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author | Guennadi Liakhovetski <guennadi.liakhovetski@intel.com> | 2017-11-08 11:00:12 -0500 |
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committer | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2018-01-04 06:39:18 -0500 |
commit | 563a01e1012dddbe120d1e1e1c466ea0639a098b (patch) | |
tree | bd7130c3a3bf6d3b8314844e9c9477a026224bf8 /Documentation/media/uapi/v4l/pixfmt-meta-uvc.rst | |
parent | 94c53e26dc74744cc4f9a8ddc593b7aef96ba764 (diff) | |
download | op-kernel-dev-563a01e1012dddbe120d1e1e1c466ea0639a098b.zip op-kernel-dev-563a01e1012dddbe120d1e1e1c466ea0639a098b.tar.gz |
media: v4l: Add a UVC Metadata format
Add a pixel format, used by the UVC driver to stream metadata.
Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@intel.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Diffstat (limited to 'Documentation/media/uapi/v4l/pixfmt-meta-uvc.rst')
-rw-r--r-- | Documentation/media/uapi/v4l/pixfmt-meta-uvc.rst | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/Documentation/media/uapi/v4l/pixfmt-meta-uvc.rst b/Documentation/media/uapi/v4l/pixfmt-meta-uvc.rst new file mode 100644 index 0000000..b5165dc --- /dev/null +++ b/Documentation/media/uapi/v4l/pixfmt-meta-uvc.rst @@ -0,0 +1,51 @@ +.. -*- coding: utf-8; mode: rst -*- + +.. _v4l2-meta-fmt-uvc: + +******************************* +V4L2_META_FMT_UVC ('UVCH') +******************************* + +UVC Payload Header Data + + +Description +=========== + +This format describes standard UVC metadata, extracted from UVC packet headers +and provided by the UVC driver through metadata video nodes. That data includes +exact copies of the standard part of UVC Payload Header contents and auxiliary +timing information, required for precise interpretation of timestamps, contained +in those headers. See section "2.4.3.3 Video and Still Image Payload Headers" of +the "UVC 1.5 Class specification" for details. + +Each UVC payload header can be between 2 and 12 bytes large. Buffers can +contain multiple headers, if multiple such headers have been transmitted by the +camera for the respective frame. However, the driver may drop headers when the +buffer is full, when they contain no useful information (e.g. those without the +SCR field or with that field identical to the previous header), or generally to +perform rate limiting when the device sends a large number of headers. + +Each individual block contains the following fields: + +.. flat-table:: UVC Metadata Block + :widths: 1 4 + :header-rows: 1 + :stub-columns: 0 + + * - Field + - Description + * - __u64 ts; + - system timestamp in host byte order, measured by the driver upon + reception of the payload + * - __u16 sof; + - USB Frame Number in host byte order, also obtained by the driver as + close as possible to the above timestamp to enable correlation between + them + * - :cspan:`1` *The rest is an exact copy of the UVC payload header:* + * - __u8 length; + - length of the rest of the block, including this field + * - __u8 flags; + - Flags, indicating presence of other standard UVC fields + * - __u8 buf[]; + - The rest of the header, possibly including UVC PTS and SCR fields |