Hi Bastien, On Friday 03 Jun 2016 12:53:31 Bastien Nocera wrote: > On Fri, 2016-06-03 at 01:37 +0300, Laurent Pinchart wrote: > > On Tuesday 31 May 2016 12:38:49 Bastien Nocera wrote: > >> Hey, > >> > >> I saw your commits to add quirks for Arkmicro "webcams". I recently > >> bought a dirt cheap "EasyCap" device on eBay, but it only seems to > >> support 640x480 instead of the native "NRSC" resolution as > >> mentioned on the device's box. > >> > >> $ v4l2-ctl --list-formats-ext -d /dev/video0 > >> ioctl: VIDIOC_ENUM_FMT > >> > >> Index : 0 > >> Type : Video Capture > >> Pixel Format: 'MJPG' (compressed) > >> Name : Motion-JPEG > >> > >> Size: Discrete 640x480 > >> > >> Interval: Discrete 0.017s (60.000 fps) > >> Interval: Discrete 0.033s (30.000 fps) > >> Interval: Discrete 0.067s (15.000 fps) > >> Interval: Discrete 0.200s (5.000 fps) > >> > >> Size: Discrete 352x288 > >> > >> Interval: Discrete 0.017s (60.000 fps) > >> Interval: Discrete 0.033s (30.000 fps) > >> Interval: Discrete 0.067s (15.000 fps) > >> Interval: Discrete 0.200s (5.000 fps) > >> > >> Device is: > >> Bus 003 Device 066: ID 18ec:5850 Arkmicro Technologies Inc. > >> > >> In your professional opinion, should I try using > >> UVC_QUIRK_PROBE_DEF or UVC_QUIRK_PROBE_MINMAX as a quirk for this device? > >> Is there a stand-alone driver somewhere that I can use for testing > >> (rather than recompiling a whole kernel)? > > > > Those quirks will not affect the available resolutions. > > OK. I also made my own testing tree to copy/paste those devices. > > > UVC devices expose a list of resolutions they support through the USB > > descriptors, and the uvcvideo device merely uses that list to expose > > supported resolutions to userspace. > > Full lsusb below. Thanks. The device only advertises two resolutions, 640x480 and 352x288. > > If the device doesn't expose resolutions other than the above two, the > > box could be lying, or the device could use non-standard extensions to UVC > > to support additional resolutions. The first step would be to try the > > camera in a Windows machine to see if additional resolutions are > > available (without installing any additional device-specific software). > > I should be able to find a Windows somewhere, but which application > should I use to see if those resolutions are indeed available? My (lack of) Windows knowledge doesn't allow me to answer that question, but I'm sure searching online will give you answers. > BTW, given the price of the device, I'd be fine getting one for you to > test (6€ from eBay, shipping included). Thanks, but I'm already overwhelmed with work, I'd rather have you performing the tests. Beside, I have no Windows machine :-) -- Regards, Laurent Pinchart -- 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
