[libcamera-devel] [PATCH 4/4] ipa: rkisp1: Raise maximum analogue gain

[Jacopo Mondi]

Hi Mikhail

On Thu, Jan 19, 2023 at 06:59:05PM +0300, Mikhail Rudenko via libcamera-devel wrote:
> Omnivision OV4689 sensor driver exposes maximum analogue gain of
> 16x. Raise kMaxAnalogueGain to 16.0, so that the full gain range can
> be used.
>
> Signed-off-by: Mikhail Rudenko <mike.rudenko at gmail.com>
> ---
>  src/ipa/rkisp1/algorithms/agc.cpp | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/src/ipa/rkisp1/algorithms/agc.cpp b/src/ipa/rkisp1/algorithms/agc.cpp
> index e3470e25..e4cb2fc7 100644
> --- a/src/ipa/rkisp1/algorithms/agc.cpp
> +++ b/src/ipa/rkisp1/algorithms/agc.cpp
> @@ -38,7 +38,7 @@ LOG_DEFINE_CATEGORY(RkISP1Agc)
>
>  /* Limits for analogue gain values */
>  static constexpr double kMinAnalogueGain = 1.0;
> -static constexpr double kMaxAnalogueGain = 8.0;
> +static constexpr double kMaxAnalogueGain = 16.0;

I'm very surprised we have such an hard limit..

Should it be made configurable ? Should we allow the sensor tuning
file to provide this value ? Not something required for you to do to
fix this ofc

>
>  /* \todo Honour the FrameDurationLimits control instead of hardcoding a limit */
>  static constexpr utils::Duration kMaxShutterSpeed = 60ms;
> --
> 2.39.0
>