[libcamera-devel] [RFC PATCH 06/10] qcam: main_window: Use offset mapping FrameBuffer

[Hirokazu Honda]

FrameBuffer::Plane has offset info now. This uses the offset
in mapping FrameBuffer in MainWindow.

Signed-off-by: Hirokazu Honda <hiroh at chromium.org>
---
 src/qcam/main_window.cpp | 15 ++++++++++-----
 src/qcam/main_window.h   |  1 +
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/src/qcam/main_window.cpp b/src/qcam/main_window.cpp
index 39d034de..f815d281 100644
--- a/src/qcam/main_window.cpp
+++ b/src/qcam/main_window.cpp
@@ -10,6 +10,7 @@
 #include <iomanip>
 #include <string>
 #include <sys/mman.h>
+#include <unistd.h>
 
 #include <QComboBox>
 #include <QCoreApplication>
@@ -472,9 +473,11 @@ int MainWindow::startCapture()
 		for (const std::unique_ptr<FrameBuffer> &buffer : allocator_->buffers(stream)) {
 			/* Map memory buffers and cache the mappings. */
 			const FrameBuffer::Plane &plane = buffer->planes().front();
-			void *memory = mmap(NULL, plane.length, PROT_READ, MAP_SHARED,
+			size_t length = lseek(plane.fd.fd(), 0, SEEK_END);
+			void *memory = mmap(NULL, length, PROT_READ, MAP_SHARED,
 					    plane.fd.fd(), 0);
-			mappedBuffers_[buffer.get()] = { memory, plane.length };
+			mappedBuffers_[buffer.get()] = { memory, length };
+			planeData_[buffer.get()] = { static_cast<uint8_t *>(memory) + plane.offset, plane.length };
 
 			/* Store buffers on the free list. */
 			freeBuffers_[stream].enqueue(buffer.get());
@@ -541,6 +544,7 @@ error:
 		munmap(buffer.memory, buffer.size);
 	}
 	mappedBuffers_.clear();
+	planeData_.clear();
 
 	freeBuffers_.clear();
 
@@ -577,6 +581,7 @@ void MainWindow::stopCapture()
 		munmap(buffer.memory, buffer.size);
 	}
 	mappedBuffers_.clear();
+	planeData_.clear();
 
 	requests_.clear();
 	freeQueue_.clear();
@@ -673,10 +678,10 @@ void MainWindow::processRaw(FrameBuffer *buffer,
 							"DNG Files (*.dng)");
 
 	if (!filename.isEmpty()) {
-		const MappedBuffer &mapped = mappedBuffers_[buffer];
+		void *memory = planeData_[buffer].memory;
 		DNGWriter::write(filename.toStdString().c_str(), camera_.get(),
 				 rawStream_->configuration(), metadata, buffer,
-				 mapped.memory);
+				 memory);
 	}
 #endif
 
@@ -753,7 +758,7 @@ void MainWindow::processViewfinder(FrameBuffer *buffer)
 		<< "fps:" << Qt::fixed << qSetRealNumberPrecision(2) << fps;
 
 	/* Render the frame on the viewfinder. */
-	viewfinder_->render(buffer, &mappedBuffers_[buffer]);
+	viewfinder_->render(buffer, &planeData_[buffer]);
 }
 
 void MainWindow::queueRequest(FrameBuffer *buffer)
diff --git a/src/qcam/main_window.h b/src/qcam/main_window.h
index 85d56ce4..d7ea994c 100644
--- a/src/qcam/main_window.h
+++ b/src/qcam/main_window.h
@@ -107,6 +107,7 @@ private:
 
 	std::unique_ptr<CameraConfiguration> config_;
 	std::map<FrameBuffer *, MappedBuffer> mappedBuffers_;
+	std::map<FrameBuffer *, MappedBuffer> planeData_;
 
 	/* Capture state, buffers queue and statistics */
 	bool isCapturing_;
-- 
2.33.0.rc1.237.g0d66db33f3-goog