pipeline: rkisp1: Filter out sensor sizes not supported by the pipeline

It is possible that the maximum sensor size (returned by
CameraSensor::resolution()) is not supported by the pipeline. In such
cases, a filter function is required to filter out resolutions of the
camera sensor, which cannot be supported by the pipeline.

Introduce the filter function filterSensorResolution() in RkISP1Path
class and use it for validate() and generateConfiguration(). The
maximum sensor resolution is picked from that filtered set of
resolutions instead of CameraSensor::resolution().

Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Tested-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>

Author: Umang Jain

src/libcamera/pipeline/rkisp1/rkisp1_path.cpp

@@ -123,12 +123,50 @@ void RkISP1Path::populateFormats()
 	}
 }
 
+/**
+ * \brief Filter the sensor resolutions that can be supported
+ * \param[in] sensor The camera sensor
+ *
+ * This function retrieves all the sizes supported by the sensor and
+ * filters all the resolutions that can be supported on the pipeline.
+ * It is possible that the sensor's maximum output resolution is higher
+ * than the ISP maximum input. In that case, this function filters out all
+ * the resolution incapable of being supported and returns the maximum
+ * sensor resolution that can be supported by the pipeline.
+ *
+ * \return Maximum sensor size supported on the pipeline
+ */
+Size RkISP1Path::filterSensorResolution(const CameraSensor *sensor)
+{
+	auto iter = sensorSizesMap_.find(sensor);
+	if (iter != sensorSizesMap_.end())
+		return iter->second.back();
+
+	std::vector<Size> &sizes = sensorSizesMap_[sensor];
+	for (unsigned int code : sensor->mbusCodes()) {
+		for (const Size &size : sensor->sizes(code)) {
+			if (size.width > maxResolution_.width ||
+			    size.height > maxResolution_.height)
+				continue;
+
+			sizes.push_back(size);
+		}
+	}
+
+	/* Sort in increasing order and remove duplicates. */
+	std::sort(sizes.begin(), sizes.end());
+	auto last = std::unique(sizes.begin(), sizes.end());
+	sizes.erase(last, sizes.end());
+
+	return sizes.back();
+}
+
 StreamConfiguration
 RkISP1Path::generateConfiguration(const CameraSensor *sensor, const Size &size,
 				  StreamRole role)
 {
 	const std::vector<unsigned int> &mbusCodes = sensor->mbusCodes();
-	const Size &resolution = sensor->resolution();
+	Size resolution = filterSensorResolution(sensor);
 
 	/* Min and max resolutions to populate the available stream formats. */
 	Size maxResolution = maxResolution_.boundedToAspectRatio(resolution)
@@ -217,7 +255,7 @@ CameraConfiguration::Status RkISP1Path::validate(const CameraSensor *sensor,
 						 StreamConfiguration *cfg)
 {
 	const std::vector<unsigned int> &mbusCodes = sensor->mbusCodes();
-	const Size &resolution = sensor->resolution();
+	Size resolution = filterSensorResolution(sensor);
 
 	const StreamConfiguration reqCfg = *cfg;
 	CameraConfiguration::Status status = CameraConfiguration::Valid;

src/libcamera/pipeline/rkisp1/rkisp1_path.h

@@ -7,6 +7,7 @@
 
 #pragma once
 
+#include <map>
 #include <memory>
 #include <set>
 #include <vector>
@@ -62,6 +63,7 @@ class RkISP1Path
 
 private:
 	void populateFormats();
+	Size filterSensorResolution(const CameraSensor *sensor);
 
 	static constexpr unsigned int RKISP1_BUFFER_COUNT = 4;
 
@@ -76,6 +78,12 @@ class RkISP1Path
 	std::unique_ptr<V4L2Subdevice> resizer_;
 	std::unique_ptr<V4L2VideoDevice> video_;
 	MediaLink *link_;
+
+	/*
+	 * Map from camera sensors to the sizes (in increasing order),
+	 * which are guaranteed to be supported by the pipeline.
+	 */
+	std::map<const CameraSensor *, std::vector<Size>> sensorSizesMap_;
 };
 
 class RkISP1MainPath : public RkISP1Path