libcamera: converter: Add interface to support cropping capability

If the converter has cropping capability on its input, the interface
should support it by providing appropriate virtual functions. Provide
Feature::InputCrop in Feature enumeration for the same.

Provide virtual setInputCrop() and inputCropBounds() interfaces so that
the converter can implement its own cropping functionality.

The V4L2M2MConverter implements these interfaces of the Converter
interface. Not all V4L2M2M converters will have cropping ability
on its input, hence it needs to be discovered at construction time.
If the capability to crop is identified successfully, the cropping
bounds are determined during configure() time.

Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Stefan Klug <stefan.klug@ideasonboard.com>

2 files changed, 16 insertions, 0 deletions

diff --git a/include/libcamera/internal/converter.h b/include/libcamera/internal/converter.h
index 6623de4d..ffbb6f34 100644
--- a/include/libcamera/internal/converter.h
+++ b/include/libcamera/internal/converter.h
@@ -14,6 +14,7 @@
 #include <memory>
 #include <string>
 #include <tuple>
+#include <utility>
 #include <vector>
 
 #include <libcamera/base/class.h>
@@ -35,6 +36,7 @@ class Converter
 public:
 	enum class Feature {
 		None = 0,
+		InputCrop = (1 << 0),
 	};
 
 	using Features = Flags<Feature>;
@@ -63,6 +65,9 @@ public:
 	virtual int queueBuffers(FrameBuffer *input,
 				 const std::map<const Stream *, FrameBuffer *> &outputs) = 0;
 
+	virtual int setInputCrop(const Stream *stream, Rectangle *rect) = 0;
+	virtual std::pair<Rectangle, Rectangle> inputCropBounds(const Stream *stream) = 0;
+
 	Signal<FrameBuffer *> inputBufferReady;
 	Signal<FrameBuffer *> outputBufferReady;
 
diff --git a/include/libcamera/internal/converter/converter_v4l2_m2m.h b/include/libcamera/internal/converter/converter_v4l2_m2m.h
index b9e59899..0bc0d053 100644
--- a/include/libcamera/internal/converter/converter_v4l2_m2m.h
+++ b/include/libcamera/internal/converter/converter_v4l2_m2m.h
@@ -30,6 +30,7 @@ class Size;
 class SizeRange;
 class Stream;
 struct StreamConfiguration;
+class Rectangle;
 class V4L2M2MDevice;
 
 class V4L2M2MConverter : public Converter
@@ -57,6 +58,9 @@ public:
 	int queueBuffers(FrameBuffer *input,
 			 const std::map<const Stream *, FrameBuffer *> &outputs);
 
+	int setInputCrop(const Stream *stream, Rectangle *rect);
+	std::pair<Rectangle, Rectangle> inputCropBounds(const Stream *stream);
+
 private:
 	class V4L2M2MStream : protected Loggable
 	{
@@ -75,6 +79,11 @@ private:
 
 		int queueBuffers(FrameBuffer *input, FrameBuffer *output);
 
+		int setInputSelection(unsigned int target, Rectangle *rect);
+		int getInputSelection(unsigned int target, Rectangle *rect);
+
+		std::pair<Rectangle, Rectangle> inputCropBounds();
+
 	protected:
 		std::string logPrefix() const override;
 
@@ -88,6 +97,8 @@ private:
 
 		unsigned int inputBufferCount_;
 		unsigned int outputBufferCount_;
+
+		std::pair<Rectangle, Rectangle> inputCropBounds_;
 	};
 
 	std::unique_ptr<V4L2M2MDevice> m2m_;