libcamera: Switch to FrameBuffer interface

Switch to the FrameBuffer interface where all buffers are treated as
external buffers and are allocated outside the camera. Applications
allocating buffers using libcamera are switched to use the
FrameBufferAllocator helper.

Follow-up changes to this one will finalize the transition to the new
FrameBuffer interface by removing code that is left unused after this
change.

Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

3 files changed, 55 insertions, 61 deletions

diff --git a/src/v4l2/v4l2_camera.cpp b/src/v4l2/v4l2_camera.cpp
index e4a03c41..10db15d6 100644
--- a/src/v4l2/v4l2_camera.cpp
+++ b/src/v4l2/v4l2_camera.cpp
@@ -16,24 +16,15 @@ using namespace libcamera;
 
 LOG_DECLARE_CATEGORY(V4L2Compat);
 
-V4L2FrameMetadata::V4L2FrameMetadata(Buffer *buffer)
-	: index_(buffer->index()),
-	  bytesused_(buffer->metadata().planes[0].bytesused),
-	  timestamp_(buffer->metadata().timestamp),
-	  sequence_(buffer->metadata().sequence),
-	  status_(buffer->metadata().status)
-{
-}
-
 V4L2Camera::V4L2Camera(std::shared_ptr<Camera> camera)
-	: camera_(camera), isRunning_(false)
+	: camera_(camera), isRunning_(false), bufferAllocator_(nullptr)
 {
 	camera_->requestCompleted.connect(this, &V4L2Camera::requestComplete);
 }
 
 V4L2Camera::~V4L2Camera()
 {
-	camera_->release();
+	close();
 }
 
 int V4L2Camera::open()
@@ -50,11 +41,16 @@ int V4L2Camera::open()
 		return -EINVAL;
 	}
 
+	bufferAllocator_ = FrameBufferAllocator::create(camera_);
+
 	return 0;
 }
 
 void V4L2Camera::close()
 {
+	delete bufferAllocator_;
+	bufferAllocator_ = nullptr;
+
 	camera_->release();
 }
 
@@ -63,12 +59,12 @@ void V4L2Camera::getStreamConfig(StreamConfiguration *streamConfig)
 	*streamConfig = config_->at(0);
 }
 
-std::vector<V4L2FrameMetadata> V4L2Camera::completedBuffers()
+std::vector<V4L2Camera::Buffer> V4L2Camera::completedBuffers()
 {
-	std::vector<V4L2FrameMetadata> v;
+	std::vector<Buffer> v;
 
 	bufferLock_.lock();
-	for (std::unique_ptr<V4L2FrameMetadata> &metadata : completedBuffers_)
+	for (std::unique_ptr<Buffer> &metadata : completedBuffers_)
 		v.push_back(*metadata.get());
 	completedBuffers_.clear();
 	bufferLock_.unlock();
@@ -83,9 +79,9 @@ void V4L2Camera::requestComplete(Request *request)
 
 	/* We only have one stream at the moment. */
 	bufferLock_.lock();
-	Buffer *buffer = request->buffers().begin()->second;
-	std::unique_ptr<V4L2FrameMetadata> metadata =
-		utils::make_unique<V4L2FrameMetadata>(buffer);
+	FrameBuffer *buffer = request->buffers().begin()->second;
+	std::unique_ptr<Buffer> metadata =
+		utils::make_unique<Buffer>(request->cookie(), buffer->metadata());
 	completedBuffers_.push_back(std::move(metadata));
 	bufferLock_.unlock();
 
@@ -126,18 +122,31 @@ int V4L2Camera::configure(StreamConfiguration *streamConfigOut,
 int V4L2Camera::allocBuffers(unsigned int count)
 {
 	int ret = camera_->allocateBuffers();
-	return ret == -EACCES ? -EBUSY : ret;
+	if (ret)
+		return ret == -EACCES ? -EBUSY : ret;
+
+	Stream *stream = *camera_->streams().begin();
+
+	return bufferAllocator_->allocate(stream);
 }
 
 void V4L2Camera::freeBuffers()
 {
+	Stream *stream = *camera_->streams().begin();
+	bufferAllocator_->free(stream);
 	camera_->freeBuffers();
 }
 
 FileDescriptor V4L2Camera::getBufferFd(unsigned int index)
 {
 	Stream *stream = *camera_->streams().begin();
-	return stream->buffers()[index].planes()[0].fd;
+	const std::vector<std::unique_ptr<FrameBuffer>> &buffers =
+		bufferAllocator_->buffers(stream);
+
+	if (buffers.size() <= index)
+		return FileDescriptor();
+
+	return buffers[index]->planes()[0].fd;
 }
 
 int V4L2Camera::streamOn()
@@ -180,21 +189,16 @@ int V4L2Camera::streamOff()
 
 int V4L2Camera::qbuf(unsigned int index)
 {
-	Stream *stream = config_->at(0).stream();
-	std::unique_ptr<Buffer> buffer = stream->createBuffer(index);
-	if (!buffer) {
-		LOG(V4L2Compat, Error) << "Can't create buffer";
-		return -ENOMEM;
-	}
-
 	std::unique_ptr<Request> request =
-		std::unique_ptr<Request>(camera_->createRequest());
+		std::unique_ptr<Request>(camera_->createRequest(index));
 	if (!request) {
 		LOG(V4L2Compat, Error) << "Can't create request";
 		return -ENOMEM;
 	}
 
-	int ret = request->addBuffer(stream, std::move(buffer));
+	Stream *stream = config_->at(0).stream();
+	FrameBuffer *buffer = bufferAllocator_->buffers(stream)[index].get();
+	int ret = request->addBuffer(stream, buffer);
 	if (ret < 0) {
 		LOG(V4L2Compat, Error) << "Can't set buffer for request";
 		return -ENOMEM;
diff --git a/src/v4l2/v4l2_camera.h b/src/v4l2/v4l2_camera.h
index 06eab0e1..f1f04d9e 100644
--- a/src/v4l2/v4l2_camera.h
+++ b/src/v4l2/v4l2_camera.h
@@ -9,50 +9,38 @@
 #define __V4L2_CAMERA_H__
 
 #include <deque>
-#include <linux/videodev2.h>
 #include <mutex>
+#include <utility>
 
 #include <libcamera/buffer.h>
 #include <libcamera/camera.h>
 #include <libcamera/file_descriptor.h>
+#include <libcamera/framebuffer_allocator.h>
 
 #include "semaphore.h"
 
 using namespace libcamera;
 
-class V4L2FrameMetadata
+class V4L2Camera : public Object
 {
 public:
-	V4L2FrameMetadata(Buffer *buffer);
-
-	int index() const { return index_; }
-
-	unsigned int bytesused() const { return bytesused_; }
-	uint64_t timestamp() const { return timestamp_; }
-	unsigned int sequence() const { return sequence_; }
-
-	FrameMetadata::Status status() const { return status_; }
-
-private:
-	int index_;
+	struct Buffer {
+		Buffer(unsigned int index, const FrameMetadata &data)
+			: index(index), data(data)
+		{
+		}
 
-	unsigned int bytesused_;
-	uint64_t timestamp_;
-	unsigned int sequence_;
+		unsigned int index;
+		FrameMetadata data;
+	};
 
-	FrameMetadata::Status status_;
-};
-
-class V4L2Camera : public Object
-{
-public:
 	V4L2Camera(std::shared_ptr<Camera> camera);
 	~V4L2Camera();
 
 	int open();
 	void close();
 	void getStreamConfig(StreamConfiguration *streamConfig);
-	std::vector<V4L2FrameMetadata> completedBuffers();
+	std::vector<Buffer> completedBuffers();
 
 	int configure(StreamConfiguration *streamConfigOut,
 		      const Size &size, PixelFormat pixelformat,
@@ -78,9 +66,10 @@ private:
 	bool isRunning_;
 
 	std::mutex bufferLock_;
+	FrameBufferAllocator *bufferAllocator_;
 
 	std::deque<std::unique_ptr<Request>> pendingRequests_;
-	std::deque<std::unique_ptr<V4L2FrameMetadata>> completedBuffers_;
+	std::deque<std::unique_ptr<Buffer>> completedBuffers_;
 };
 
 #endif /* __V4L2_CAMERA_H__ */
diff --git a/src/v4l2/v4l2_camera_proxy.cpp b/src/v4l2/v4l2_camera_proxy.cpp
index 5158eac4..28e58722 100644
--- a/src/v4l2/v4l2_camera_proxy.cpp
+++ b/src/v4l2/v4l2_camera_proxy.cpp
@@ -187,17 +187,18 @@ void V4L2CameraProxy::querycap(std::shared_ptr<Camera> camera)
 
 void V4L2CameraProxy::updateBuffers()
 {
-	std::vector<V4L2FrameMetadata> completedBuffers = vcam_->completedBuffers();
-	for (V4L2FrameMetadata &fmd : completedBuffers) {
-		struct v4l2_buffer &buf = buffers_[fmd.index()];
+	std::vector<V4L2Camera::Buffer> completedBuffers = vcam_->completedBuffers();
+	for (const V4L2Camera::Buffer &buffer : completedBuffers) {
+		const FrameMetadata &fmd = buffer.data;
+		struct v4l2_buffer &buf = buffers_[buffer.index];
 
-		switch (fmd.status()) {
+		switch (fmd.status) {
 		case FrameMetadata::FrameSuccess:
-			buf.bytesused = fmd.bytesused();
+			buf.bytesused = fmd.planes[0].bytesused;
 			buf.field = V4L2_FIELD_NONE;
-			buf.timestamp.tv_sec = fmd.timestamp() / 1000000000;
-			buf.timestamp.tv_usec = fmd.timestamp() % 1000000;
-			buf.sequence = fmd.sequence();
+			buf.timestamp.tv_sec = fmd.timestamp / 1000000000;
+			buf.timestamp.tv_usec = fmd.timestamp % 1000000;
+			buf.sequence = fmd.sequence;
 
 			buf.flags |= V4L2_BUF_FLAG_DONE;
 			break;