but not how to >> interpret the hex numbers presented. It equally seems like an obvious >> guess that for signal and snr the bigger the better, but in some cases >> I have seen clear channels have decent numbers, as high as 014a, but >> not sticking there, and still not getting a decent lock. > > The SNR and strength values vary in terms of how they are interpreted, > which is why everybody says that you can only rely on the FE_HAS_LOCK > field across different products. For your product, both the SNR and > strength field return the SNR in 0.1dB increments. A value of 0x014a > translates to an SNR of 33.0 dB. > Which leaves me wondering, what is "good" and "bad" for SNR? It looks to me as if it takes a consistent 146+ to lock and stay there, but is that really "good", or just "adequate?" >> I need to script all of this up, so I can do a more thorough jobe, but >> so far every encrypted channel I've looked at is good, every clear >> channel bad. Given a pattern like this, I'd say that Comcast is doing >> this on purpose, to nudge people into getting set-top boxes. > > Doubtful. While I don't trust Comcast any further than I can throw > them, I suspect in this case you will find that your situation is > greatly improved once you update your driver. > Have there been more changes since Oct 29/Nov 1? I'm a little behind on my kernel, and wouldn't mind refreshing. Is your stuff into the v4l mainline, or still just in your space? Thanks, Dale _______________________________________________ ivtv-users mailing list [email protected] http://ivtvdriver.org/mailman/listinfo/ivtv-users
