Re: [RFC] v4l2 support for thermopile devices
From: Antonio Ospite
Date: Thu Nov 03 2016 - 04:03:38 EST
On Wed, 2 Nov 2016 23:10:41 -0700
Matt Ranostay <matt@xxxxxxxxxxxxxxxxxxx> wrote:
> On Fri, Oct 28, 2016 at 7:59 PM, Matt Ranostay <matt@xxxxxxxxxxxxxxxxxxx> wrote:
> > On Fri, Oct 28, 2016 at 2:53 PM, Hans Verkuil <hverkuil@xxxxxxxxx> wrote:
> >> Hi Matt,
> >> On 28/10/16 22:14, Matt Ranostay wrote:
> >>> So want to toss a few thoughts on adding support for thermopile
> >>> devices (could be used for FLIR Lepton as well) that output pixel
> >>> data.
> >>> These typically aren't DMA'able devices since they are low speed
> >>> (partly to limiting the functionality to be in compliance with ITAR)
> >>> and data is piped over i2c/spi.
> >>> My question is that there doesn't seem to be an other driver that
> >>> polls frames off of a device and pushes it to the video buffer, and
> >>> wanted to be sure that this doesn't currently exist somewhere.
> >> Not anymore, but if you go back to kernel 3.6 then you'll find this driver:
> >> drivers/media/video/bw-qcam.c
> >> It was for a grayscale parallel port webcam (which explains why it was
> >> removed in 3.7 :-) ), and it used polling to get the pixels.
> > Yikes parallel port, but I'll take a look at that for some reference :)
> So does anyone know of any software that is using V4L2_PIX_FMT_Y12
> currently? Want to test my driver but seems there isn't anything that
> uses that format (ffmpeg, mplayer, etc).
> Raw data seems correct but would like to visualize it :). Suspect I'll
> need to write a test case application though
You could add a conversion routine in libv4lconvert from v4l-utils to
have a grayscale representation of Y12, I did something similar for the
kinect depth map, discarding the least significant bits:
After that any v4l2 program using libv4l2 will at least be able to show
You can play with "false color" representations too in libv4lconvert,
however I don't know if such representations are generic enough to be
mainlined, in the Kinect case the false color representation of the
depth map was done in specialized software like libfreenect.
A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?