On Wed, 2011-08-24 at 08:24 -0400, Devin Heitmueller wrote: > On Wed, Aug 24, 2011 at 6:37 AM, Andy Walls <[email protected]> wrote: > > What's wrong aside from the human readable output mode of femon being > > broken? Do you have a picture or not? > > > > You have a lock. > > You have a pretty high SNR value (my ATSC reception always has a value > > of less than 0x100). > > You have 0 block errors and uncorrectable errors. > > > > Regards, > > Andy > > Andy, > > My guess is that this is actually the s5h1409 being dumb in a couple of ways: > > It puts the same SNR value into both the strength and signal fields. > > Most demods treat the signal field as a scaled value from 0-65535 > where 65535=100%. So femon probably treats 0x012c as 300/65535 which > as a percentage is rounded to "0%". > > So while part of this is femon making some assumptions about how the > values are rendered, much of the problem continues to be the lack of > uniformity for the strength/snr fields in the DVB interface, and the > s5h1409 just happens to do it in an unpopular way. > > Nick: Just use the non-human readable values. This problem isn't > going to be fixed anytime in the near future given the inability of > the LinuxTV community to agree on a format for providing SNR/signal > info across all demod drivers (I've been pushing for that for *years* > now). > > Devin >
Thanks Andy and Devin for your responses :) It seems both femon and I assumed the upper bound for the signal quality and snr was 0xffff. That makes sense that femon would not accurately report those values in the "human readable" format. Do either of you know off hand what the upper limit is for those values? If not don't waste your time, I'll dig around for them. Devin: In the past I'm pretty sure I've seen the signal strength and snr values differ (albeit not by much) but for the most part they're exactly the same. For example: status SCVYL | signal 00f0 | snr 00f0 | ... | FE_HAS_LOCK status SCVYL | signal 00f5 | snr 00f0 | ... | FE_HAS_LOCK status SCVYL | signal 00f0 | snr 00f5 | ... | FE_HAS_LOCK status SCVYL | signal 00f5 | snr 00f0 | ... | FE_HAS_LOCK status SCVYL | signal 00f0 | snr 00f0 | ... | FE_HAS_LOCK Anyway, thanks for your help guys! nick _______________________________________________ ivtv-users mailing list [email protected] http://ivtvdriver.org/mailman/listinfo/ivtv-users
