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.
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 <hdegoede@redhat.com>
Reviewed-by: Hans de Goede <hansg@kernel.org>
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
.../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 | 20 +++++++++++++++++--
drivers/media/usb/uvc/uvcvideo.h | 1 +
drivers/media/v4l2-core/v4l2-ioctl.c | 1 +
include/uapi/linux/videodev2.h | 1 +
7 files changed, 46 insertions(+), 2 deletions(-)
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 e8f3dc93a56921924f57e7d5a03ea2fa182a4448..87101630e528297c57b22ffc2fe553e3864d25cc 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -25816,6 +25816,7 @@ 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 bc84e849174397f41d1e20bf890a876eeb5a9c67..b09f81d907d64f7d7a3b0dc52de319879b7e68be 100644
--- a/drivers/media/usb/uvc/uvc_metadata.c
+++ b/drivers/media/usb/uvc/uvc_metadata.c
@@ -190,13 +190,29 @@ int uvc_meta_init(struct uvc_device *dev)
static const u32 uvch_only[] = {V4L2_META_FMT_UVC, 0};
static const u32 d4xx_format[] = {V4L2_META_FMT_UVC, V4L2_META_FMT_D4XX,
0};
+ static const u32 all_formats[] = {V4L2_META_FMT_UVC, V4L2_META_FMT_D4XX,
+ V4L2_META_FMT_UVC_MSXU_1_5, 0};
+ static const u32 ms_format[] = {V4L2_META_FMT_UVC,
+ V4L2_META_FMT_UVC_MSXU_1_5, 0};
+ bool support_msxu;
+
+ support_msxu = dev->quirks & UVC_QUIRK_MSXU_META;
switch (dev->info->meta_format) {
+ case V4L2_META_FMT_UVC_MSXU_1_5:
+ dev->meta_formats = ms_format;
+ break;
case V4L2_META_FMT_D4XX:
- dev->meta_formats = d4xx_format;
+ if (support_msxu)
+ dev->meta_formats = all_formats;
+ else
+ dev->meta_formats = d4xx_format;
break;
case 0:
- dev->meta_formats = uvch_only;
+ if (support_msxu)
+ dev->meta_formats = ms_format;
+ else
+ dev->meta_formats = uvch_only;
break;
default:
dev_err(&dev->udev->dev, "Unknown metadata format 0x%x\n",
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index 502f1d5608637cd28ce6f01aee31c4f5df160081..3578ce72fb6a1153ae79c244ec10093e8efdd739 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 650dc1956f73d2f1943b56c42140c7b8d757259f..ba508f7fb577021497009ab23a7be5add23fd08c 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -1459,6 +1459,7 @@ 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 9e3b366d5fc79d8a04c6f0752858fc23363db65c..75f2096b2d4fed5e0235ea4732d35044ff77a98b 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -861,6 +861,7 @@ 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 */
--
2.50.0.rc2.692.g299adb8693-googHi Ricardo,
Thank you for the new version of this series.
On 17-Jun-25 16:42, 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.
>
> 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 <hdegoede@redhat.com>
> Reviewed-by: Hans de Goede <hansg@kernel.org>
> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
> ---
> .../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 | 20 +++++++++++++++++--
> drivers/media/usb/uvc/uvcvideo.h | 1 +
> drivers/media/v4l2-core/v4l2-ioctl.c | 1 +
> include/uapi/linux/videodev2.h | 1 +
> 7 files changed, 46 insertions(+), 2 deletions(-)
>
> 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 e8f3dc93a56921924f57e7d5a03ea2fa182a4448..87101630e528297c57b22ffc2fe553e3864d25cc 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -25816,6 +25816,7 @@ 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 bc84e849174397f41d1e20bf890a876eeb5a9c67..b09f81d907d64f7d7a3b0dc52de319879b7e68be 100644
> --- a/drivers/media/usb/uvc/uvc_metadata.c
> +++ b/drivers/media/usb/uvc/uvc_metadata.c
> @@ -190,13 +190,29 @@ int uvc_meta_init(struct uvc_device *dev)
> static const u32 uvch_only[] = {V4L2_META_FMT_UVC, 0};
> static const u32 d4xx_format[] = {V4L2_META_FMT_UVC, V4L2_META_FMT_D4XX,
> 0};
> + static const u32 all_formats[] = {V4L2_META_FMT_UVC, V4L2_META_FMT_D4XX,
> + V4L2_META_FMT_UVC_MSXU_1_5, 0};
> + static const u32 ms_format[] = {V4L2_META_FMT_UVC,
> + V4L2_META_FMT_UVC_MSXU_1_5, 0};
Hmm, this does not look great, I guess we are not expecting any
new metadata formats soon but just needing the 4 arrays here and
then ... (continued below).
> + bool support_msxu;
> +
> + support_msxu = dev->quirks & UVC_QUIRK_MSXU_META;
>
> switch (dev->info->meta_format) {
> + case V4L2_META_FMT_UVC_MSXU_1_5:
> + dev->meta_formats = ms_format;
> + break;
> case V4L2_META_FMT_D4XX:
> - dev->meta_formats = d4xx_format;
> + if (support_msxu)
> + dev->meta_formats = all_formats;
> + else
> + dev->meta_formats = d4xx_format;
> break;
> case 0:
> - dev->meta_formats = uvch_only;
> + if (support_msxu)
> + dev->meta_formats = ms_format;
> + else
> + dev->meta_formats = uvch_only;
Also having these if else's here both don't look nice /
this does not feel clean.
My suggestion would be to instead do the following:
1. Add a #define UVC_MAX_META_DATA_FORMATS 3 to uvcvideo.h
2. In the struct uvc_device definition change meta_formats to:
u32 meta_formats[UVC_MAX_META_DATA_FORMATS + 1];
3. Change uvc_meta_init() to:
void uvc_meta_init(struct uvc_device *dev)
{
unsigned int i = 0;
dev->meta_formats[i++] = V4L2_META_FMT_UVC;
if (dev->info->meta_format)
dev->meta_formats[i++] = dev->info->meta_format;
if (dev->quirks & UVC_QUIRK_MSXU_META)
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;
}
Note uvc_meta_init() now also is void, so no more need to error check it.
The only downside I can see is that if we ever actually start setting
dev->info->meta_format = V4L2_META_FMT_UVC_MSXU_1_5 and a user manually
enables the quirk we get V4L2_META_FMT_UVC_MSXU_1_5 listed twice, but
that should not cause any issues and normally that will never happen.
IMHO this is better, then the switch-case + if-else code.
Stating the obvious: some / most of these changes should be done in patch 3/5
already.
Regards,
Hans
> break;
> default:
> dev_err(&dev->udev->dev, "Unknown metadata format 0x%x\n",
> diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
> index 502f1d5608637cd28ce6f01aee31c4f5df160081..3578ce72fb6a1153ae79c244ec10093e8efdd739 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 650dc1956f73d2f1943b56c42140c7b8d757259f..ba508f7fb577021497009ab23a7be5add23fd08c 100644
> --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> @@ -1459,6 +1459,7 @@ 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 9e3b366d5fc79d8a04c6f0752858fc23363db65c..75f2096b2d4fed5e0235ea4732d35044ff77a98b 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -861,6 +861,7 @@ 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 */
>
On Mon, 7 Jul 2025 at 13:34, Hans de Goede <hansg@kernel.org> wrote:
>
> Hi Ricardo,
>
> Thank you for the new version of this series.
>
> On 17-Jun-25 16:42, 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.
> >
> > 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 <hdegoede@redhat.com>
> > Reviewed-by: Hans de Goede <hansg@kernel.org>
> > Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
> > ---
> > .../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 | 20 +++++++++++++++++--
> > drivers/media/usb/uvc/uvcvideo.h | 1 +
> > drivers/media/v4l2-core/v4l2-ioctl.c | 1 +
> > include/uapi/linux/videodev2.h | 1 +
> > 7 files changed, 46 insertions(+), 2 deletions(-)
> >
> > 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 e8f3dc93a56921924f57e7d5a03ea2fa182a4448..87101630e528297c57b22ffc2fe553e3864d25cc 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -25816,6 +25816,7 @@ 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 bc84e849174397f41d1e20bf890a876eeb5a9c67..b09f81d907d64f7d7a3b0dc52de319879b7e68be 100644
> > --- a/drivers/media/usb/uvc/uvc_metadata.c
> > +++ b/drivers/media/usb/uvc/uvc_metadata.c
> > @@ -190,13 +190,29 @@ int uvc_meta_init(struct uvc_device *dev)
> > static const u32 uvch_only[] = {V4L2_META_FMT_UVC, 0};
> > static const u32 d4xx_format[] = {V4L2_META_FMT_UVC, V4L2_META_FMT_D4XX,
> > 0};
> > + static const u32 all_formats[] = {V4L2_META_FMT_UVC, V4L2_META_FMT_D4XX,
> > + V4L2_META_FMT_UVC_MSXU_1_5, 0};
> > + static const u32 ms_format[] = {V4L2_META_FMT_UVC,
> > + V4L2_META_FMT_UVC_MSXU_1_5, 0};
>
> Hmm, this does not look great, I guess we are not expecting any
> new metadata formats soon but just needing the 4 arrays here and
> then ... (continued below).
Yeah, this looks better :)
Will implement it as you describe. Just a couple of comments.
>
>
> > + bool support_msxu;
> > +
> > + support_msxu = dev->quirks & UVC_QUIRK_MSXU_META;
> >
> > switch (dev->info->meta_format) {
> > + case V4L2_META_FMT_UVC_MSXU_1_5:
> > + dev->meta_formats = ms_format;
> > + break;
> > case V4L2_META_FMT_D4XX:
> > - dev->meta_formats = d4xx_format;
> > + if (support_msxu)
> > + dev->meta_formats = all_formats;
> > + else
> > + dev->meta_formats = d4xx_format;
> > break;
> > case 0:
> > - dev->meta_formats = uvch_only;
> > + if (support_msxu)
> > + dev->meta_formats = ms_format;
> > + else
> > + dev->meta_formats = uvch_only;
>
> Also having these if else's here both don't look nice /
> this does not feel clean.
>
> My suggestion would be to instead do the following:
>
> 1. Add a #define UVC_MAX_META_DATA_FORMATS 3 to uvcvideo.h
> 2. In the struct uvc_device definition change meta_formats to:
>
> u32 meta_formats[UVC_MAX_META_DATA_FORMATS + 1];
>
> 3. Change uvc_meta_init() to:
>
> void uvc_meta_init(struct uvc_device *dev)
> {
> unsigned int i = 0;
>
> dev->meta_formats[i++] = V4L2_META_FMT_UVC;
>
> if (dev->info->meta_format)
> dev->meta_formats[i++] = dev->info->meta_format;
>
> if (dev->quirks & UVC_QUIRK_MSXU_META)
if (dev->quirks & UVC_QUIRK_MSXU_META) &&
dev->meta_formats[i-1] != 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 */
Do we really need this comment? Even if we add more formats the total
number of formats supported will never be more than 3.
FMT_UVC, device_specific, msxu
>
> dev->meta_formats[i++] = 0;
> }
>
> Note uvc_meta_init() now also is void, so no more need to error check it.
>
> The only downside I can see is that if we ever actually start setting
> dev->info->meta_format = V4L2_META_FMT_UVC_MSXU_1_5 and a user manually
> enables the quirk we get V4L2_META_FMT_UVC_MSXU_1_5 listed twice, but
> that should not cause any issues and normally that will never happen.
>
> IMHO this is better, then the switch-case + if-else code.
>
> Stating the obvious: some / most of these changes should be done in patch 3/5
> already.
>
> Regards,
>
> Hans
>
>
>
>
> > break;
> > default:
> > dev_err(&dev->udev->dev, "Unknown metadata format 0x%x\n",
> > diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
> > index 502f1d5608637cd28ce6f01aee31c4f5df160081..3578ce72fb6a1153ae79c244ec10093e8efdd739 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 650dc1956f73d2f1943b56c42140c7b8d757259f..ba508f7fb577021497009ab23a7be5add23fd08c 100644
> > --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> > +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> > @@ -1459,6 +1459,7 @@ 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 9e3b366d5fc79d8a04c6f0752858fc23363db65c..75f2096b2d4fed5e0235ea4732d35044ff77a98b 100644
> > --- a/include/uapi/linux/videodev2.h
> > +++ b/include/uapi/linux/videodev2.h
> > @@ -861,6 +861,7 @@ 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 */
> >
>
--
Ricardo Ribalda
Hi,
On 7-Jul-25 13:44, Ricardo Ribalda wrote:
> On Mon, 7 Jul 2025 at 13:34, Hans de Goede <hansg@kernel.org> wrote:
>>
>> Hi Ricardo,
>>
>> Thank you for the new version of this series.
>>
>> On 17-Jun-25 16:42, 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.
>>>
>>> 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 <hdegoede@redhat.com>
>>> Reviewed-by: Hans de Goede <hansg@kernel.org>
>>> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
>>> ---
>>> .../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 | 20 +++++++++++++++++--
>>> drivers/media/usb/uvc/uvcvideo.h | 1 +
>>> drivers/media/v4l2-core/v4l2-ioctl.c | 1 +
>>> include/uapi/linux/videodev2.h | 1 +
>>> 7 files changed, 46 insertions(+), 2 deletions(-)
>>>
>>> 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 e8f3dc93a56921924f57e7d5a03ea2fa182a4448..87101630e528297c57b22ffc2fe553e3864d25cc 100644
>>> --- a/MAINTAINERS
>>> +++ b/MAINTAINERS
>>> @@ -25816,6 +25816,7 @@ 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 bc84e849174397f41d1e20bf890a876eeb5a9c67..b09f81d907d64f7d7a3b0dc52de319879b7e68be 100644
>>> --- a/drivers/media/usb/uvc/uvc_metadata.c
>>> +++ b/drivers/media/usb/uvc/uvc_metadata.c
>>> @@ -190,13 +190,29 @@ int uvc_meta_init(struct uvc_device *dev)
>>> static const u32 uvch_only[] = {V4L2_META_FMT_UVC, 0};
>>> static const u32 d4xx_format[] = {V4L2_META_FMT_UVC, V4L2_META_FMT_D4XX,
>>> 0};
>>> + static const u32 all_formats[] = {V4L2_META_FMT_UVC, V4L2_META_FMT_D4XX,
>>> + V4L2_META_FMT_UVC_MSXU_1_5, 0};
>>> + static const u32 ms_format[] = {V4L2_META_FMT_UVC,
>>> + V4L2_META_FMT_UVC_MSXU_1_5, 0};
>>
>> Hmm, this does not look great, I guess we are not expecting any
>> new metadata formats soon but just needing the 4 arrays here and
>> then ... (continued below).
>
> Yeah, this looks better :)
>
>
> Will implement it as you describe. Just a couple of comments.
>
>
>
>>
>>
>>> + bool support_msxu;
>>> +
>>> + support_msxu = dev->quirks & UVC_QUIRK_MSXU_META;
>>>
>>> switch (dev->info->meta_format) {
>>> + case V4L2_META_FMT_UVC_MSXU_1_5:
>>> + dev->meta_formats = ms_format;
>>> + break;
>>> case V4L2_META_FMT_D4XX:
>>> - dev->meta_formats = d4xx_format;
>>> + if (support_msxu)
>>> + dev->meta_formats = all_formats;
>>> + else
>>> + dev->meta_formats = d4xx_format;
>>> break;
>>> case 0:
>>> - dev->meta_formats = uvch_only;
>>> + if (support_msxu)
>>> + dev->meta_formats = ms_format;
>>> + else
>>> + dev->meta_formats = uvch_only;
>>
>> Also having these if else's here both don't look nice /
>> this does not feel clean.
>>
>> My suggestion would be to instead do the following:
>>
>> 1. Add a #define UVC_MAX_META_DATA_FORMATS 3 to uvcvideo.h
>> 2. In the struct uvc_device definition change meta_formats to:
>>
>> u32 meta_formats[UVC_MAX_META_DATA_FORMATS + 1];
>>
>> 3. Change uvc_meta_init() to:
>>
>> void uvc_meta_init(struct uvc_device *dev)
>> {
>> unsigned int i = 0;
>>
>> dev->meta_formats[i++] = V4L2_META_FMT_UVC;
>>
>> if (dev->info->meta_format)
>> dev->meta_formats[i++] = dev->info->meta_format;
>>
>> if (dev->quirks & UVC_QUIRK_MSXU_META)
>
> if (dev->quirks & UVC_QUIRK_MSXU_META) &&
> dev->meta_formats[i-1] != 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 */
>
> Do we really need this comment? Even if we add more formats the total
> number of formats supported will never be more than 3.
>
> FMT_UVC, device_specific, msxu
The comment is at the place where one would add a new if in case
for some reason we do add another path to add a meta-format in
that case if all 3 (with the new if) if conditions evaluate to
true then we would overrun the array.
Unfortunately there is no way to do e.g. a static_assert()
for that, which is why I still believe at least having
the comment would be good.
That and/or add a:
WARN_ON(i > UVC_MAX_META_DATA_FORMATS);
Before adding the final 0 terminator. I actually had
the WARN_ON in there first, but a comment seemed to make
more sense...
Regards,
Hans
>> dev->meta_formats[i++] = 0;
>> }
>>
>> Note uvc_meta_init() now also is void, so no more need to error check it.
>>
>> The only downside I can see is that if we ever actually start setting
>> dev->info->meta_format = V4L2_META_FMT_UVC_MSXU_1_5 and a user manually
>> enables the quirk we get V4L2_META_FMT_UVC_MSXU_1_5 listed twice, but
>> that should not cause any issues and normally that will never happen.
>>
>> IMHO this is better, then the switch-case + if-else code.
>>
>> Stating the obvious: some / most of these changes should be done in patch 3/5
>> already.
>>
>> Regards,
>>
>> Hans
>>
>>
>>
>>
>>> break;
>>> default:
>>> dev_err(&dev->udev->dev, "Unknown metadata format 0x%x\n",
>>> diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
>>> index 502f1d5608637cd28ce6f01aee31c4f5df160081..3578ce72fb6a1153ae79c244ec10093e8efdd739 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 650dc1956f73d2f1943b56c42140c7b8d757259f..ba508f7fb577021497009ab23a7be5add23fd08c 100644
>>> --- a/drivers/media/v4l2-core/v4l2-ioctl.c
>>> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
>>> @@ -1459,6 +1459,7 @@ 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 9e3b366d5fc79d8a04c6f0752858fc23363db65c..75f2096b2d4fed5e0235ea4732d35044ff77a98b 100644
>>> --- a/include/uapi/linux/videodev2.h
>>> +++ b/include/uapi/linux/videodev2.h
>>> @@ -861,6 +861,7 @@ 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 */
>>>
>>
>
>
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