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>

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;