Mike, That's probably it. When I set up the DVB in mythtv there's two options that look like they'll keep the DVB card open...
"Open DVB card on demand" - was unchecked. I'll check that to have mythtv close the card when not in use. "Use DVB Card for active EIT scan" - was checked. The help on that option says it keeps the DVB card constantly in use. I'll uncheck it. I saw these options mentioned in another post but wasn't sure how they applied. Your explanation made it clear. I'll have to wait to try this later tonight when I get home and post a reply as to the results. Thanks again... you've gone above-and-beyond explaining parts of v4l that you probably don't directy support. -vincent > Vincent: > > Ah, I misread your post. I thought you were trying to scan for digital > cable channels. But you said analog and you had clearly stated > /dev/video0, the V4L device entry point. While it's possible that there > might be problem in the tuner chip's driver, there's another more likely > possibility: You can't run the DVB and V4L sides at the same time. If > something is holding the DVB side open, the V4L side will be prevented > from tuning or streaming - it can't run because the hardware resources > needed are busy servicing the DVB side. > > If you're running this completely under MythTV and you've told MythTV > that the two devices are related to one another (have you?) then this > collision should not have happened. If MythTV doesn't know that the two > sides map to the same hardware then it might erroneously try to operate > both sides at once. Alternatively if you might have had something else > holding the DVB side open when you tried to touch the V4L side (for > example an instance of the DVB azap utility), then the V4L side won't > operate. > > Knowing that, does this help? > > -Mike On Sun, Jan 4, 2009 at 10:01 PM, fivenote <[email protected]> wrote: > Thanks Mike. > > I think I am telling it QAM mode. In myth TV backend config I choose > "us-cable" as the "Channel frequency table". I'm doing exactly as I > did yesterday when it found all the cable channels. Only thing I > changed was to compile the latest v4l drivers from > http://linuxtv.org/hg/v4l-dvb. After that the DVB/broadcast channels > started working and MPEG/cable channels disappeared. > > My developer's sense (I'm a web app developer) says the fix for the > DVB broke the analog side. Please feel free to pass this on to the DVB > develpoers. > > BTW... overall the developers that contribute here are doing a great > job. I'm excitied to be so close to having this all work. > > -vincent > > On Sun, Jan 4, 2009 at 9:39 PM, Mike Isely <[email protected]> wrote: >> On Sun, 4 Jan 2009, fivenote wrote: >> >>> Mike, >>> >>> Thanks so much. Your explanation made sense. I got the latest v4l >>> driver source from linuxtv.org. It compiled and installed ok. I >>> noticed it came with a version of pvrusb2 so I used that instead of >>> the pvrisb2 I had compiled separately before. >>> >>> Now I get tons of HD ATSC channels. But I lost my cable channels. I >>> scanned the input connection for [MPEG : /dev/video0] and get all "no >>> signal". I had all my expected channels before upgrading the v4l >>> drivers and now none. I checked the myth and system logs,but nothing >>> obvious. >>> >>> That figures, doesn't it? One day you got cable and no ATSC, the next >>> day all ATSC and no cable. >>> >>> Is the scan and lock for the cable channels likely an issue with the >>> same tda18271.ko? >> >> Cable broadcasts as I understand it are QAM not ATSC. Probably >> somewhere you need to tell MythTV it is dealing with a cable signal so >> that the tuner can drop into QAM mode. >> >> At least that's a guess. I don't get cable here (I *HATE* the cable >> companies) so I don't know this for a fact. But it's what I understand >> about digital cable reception. The modulation standard is different and >> the tuner has to know to look for this. Why is this the case? I have >> no idea; seems stupid to me to have different modulation standards for >> cable versus over-the-air. >> >> If you know the tuner (i.e. tda18271.ko) is running in QAM mode then you >> may have hit a new problem - and if that is the case I know a couple DVB >> developers who will want to hear about this. >> >> -Mike >> >> -- >> >> Mike Isely >> isely @ pobox (dot) com >> PGP: 03 54 43 4D 75 E5 CC 92 71 16 01 E2 B5 F5 C1 E8 >> > > > > -- > ~~~~~~~~~~~~~~~~~~~~ > VAO - [email protected] > ~~~~~~~~~~~~~~~~~~~~ > > > > -- > ~~~~~~~~~~~~~~~~~~~~ > VAO - [email protected] > ~~~~~~~~~~~~~~~~~~~~ > -- ~~~~~~~~~~~~~~~~~~~~ VAO - [email protected] ~~~~~~~~~~~~~~~~~~~~ _______________________________________________ pvrusb2 mailing list [email protected] http://www.isely.net/cgi-bin/mailman/listinfo/pvrusb2
