[libcamera-devel] [PATCH v4 6/9] android: camera_device: Allocate buffer pools

[Jacopo Mondi]

After the Camera has been configured, walk the list of collected
CameraStream instances and allocate memory for the ones that needs
intermediate buffers reserved by the libcamera FrameBufferAllocator.

Maintain a map between each Stream and a vector of pointers to the
associated buffers.

Reviewed-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
---
 src/android/camera_device.cpp | 36 +++++++++++++++++++++++++++++++++++
 src/android/camera_device.h   |  6 ++++++
 2 files changed, 42 insertions(+)

diff --git a/src/android/camera_device.cpp b/src/android/camera_device.cpp
index 8692771a4538..07041dd916d5 100644
--- a/src/android/camera_device.cpp
+++ b/src/android/camera_device.cpp
@@ -1191,6 +1191,7 @@ int CameraDevice::configureStreams(camera3_stream_configuration_t *stream_list)
 	streams_.clear();
 	streams_.reserve(stream_list->num_streams);
 	allocator_.freeAll();
+	bufferPool_.clear();
 
 	/* First handle all non-MJPEG streams. */
 	camera3_stream_t *jpegStream = nullptr;
@@ -1338,6 +1339,25 @@ int CameraDevice::configureStreams(camera3_stream_configuration_t *stream_list)
 		return ret;
 	}
 
+	/*
+	 * Now that the camera has been configured allocate buffers for
+	 * the streams that need memory reserved by libcamera.
+	 */
+	for (const CameraStream &cameraStream : streams_) {
+		const StreamConfiguration &cfg = config_->at(cameraStream.index());
+		Stream *stream = cfg.stream();
+
+		if (cameraStream.type() != CameraStream::Type::Internal)
+			continue;
+
+		ret = allocateBufferPool(stream);
+		if (ret) {
+			LOG(HAL, Error) << "Failed to allocate buffers for stream "
+					<< cameraStream.index();
+			return ret;
+		}
+	}
+
 	return 0;
 }
 
@@ -1371,6 +1391,22 @@ FrameBuffer *CameraDevice::createFrameBuffer(const buffer_handle_t camera3buffer
 	return new FrameBuffer(std::move(planes));
 }
 
+int CameraDevice::allocateBufferPool(Stream *stream)
+{
+	int ret = allocator_.allocate(stream);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * Save a pointer to the reserved frame buffer for usage in
+	 * the HAL.
+	 */
+	for (const auto &frameBuffer : allocator_.buffers(stream))
+		bufferPool_[stream].push_back(frameBuffer.get());
+
+	return 0;
+}
+
 int CameraDevice::processCaptureRequest(camera3_capture_request_t *camera3Request)
 {
 	if (!camera3Request->num_output_buffers) {
diff --git a/src/android/camera_device.h b/src/android/camera_device.h
index 75e3305089d9..c46610725e12 100644
--- a/src/android/camera_device.h
+++ b/src/android/camera_device.h
@@ -166,6 +166,9 @@ protected:
 	std::string logPrefix() const override;
 
 private:
+	using FrameBufferPool = std::map<libcamera::Stream *,
+					 std::vector<libcamera::FrameBuffer *>>;
+
 	CameraDevice(unsigned int id, const std::shared_ptr<libcamera::Camera> &camera);
 
 	struct Camera3RequestDescriptor {
@@ -194,6 +197,8 @@ private:
 
 	std::tuple<uint32_t, uint32_t> calculateStaticMetadataSize();
 	libcamera::FrameBuffer *createFrameBuffer(const buffer_handle_t camera3buffer);
+	int allocateBufferPool(libcamera::Stream *stream);
+
 	void notifyShutter(uint32_t frameNumber, uint64_t timestamp);
 	void notifyError(uint32_t frameNumber, camera3_stream_t *stream);
 	CameraMetadata *requestTemplatePreview();
@@ -208,6 +213,7 @@ private:
 	std::shared_ptr<libcamera::Camera> camera_;
 	std::unique_ptr<libcamera::CameraConfiguration> config_;
 	libcamera::FrameBufferAllocator allocator_;
+	FrameBufferPool bufferPool_;
 
 	CameraMetadata *staticMetadata_;
 	std::map<unsigned int, const CameraMetadata *> requestTemplates_;
-- 
2.28.0