From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: Bastien Nocera <hadess@hadess.net>
Cc: linux-media@vger.kernel.org
Subject: Re: NTSC/PAL resolution support for "EasyCap" device
Date: Fri, 03 Jun 2016 14:08:12 +0300 [thread overview]
Message-ID: <1495486.1uKbyyPPu6@avalon> (raw)
In-Reply-To: <1464951211.2432.44.camel@hadess.net>
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
next prev parent reply other threads:[~2016-06-03 11:08 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1464691129.3878.59.camel@hadess.net>
2016-06-02 22:37 ` NTSC/PAL resolution support for "EasyCap" device Laurent Pinchart
2016-06-03 10:53 ` Bastien Nocera
2016-06-03 11:08 ` Laurent Pinchart [this message]
2016-06-03 11:35 ` Bastien Nocera
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