[libcamera-devel] [PATCH] camera_sensor: Add minimum and maximum line length to IPACameraSensorInfo

Naushir Patuck naush at raspberrypi.com
Mon Oct 10 09:42:32 CEST 2022


Add fields for minimum and maximum line length (in units of pixels) to the
IPACameraSensorInfo structure. This replaces the existing lineLength field.

Update the ipu3, raspberrypi and rkisp1 IPAs to use IPACameraSensorInfo::minLineLength
instead of IPACameraSensorInfo::lineLength, as logically we will always want to
use the fastest sensor readout by default.

Since the IPAs now use minLineLength for their calculations, set the starting
value of the V4L2_CID_HBLANK control to its minimum in CameraSensor::init().

Signed-off-by: Naushir Patuck <naush at raspberrypi.com>
Tested-by: Dave Stevenson <dave.stevenson at raspberrypi.com>
---
 include/libcamera/ipa/core.mojom    | 21 +++++++++++++------
 src/ipa/ipu3/ipu3.cpp               |  6 ++++--
 src/ipa/raspberrypi/raspberrypi.cpp |  2 +-
 src/ipa/rkisp1/rkisp1.cpp           |  2 +-
 src/libcamera/camera_sensor.cpp     | 32 +++++++++++++++++++++++++++--
 5 files changed, 51 insertions(+), 12 deletions(-)

diff --git a/include/libcamera/ipa/core.mojom b/include/libcamera/ipa/core.mojom
index 74f3339e56f2..2bc3028c22d6 100644
--- a/include/libcamera/ipa/core.mojom
+++ b/include/libcamera/ipa/core.mojom
@@ -172,10 +172,17 @@ module libcamera;
  */
 
 /**
- * \var IPACameraSensorInfo::lineLength
- * \brief Total line length in pixels
+ * \var IPACameraSensorInfo::minLineLength
+ * \brief The minimum line length in pixels
  *
- * The total line length in pixel clock periods, including blanking.
+ * The minimum allowable line length in pixel clock periods, including blanking.
+ */
+
+/**
+ * \var IPACameraSensorInfo::maxLineLength
+ * \brief The maximum line length in pixels
+ *
+ * The maximum allowable line length in pixel clock periods, including blanking.
  */
 
 /**
@@ -189,7 +196,7 @@ module libcamera;
  * To obtain the minimum frame duration:
  *
  * \verbatim
-       frameDuration(s) = minFrameLength(lines) * lineLength(pixels) / pixelRate(pixels per second)
+       frameDuration(s) = minFrameLength(lines) * minLineLength(pixels) / pixelRate(pixels per second)
    \endverbatim
  */
 
@@ -204,7 +211,7 @@ module libcamera;
  * To obtain the maximum frame duration:
  *
  * \verbatim
-       frameDuration(s) = maxFrameLength(lines) * lineLength(pixels) / pixelRate(pixels per second)
+       frameDuration(s) = maxFrameLength(lines) * maxLineLength(pixels) / pixelRate(pixels per second)
    \endverbatim
  */
 struct IPACameraSensorInfo {
@@ -217,7 +224,9 @@ struct IPACameraSensorInfo {
 	Size outputSize;
 
 	uint64 pixelRate;
-	uint32 lineLength;
+
+	uint32 minLineLength;
+	uint32 maxLineLength;
 
 	uint32 minFrameLength;
 	uint32 maxFrameLength;
diff --git a/src/ipa/ipu3/ipu3.cpp b/src/ipa/ipu3/ipu3.cpp
index b93a09d40c39..c89f76c56ee3 100644
--- a/src/ipa/ipu3/ipu3.cpp
+++ b/src/ipa/ipu3/ipu3.cpp
@@ -336,7 +336,8 @@ int IPAIPU3::init(const IPASettings &settings,
 
 	/* Clean context */
 	context_.configuration = {};
-	context_.configuration.sensor.lineDuration = sensorInfo.lineLength * 1.0s / sensorInfo.pixelRate;
+	context_.configuration.sensor.lineDuration = sensorInfo.minLineLength
+						   * 1.0s / sensorInfo.pixelRate;
 
 	/* Load the tuning data file. */
 	File file(settings.configurationFile);
@@ -499,7 +500,8 @@ int IPAIPU3::configure(const IPAConfigInfo &configInfo,
 	context_.frameContexts.clear();
 
 	/* Initialise the sensor configuration. */
-	context_.configuration.sensor.lineDuration = sensorInfo_.lineLength * 1.0s / sensorInfo_.pixelRate;
+	context_.configuration.sensor.lineDuration = sensorInfo_.minLineLength
+						   * 1.0s / sensorInfo_.pixelRate;
 
 	/*
 	 * Compute the sensor V4L2 controls to be used by the algorithms and
diff --git a/src/ipa/raspberrypi/raspberrypi.cpp b/src/ipa/raspberrypi/raspberrypi.cpp
index 8d731435764e..358a119da222 100644
--- a/src/ipa/raspberrypi/raspberrypi.cpp
+++ b/src/ipa/raspberrypi/raspberrypi.cpp
@@ -356,7 +356,7 @@ void IPARPi::setMode(const IPACameraSensorInfo &sensorInfo)
 	 * Calculate the line length as the ratio between the line length in
 	 * pixels and the pixel rate.
 	 */
-	mode_.lineLength = sensorInfo.lineLength * (1.0s / sensorInfo.pixelRate);
+	mode_.lineLength = sensorInfo.minLineLength * (1.0s / sensorInfo.pixelRate);
 
 	/*
 	 * Set the frame length limits for the mode to ensure exposure and
diff --git a/src/ipa/rkisp1/rkisp1.cpp b/src/ipa/rkisp1/rkisp1.cpp
index 32feb1682749..ddb22d98eb41 100644
--- a/src/ipa/rkisp1/rkisp1.cpp
+++ b/src/ipa/rkisp1/rkisp1.cpp
@@ -246,7 +246,7 @@ int IPARkISP1::configure([[maybe_unused]] const IPACameraSensorInfo &info,
 	context_.configuration.hw.revision = hwRevision_;
 
 	context_.configuration.sensor.size = info.outputSize;
-	context_.configuration.sensor.lineDuration = info.lineLength * 1.0s / info.pixelRate;
+	context_.configuration.sensor.lineDuration = info.minLineLength * 1.0s / info.pixelRate;
 
 	/*
 	 * When the AGC computes the new exposure values for a frame, it needs
diff --git a/src/libcamera/camera_sensor.cpp b/src/libcamera/camera_sensor.cpp
index 911fd0beae4e..572a313a8f99 100644
--- a/src/libcamera/camera_sensor.cpp
+++ b/src/libcamera/camera_sensor.cpp
@@ -176,6 +176,32 @@ int CameraSensor::init()
 	if (ret)
 		return ret;
 
+	/*
+	 * Set HBLANK to the minimum to start with a well-defined line length,
+	 * allowing IPA modules that do not modify HBLANK to use the sensor
+	 * minimum line length in their calculations.
+	 *
+	 * At present, there is no way of knowing if a control is read-only.
+	 * As a workaround, assume that if the minimum and maximum values of
+	 * the V4L2_CID_HBLANK control are the same, it implies the control
+	 * is read-only.
+	 *
+	 * \todo The control API ought to have a flag to specify if a control
+	 * is read-only which could be used below.
+	 */
+	const ControlInfo hblank = ctrls.infoMap()->at(V4L2_CID_HBLANK);
+	const int32_t hblankMin = hblank.min().get<int32_t>();
+	const int32_t hblankMax = hblank.max().get<int32_t>();
+
+	if (hblankMin != hblankMax) {
+		ControlList ctrl(subdev_->controls());
+
+		ctrl.set(V4L2_CID_HBLANK, hblankMin);
+		ret = subdev_->setControls(&ctrl);
+		if (ret)
+			return ret;
+	}
+
 	return applyTestPatternMode(controls::draft::TestPatternModeEnum::TestPatternModeOff);
 }
 
@@ -883,10 +909,12 @@ int CameraSensor::sensorInfo(IPACameraSensorInfo *info) const
 		return -EINVAL;
 	}
 
-	int32_t hblank = ctrls.get(V4L2_CID_HBLANK).get<int32_t>();
-	info->lineLength = info->outputSize.width + hblank;
 	info->pixelRate = ctrls.get(V4L2_CID_PIXEL_RATE).get<int64_t>();
 
+	const ControlInfo hblank = ctrls.infoMap()->at(V4L2_CID_HBLANK);
+	info->minLineLength = info->outputSize.width + hblank.min().get<int32_t>();
+	info->maxLineLength = info->outputSize.width + hblank.max().get<int32_t>();
+
 	const ControlInfo vblank = ctrls.infoMap()->at(V4L2_CID_VBLANK);
 	info->minFrameLength = info->outputSize.height + vblank.min().get<int32_t>();
 	info->maxFrameLength = info->outputSize.height + vblank.max().get<int32_t>();
-- 
2.25.1



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