[libcamera-devel] [PATCH 12/15] android: camera_stream: Add methods to get/put buffers

[Laurent Pinchart]

From: Jacopo Mondi <jacopo at jmondi.org>

Add two methods to the CameraStream class to get and put FrameBuffer
pointers from the pool of allocated buffers.

Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
---
 src/android/camera_stream.cpp | 35 +++++++++++++++++++++++++++++++++--
 src/android/camera_stream.h   |  4 ++++
 2 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/src/android/camera_stream.cpp b/src/android/camera_stream.cpp
index dbde1e786300..c4b727eee63e 100644
--- a/src/android/camera_stream.cpp
+++ b/src/android/camera_stream.cpp
@@ -19,21 +19,24 @@ LOG_DECLARE_CATEGORY(HAL);
 CameraStream::CameraStream(CameraDevice *cameraDev, Type type,
 			   camera3_stream_t *androidStream, unsigned int index)
 	: cameraDevice_(cameraDev), type_(type), androidStream_(androidStream),
-	  index_(index), encoder_(nullptr), allocator_(nullptr)
+	  index_(index), encoder_(nullptr), allocator_(nullptr), mutex_(nullptr)
 {
 	config_ = cameraDevice_->cameraConfiguration();
 
 	if (type_ == Type::Internal || type_ == Type::Mapped)
 		encoder_ = new EncoderLibJpeg();
 
-	if (type == Type::Internal)
+	if (type == Type::Internal) {
 		allocator_ = new FrameBufferAllocator(cameraDevice_->camera());
+		mutex_ = new std::mutex();
+	}
 }
 
 CameraStream::~CameraStream()
 {
 	delete encoder_;
 	delete allocator_;
+	delete mutex_;
 }
 
 const StreamConfiguration &CameraStream::streamConfiguration() const
@@ -135,3 +138,31 @@ int CameraStream::process(libcamera::FrameBuffer *source, MappedCamera3Buffer *d
 
 	return 0;
 }
+
+FrameBuffer *CameraStream::getBuffer()
+{
+	if (!allocator_)
+		return nullptr;
+
+	std::lock_guard<std::mutex> locker(*mutex_);
+
+	if (buffers_.empty()) {
+		LOG(HAL, Error) << "Buffer underrun";
+		return nullptr;
+	}
+
+	FrameBuffer *buffer = buffers_.back();
+	buffers_.pop_back();
+
+	return buffer;
+}
+
+void CameraStream::putBuffer(libcamera::FrameBuffer *buffer)
+{
+	if (!allocator_)
+		return;
+
+	std::lock_guard<std::mutex> locker(*mutex_);
+
+	buffers_.push_back(buffer);
+}
diff --git a/src/android/camera_stream.h b/src/android/camera_stream.h
index c6ff79230b7e..b79a97606c60 100644
--- a/src/android/camera_stream.h
+++ b/src/android/camera_stream.h
@@ -8,6 +8,7 @@
 #define __ANDROID_CAMERA_STREAM_H__
 
 #include <memory>
+#include <mutex>
 #include <vector>
 
 #include <hardware/camera3.h>
@@ -127,6 +128,8 @@ public:
 	int process(libcamera::FrameBuffer *source,
 		    MappedCamera3Buffer *dest,
 		    CameraMetadata *metadata);
+	libcamera::FrameBuffer *getBuffer();
+	void putBuffer(libcamera::FrameBuffer *buffer);
 
 private:
 	CameraDevice *cameraDevice_;
@@ -143,6 +146,7 @@ private:
 	Encoder *encoder_;
 	libcamera::FrameBufferAllocator *allocator_;
 	std::vector<libcamera::FrameBuffer *> buffers_;
+	std::mutex *mutex_;
 };
 
 #endif /* __ANDROID_CAMERA_STREAM__ */
-- 
Regards,

Laurent Pinchart