[libcamera-devel] [PATCH v3 10/11] libcamera: ipu3: Add helper for parameter and statistic buffers

[Niklas Söderlund]

Add a helper class to aid in associating a parameter and statistic
buffer with each request queued to the pipeline. The helper helps with
tracking the state of the extra buffers and in completing the request
once all extra processing is done.

This change only adds the helper more work is needed to integrate it
with the pipeline and an IPA.

Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
Reviewed-by: Jacopo Mondi <jacopo at jmondi.org>
---
* Changes since v1
- Move mapping of buffers to IPA to the pipeline handler and a separate
  patch.
- Move all pipeline interactions out of helper.

* Changes since v2
- Add todo to remove dynamic memory allocation.
- Remove unused find(Request *request).
---
 src/libcamera/pipeline/ipu3/frames.cpp  | 129 ++++++++++++++++++++++++
 src/libcamera/pipeline/ipu3/frames.h    |  61 +++++++++++
 src/libcamera/pipeline/ipu3/meson.build |   1 +
 3 files changed, 191 insertions(+)
 create mode 100644 src/libcamera/pipeline/ipu3/frames.cpp
 create mode 100644 src/libcamera/pipeline/ipu3/frames.h

diff --git a/src/libcamera/pipeline/ipu3/frames.cpp b/src/libcamera/pipeline/ipu3/frames.cpp
new file mode 100644
index 0000000000000000..b7f7f0a6575714d9
--- /dev/null
+++ b/src/libcamera/pipeline/ipu3/frames.cpp
@@ -0,0 +1,129 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2020, Google Inc.
+ *
+ * frames.cpp - Intel IPU3 Frames helper
+ */
+
+#include "frames.h"
+
+#include <libcamera/buffer.h>
+#include <libcamera/request.h>
+
+#include "libcamera/internal/pipeline_handler.h"
+#include "libcamera/internal/v4l2_videodevice.h"
+
+namespace libcamera {
+
+LOG_DECLARE_CATEGORY(IPU3)
+
+IPU3Frames::IPU3Frames()
+	: nextId_(0)
+{
+}
+
+void IPU3Frames::init(const std::vector<std::unique_ptr<FrameBuffer>> &paramBuffers,
+		      const std::vector<std::unique_ptr<FrameBuffer>> &statBuffers)
+{
+	for (const std::unique_ptr<FrameBuffer> &buffer : paramBuffers)
+		availableParamBuffers_.push(buffer.get());
+
+	for (const std::unique_ptr<FrameBuffer> &buffer : statBuffers)
+		availableStatBuffers_.push(buffer.get());
+
+	nextId_ = 0;
+	frameInfo_.clear();
+}
+
+void IPU3Frames::clear()
+{
+	availableParamBuffers_ = {};
+	availableStatBuffers_ = {};
+}
+
+IPU3Frames::Info *IPU3Frames::create(Request *request)
+{
+	unsigned int id = nextId_++;
+
+	if (availableParamBuffers_.empty()) {
+		LOG(IPU3, Error) << "Parameters buffer underrun";
+		return nullptr;
+	}
+	FrameBuffer *paramBuffer = availableParamBuffers_.front();
+
+	if (availableStatBuffers_.empty()) {
+		LOG(IPU3, Error) << "Statisitc buffer underrun";
+		return nullptr;
+	}
+	FrameBuffer *statBuffer = availableStatBuffers_.front();
+
+	availableParamBuffers_.pop();
+	availableStatBuffers_.pop();
+
+	/* \todo Remove the dynamic allocation of Info */
+	std::unique_ptr<Info> info = std::make_unique<Info>();
+
+	info->id = id;
+	info->request = request;
+	info->rawBuffer = nullptr;
+	info->paramBuffer = paramBuffer;
+	info->statBuffer = statBuffer;
+	info->paramDequeued = false;
+	info->metadataProcessed = false;
+
+	frameInfo_[id] = std::move(info);
+
+	return frameInfo_[id].get();
+}
+
+bool IPU3Frames::tryComplete(IPU3Frames::Info *info)
+{
+	Request *request = info->request;
+
+	if (request->hasPendingBuffers())
+		return false;
+
+	if (!info->metadataProcessed)
+		return false;
+
+	if (!info->paramDequeued)
+		return false;
+
+	/* Return params and stat buffer for reuse. */
+	availableParamBuffers_.push(info->paramBuffer);
+	availableStatBuffers_.push(info->statBuffer);
+
+	/* Delete the extended frame information. */
+	frameInfo_.erase(info->id);
+
+	return true;
+}
+
+IPU3Frames::Info *IPU3Frames::find(unsigned int id)
+{
+	const auto &itInfo = frameInfo_.find(id);
+
+	if (itInfo != frameInfo_.end())
+		return itInfo->second.get();
+
+	return nullptr;
+}
+
+IPU3Frames::Info *IPU3Frames::find(FrameBuffer *buffer)
+{
+	for (auto const &itInfo : frameInfo_) {
+		Info *info = itInfo.second.get();
+
+		for (auto const itBuffers : info->request->buffers())
+			if (itBuffers.second == buffer)
+				return info;
+
+		if (info->rawBuffer == buffer || info->paramBuffer == buffer ||
+		    info->statBuffer == buffer)
+			return info;
+	}
+
+	return nullptr;
+}
+
+} /* namespace libcamera */
diff --git a/src/libcamera/pipeline/ipu3/frames.h b/src/libcamera/pipeline/ipu3/frames.h
new file mode 100644
index 0000000000000000..93379d20722d65fb
--- /dev/null
+++ b/src/libcamera/pipeline/ipu3/frames.h
@@ -0,0 +1,61 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2020, Google Inc.
+ *
+ * frames.h - Intel IPU3 Frames helper
+ */
+#ifndef __LIBCAMERA_PIPELINE_IPU3_FRAMES_H__
+#define __LIBCAMERA_PIPELINE_IPU3_FRAMES_H__
+
+#include <map>
+#include <memory>
+#include <queue>
+#include <vector>
+
+namespace libcamera {
+
+class FrameBuffer;
+class IPAProxy;
+class PipelineHandler;
+class Request;
+class V4L2VideoDevice;
+struct IPABuffer;
+
+class IPU3Frames
+{
+public:
+	struct Info {
+		unsigned int id;
+		Request *request;
+
+		FrameBuffer *rawBuffer;
+		FrameBuffer *paramBuffer;
+		FrameBuffer *statBuffer;
+
+		bool paramDequeued;
+		bool metadataProcessed;
+	};
+
+	IPU3Frames();
+
+	void init(const std::vector<std::unique_ptr<FrameBuffer>> &paramBuffers,
+		  const std::vector<std::unique_ptr<FrameBuffer>> &statBuffers);
+	void clear();
+
+	Info *create(Request *request);
+	bool tryComplete(IPU3Frames::Info *info);
+
+	Info *find(unsigned int id);
+	Info *find(FrameBuffer *buffer);
+
+private:
+	std::queue<FrameBuffer *> availableParamBuffers_;
+	std::queue<FrameBuffer *> availableStatBuffers_;
+
+	unsigned int nextId_;
+	std::map<unsigned int, std::unique_ptr<Info>> frameInfo_;
+};
+
+} /* namespace libcamera */
+
+#endif /* __LIBCAMERA_PIPELINE_IPU3_FRAMES_H__ */
diff --git a/src/libcamera/pipeline/ipu3/meson.build b/src/libcamera/pipeline/ipu3/meson.build
index d60e07ae6ccac2bc..a1b0b31ac5bcf864 100644
--- a/src/libcamera/pipeline/ipu3/meson.build
+++ b/src/libcamera/pipeline/ipu3/meson.build
@@ -2,6 +2,7 @@
 
 libcamera_sources += files([
     'cio2.cpp',
+    'frames.cpp',
     'imgu.cpp',
     'ipu3.cpp',
 ])
-- 
2.30.0