Hi,
On 9/7/06, Martin Rubli <[EMAIL PROTECTED]> wrote:
> Hi,
>
> The UVC driver returns the size of the currently set format. So if you do
> a S_FMT with 640x480 first, CROPCAP should indeed return 640x480.
>
> The problem with CROPCAP is that for the most part it doesn't apply to
> digital devices. For a while, the call wasn't supported at all but it
> seems that it is mandatory, so we just tried to return _something_ that
> makes sense. If you have any suggestions as to the interpretation of the
> V4L2 spec, I'd be happy to hear your view.
Currently i think very less information is given by uvcvideo driver.
When i applied one by one ioctl's to get what my webcam can supports
and what not in terms of frame formats, various width and heights.
I found if i use v4l2_enumfrmfmt.h then i am getting various sizes.
Is not it possible ti include this header file in uvcviodeo.c and let
ioctl given in that header file give the various sizes supported by
webcam hardware. So is it possible to make that VIDIOC_ENUM_FMT be
included in uvcviudeo.c
OR / ALSO
in my example when i see this output
Device /dev/video0 opened: USB Video Class device.
Enumerating frame formats:
{ pixelformat = 'MJPG', description = 'MJPEG' }
{ discrete: width = 160, height = 120 }
{ discrete: 1/30 }
{ discrete: 1/25 }
{ discrete: 1/20 }
{ discrete: 1/15 }
{ discrete: 1/10 }
{ discrete: 1/5 }
{ discrete: width = 176, height = 144 }
{ discrete: 1/30 }
{ discrete: 1/25 }
{ discrete: 1/20 }
{ discrete: 1/15 }
{ discrete: 1/10 }
{ discrete: 1/5 }
{ discrete: width = 320, height = 240 }
{ discrete: 1/30 }
{ discrete: 1/25 }
{ discrete: 1/20 }
{ discrete: 1/15 }
{ discrete: 1/10 }
{ discrete: 1/5 }
{ discrete: width = 352, height = 288 }
{ discrete: 1/30 }
{ discrete: 1/25 }
{ discrete: 1/20 }
{ discrete: 1/15 }
{ discrete: 1/10 }
{ discrete: 1/5 }
{ discrete: width = 432, height = 240 }
{ discrete: 1/30 }
{ discrete: 1/25 }
{ discrete: 1/20 }
{ discrete: 1/15 }
{ discrete: 1/10 }
{ discrete: 1/5 }
{ discrete: width = 480, height = 360 }
{ discrete: 1/30 }
{ discrete: 1/25 }
{ discrete: 1/20 }
{ discrete: 1/15 }
{ discrete: 1/10 }
{ discrete: 1/5 }
{ discrete: width = 512, height = 288 }
{ discrete: 1/30 }
{ discrete: 1/25 }
{ discrete: 1/20 }
{ discrete: 1/15 }
{ discrete: 1/10 }
{ discrete: 1/5 }
{ discrete: width = 640, height = 360 }
{ discrete: 1/30 }
{ discrete: 1/25 }
{ discrete: 1/20 }
{ discrete: 1/15 }
{ discrete: 1/10 }
{ discrete: 1/5 }
{ discrete: width = 640, height = 480 }
{ discrete: 1/30 }
{ discrete: 1/25 }
{ discrete: 1/20 }
{ discrete: 1/15 }
{ discrete: 1/10 }
{ discrete: 1/5 }
{ pixelformat = 'YUYV', description = 'Uncompressed' }
{ discrete: width = 640, height = 360 }
{ discrete: 1/30 }
{ discrete: 1/25 }
{ discrete: 1/20 }
{ discrete: 1/15 }
{ discrete: 1/10 }
{ discrete: 1/5 }
{ discrete: width = 640, height = 480 }
{ discrete: 1/30 }
{ discrete: 1/25 }
{ discrete: 1/20 }
{ discrete: 1/15 }
{ discrete: 1/10 }
{ discrete: 1/5 }
It clearly showed that as MJPG is default frame thru ioclt,s i am
getting therefore i am getting the first value in above output as
width=160 and height=120.
But same output showed max width=640 and height=480. So can it be
possible to modify ioctl code to return either max values for default
frame when applied VIDIOC_CROPCAP ??
Or can it be possible in uvcvideo to have max and min width and height
structure members and let them return max and min values. I know it
was case for V4l but not for V4l2.
All above are my thought for uvcvideo. This all i am thinking for if
anyone want to write a video viewer app then how come he will get that
info to show streaming video in various supported sizes( Me is also
trying to write video viewer but first to understand all v4l2 API
well)
>
> What are you trying to do in this particular case?
As said above trying to lean V4l2 APIs and checking ioctl's info.
>
> Cheers,
> Martin
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