[libcamera-devel] New warnings for pixel formats on Raspberry Pi platforms

[Laurent Pinchart]

Hi Naush,

On Fri, Aug 05, 2022 at 03:26:16PM +0100, Naushir Patuck via libcamera-devel wrote:
> Hi,
> 
> A recent change (commit f25ad4a2b16b libcamera: formats: Reimplement V4L2
> PixelFormatInfo::info()) has started throwing WARN messages on the Raspberry Pi
> platform:
>  
> [24:06:09.085738817] [8392]  INFO Camera camera_manager.cpp:293 libcamera v0.0.0
> [24:06:09.196596920] [8408]  WARN V4L2 v4l2_pixelformat.cpp:301 Unsupported V4L2 pixel format SENS
> [24:06:09.196729049] [8408]  WARN Formats formats.cpp:838 Unsupported pixel format 0x00000000
> [24:06:09.198112797] [8408]  WARN V4L2 v4l2_pixelformat.cpp:301 Unsupported V4L2 pixel format BSTA
> [24:06:09.198203814] [8408]  WARN Formats formats.cpp:838 Unsupported pixel format 0x00000000
> [24:06:09.199839579] [8408]  INFO RPI raspberrypi.cpp:1374 Registered camera /base/soc/i2c0mux/i2c at 1/imx477 at 1a to Unicam device /dev/media0 and ISP device /dev/media3

Oops.

> This is because our meta formats for statistics and embedded data do not have
> defined types in libcamera::formats::PixelFormat.  The reason for this is that
> they are metadata formats used exclusively internally in the pipeline handler,
> and can never be selected by the application.
> 
> I'm not sure how to fix this.  Do I need to add entries in formats.yaml to
> generate types in libcamera::formats::PixelFormat, meaning I also have to add 
> new 4CCs in the drm headers... :-( Given these are metadata formats, and not
> user selectable, is this the right thing to do?

No, I don't think this is the right thing to do, we shouldn't expose
those formats externally. We probably need a way to only warn when
legitimate.

-- 
Regards,

Laurent Pinchart