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 003971F4CB3; Mon, 14 Jul 2025 16:27:33 +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=1752510455; cv=none; b=q38G1IE2C3zP61rydvN6KNWFJSfutYe8zj9jX8+z9+IASNTtLW7GJEm+LOqUxmE+hPimzlKqn6ZTCK7wFG8xPl5mxMfquhSUPjNdGvv8jI9DRpjG4JvA9gLmwIsIOv8wtX+KqG0GbOC61J3mEcF/0IR1JjodDd7y0CSgows2Kfk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752510455; c=relaxed/simple; bh=y2jxOeKNkzNzjBd4Buy6KiV3RBEW4nmi1WrMEKekot0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=tgLl/mwzJAcgVU5clX++/Z8avM+0EuoxXTZIsnJD9InurdsqCywBc9Qjz50NlnsTJd92CgvS3mG0fOfEpExbr4Cs1JDDPXY+TexyJ0v8agmeq97ABrHfaKZJoKolP2wIkoVTQxZn7aLif/X6SqBJPrSWYirQSgPij/GAI9eRB7k= 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=FKQYgf3E; 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="FKQYgf3E" Received: from pendragon.ideasonboard.com (81-175-209-231.bb.dnainternet.fi [81.175.209.231]) by perceval.ideasonboard.com (Postfix) with UTF8SMTPSA id 297771127; Mon, 14 Jul 2025 18:27:00 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1752510420; bh=y2jxOeKNkzNzjBd4Buy6KiV3RBEW4nmi1WrMEKekot0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=FKQYgf3ER7OVDPog8Mh2kcdc6NWCh26CQuAzJ318DJdqa6Dt2DpnFNjdxTdAZFhwt ZdGUod3lYmWt4Okal3O+RvJnqxGnCKIm1T63wiKSKS4z7amac8zX2v8cicW8RenkI1 DWT2mn8lqFWdb7wW4mjwKjpVcQcV5c6PtOQTPYBY= Date: Mon, 14 Jul 2025 19:27:00 +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: <20250714162700.GA20231@pendragon.ideasonboard.com> References: <20250707-uvc-meta-v8-0-ed17f8b1218b@chromium.org> <20250707-uvc-meta-v8-4-ed17f8b1218b@chromium.org> <20250714145935.GL8243@pendragon.ideasonboard.com> Precedence: bulk X-Mailing-List: linux-usb@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: On Mon, Jul 14, 2025 at 06:21:05PM +0200, Ricardo Ribalda wrote: > On Mon, 14 Jul 2025 at 17:00, Laurent Pinchart wrote: > > > > Hi Ricardo, > > > > A bit of a stupid question, or rather a question that I wonder why I > > didn't think of before. > > I believe we discussed this in the very beginning, when I just enabled > V4L2_META_FMT_D4XX for all the devices. Sorry if that was the case, it was a while ago. > We thought that it could break applications. Imagine an APP that can > work with D4XX but not with other formats: if it tries to parse MSXU > format it might crash. How so, if V4L2_META_FMT_D4XX and V4L2_META_FMT_UVC_MSXU_1_5 identify the same format ? > > 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