On 2 March 2010 16:06, Max Thrun <bear24rw@xxxxxxxxx> wrote: > > > On Tue, Mar 2, 2010 at 10:39 AM, Antonio Ospite <ospite@xxxxxxxxxxxxxxxxx> > wrote: >> >> On Tue, 2 Mar 2010 11:26:15 +0000 >> "M.Ebrahimi" <m.ebrahimi@xxxxxxxx> wrote: >> >> > On 28 February 2010 19:55, Jean-Francois Moine <moinejf@xxxxxxx> wrote: >> > > On Sun, 28 Feb 2010 20:18:50 +0100 >> > > Antonio Ospite <ospite@xxxxxxxxxxxxxxxxx> wrote: >> > > >> > >> Maybe we could just use >> > >> V4L2_CID_POWER_LINE_FREQUENCY_DISABLED = 0, >> > >> V4L2_CID_POWER_LINE_FREQUENCY_50HZ = 1, >> > >> >> > >> It looks like the code matches the DISABLED state (writing 0 to the >> > >> register). Mosalam? >> > > >> > > I don't know the ov772x sensor. I think it should look like the ov7670 >> > > where there are 3 registers to control the light frequency: one >> > > register tells if light frequency filter must be used, and which >> > > frequency 50Hz or 60Hz; the two other ones give the filter values for >> > > each frequency. >> > > >> > >> > I think it's safe to go with disabled/50hz. Perhaps later if needed >> > can patch it to control the filter values. Since it seems there is no >> > flickering in the 60hz regions at available frame rates, and this >> > register almost perfectly removes light flickers in the 50hz regions >> > (by modifying exposure/frame rate). >> > >> > Mosalam >> > >> >> Mosalam did you spot the register from a PS3 usb dump or by looking at >> the sensor datasheet? None, I got that register from sniffing a Windows driver for another camera that turned out to be using ov7620 or something similar, though I thought it has the same sensor. I double checked, this register is for frame rate adjustment (decreasing frame rate / increasing exposure) . And this has been used in some other drivers (e.g. gspca_sonixb) to remove light flicker as well. >> >> -- >> Antonio Ospite >> http://ao2.it >> >> PGP public key ID: 0x4553B001 >> >> A: Because it messes up the order in which people normally read text. >> See http://en.wikipedia.org/wiki/Posting_style >> Q: Why is top-posting such a bad thing? >> A: Top-posting. >> Q: What is the most annoying thing in e-mail? > > I'd also like to know where you got the 2b register from, cause someone else > also said 2b was filtering but the datasheet says it LSB of dummy pixel... > >- Max Thrun Definitely it is adjusting the frame rate (see the ov7620 DS for the description how the register value is used, for instance). I have no idea why the ov7720 datasheet says otherwise. Since this patch does not use the banding filter registers mentioned in the datasheet maybe should be discarded. I am working on 75 FPS at VGA, when I get that working well I can get back to this again. Thanks for the comments. Mosalam -- 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
