[PATCH] media: uvcvideo: Add GUID for BGRA/X 8:8:8:8

[PATCH] media: uvcvideo: Add GUID for BGRA/X 8:8:8:8

[Marek Vasut]

The Cypress EZUSB FX3 UVC example can be configured to report pixel
format "e436eb7e-524f-11ce-9f53-0020af0ba770". This is its GUID for
BGRA/X 8:8:8:8.

The UVC 1.5 spec [1] only defines GUIDs for YUY2, NV12, M420 and I420.
This seems to be an extension documented in the Microsoft Windows Media
Format SDK[2]. This Media Format SDK defines this GUID as corresponding
to `MEDIASUBTYPE_RGB32`.

Note that in my case, the FX3 UVC can output either channel order,
BGR or RGB or any other mix for that matter. Since Linux commit
1b8dc32286a1a ("[media] uvcvideo: Add GUID for BGR 8:8:8")
defined a GUID for `MEDIASUBTYPE_RGB24` channel order as BGR, keep
this change consistent and define `MEDIASUBTYPE_RGB32` as BGR as well.

[1]: https://www.usb.org/document-library/video-class-v15-document-set
[2]: https://learn.microsoft.com/en-us/windows/win32/wmformat/media-type-identifiers

Signed-off-by: Marek Vasut <marex@denx.de>
---
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: William Manley <will@williammanley.net>
---
 include/media/v4l2-uvc.h | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/include/media/v4l2-uvc.h b/include/media/v4l2-uvc.h
index f83e31661333b..c10e9086338be 100644
--- a/include/media/v4l2-uvc.h
+++ b/include/media/v4l2-uvc.h
@@ -99,6 +99,9 @@
 #define UVC_GUID_FORMAT_BGR3 \
 	{ 0x7d, 0xeb, 0x36, 0xe4, 0x4f, 0x52, 0xce, 0x11, \
 	 0x9f, 0x53, 0x00, 0x20, 0xaf, 0x0b, 0xa7, 0x70}
+#define UVC_GUID_FORMAT_BGR4 \
+	{ 0x7e, 0xeb, 0x36, 0xe4, 0x4f, 0x52, 0xce, 0x11, \
+	 0x9f, 0x53, 0x00, 0x20, 0xaf, 0x0b, 0xa7, 0x70}
 #define UVC_GUID_FORMAT_M420 \
 	{ 'M',  '4',  '2',  '0', 0x00, 0x00, 0x10, 0x00, \
 	 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
@@ -266,6 +269,11 @@ static struct uvc_format_desc uvc_fmts[] = {
 		.guid		= UVC_GUID_FORMAT_BGR3,
 		.fcc		= V4L2_PIX_FMT_BGR24,
 	},
+	{
+		.name		= "BGRA/X 8:8:8:8 (BGR4)",
+		.guid		= UVC_GUID_FORMAT_BGR4,
+		.fcc		= V4L2_PIX_FMT_BGR32,
+	},
 	{
 		.name		= "H.264",
 		.guid		= UVC_GUID_FORMAT_H264,
-- 
2.39.0

Re: [PATCH] media: uvcvideo: Add GUID for BGRA/X 8:8:8:8

[Laurent Pinchart]

Hi Marek,

Thank you for the patch.

On Tue, Jan 10, 2023 at 08:53:31PM +0100, Marek Vasut wrote:
> The Cypress EZUSB FX3 UVC example can be configured to report pixel
> format "e436eb7e-524f-11ce-9f53-0020af0ba770". This is its GUID for
> BGRA/X 8:8:8:8.
> 
> The UVC 1.5 spec [1] only defines GUIDs for YUY2, NV12, M420 and I420.
> This seems to be an extension documented in the Microsoft Windows Media
> Format SDK[2]. This Media Format SDK defines this GUID as corresponding
> to `MEDIASUBTYPE_RGB32`.
> 
> Note that in my case, the FX3 UVC can output either channel order,
> BGR or RGB or any other mix for that matter. Since Linux commit
> 1b8dc32286a1a ("[media] uvcvideo: Add GUID for BGR 8:8:8")
> defined a GUID for `MEDIASUBTYPE_RGB24` channel order as BGR, keep
> this change consistent and define `MEDIASUBTYPE_RGB32` as BGR as well.

I'd like to see documentation of the MEDIASUBTYPE_RGB32 format that
indicates the components order precisely. While there's a high chance it
maps to a BGR (in the V4L2 nomenclature) format, there would still be
two different options for the A or X component.

> [1]: https://www.usb.org/document-library/video-class-v15-document-set
> [2]: https://learn.microsoft.com/en-us/windows/win32/wmformat/media-type-identifiers
> 
> Signed-off-by: Marek Vasut <marex@denx.de>
> ---
> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
> Cc: William Manley <will@williammanley.net>
> ---
>  include/media/v4l2-uvc.h | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/include/media/v4l2-uvc.h b/include/media/v4l2-uvc.h
> index f83e31661333b..c10e9086338be 100644
> --- a/include/media/v4l2-uvc.h
> +++ b/include/media/v4l2-uvc.h
> @@ -99,6 +99,9 @@
>  #define UVC_GUID_FORMAT_BGR3 \
>  	{ 0x7d, 0xeb, 0x36, 0xe4, 0x4f, 0x52, 0xce, 0x11, \
>  	 0x9f, 0x53, 0x00, 0x20, 0xaf, 0x0b, 0xa7, 0x70}
> +#define UVC_GUID_FORMAT_BGR4 \
> +	{ 0x7e, 0xeb, 0x36, 0xe4, 0x4f, 0x52, 0xce, 0x11, \
> +	 0x9f, 0x53, 0x00, 0x20, 0xaf, 0x0b, 0xa7, 0x70}
>  #define UVC_GUID_FORMAT_M420 \
>  	{ 'M',  '4',  '2',  '0', 0x00, 0x00, 0x10, 0x00, \
>  	 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
> @@ -266,6 +269,11 @@ static struct uvc_format_desc uvc_fmts[] = {
>  		.guid		= UVC_GUID_FORMAT_BGR3,
>  		.fcc		= V4L2_PIX_FMT_BGR24,
>  	},
> +	{
> +		.name		= "BGRA/X 8:8:8:8 (BGR4)",
> +		.guid		= UVC_GUID_FORMAT_BGR4,
> +		.fcc		= V4L2_PIX_FMT_BGR32,
> +	},
>  	{
>  		.name		= "H.264",
>  		.guid		= UVC_GUID_FORMAT_H264,

-- 
Regards,

Laurent Pinchart

Re: [PATCH] media: uvcvideo: Add GUID for BGRA/X 8:8:8:8

[Marek Vasut]

On 1/13/23 00:15, Laurent Pinchart wrote:
> Hi Marek,

Hi,

> Thank you for the patch.
> 
> On Tue, Jan 10, 2023 at 08:53:31PM +0100, Marek Vasut wrote:
>> The Cypress EZUSB FX3 UVC example can be configured to report pixel
>> format "e436eb7e-524f-11ce-9f53-0020af0ba770". This is its GUID for
>> BGRA/X 8:8:8:8.
>>
>> The UVC 1.5 spec [1] only defines GUIDs for YUY2, NV12, M420 and I420.
>> This seems to be an extension documented in the Microsoft Windows Media
>> Format SDK[2]. This Media Format SDK defines this GUID as corresponding
>> to `MEDIASUBTYPE_RGB32`.
>>
>> Note that in my case, the FX3 UVC can output either channel order,
>> BGR or RGB or any other mix for that matter. Since Linux commit
>> 1b8dc32286a1a ("[media] uvcvideo: Add GUID for BGR 8:8:8")
>> defined a GUID for `MEDIASUBTYPE_RGB24` channel order as BGR, keep
>> this change consistent and define `MEDIASUBTYPE_RGB32` as BGR as well.
> 
> I'd like to see documentation of the MEDIASUBTYPE_RGB32 format that
> indicates the components order precisely. While there's a high chance it
> maps to a BGR (in the V4L2 nomenclature) format, there would still be
> two different options for the A or X component.

Maybe this ?

https://github.com/MicrosoftDocs/win32/blob/docs/desktop-src/DirectShow/uncompressed-rgb-video-subtypes.md

"
Remarks
...
For RGB 32, every pixel is an RGBQUAD. Each color is one byte, with a 
value from 0 to 255, inclusive. The memory layout is:
Byte    0       1       2       3
Value   Blue    Green   Red     Alpha or Don't Care
"

Maps to

drivers/media/v4l2-core/v4l2-ioctl.c:   case V4L2_PIX_FMT_BGR32: 
descr = "32-bit BGRA/X 8-8-8-8"; break;

Re: [PATCH] media: uvcvideo: Add GUID for BGRA/X 8:8:8:8

[Laurent Pinchart]

Hi Marek,

On Fri, Jan 13, 2023 at 02:03:33AM +0100, Marek Vasut wrote:
> On 1/13/23 00:15, Laurent Pinchart wrote:
> > On Tue, Jan 10, 2023 at 08:53:31PM +0100, Marek Vasut wrote:
> >> The Cypress EZUSB FX3 UVC example can be configured to report pixel
> >> format "e436eb7e-524f-11ce-9f53-0020af0ba770". This is its GUID for
> >> BGRA/X 8:8:8:8.
> >>
> >> The UVC 1.5 spec [1] only defines GUIDs for YUY2, NV12, M420 and I420.
> >> This seems to be an extension documented in the Microsoft Windows Media
> >> Format SDK[2]. This Media Format SDK defines this GUID as corresponding
> >> to `MEDIASUBTYPE_RGB32`.
> >>
> >> Note that in my case, the FX3 UVC can output either channel order,
> >> BGR or RGB or any other mix for that matter. Since Linux commit
> >> 1b8dc32286a1a ("[media] uvcvideo: Add GUID for BGR 8:8:8")
> >> defined a GUID for `MEDIASUBTYPE_RGB24` channel order as BGR, keep
> >> this change consistent and define `MEDIASUBTYPE_RGB32` as BGR as well.
> > 
> > I'd like to see documentation of the MEDIASUBTYPE_RGB32 format that
> > indicates the components order precisely. While there's a high chance it
> > maps to a BGR (in the V4L2 nomenclature) format, there would still be
> > two different options for the A or X component.
> 
> Maybe this ?
> 
> https://github.com/MicrosoftDocs/win32/blob/docs/desktop-src/DirectShow/uncompressed-rgb-video-subtypes.md
> 
> "
> Remarks
> ...
> For RGB 32, every pixel is an RGBQUAD. Each color is one byte, with a 
> value from 0 to 255, inclusive. The memory layout is:
> Byte    0       1       2       3
> Value   Blue    Green   Red     Alpha or Don't Care
> "
> 
> Maps to
> 
> drivers/media/v4l2-core/v4l2-ioctl.c:   case V4L2_PIX_FMT_BGR32: 
> descr = "32-bit BGRA/X 8-8-8-8"; break;

Thank you for digging it up. Looks good to me, except that
V4L2_PIX_FMT_BGR32 is deprecated (see
https://linuxtv.org/downloads/v4l-dvb-apis/userspace-api/v4l/pixfmt-rgb.html#deprecated-rgb-formats).
You should use V4L2_PIX_FMT_BGRA32 or V4L2_PIX_FMT_BGRX32 instead.

-- 
Regards,

Laurent Pinchart

Re: [PATCH] media: uvcvideo: Add GUID for BGRA/X 8:8:8:8

[Marek Vasut]

On 1/15/23 22:32, Laurent Pinchart wrote:
> Hi Marek,
> 
> On Fri, Jan 13, 2023 at 02:03:33AM +0100, Marek Vasut wrote:
>> On 1/13/23 00:15, Laurent Pinchart wrote:
>>> On Tue, Jan 10, 2023 at 08:53:31PM +0100, Marek Vasut wrote:
>>>> The Cypress EZUSB FX3 UVC example can be configured to report pixel
>>>> format "e436eb7e-524f-11ce-9f53-0020af0ba770". This is its GUID for
>>>> BGRA/X 8:8:8:8.
>>>>
>>>> The UVC 1.5 spec [1] only defines GUIDs for YUY2, NV12, M420 and I420.
>>>> This seems to be an extension documented in the Microsoft Windows Media
>>>> Format SDK[2]. This Media Format SDK defines this GUID as corresponding
>>>> to `MEDIASUBTYPE_RGB32`.
>>>>
>>>> Note that in my case, the FX3 UVC can output either channel order,
>>>> BGR or RGB or any other mix for that matter. Since Linux commit
>>>> 1b8dc32286a1a ("[media] uvcvideo: Add GUID for BGR 8:8:8")
>>>> defined a GUID for `MEDIASUBTYPE_RGB24` channel order as BGR, keep
>>>> this change consistent and define `MEDIASUBTYPE_RGB32` as BGR as well.
>>>
>>> I'd like to see documentation of the MEDIASUBTYPE_RGB32 format that
>>> indicates the components order precisely. While there's a high chance it
>>> maps to a BGR (in the V4L2 nomenclature) format, there would still be
>>> two different options for the A or X component.
>>
>> Maybe this ?
>>
>> https://github.com/MicrosoftDocs/win32/blob/docs/desktop-src/DirectShow/uncompressed-rgb-video-subtypes.md
>>
>> "
>> Remarks
>> ...
>> For RGB 32, every pixel is an RGBQUAD. Each color is one byte, with a
>> value from 0 to 255, inclusive. The memory layout is:
>> Byte    0       1       2       3
>> Value   Blue    Green   Red     Alpha or Don't Care
>> "
>>
>> Maps to
>>
>> drivers/media/v4l2-core/v4l2-ioctl.c:   case V4L2_PIX_FMT_BGR32:
>> descr = "32-bit BGRA/X 8-8-8-8"; break;
> 
> Thank you for digging it up. Looks good to me, except that
> V4L2_PIX_FMT_BGR32 is deprecated (see
> https://linuxtv.org/downloads/v4l-dvb-apis/userspace-api/v4l/pixfmt-rgb.html#deprecated-rgb-formats).
> You should use V4L2_PIX_FMT_BGRA32 or V4L2_PIX_FMT_BGRX32 instead.

V4L2_PIX_FMT_XBGR32 , right ?

Re: [PATCH] media: uvcvideo: Add GUID for BGRA/X 8:8:8:8

[Laurent Pinchart]

Hi Marek,

On Mon, Jan 16, 2023 at 12:45:34AM +0100, Marek Vasut wrote:
> On 1/15/23 22:32, Laurent Pinchart wrote:
> > On Fri, Jan 13, 2023 at 02:03:33AM +0100, Marek Vasut wrote:
> >> On 1/13/23 00:15, Laurent Pinchart wrote:
> >>> On Tue, Jan 10, 2023 at 08:53:31PM +0100, Marek Vasut wrote:
> >>>> The Cypress EZUSB FX3 UVC example can be configured to report pixel
> >>>> format "e436eb7e-524f-11ce-9f53-0020af0ba770". This is its GUID for
> >>>> BGRA/X 8:8:8:8.
> >>>>
> >>>> The UVC 1.5 spec [1] only defines GUIDs for YUY2, NV12, M420 and I420.
> >>>> This seems to be an extension documented in the Microsoft Windows Media
> >>>> Format SDK[2]. This Media Format SDK defines this GUID as corresponding
> >>>> to `MEDIASUBTYPE_RGB32`.
> >>>>
> >>>> Note that in my case, the FX3 UVC can output either channel order,
> >>>> BGR or RGB or any other mix for that matter. Since Linux commit
> >>>> 1b8dc32286a1a ("[media] uvcvideo: Add GUID for BGR 8:8:8")
> >>>> defined a GUID for `MEDIASUBTYPE_RGB24` channel order as BGR, keep
> >>>> this change consistent and define `MEDIASUBTYPE_RGB32` as BGR as well.
> >>>
> >>> I'd like to see documentation of the MEDIASUBTYPE_RGB32 format that
> >>> indicates the components order precisely. While there's a high chance it
> >>> maps to a BGR (in the V4L2 nomenclature) format, there would still be
> >>> two different options for the A or X component.
> >>
> >> Maybe this ?
> >>
> >> https://github.com/MicrosoftDocs/win32/blob/docs/desktop-src/DirectShow/uncompressed-rgb-video-subtypes.md
> >>
> >> "
> >> Remarks
> >> ...
> >> For RGB 32, every pixel is an RGBQUAD. Each color is one byte, with a
> >> value from 0 to 255, inclusive. The memory layout is:
> >> Byte    0       1       2       3
> >> Value   Blue    Green   Red     Alpha or Don't Care
> >> "
> >>
> >> Maps to
> >>
> >> drivers/media/v4l2-core/v4l2-ioctl.c:   case V4L2_PIX_FMT_BGR32:
> >> descr = "32-bit BGRA/X 8-8-8-8"; break;
> > 
> > Thank you for digging it up. Looks good to me, except that
> > V4L2_PIX_FMT_BGR32 is deprecated (see
> > https://linuxtv.org/downloads/v4l-dvb-apis/userspace-api/v4l/pixfmt-rgb.html#deprecated-rgb-formats).
> > You should use V4L2_PIX_FMT_BGRA32 or V4L2_PIX_FMT_BGRX32 instead.
> 
> V4L2_PIX_FMT_XBGR32 , right ?

Yes, my bad. 4CCs are awful :-)

We could also use V4L2_PIX_FMT_ABGR32, but I don't think a UVC camera
would meaningfully produce an alpha channel.

I can change the pixel format when applying the patch if this is fine
with you.

-- 
Regards,

Laurent Pinchart

Re: [PATCH] media: uvcvideo: Add GUID for BGRA/X 8:8:8:8

[Marek Vasut]

On 1/16/23 01:32, Laurent Pinchart wrote:
> Hi Marek,

Hi,

> On Mon, Jan 16, 2023 at 12:45:34AM +0100, Marek Vasut wrote:
>> On 1/15/23 22:32, Laurent Pinchart wrote:
>>> On Fri, Jan 13, 2023 at 02:03:33AM +0100, Marek Vasut wrote:
>>>> On 1/13/23 00:15, Laurent Pinchart wrote:
>>>>> On Tue, Jan 10, 2023 at 08:53:31PM +0100, Marek Vasut wrote:
>>>>>> The Cypress EZUSB FX3 UVC example can be configured to report pixel
>>>>>> format "e436eb7e-524f-11ce-9f53-0020af0ba770". This is its GUID for
>>>>>> BGRA/X 8:8:8:8.
>>>>>>
>>>>>> The UVC 1.5 spec [1] only defines GUIDs for YUY2, NV12, M420 and I420.
>>>>>> This seems to be an extension documented in the Microsoft Windows Media
>>>>>> Format SDK[2]. This Media Format SDK defines this GUID as corresponding
>>>>>> to `MEDIASUBTYPE_RGB32`.
>>>>>>
>>>>>> Note that in my case, the FX3 UVC can output either channel order,
>>>>>> BGR or RGB or any other mix for that matter. Since Linux commit
>>>>>> 1b8dc32286a1a ("[media] uvcvideo: Add GUID for BGR 8:8:8")
>>>>>> defined a GUID for `MEDIASUBTYPE_RGB24` channel order as BGR, keep
>>>>>> this change consistent and define `MEDIASUBTYPE_RGB32` as BGR as well.
>>>>>
>>>>> I'd like to see documentation of the MEDIASUBTYPE_RGB32 format that
>>>>> indicates the components order precisely. While there's a high chance it
>>>>> maps to a BGR (in the V4L2 nomenclature) format, there would still be
>>>>> two different options for the A or X component.
>>>>
>>>> Maybe this ?
>>>>
>>>> https://github.com/MicrosoftDocs/win32/blob/docs/desktop-src/DirectShow/uncompressed-rgb-video-subtypes.md
>>>>
>>>> "
>>>> Remarks
>>>> ...
>>>> For RGB 32, every pixel is an RGBQUAD. Each color is one byte, with a
>>>> value from 0 to 255, inclusive. The memory layout is:
>>>> Byte    0       1       2       3
>>>> Value   Blue    Green   Red     Alpha or Don't Care
>>>> "
>>>>
>>>> Maps to
>>>>
>>>> drivers/media/v4l2-core/v4l2-ioctl.c:   case V4L2_PIX_FMT_BGR32:
>>>> descr = "32-bit BGRA/X 8-8-8-8"; break;
>>>
>>> Thank you for digging it up. Looks good to me, except that
>>> V4L2_PIX_FMT_BGR32 is deprecated (see
>>> https://linuxtv.org/downloads/v4l-dvb-apis/userspace-api/v4l/pixfmt-rgb.html#deprecated-rgb-formats).
>>> You should use V4L2_PIX_FMT_BGRA32 or V4L2_PIX_FMT_BGRX32 instead.
>>
>> V4L2_PIX_FMT_XBGR32 , right ?
> 
> Yes, my bad. 4CCs are awful :-)
> 
> We could also use V4L2_PIX_FMT_ABGR32, but I don't think a UVC camera
> would meaningfully produce an alpha channel.
> 
> I can change the pixel format when applying the patch if this is fine
> with you.

I sent a V2 with a couple more links for future reference.