On 07/28/2017 02:33 PM, Guennadi Liakhovetski wrote:
> Add a pixel format, used by the UVC driver to stream metadata.
>
> Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@xxxxxxxxx>
> ---
> Documentation/media/uapi/v4l/meta-formats.rst | 1 +
> Documentation/media/uapi/v4l/pixfmt-meta-uvc.rst | 39 ++++++++++++++++++++++++
> include/uapi/linux/videodev2.h | 1 +
> 3 files changed, 41 insertions(+)
> create mode 100644 Documentation/media/uapi/v4l/pixfmt-meta-uvc.rst
>
> diff --git a/Documentation/media/uapi/v4l/meta-formats.rst b/Documentation/media/uapi/v4l/meta-formats.rst
> index 01e24e3..1bb45a3f 100644
> --- a/Documentation/media/uapi/v4l/meta-formats.rst
> +++ b/Documentation/media/uapi/v4l/meta-formats.rst
> @@ -14,3 +14,4 @@ These formats are used for the :ref:`metadata` interface only.
>
> pixfmt-meta-vsp1-hgo
> pixfmt-meta-vsp1-hgt
> + pixfmt-meta-uvc
> 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..58f78cb
> --- /dev/null
> +++ b/Documentation/media/uapi/v4l/pixfmt-meta-uvc.rst
> @@ -0,0 +1,39 @@
> +.. -*- coding: utf-8; mode: rst -*-
> +
> +.. _v4l2-meta-fmt-uvc:
> +
> +*******************************
> +V4L2_META_FMT_UVC ('UVCH')
> +*******************************
> +
> +UVC Payload Header Data
> +
> +
> +Description
> +===========
> +
> +This format describes data, supplied by the UVC driver from metadata video
> +nodes. That data includes UVC Payload Header contents and auxiliary timing
> +information, required for precise interpretation of timestamps, contained in
> +those headers. Buffers, streamed via UVC metadata nodes, are composed of blocks
> +of variable length. Those blocks contain are described by struct uvc_meta_buf
> +and contain the following fields:
> +
> +.. flat-table:: UVC Metadata Block
> + :widths: 1 4
> + :header-rows: 1
> + :stub-columns: 0
> +
> + * - Field
> + - Description
> + * - struct timespec ts;
> + - system timestamp, measured by the driver upon reception of the payload
Out of date: this is now a __u64 ns field.
> + * - __u16 sof;
> + - USB Frame Number, also obtained by the driver
> + * - :cspan:`1` *The rest is an exact copy of the 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
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index 45cf735..0aad91c 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -682,6 +682,7 @@ struct v4l2_pix_format {
> /* Meta-data formats */
> #define V4L2_META_FMT_VSP1_HGO v4l2_fourcc('V', 'S', 'P', 'H') /* R-Car VSP1 1-D Histogram */
> #define V4L2_META_FMT_VSP1_HGT v4l2_fourcc('V', 'S', 'P', 'T') /* R-Car VSP1 2-D Histogram */
> +#define V4L2_META_FMT_UVC v4l2_fourcc('U', 'V', 'C', 'H') /* UVC Payload Header metadata */
>
> /* priv field value to indicates that subsequent fields are valid. */
> #define V4L2_PIX_FMT_PRIV_MAGIC 0xfeedcafe
>
