[libcamera-devel] [PATCH v2 3/3] ipa: ipu3: Calculate frame duration from minimum VBLANK value

[paul.elder at ideasonboard.com]

Hi Umang,

On Tue, Jun 08, 2021 at 01:12:25PM +0530, Umang Jain wrote:
> Frame duration is hard-coded for CTS as per [1]. Ideally, to accurately
> calculate the frame duration, it needs the VBLANK value from every
> frame's exposure. However, this particular bit is yet to be implemented
> in IPAIPU3.
> 
> Meanwhile, we can atleast head in the right direction by not hard

s/atleast/at least/

> coding the value, instead using the default VBLANK value as reported
> by the sensor. Update the existing \todo, to use the derived VBLANK
> value as and when it's available from each frame exposure.
> 
> [1] 6c5f3fe6ced7 ("ipa: ipu3: Set output frame duration metadata")
> 
> Signed-off-by: Umang Jain <umang.jain at ideasonboard.com>
> Tested-by: Paul Elder <paul.elder at ideasonboard.com>
> Tested-by: Jean-Michel Hautbois <jeanmichel.hautbois at ideasonboard.com>
> Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> Reviewed-by: Jean-Michel Hautbois <jeanmichel.hautbois at ideasonboard.com>

Reviewed-by: Paul Elder <paul.elder at ideasonboard.com>

> ---
>  src/ipa/ipu3/ipu3.cpp | 16 +++++++++++++---
>  1 file changed, 13 insertions(+), 3 deletions(-)
> 
> diff --git a/src/ipa/ipu3/ipu3.cpp b/src/ipa/ipu3/ipu3.cpp
> index 97ddb863..415ea9e5 100644
> --- a/src/ipa/ipu3/ipu3.cpp
> +++ b/src/ipa/ipu3/ipu3.cpp
> @@ -66,6 +66,7 @@ private:
>  	IPACameraSensorInfo sensorInfo_;
>  
>  	/* Camera sensor controls. */
> +	uint32_t defVBlank_;
>  	uint32_t exposure_;
>  	uint32_t minExposure_;
>  	uint32_t maxExposure_;
> @@ -162,6 +163,12 @@ void IPAIPU3::configure(const IPAConfigInfo &configInfo)
>  		return;
>  	}
>  
> +	const auto itVBlank = ctrls_.find(V4L2_CID_VBLANK);
> +	if (itVBlank == ctrls_.end()) {
> +		LOG(IPAIPU3, Error) << "Can't find VBLANK control";
> +		return;
> +	}
> +
>  	minExposure_ = std::max(itExp->second.min().get<int32_t>(), 1);
>  	maxExposure_ = itExp->second.max().get<int32_t>();
>  	exposure_ = minExposure_;
> @@ -170,6 +177,8 @@ void IPAIPU3::configure(const IPAConfigInfo &configInfo)
>  	maxGain_ = itGain->second.max().get<int32_t>();
>  	gain_ = minGain_;
>  
> +	defVBlank_ = itVBlank->second.def().get<int32_t>();
> +
>  	params_ = {};
>  
>  	calculateBdsGrid(configInfo.bdsOutputSize);
> @@ -273,9 +282,10 @@ void IPAIPU3::parseStatistics(unsigned int frame,
>  	if (agcAlgo_->updateControls())
>  		setControls(frame);
>  
> -	/* \todo Populate this with real values */
> -	ctrls.set(controls::FrameDuration,
> -		  static_cast<int64_t>(33334));
> +	/* \todo Use VBlank value calculated from each frame exposure. */
> +	int64_t frameDuration = sensorInfo_.lineLength * (defVBlank_ + sensorInfo_.outputSize.height) /
> +				(sensorInfo_.pixelRate / 1e6);
> +	ctrls.set(controls::FrameDuration, frameDuration);
>  
>  	IPU3Action op;
>  	op.op = ActionMetadataReady;
> -- 
> 2.31.1
>