Hi Guennadi, On Friday, 3 August 2018 14:07:12 EEST Guennadi Liakhovetski wrote: > Hi Laurent, > > Thanks for the review. A general note: I think you're requesting a rather > detailed information about many parameters. That isn't a problem by > itself, however, it is difficult to obtain some of that information. I'll > address whatever comments I can in an updated version, just answering some > questions here. I directed youor questions, that I couldn't answer myself > to respective people, but I have no idea if and when I get replies. So, > it's up to you whether to wait for that additional information or to take > at least what we have now. I've replied to v2, and apart from a few minor points, I think we can apply the current version. There are a few small questions I would still like to have answers to, but if it takes to long to obtain that, let's not miss v4.20. > On Sun, 29 Jul 2018, Laurent Pinchart wrote: > > On Saturday, 23 December 2017 13:11:00 EEST Guennadi Liakhovetski wrote: > >> From: Guennadi Liakhovetski <guennadi.liakhovetski@xxxxxxxxx> > >> > >> D4M is a mobile model from the D4XX family of Intel RealSense cameras. > >> This patch adds a descriptor for it, which enables reading per-frame > >> metadata from it. > >> > >> Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@xxxxxxxxx> > >> --- > >> > >> Documentation/media/uapi/v4l/pixfmt-meta-d4xx.rst | 202 ++++++++++++++++ > >> drivers/media/usb/uvc/uvc_driver.c | 11 ++ > >> include/uapi/linux/videodev2.h | 1 + > >> 3 files changed, 214 insertions(+) > >> create mode 100644 Documentation/media/uapi/v4l/pixfmt-meta-d4xx.rst > >> > >> diff --git a/Documentation/media/uapi/v4l/pixfmt-meta-d4xx.rst > >> b/Documentation/media/uapi/v4l/pixfmt-meta-d4xx.rst new file mode 100644 > >> index 0000000..950780d > >> --- /dev/null > >> +++ b/Documentation/media/uapi/v4l/pixfmt-meta-d4xx.rst [snip] > >> + * - :cspan:`1` *Configuration* > >> + * - __u32 ID > >> + - 0x80000002 > >> + * - __u32 Size > >> + - Size in bytes (currently 40) > >> + * - __u32 Version > >> + - Version of the struct > >> + * - __u32 Flags > >> + - A bitmask of flags: see [4_] below > >> + * - __u8 Hardware type > >> + - Camera hardware version [5_] > >> + * - __u8 SKU ID > >> + - Camera hardware configuration [6_] > >> + * - __u32 Cookie > >> + - Internal synchronisation > > > > Internal synchronisation with what ? :-) This is still something I'd like to understand (and I understand it may still take time to receive an answer from the right person). > >> + * - __u16 Format > >> + - Image format code [7_] > >> + * - __u16 Width > >> + - Width in pixels > >> + * - __u16 Height > >> + - Height in pixels > >> + * - __u16 Framerate > >> + - Requested framerate > > > > What's the unit of this value ? > > Is anything other than frames per second used in V4L? V4L2 expresses the frame rate as a fraction, hence my question, to know whether this field contained the number of frames per second as an integer, or used a different representation (such as a fixed point decimal value for instance). > >> + * - __u16 Trigger > >> + - Byte 0: bit 0: depth and RGB are synchronised, bit 1: external > >> trigger > >> + > >> +.. _1: > >> + > >> +[1] > >> https://docs.microsoft.com/en-us/windows-hardware/drivers/stream/uvc-ext > >> ensions-1-5 > > > > Should we at some point replicate that documentation in the V4L2 spec ? > > Without copying it of course, as that would be a copyright violation. > > Well, we don't replicate the UVC itself or any other standards, do we? Of > course, that document doesn't have the same status as an official > vendor-neutral standard, but still, we don't replicate data sheets either. > Besides, I think there are cameras that use this, and windows supports > this, so, don't think it will disappear overnight... Probably not overnight, you're right. I'm a bit worried about the link becoming invalid though. In any case that's not a blocker, but I might at some point decide to replicate the documentation. [snip] -- Regards, Laurent Pinchart
