From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2CE73BA4A; Mon, 14 Jul 2025 15:00:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.167.242.64 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752505211; cv=none; b=B7VxyEgXu8DeU648nDBXKrULZtj8wzS7wInzuDqcK90ZH9d+2XOh9kRXfepURfEP/RKwMnICrc+OPXl4VvCzf0Lv4XQUHlqXZxSzJmX6Hu34tbjQ/fEyAfY5iosLuivgZNn5CgBzk2iBHxHACOZVfGIrpJn9uyhiZtv1m/8D4jc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752505211; c=relaxed/simple; bh=hWXImk9YMy9ZCnkf+3TPjpsIRN55aGjiy7dHkpwhaK0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=pDbFdqUv1cHySkzLOEIg6fRifnzkiWRZn72s62tp9eHCMlUZ28wOPvDEoaPnBLHHUrB4Qa1la1SGigJPUgmvCDRduwasqW+9ai0hztfJm7vqJl+OdSHBl4y8TKchW97r7TaDMn7o8nhn50Vih6dItEql/vfTsKsoE3GzF5Bnwrs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ideasonboard.com; spf=pass smtp.mailfrom=ideasonboard.com; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b=hAkJkpN2; arc=none smtp.client-ip=213.167.242.64 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="hAkJkpN2" Received: from pendragon.ideasonboard.com (81-175-209-231.bb.dnainternet.fi [81.175.209.231]) by perceval.ideasonboard.com (Postfix) with UTF8SMTPSA id 4A011166D; Mon, 14 Jul 2025 16:59:35 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1752505175; bh=hWXImk9YMy9ZCnkf+3TPjpsIRN55aGjiy7dHkpwhaK0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=hAkJkpN2Q/zxM2o9n8H+a5grkZhHi9uyrFjRXMUijcFlumcOYLqwI8YCaWio4c66J nMDdXz9NfCdWACwdwO8Y2/+GDkOhNp662LUo2fY7MWedmVFbjWSr+mAvrcyQ4xEdqA W8POSXzE814u0Q+u3xAJPCb6tcbJ2VvowbWdo0Aw= Date: Mon, 14 Jul 2025 17:59:35 +0300 From: Laurent Pinchart To: Ricardo Ribalda Cc: Mauro Carvalho Chehab , Guennadi Liakhovetski , Greg Kroah-Hartman , Hans de Goede , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org Subject: Re: [PATCH v8 4/5] media: uvcvideo: Introduce V4L2_META_FMT_UVC_MSXU_1_5 Message-ID: <20250714145935.GL8243@pendragon.ideasonboard.com> References: <20250707-uvc-meta-v8-0-ed17f8b1218b@chromium.org> <20250707-uvc-meta-v8-4-ed17f8b1218b@chromium.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20250707-uvc-meta-v8-4-ed17f8b1218b@chromium.org> Hi Ricardo, A bit of a stupid question, or rather a question that I wonder why I didn't think of before. On Mon, Jul 07, 2025 at 06:34:04PM +0000, Ricardo Ribalda wrote: > The UVC driver provides two metadata types V4L2_META_FMT_UVC, and > V4L2_META_FMT_D4XX. The only difference between the two of them is that > V4L2_META_FMT_UVC only copies PTS, SCR, size and flags, and > V4L2_META_FMT_D4XX copies the whole metadata section. > > Now we only enable V4L2_META_FMT_D4XX for the Intel D4xx family of > devices, but it is useful to have the whole metadata payload for any > device where vendors include other metadata, such as the one described by > Microsoft: > https://learn.microsoft.com/en-us/windows-hardware/drivers/stream/mf-capture-metadata > > This patch introduces a new format V4L2_META_FMT_UVC_MSXU_1_5, that is > identical to V4L2_META_FMT_D4XX. Wouldn't it be simpler for everybody to just #define V4L2_META_FMT_UVC_MSXU_1_5 v4l2_fourcc('D', '4', 'X', 'X') /* UVC MSXU metadata */ #define V4L2_META_FMT_D4XX V4L2_META_FMT_UVC_MSXU_1_5 /* For backward compatibility */ ? I'm a bit uncomfortable with committing to a UABI with two different 4CCs for the exact same format. > Let the user enable this format with a quirk for now. This way they can > test if their devices provide useful metadata without rebuilding the > kernel. They can later contribute patches to auto-quirk their devices. > We will also work in methods to auto-detect devices compatible with this > new metadata format. > > Suggested-by: Hans de Goede > Reviewed-by: Hans de Goede > Signed-off-by: Ricardo Ribalda > --- > .../userspace-api/media/v4l/meta-formats.rst | 1 + > .../media/v4l/metafmt-uvc-msxu-1-5.rst | 23 ++++++++++++++++++++++ > MAINTAINERS | 1 + > drivers/media/usb/uvc/uvc_metadata.c | 4 ++++ > drivers/media/usb/uvc/uvcvideo.h | 1 + > drivers/media/v4l2-core/v4l2-ioctl.c | 1 + > include/uapi/linux/videodev2.h | 1 + > 7 files changed, 32 insertions(+) > > diff --git a/Documentation/userspace-api/media/v4l/meta-formats.rst b/Documentation/userspace-api/media/v4l/meta-formats.rst > index bb6876cfc271e1a0543eee4209d6251e1a6a73cc..0de80328c36bf148051a19abe9e5241234ddfe5c 100644 > --- a/Documentation/userspace-api/media/v4l/meta-formats.rst > +++ b/Documentation/userspace-api/media/v4l/meta-formats.rst > @@ -20,6 +20,7 @@ These formats are used for the :ref:`metadata` interface only. > metafmt-pisp-fe > metafmt-rkisp1 > metafmt-uvc > + metafmt-uvc-msxu-1-5 > metafmt-vivid > metafmt-vsp1-hgo > metafmt-vsp1-hgt > diff --git a/Documentation/userspace-api/media/v4l/metafmt-uvc-msxu-1-5.rst b/Documentation/userspace-api/media/v4l/metafmt-uvc-msxu-1-5.rst > new file mode 100644 > index 0000000000000000000000000000000000000000..dd1c3076df243d770a13e7f6d07c3296a269e16a > --- /dev/null > +++ b/Documentation/userspace-api/media/v4l/metafmt-uvc-msxu-1-5.rst > @@ -0,0 +1,23 @@ > +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later > + > +.. _v4l2-meta-fmt-uvc-msxu-1-5: > + > +*********************************** > +V4L2_META_FMT_UVC_MSXU_1_5 ('UVCM') > +*********************************** > + > +Microsoft(R)'s UVC Payload Metadata. > + > + > +Description > +=========== > + > +V4L2_META_FMT_UVC_MSXU_1_5 buffers follow the metadata buffer layout of > +V4L2_META_FMT_UVC with the only difference that it includes all the UVC > +metadata in the `buffer[]` field, not just the first 2-12 bytes. > + > +The metadata format follows the specification from Microsoft(R) [1]. > + > +.. _1: > + > +[1] https://docs.microsoft.com/en-us/windows-hardware/drivers/stream/uvc-extensions-1-5 > diff --git a/MAINTAINERS b/MAINTAINERS > index 658543062bba3b7e600699d7271ffc89250ba7e5..fdde1d37ed2ef9058e3ea3417bec25afe454dfc0 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -25827,6 +25827,7 @@ S: Maintained > W: http://www.ideasonboard.org/uvc/ > T: git git://linuxtv.org/media.git > F: Documentation/userspace-api/media/drivers/uvcvideo.rst > +F: Documentation/userspace-api/media/v4l/metafmt-uvc-msxu-1-5.rst > F: Documentation/userspace-api/media/v4l/metafmt-uvc.rst > F: drivers/media/common/uvc.c > F: drivers/media/usb/uvc/ > diff --git a/drivers/media/usb/uvc/uvc_metadata.c b/drivers/media/usb/uvc/uvc_metadata.c > index 4bcbc22f47e67c52baf6e133f240131ff3d32a03..77e03273d3cf6b00cac6ebb9b29b941f1cbfd9f7 100644 > --- a/drivers/media/usb/uvc/uvc_metadata.c > +++ b/drivers/media/usb/uvc/uvc_metadata.c > @@ -195,6 +195,10 @@ void uvc_meta_init(struct uvc_device *dev) > !WARN_ON(dev->info->meta_format == V4L2_META_FMT_UVC)) > dev->meta_formats[i++] = dev->info->meta_format; > > + if (dev->quirks & UVC_QUIRK_MSXU_META && > + !WARN_ON(dev->info->meta_format == V4L2_META_FMT_UVC_MSXU_1_5)) > + dev->meta_formats[i++] = V4L2_META_FMT_UVC_MSXU_1_5; > + > /* IMPORTANT: for new meta-formats update UVC_MAX_META_DATA_FORMATS. */ > dev->meta_formats[i++] = 0; > } > diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h > index b3c094c6591e7a71fc00e1096bcf493a83f330ad..616adc417c62a58686beccbc440a5dfac0a2d588 100644 > --- a/drivers/media/usb/uvc/uvcvideo.h > +++ b/drivers/media/usb/uvc/uvcvideo.h > @@ -77,6 +77,7 @@ > #define UVC_QUIRK_DISABLE_AUTOSUSPEND 0x00008000 > #define UVC_QUIRK_INVALID_DEVICE_SOF 0x00010000 > #define UVC_QUIRK_MJPEG_NO_EOF 0x00020000 > +#define UVC_QUIRK_MSXU_META 0x00040000 > > /* Format flags */ > #define UVC_FMT_FLAG_COMPRESSED 0x00000001 > diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c > index be94a79b976e3de4eb957f5d2584ec6d4230469e..993b36417b4655456ce545cb42a41b55b98e4d6c 100644 > --- a/drivers/media/v4l2-core/v4l2-ioctl.c > +++ b/drivers/media/v4l2-core/v4l2-ioctl.c > @@ -1463,6 +1463,7 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt) > case V4L2_META_FMT_VSP1_HGO: descr = "R-Car VSP1 1-D Histogram"; break; > case V4L2_META_FMT_VSP1_HGT: descr = "R-Car VSP1 2-D Histogram"; break; > case V4L2_META_FMT_UVC: descr = "UVC Payload Header Metadata"; break; > + case V4L2_META_FMT_UVC_MSXU_1_5: descr = "UVC MSXU Metadata"; break; > case V4L2_META_FMT_D4XX: descr = "Intel D4xx UVC Metadata"; break; > case V4L2_META_FMT_VIVID: descr = "Vivid Metadata"; break; > case V4L2_META_FMT_RK_ISP1_PARAMS: descr = "Rockchip ISP1 3A Parameters"; break; > diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h > index 6f7bd38dd5aa4b1b2084685512512a380d76a5e4..863bc5b7dec32303e852d7e9c3891011ce5a3d71 100644 > --- a/include/uapi/linux/videodev2.h > +++ b/include/uapi/linux/videodev2.h > @@ -867,6 +867,7 @@ struct v4l2_pix_format { > #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 */ > #define V4L2_META_FMT_D4XX v4l2_fourcc('D', '4', 'X', 'X') /* D4XX Payload Header metadata */ > +#define V4L2_META_FMT_UVC_MSXU_1_5 v4l2_fourcc('U', 'V', 'C', 'M') /* UVC MSXU metadata */ > #define V4L2_META_FMT_VIVID v4l2_fourcc('V', 'I', 'V', 'D') /* Vivid Metadata */ > > /* Vendor specific - used for RK_ISP1 camera sub-system */ -- Regards, Laurent Pinchart