test: camera: Add buffer import and mapping test

Test buffer importing and mapping by streaming the VIMC camera to VIVID
video output device performing zero-copy memory sharing using dmabuf
file descriptors.

The test cycle 20 buffers between the camera and the output with a 1:1
buffer index to dmabuf fd mapping, then randomises the mapping with the
same number of buffers on each side for 20 more frames, to finally
increase the number of buffers on the output side for the 20 last
frames. No remapping of dmabuf fd to buffer index should occur for the
first 40 frames.

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

2 files changed, 426 insertions, 0 deletions

diff --git a/test/camera/buffer_import.cpp b/test/camera/buffer_import.cpp
new file mode 100644
index 00000000..d6e4fd5b
--- /dev/null
+++ b/test/camera/buffer_import.cpp
@@ -0,0 +1,425 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2019, Google Inc.
+ *
+ * libcamera Camera API tests
+ *
+ * Test importing buffers exported from the VIVID output device into a Camera
+ */
+
+#include <algorithm>
+#include <iostream>
+#include <numeric>
+#include <random>
+#include <vector>
+
+#include "device_enumerator.h"
+#include "media_device.h"
+#include "v4l2_videodevice.h"
+
+#include "camera_test.h"
+
+using namespace libcamera;
+
+/* Keep SINK_BUFFER_COUNT > CAMERA_BUFFER_COUNT + 1 */
+static constexpr unsigned int SINK_BUFFER_COUNT = 8;
+static constexpr unsigned int CAMERA_BUFFER_COUNT = 4;
+
+class FrameSink
+{
+public:
+	int init()
+	{
+		int ret;
+
+		/* Locate and open the video device. */
+		std::string videoDeviceName = "vivid-000-vid-out";
+
+		std::unique_ptr<DeviceEnumerator> enumerator =
+			DeviceEnumerator::create();
+		if (!enumerator) {
+			std::cout << "Failed to create device enumerator" << std::endl;
+			return TestFail;
+		}
+
+		if (enumerator->enumerate()) {
+			std::cout << "Failed to enumerate media devices" << std::endl;
+			return TestFail;
+		}
+
+		DeviceMatch dm("vivid");
+		dm.add(videoDeviceName);
+
+		media_ = enumerator->search(dm);
+		if (!media_) {
+			std::cout << "No vivid output device available" << std::endl;
+			return TestSkip;
+		}
+
+		video_ = V4L2VideoDevice::fromEntityName(media_.get(), videoDeviceName);
+		if (!video_) {
+			std::cout << "Unable to open " << videoDeviceName << std::endl;
+			return TestFail;
+		}
+
+		if (video_->open())
+			return TestFail;
+
+		/* Configure the format. */
+		ret = video_->getFormat(&format_);
+		if (ret) {
+			std::cout << "Failed to get format on output device" << std::endl;
+			return ret;
+		}
+
+		format_.size.width = 640;
+		format_.size.height = 480;
+		format_.fourcc = V4L2_PIX_FMT_RGB24;
+		format_.planesCount = 1;
+		format_.planes[0].size = 640 * 480 * 3;
+		format_.planes[0].bpl = 640 * 3;
+
+		if (video_->setFormat(&format_)) {
+			cleanup();
+			return TestFail;
+		}
+
+		/* Export the buffers to a pool. */
+		pool_.createBuffers(SINK_BUFFER_COUNT);
+		ret = video_->exportBuffers(&pool_);
+		if (ret) {
+			std::cout << "Failed to export buffers" << std::endl;
+			cleanup();
+			return TestFail;
+		}
+
+		/* Only use the first CAMERA_BUFFER_COUNT buffers to start with. */
+		availableBuffers_.resize(CAMERA_BUFFER_COUNT);
+		std::iota(availableBuffers_.begin(), availableBuffers_.end(), 0);
+
+		/* Connect the buffer ready signal. */
+		video_->bufferReady.connect(this, &FrameSink::bufferComplete);
+
+		return TestPass;
+	}
+
+	void cleanup()
+	{
+		if (video_) {
+			video_->streamOff();
+			video_->releaseBuffers();
+			video_->close();
+			delete video_;
+		}
+
+		if (media_)
+			media_->release();
+	}
+
+	int start()
+	{
+		requestsCount_ = 0;
+		done_ = false;
+
+		int ret = video_->streamOn();
+		if (ret < 0)
+			return ret;
+
+		/* Queue all the initial requests. */
+		for (unsigned int index = 0; index < CAMERA_BUFFER_COUNT; ++index)
+			queueRequest(index);
+
+		return 0;
+	}
+
+	int stop()
+	{
+		return video_->streamOff();
+	}
+
+	void requestComplete(uint64_t cookie, const Buffer *metadata)
+	{
+		unsigned int index = cookie;
+
+		Buffer *buffer = new Buffer(index, metadata);
+		int ret = video_->queueBuffer(buffer);
+		if (ret < 0)
+			std::cout << "Failed to queue buffer to sink" << std::endl;
+	}
+
+	bool done() const { return done_; }
+	const V4L2DeviceFormat &format() const { return format_; }
+
+	Signal<uint64_t, int> requestReady;
+
+private:
+	void queueRequest(unsigned int index)
+	{
+		auto it = std::find(availableBuffers_.begin(),
+				    availableBuffers_.end(), index);
+		availableBuffers_.erase(it);
+
+		uint64_t cookie = index;
+		BufferMemory &mem = pool_.buffers()[index];
+		int dmabuf = mem.planes()[0].dmabuf();
+
+		requestReady.emit(cookie, dmabuf);
+
+		requestsCount_++;
+	}
+
+	void bufferComplete(Buffer *buffer)
+	{
+		availableBuffers_.push_back(buffer->index());
+
+		/*
+		 * Pick the buffer for the next request among the available
+		 * buffers.
+		 *
+		 * For the first 20 frames, select the buffer that has just
+		 * completed to keep the mapping of dmabuf fds to buffers
+		 * unchanged in the camera.
+		 *
+		 * For the next 20 frames, cycle randomly over the available
+		 * buffers. The mapping should still be kept unchanged, as the
+		 * camera should map using the cached fds.
+		 *
+		 * For the last 20 frames, cycles through all buffers, which
+		 * should trash the mappings.
+		 */
+		unsigned int index = buffer->index();
+		delete buffer;
+
+		std::cout << "Completed buffer, request=" << requestsCount_
+			  << ", available buffers=" << availableBuffers_.size()
+			  << std::endl;
+
+		if (requestsCount_ >= 60) {
+			if (availableBuffers_.size() == SINK_BUFFER_COUNT)
+				done_ = true;
+			return;
+		}
+
+		if (requestsCount_ == 40) {
+			/* Add the remaining of the buffers. */
+			for (unsigned int i = CAMERA_BUFFER_COUNT;
+			     i < SINK_BUFFER_COUNT; ++i)
+				availableBuffers_.push_back(i);
+		}
+
+		if (requestsCount_ >= 20) {
+			/*
+			 * Wait until we have enough buffers to make this
+			 * meaningful. Preferably half of the camera buffers,
+			 * but no less than 2 in any case.
+			 */
+			const unsigned int min_pool_size =
+				std::min(CAMERA_BUFFER_COUNT / 2, 2U);
+			if (availableBuffers_.size() < min_pool_size)
+				return;
+
+			/* Pick a buffer at random. */
+			unsigned int pos = random_() % availableBuffers_.size();
+			index = availableBuffers_[pos];
+		}
+
+		queueRequest(index);
+	}
+
+	std::shared_ptr<MediaDevice> media_;
+	V4L2VideoDevice *video_;
+	BufferPool pool_;
+	V4L2DeviceFormat format_;
+
+	unsigned int requestsCount_;
+	std::vector<int> availableBuffers_;
+	std::random_device random_;
+
+	bool done_;
+};
+
+class BufferImportTest : public CameraTest
+{
+public:
+	BufferImportTest()
+		: CameraTest()
+	{
+	}
+
+	void queueRequest(uint64_t cookie, int dmabuf)
+	{
+		Request *request = camera_->createRequest(cookie);
+
+		std::unique_ptr<Buffer> buffer = stream_->createBuffer({ dmabuf, -1, -1 });
+		request->addBuffer(move(buffer));
+		camera_->queueRequest(request);
+	}
+
+protected:
+	void bufferComplete(Request *request, Buffer *buffer)
+	{
+		if (buffer->status() != Buffer::BufferSuccess)
+			return;
+
+		unsigned int index = buffer->index();
+		int dmabuf = buffer->dmabufs()[0];
+
+		/* Record dmabuf to index remappings. */
+		bool remapped = false;
+		if (bufferMappings_.find(index) != bufferMappings_.end()) {
+			if (bufferMappings_[index] != dmabuf)
+				remapped = true;
+		}
+
+		std::cout << "Completed request " << framesCaptured_
+			  << ": dmabuf fd " << dmabuf
+			  << " -> index " << index
+			  << " (" << (remapped ? 'R' : '-') << ")"
+			  << std::endl;
+
+		if (remapped)
+			bufferRemappings_.push_back(framesCaptured_);
+
+		bufferMappings_[index] = dmabuf;
+		framesCaptured_++;
+
+		sink_.requestComplete(request->cookie(), buffer);
+
+		if (framesCaptured_ == 60)
+			sink_.stop();
+	}
+
+	int initCamera()
+	{
+		if (camera_->acquire()) {
+			std::cout << "Failed to acquire the camera" << std::endl;
+			return TestFail;
+		}
+
+		/*
+		 * Configure the Stream to work with externally allocated
+		 * buffers by setting the memoryType to ExternalMemory.
+		 */
+		std::unique_ptr<CameraConfiguration> config;
+		config = camera_->generateConfiguration({ StreamRole::VideoRecording });
+		if (!config || config->size() != 1) {
+			std::cout << "Failed to generate configuration" << std::endl;
+			return TestFail;
+		}
+
+		const V4L2DeviceFormat &format = sink_.format();
+
+		StreamConfiguration &cfg = config->at(0);
+		cfg.size = format.size;
+		cfg.pixelFormat = format.fourcc;
+		cfg.bufferCount = CAMERA_BUFFER_COUNT;
+		cfg.memoryType = ExternalMemory;
+
+		if (camera_->configure(config.get())) {
+			std::cout << "Failed to set configuration" << std::endl;
+			return TestFail;
+		}
+
+		stream_ = cfg.stream();
+
+		/* Allocate buffers. */
+		if (camera_->allocateBuffers()) {
+			std::cout << "Failed to allocate buffers" << std::endl;
+			return TestFail;
+		}
+
+		/* Connect the buffer completed signal. */
+		camera_->bufferCompleted.connect(this, &BufferImportTest::bufferComplete);
+
+		return TestPass;
+	}
+
+	int init()
+	{
+		int ret = CameraTest::init();
+		if (ret)
+			return ret;
+
+		ret = sink_.init();
+		if (ret != TestPass) {
+			cleanup();
+			return ret;
+		}
+
+		ret = initCamera();
+		if (ret != TestPass) {
+			cleanup();
+			return ret;
+		}
+
+		sink_.requestReady.connect(this, &BufferImportTest::queueRequest);
+		return TestPass;
+	}
+
+	int run()
+	{
+		int ret;
+
+		framesCaptured_ = 0;
+
+		if (camera_->start()) {
+			std::cout << "Failed to start camera" << std::endl;
+			return TestFail;
+		}
+
+		ret = sink_.start();
+		if (ret < 0) {
+			std::cout << "Failed to start sink" << std::endl;
+			return TestFail;
+		}
+
+		EventDispatcher *dispatcher = CameraManager::instance()->eventDispatcher();
+
+		Timer timer;
+		timer.start(3000);
+		while (timer.isRunning() && !sink_.done())
+			dispatcher->processEvents();
+
+		std::cout << framesCaptured_ << " frames captured, "
+			  << bufferRemappings_.size() << " buffers remapped"
+			  << std::endl;
+
+		if (framesCaptured_ < 60) {
+			std::cout << "Too few frames captured" << std::endl;
+			return TestFail;
+		}
+
+		if (bufferRemappings_.empty()) {
+			std::cout << "No buffer remappings" << std::endl;
+			return TestFail;
+		}
+
+		if (bufferRemappings_[0] < 40) {
+			std::cout << "Early buffer remapping" << std::endl;
+			return TestFail;
+		}
+
+		return TestPass;
+	}
+
+	void cleanup()
+	{
+		sink_.cleanup();
+
+		camera_->stop();
+		camera_->freeBuffers();
+
+		CameraTest::cleanup();
+	}
+
+private:
+	Stream *stream_;
+
+	std::map<unsigned int, int> bufferMappings_;
+	std::vector<unsigned int> bufferRemappings_;
+	unsigned int framesCaptured_;
+
+	FrameSink sink_;
+};
+
+TEST_REGISTER(BufferImportTest);
diff --git a/test/camera/meson.build b/test/camera/meson.build
index 35e97ce5..d6fd66b8 100644
--- a/test/camera/meson.build
+++ b/test/camera/meson.build
@@ -3,6 +3,7 @@
 camera_tests = [
     [ 'configuration_default',  'configuration_default.cpp' ],
     [ 'configuration_set',      'configuration_set.cpp' ],
+    [ 'buffer_import',          'buffer_import.cpp' ],
     [ 'statemachine',           'statemachine.cpp' ],
     [ 'capture',                'capture.cpp' ],
 ]