fml13v01-buildroot/package/starfive/libcamera-apps/0008-In-DRM-preview-zoom-the-input-image-to-fit-the-scree.patch

From 526cbca855ea6310dc846cc05158d403aea456e1 Mon Sep 17 00:00:00 2001
From: "zejian.su" <zejian.su@starfivetech.com>
Date: Mon, 27 Nov 2023 18:02:17 +0800
Subject: [PATCH 1/2] In DRM preview, zoom the input image to fit the screen.

1. Use the atomic drm mode.
2. Find a mode in the connector with most closed area with the input image.
3. Set the plane property to scale the input image.

Signed-off-by: zejian.su <zejian.su@starfivetech.com>
---
 preview/drm_preview.cpp | 184 ++++++++++++++++++++++++++++++++--------
 1 file changed, 147 insertions(+), 37 deletions(-)

diff --git a/preview/drm_preview.cpp b/preview/drm_preview.cpp
index 38fc6a2..405bdca 100644
--- a/preview/drm_preview.cpp
+++ b/preview/drm_preview.cpp
@@ -17,6 +17,92 @@
 
 #include "preview.hpp"
 
+class DRMObject
+{
+public:
+	DRMObject(int drmfd, uint32_t id, uint32_t type) 
+		: id_(id), type_(type){
+		drmModeObjectProperties *properties = drmModeObjectGetProperties(drmfd, id, type);
+		if (!properties)
+			return;
+
+		drmModePropertyPtr property;
+		for (uint32_t i = 0; i < properties->count_props; i++) {
+			property = drmModeGetProperty(drmfd, properties->props[i]);
+			property_[std::string(property->name)] = property->prop_id;
+			drmModeFreeProperty(property);
+		}
+
+		drmModeFreeObjectProperties(properties);
+	}
+
+	uint32_t getID() const {return id_;};
+
+public:
+	std::unordered_map<std::string, uint32_t> property_;
+
+private:
+	uint32_t id_;
+	uint32_t type_;
+};
+
+class AtomicRequest
+{
+public:
+	enum Flags {
+		FlagAllowModeset = (1 << 0),
+		FlagAsync = (1 << 1),
+		FlagTestOnly = (1 << 2),
+	};
+
+	AtomicRequest() : valid_(true) {
+		request_ = drmModeAtomicAlloc();
+		if (!request_)
+			valid_ = false;
+	}
+
+	~AtomicRequest() {
+		if (request_)
+			drmModeAtomicFree(request_);
+	}
+
+	bool isValid() const { return valid_; }
+
+	int addProperty(int drmfd, const DRMObject *object, const std::string &propertyName,
+			uint64_t value) {
+
+		if (!valid_)
+			return -EINVAL;
+		
+		auto it = object->property_.find(propertyName);
+		if(it == object->property_.end())
+			return -EINVAL;
+
+		if(drmModeAtomicAddProperty(request_, object->getID(), it->second, value) < 0) {
+			std::string errMsg = "drmModeAtomicAddProperty() failed -- object: " +
+				std::to_string(object->getID()) + ", property: " + std::to_string(it->second);
+			throw std::runtime_error(errMsg);
+		}
+
+		return 0;
+	}
+	
+	int commit(int drmfd, unsigned int flags = 0) {
+		if(drmModeAtomicCommit(drmfd, request_, flags, NULL) < 0)
+			throw std::runtime_error("drmModeAtomicCommit() failed");
+		return 0;
+	}
+
+private:
+	AtomicRequest(const AtomicRequest &) = delete;
+	AtomicRequest(const AtomicRequest &&) = delete;
+	AtomicRequest &operator=(const AtomicRequest &) = delete;
+	AtomicRequest &operator=(const AtomicRequest &&) = delete;
+
+	bool valid_;
+	drmModeAtomicReq *request_;
+};
+
 class DrmPreview : public Preview
 {
 public:
@@ -48,6 +134,7 @@ private:
 	void makeBuffer(int fd, size_t size, StreamInfo const &info, Buffer &buffer);
 	void findCrtc();
 	void findPlane();
+	void fitDisplaySize();
 	int drmfd_;
 	int conId_;
 	drmModeConnector *con_;
@@ -61,11 +148,18 @@ private:
 	unsigned int height_;
 	unsigned int screen_width_;
 	unsigned int screen_height_;
+	unsigned int display_x_;
+	unsigned int display_y_;
+	unsigned int display_w_;
+	unsigned int display_h_;
 	std::map<int, Buffer> buffers_; // map the DMABUF's fd to the Buffer
 	int last_fd_;
 	unsigned int max_image_width_;
 	unsigned int max_image_height_;
 	bool first_time_;
+
+	std::unique_ptr<DRMObject> connector_;
+	std::unique_ptr<DRMObject> crtc_;
 };
 
 #define ERRSTR strerror(errno)
@@ -96,10 +190,6 @@ void DrmPreview::findCrtc()
 			if (con->encoder_id)
 			{
 				enc = drmModeGetEncoder(drmfd_, con->encoder_id);
-				//if (enc->crtc_id)
-				//{
-				//	crtc = drmModeGetCrtc(drmfd_, enc->crtc_id);
-				//}
 			} else
 			{
 				enc = drmModeGetEncoder(drmfd_, con->encoders[0]);
@@ -229,6 +319,7 @@ void DrmPreview::findPlane()
 			drmModeFreePlane(plane);
 			break;
 		}
+		planeId_ = planes->planes[0];
 	}
 	catch (std::exception const &e)
 	{
@@ -265,21 +356,16 @@ DrmPreview::DrmPreview(Options const *options) : Preview(options), last_fd_(-1),
 		//out_fourcc_ = DRM_FORMAT_YUV420;
 		out_fourcc_ = DRM_FORMAT_NV12;
 		findPlane();
+
+		drmSetClientCap(drmfd_, DRM_CLIENT_CAP_ATOMIC, 1);
+		connector_ = std::make_unique<DRMObject>(drmfd_, conId_, DRM_MODE_OBJECT_CONNECTOR);
+		crtc_ = std::make_unique<DRMObject>(drmfd_, crtcId_, DRM_MODE_OBJECT_CRTC);
 	}
 	catch (std::exception const &e)
 	{
 		close(drmfd_);
 		throw;
 	}
-
-	// Default behaviour here is to go fullscreen.
-	if (options_->fullscreen || width_ == 0 || height_ == 0 || x_ + width_ > screen_width_ ||
-		y_ + height_ > screen_height_)
-	{
-		x_ = y_ = 0;
-		width_ = screen_width_;
-		height_ = screen_height_;
-	}
 }
 
 DrmPreview::~DrmPreview()
@@ -365,9 +451,23 @@ static void setup_colour_space(int fd, int plane_id, std::optional<libcamera::Co
 	drm_set_property(fd, plane_id, "COLOR_RANGE", range);
 }
 
+void DrmPreview::fitDisplaySize()
+{
+	if((int64_t)width_ * screen_height_ > (int64_t)screen_width_ * height_) {
+		display_x_ = 0, display_w_ = screen_width_;
+		display_h_ = ((int64_t)screen_width_ * height_) / (int64_t)width_;
+		display_y_ = (screen_height_ - display_h_) >> 1;
+	} else {
+		display_y_ = 0, display_h_ = screen_height_;
+		display_w_ = ((int64_t)width_ * screen_height_) / (int64_t)height_;
+		display_x_ = (screen_width_ - display_w_) >> 1;
+	}
+}
+
 void DrmPreview::makeBuffer(int fd, size_t size, StreamInfo const &info, Buffer &buffer)
 {
 	unsigned int width = info.width, height = info.height, stride = info.stride;
+	int64_t targetArea = 0;
 	if (first_time_)
 	{
 		first_time_ = false;
@@ -379,6 +479,10 @@ void DrmPreview::makeBuffer(int fd, size_t size, StreamInfo const &info, Buffer
 	buffer.size = size;
 	buffer.info = info;
 
+	if(!width_ || !height)
+		width_ = info.width, height_ = info.height;
+	targetArea = (int64_t)width_ * height_;
+
 	if (drmPrimeFDToHandle(drmfd_, fd, &buffer.bo_handle))
 		throw std::runtime_error("drmPrimeFDToHandle failed for fd " + std::to_string(fd));
 
@@ -401,33 +505,46 @@ void DrmPreview::makeBuffer(int fd, size_t size, StreamInfo const &info, Buffer
 
 	/* find preferred mode */
 	drmModeModeInfo *modeptr = NULL, *preferred = NULL;
+	int64_t minDiff = -1;
 	for (int m = 0; m < con_->count_modes; m++) {
+		int64_t area, areaDiff;
 		modeptr = &con_->modes[m];
-		if (modeptr->hdisplay == width && modeptr->vdisplay == height) {
+
+		area = (int64_t)modeptr->hdisplay * modeptr->vdisplay;
+		areaDiff = abs(targetArea - area);
+		if(-1 == minDiff)
+			minDiff = abs(targetArea - area), preferred = modeptr;
+		else {
+			if(areaDiff < minDiff)
+				minDiff = areaDiff, preferred = modeptr;
+		}
+
+		if (!minDiff) {
 			preferred = modeptr;
 			std::cout << "find the matched mode, modes index= "
 				<< m << ", " << width << "x" << height << std::endl;
 			break;
 		}
-		if (modeptr->type & DRM_MODE_TYPE_PREFERRED) {
-			preferred = modeptr;
-			std::cout << "find perferred mode, modes index= " << m << std::endl;
-		}
-	}
-
-	if (!preferred)
-		preferred = &con_->modes[0];
-
-	// set default
-	if (drmModeSetCrtc(drmfd_, crtcId_, buffer.fb_handle, 0, 0,
-	        (uint32_t *)&conId_, 1, preferred)) {
-		throw std::runtime_error("drmModeSetCrtc() failed");
 	}
 
 	screen_width_ = preferred->hdisplay;
 	screen_height_ = preferred->vdisplay;
-	width_ = width;
-	height_ = height;
+	fitDisplaySize();
+
+	AtomicRequest ar;
+	uint32_t blob_id;
+
+	drmModeCreatePropertyBlob(drmfd_, preferred, sizeof(con_->modes[0]), &blob_id);
+	ar.addProperty(drmfd_, connector_.get(), "CRTC_ID", crtcId_);
+	ar.addProperty(drmfd_, crtc_.get(), "ACTIVE", 1);
+	ar.addProperty(drmfd_, crtc_.get(), "MODE_ID", blob_id);
+	ar.commit(drmfd_, DRM_MODE_PAGE_FLIP_EVENT | DRM_MODE_ATOMIC_NONBLOCK | DRM_MODE_ATOMIC_ALLOW_MODESET);
+
+	// set default
+	//if (drmModeSetCrtc(drmfd_, crtcId_, buffer.fb_handle, 0, 0,
+	//        (uint32_t *)&conId_, 1, preferred)) {
+	//	throw std::runtime_error("drmModeSetCrtc() failed");
+	//}
 }
 
 void DrmPreview::Show(int fd, libcamera::Span<uint8_t> span, StreamInfo const &info)
@@ -436,14 +553,7 @@ void DrmPreview::Show(int fd, libcamera::Span<uint8_t> span, StreamInfo const &i
 	if (buffer.fd == -1)
 		makeBuffer(fd, span.size(), info, buffer);
 
-	unsigned int x_off = 0, y_off = 0;
-	unsigned int w = width_, h = height_;
-	if (info.width * height_ > width_ * info.height)
-		h = width_ * info.height / info.width, y_off = (height_ - h) / 2;
-	else
-		w = height_ * info.width / info.height, x_off = (width_ - w) / 2;
-
-	if (drmModeSetPlane(drmfd_, planeId_, crtcId_, buffer.fb_handle, 0, x_off + x_, y_off + y_, w, h, 0, 0,
+	if (drmModeSetPlane(drmfd_, planeId_, crtcId_, buffer.fb_handle, 0, display_x_, display_y_, display_w_, display_h_, 0, 0,
 						buffer.info.width << 16, buffer.info.height << 16))
 		throw std::runtime_error("drmModeSetPlane failed: " + std::string(ERRSTR));
 	if (last_fd_ >= 0)
-- 
2.34.1