[PATCH] libcamera: camera_sensor_properties: ov5675: Set correct delays

[Naushir Patuck]

Hi Kieran,

On Thu, 19 Dec 2024 at 01:00, Kieran Bingham
<kieran.bingham at ideasonboard.com> wrote:
>
> The OV5675 uses different delays for gain and exposure than are configured
> in the default sensorDelays utilised by the CameraSensorLegacy.
>
> Empirical testing using a Lenovo X13s shows that the exposure delay is
> only a single frame, and the current setting of 2 frame delay produces
> exceedingly frequent oscillations in the image exposure.
>
> Update the OV5675 sensor delays table accordingly.
>
> Signed-off-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
> ---
>  src/libcamera/sensor/camera_sensor_properties.cpp | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/src/libcamera/sensor/camera_sensor_properties.cpp b/src/libcamera/sensor/camera_sensor_properties.cpp
> index bd1fc86977ce..813878386a35 100644
> --- a/src/libcamera/sensor/camera_sensor_properties.cpp
> +++ b/src/libcamera/sensor/camera_sensor_properties.cpp
> @@ -360,7 +360,12 @@ const CameraSensorProperties *CameraSensorProperties::get(const std::string &sen
>                                 { controls::draft::TestPatternModeOff, 0 },
>                                 { controls::draft::TestPatternModeColorBars, 1 },
>                         },
> -                       .sensorDelays = { },
> +                       .sensorDelays = {
> +                               .exposureDelay = 1,

>From my experience, an exposure delay of 1 is very unlikely with a
rolling shutter sensor because of the integration overlap between
successive frames.  Of course, I could be wrong since I've not
encounter this sensor before.  Perhaps it's worth looking at other
delays to see if the general interaction between vblank/exposure/gain
is causing the oscillations?

Regards,
Naush

> +                               .gainDelay = 1,
> +                               .vblankDelay = 2,
> +                               .hblankDelay = 2
> +                           },
>                 } },
>                 { "ov5693", {
>                         .unitCellSize = { 1400, 1400 },
> --
> 2.47.1
>