[PATCH v2 4/4] ipa: rkisp1: use active state in setControls

[Mikhail Rudenko]

On 2024-10-20 at 18:28 +03, Mikhail Rudenko <mike.rudenko at gmail.com> wrote:

> The results of AGC algorithm currently travel a long way before being
> actually applied. Let's consider the common case when 4 requests are
> used and frames 0-3 are queued before start(). AGC is first run when
> frame 0 stats are ready, and exposure/gain are saved in
> activeState. Then, when frame 4 is queued, they are stored in
> corresponding frameContext. Four frames later, frame 4 is captured,
> and after processing the stats buffer, exposure/gain are extracted
> from frameContext and queued to delayedControls in setControls(). On
> frame 5, delayedControls apply them. Assuming a control delay of 2, the
> settings will become effective for frame 7. So, it takes 7 frames for
> the AGC algorithm to get feedback. This results in suboptimal
> convergence rate.
>
> If we instead use just computed exposure/gain from the activeState in
> setControls, the delay is reduced from 7 frames to 3 frames. Tests
> on OV4689 sensor show faster convergence and no unwanted side effects.

Oops - forgot
Signed-off-by: Mikhail Rudenko <mike.rudenko at gmail.com>

> ---
>  src/ipa/rkisp1/rkisp1.cpp | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/src/ipa/rkisp1/rkisp1.cpp b/src/ipa/rkisp1/rkisp1.cpp
> index 680a7eee..8793d59f 100644
> --- a/src/ipa/rkisp1/rkisp1.cpp
> +++ b/src/ipa/rkisp1/rkisp1.cpp
> @@ -458,9 +458,11 @@ void IPARkISP1::setControls(unsigned int frame)
>  	 * internal sensor delays and other timing parameters into account.
>  	 */
>
> -	IPAFrameContext &frameContext = context_.frameContexts.get(frame);
> -	uint32_t exposure = frameContext.agc.exposure;
> -	uint32_t gain = context_.camHelper->gainCode(frameContext.agc.gain);
> +	const auto &agc = context_.activeState.agc;
> +	uint32_t exposure = agc.autoEnabled ?
> +			    agc.automatic.exposure : agc.manual.exposure;
> +	uint32_t gain = context_.camHelper->gainCode(agc.autoEnabled ?
> +						     agc.automatic.gain : agc.manual.gain);
>
>  	ControlList ctrls(sensorControls_);
>  	ctrls.set(V4L2_CID_EXPOSURE, static_cast<int32_t>(exposure));


--
Best regards,
Mikhail Rudenko