On Sat, Jun 27, 2009 at 12:25 AM, George Adams<g_adams27@xxxxxxxxxxx> wrote: > > Thanks again to both of you for your help. I gave the no_poweroff flag a try, but didn't see any difference. I also tried a "setchannel 3" during the middle of the encoding session, and also saw no change. > > But I think I've found the problem: > >> v4lctl setnorm NTSC; v4lctl setfreqtab us-bcast; v4lctl -v 1 setchannel 3 > vid-open: trying: v4l2-old... > vid-open: failed: v4l2-old > vid-open: trying: v4l2... > v4l2: open > v4l2: device info: > em28xx 0.1.1 / Pinnacle PCTV HD Pro Stick @ usb-0000:00:1a.7-1 > vid-open: ok: v4l2 > freq: reading /usr/share/xawtv/Index.map > v4l2: tuner cap: > v4l2: tuner rxs: > v4l2: tuner cur: MONO > cmd: "setchannel" "3" > v4l2: freq: 0.000 > v4l2: close > > > What? freq: 0.000 ? After finding the ivtv package and compiling its utils, I confirm it with this: > >> v4l2-ctl -F > Frequency: 0 (0.000000 MHz) > >> ivtv-tune -c 3 > /dev/video0: 61.250 MHz > >> v4l2-ctl -F > Frequency: 980 (61.250000 MHz) > >> v4lctl setchannel 3 > >> v4l2-ctl -F > Frequency: 0 (0.000000 MHz) > > > So mysteriously, it seems like v4lctl is just plain not working. And ivtv-tune, on the other hand, is working just fine. After I do that and start Helix Producer, I see channel 3 just like I had hoped. > > (strangely, v4lctl can do other things fine, like change the norm from NTSC to PAL. It just can't change the channel.) > > So, sorry that it went off in rabbit trails of the device powering down and so forth. I wonder what happened to my v4lctl program, though? xawtv itself (running in X) seems to work fine when I tell it to change the channel... > > > > > > >> Date: Fri, 26 Jun 2009 09:42:06 -0400 >> Subject: Re: Bah! How do I change channels? >> From: dheitmueller@xxxxxxxxxxxxxx >> To: awalls@xxxxxxxxx >> CC: g_adams27@xxxxxxxxxxx; video4linux-list@xxxxxxxxxx; linux-media@xxxxxxxxxxxxxxx >> >> On Fri, Jun 26, 2009 at 7:50 AM, Andy Walls wrote: >>> I use either v4l2-ctl or ivtv-tune >>> >>> $ ivtv-tune -d /dev/video0 -t us-bcast -c 3 >>> /dev/video0: 61.250 MHz >>> >>> $ v4l2-ctl -d /dev/video0 -f 61.250 >>> Frequency set to 980 (61.250000 MHz) >>> >>> >>> Regards, >>> Andy >> >> Hello Andy, >> >> I had sent George some email off-list with basically the same >> commands. I think what might be happening here is the tuner gets >> powered down when not in use, so I think it might be powered down >> between the v4l-ctl command and the running of the other application. >> >> I have sent him a series of commands to try where he modprobes the >> xc3028 driver with "no_poweroff=1", and we will see if that starts >> working. >> >> Devin >> >> -- >> Devin J. Heitmueller - Kernel Labs >> http://www.kernellabs.com > _________________________________________________________________ > Lauren found her dream laptop. Find the PC that’s right for you. > http://www.microsoft.com/windows/choosepc/?ocid=ftp_val_wl_290 > > -- > video4linux-list mailing list > Unsubscribe mailto:video4linux-list-request@xxxxxxxxxx?subject=unsubscribe > https://www.redhat.com/mailman/listinfo/video4linux-list > > George: Try 'v4l2-ctl -d /dev/video0 -f 61.250' to tune to broadcast channel 3 per one of Devin's e-mails to you. I do not know why setchannel is not working for you. I use both ivtv-tune v4l2-ctl and both do work and v4l2-ctl should work in this instance for you. I always open my USB TV device via mplayer not specifiying a channel and then use ivtv-tune executed by a script that is run by an application to tune channels. I happened to notice that if I closed mplayer and used ivtv-tune to tune to another channel and then open my USB TV device, it would be tuned to that channel. Andy: I too care about the environment. I am trying to find some extra time to figure out if my KWorld 330U USB TV devices are actually going into low power mode or not. I would say not as they get really hot, so I unplug them when I am not using them. I told Devin I would work on this and I have an accurate analog amp meter, but I got very busy at work and at home with the kids. However, I don't believe that the answer is to disable power management as some of these parts get so hot that leaving them in a powered state and tuned to a channel will probably damage the device. Remember, these are silicon tuners, not the old discrete tuners that have way more surface area to dissipate heat. Devin: Great job answering questions as usual. ;-) Best Regards, -- Rob Krakora Senior Software Engineer MessageNet Systems 101 East Carmel Dr. Suite 105 Carmel, IN 46032 (317)566-1677 Ext. 206 (317)663-0808 Fax -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
