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

[Umang Jain]

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
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>
---
 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