On Fri, Oct 28, 2016 at 7:59 PM, Matt Ranostay <matt@ranostay.consulting> 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 > >> >>> Also more importantly does the mailing list thinks it belongs in v4l2? >> >> >> I think it fits. It's a sensor, just with a very small resolution and >> infrared >> instead of visible light. >> >>> We already came up the opinion on the IIO list that it doesn't belong >>> in that subsystem since pushing raw pixel data to a buffer is a bit >>> hacky. Also could be generically written with regmap so other devices >>> (namely FLIR Lepton) could be easily supported. >>> >>> Need some input for the video pixel data types, which the device we >>> are using (see datasheet links below) is outputting pixel data in >>> little endian 16-bit of which a 12-bits signed value is used. Does it >>> make sense to do some basic processing on the data since greyscale is >>> going to look weird with temperatures under 0C degrees? Namely a cold >>> object is going to be brighter than the hottest object it could read. >> >> >>> Or should a new V4L2_PIX_FMT_* be defined and processing done in >>> software? >> >> >> I would recommend that. It's no big deal, as long as the new format is >> documented. >> >>> Another issue is how to report the scaling value of 0.25 C >>> for each LSB of the pixels to the respecting recording application. >> >> >> Probably through a read-only control, but I'm not sure. >> >> Regards, >> >> Hans >> >>> >>> Datasheet: >>> http://media.digikey.com/pdf/Data%20Sheets/Panasonic%20Sensors%20PDFs/Grid-EYE_AMG88.pdf >>> Datasheet: >>> https://eewiki.net/download/attachments/13599167/Grid-EYE%20SPECIFICATIONS%28Reference%29.pdf?version=1&modificationDate=1380660426690&api=v2 >>> >>> Thanks, >>> >>> Matt >>> -- >>> 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 >>> >> -- 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
