[libcamera-devel] [RFC PATCH 3/3] android: camera_buffer: Add stride/offset/size function

[Hirokazu Honda]

This adds getter functions of stride, offset and size to CameraBuffer
interface.

Signed-off-by: Hirokazu Honda <hiroh at chromium.org>
---
 src/android/camera_buffer.h              | 16 +++++
 src/android/mm/cros_camera_buffer.cpp    | 19 ++++++
 src/android/mm/generic_camera_buffer.cpp | 78 ++++++++++++++++++------
 3 files changed, 94 insertions(+), 19 deletions(-)

diff --git a/src/android/camera_buffer.h b/src/android/camera_buffer.h
index 87df2570..226a8f5c 100644
--- a/src/android/camera_buffer.h
+++ b/src/android/camera_buffer.h
@@ -31,6 +31,10 @@ public:
 	libcamera::Span<const uint8_t> plane(unsigned int plane) const;
 	libcamera::Span<uint8_t> plane(unsigned int plane);
 
+	unsigned int stride(unsigned int plane) const;
+	unsigned int offset(unsigned int plane) const;
+	unsigned int size(unsigned int plane) const;
+
 	size_t jpegBufferSize(size_t maxJpegBufferSize) const;
 };
 
@@ -62,6 +66,18 @@ Span<uint8_t> CameraBuffer::plane(unsigned int plane)			\
 {									\
 	return _d()->plane(plane);					\
 }									\
+unsigned int CameraBuffer::stride(unsigned int plane) const		\
+{									\
+	return _d()->stride(plane);					\
+}									\
+unsigned int CameraBuffer::offset(unsigned int plane) const		\
+{									\
+	return _d()->offset(plane);					\
+}									\
+unsigned int CameraBuffer::size(unsigned int plane) const		\
+{									\
+	return _d()->size(plane);					\
+}									\
 size_t CameraBuffer::jpegBufferSize(size_t maxJpegBufferSize) const	\
 {									\
 	return _d()->jpegBufferSize(maxJpegBufferSize);			\
diff --git a/src/android/mm/cros_camera_buffer.cpp b/src/android/mm/cros_camera_buffer.cpp
index 85ef6480..4ba24f79 100644
--- a/src/android/mm/cros_camera_buffer.cpp
+++ b/src/android/mm/cros_camera_buffer.cpp
@@ -31,6 +31,10 @@ public:
 
 	Span<uint8_t> plane(unsigned int plane);
 
+	unsigned int stride(unsigned int plane) const;
+	unsigned int offset(unsigned int plane) const;
+	unsigned int size(unsigned int plane) const;
+
 	size_t jpegBufferSize(size_t maxJpegBufferSize) const;
 
 private:
@@ -112,6 +116,21 @@ Span<uint8_t> CameraBuffer::Private::plane(unsigned int plane)
 		 bufferManager_->GetPlaneSize(handle_, plane) };
 }
 
+unsigned int CameraBuffer::Private::stride(unsigned int plane) const
+{
+	return cros::CameraBufferManager::GetPlaneStride(handle_, plane);
+}
+
+unsigned int CameraBuffer::Private::offset(unsigned int plane) const
+{
+	return cros::CameraBufferManager::GetPlaneOffset(handle_, plane);
+}
+
+unsigned int CameraBuffer::Private::size(unsigned int plane) const
+{
+	return cros::CameraBufferManager::GetPlaneSize(handle_, plane);
+}
+
 size_t CameraBuffer::Private::jpegBufferSize([[maybe_unused]] size_t maxJpegBufferSize) const
 {
 	return bufferManager_->GetPlaneSize(handle_, 0);
diff --git a/src/android/mm/generic_camera_buffer.cpp b/src/android/mm/generic_camera_buffer.cpp
index 6c1e4611..b296b3e3 100644
--- a/src/android/mm/generic_camera_buffer.cpp
+++ b/src/android/mm/generic_camera_buffer.cpp
@@ -34,15 +34,24 @@ public:
 
 	Span<uint8_t> plane(unsigned int plane);
 
+	unsigned int stride(unsigned int plane) const;
+	unsigned int offset(unsigned int plane) const;
+	unsigned int size(unsigned int plane) const;
+
 	size_t jpegBufferSize(size_t maxJpegBufferSize) const;
 
 private:
+	struct PlaneInfo {
+		unsigned int stride;
+		unsigned int offset;
+		unsigned int size;
+	};
+
 	bool Map();
 
 	int fd_;
 	int flags_;
-	libcamera::Size size_;
-	libcamera::PixelFormatInfo info_;
+	std::vector<PlaneInfo> planeInfo_;
 	/* \todo remove planes_ is added to MappedBuffer. */
 	std::vector<Span<uint8_t>> planes_;
 };
@@ -51,7 +60,7 @@ CameraBuffer::Private::Private([[maybe_unused]] CameraBuffer *cameraBuffer,
 			       buffer_handle_t camera3Buffer,
 			       libcamera::PixelFormat pixelFormat,
 			       const libcamera::Size &size, int flags)
-	: fd_(-1), flags_(flags), size_(size)
+	: fd_(-1), flags_(flags)
 {
 	error_ = 0;
 
@@ -68,13 +77,29 @@ CameraBuffer::Private::Private([[maybe_unused]] CameraBuffer *cameraBuffer,
 		return;
 	}
 
-	info_ = libcamera::PixelFormatInfo::info(pixelFormat);
-	if (!info_.isValid()) {
+	const auto &info = libcamera::PixelFormatInfo::info(pixelFormat);
+	if (!info.isValid()) {
 		error_ = EINVAL;
 		LOG(HAL, Error) << "Invalid pixel format: "
 				<< pixelFormat.toString();
 		return;
 	}
+
+	const unsigned int numPlanes = info.numPlanes();
+	planeInfo_.resize(numPlanes);
+	unsigned int offset = 0;
+	for (unsigned int i = 0; i < numPlanes; ++i) {
+		const unsigned int vertSubSample = info.planes[i].verticalSubSampling;
+		const unsigned int stride = info.stride(size.width, i, 1u);
+		const unsigned int planeSize =
+			stride * ((size.height + vertSubSample - 1) / vertSubSample);
+
+		planeInfo_[i].stride = stride;
+		planeInfo_[i].offset = offset;
+		planeInfo_[i].size = planeSize;
+
+		offset += planeSize;
+	}
 }
 
 CameraBuffer::Private::~Private()
@@ -83,7 +108,7 @@ CameraBuffer::Private::~Private()
 
 unsigned int CameraBuffer::Private::numPlanes() const
 {
-	return info_.numPlanes();
+	return planeInfo_.size();
 }
 
 Span<uint8_t> CameraBuffer::Private::plane(unsigned int plane)
@@ -97,6 +122,30 @@ Span<uint8_t> CameraBuffer::Private::plane(unsigned int plane)
 	return planes_[plane];
 }
 
+unsigned int CameraBuffer::Private::stride(unsigned int plane) const
+{
+	if (plane >= planeInfo_.size())
+		return 0;
+
+	return planeInfo_[plane].stride;
+}
+
+unsigned int CameraBuffer::Private::offset(unsigned int plane) const
+{
+	if (plane >= planeInfo_.size())
+		return 0;
+
+	return planeInfo_[plane].offset;
+}
+
+unsigned int CameraBuffer::Private::size(unsigned int plane) const
+{
+	if (plane >= planeInfo_.size())
+		return 0;
+
+	return planeInfo_[plane].size;
+}
+
 size_t CameraBuffer::Private::jpegBufferSize(size_t maxJpegBufferSize) const
 {
 	if (maps_.empty()) {
@@ -129,19 +178,10 @@ bool CameraBuffer::Private::Map()
 	}
 	maps_.emplace_back(static_cast<uint8_t *>(address), bufferLength);
 
-	const unsigned int numPlanes = info_.numPlanes();
-	planes_.resize(numPlanes);
-	unsigned int offset = 0;
-	for (unsigned int i = 0; i < numPlanes; ++i) {
-		const unsigned int vertSubSample = info_.planes[i].verticalSubSampling;
-		const unsigned int stride = info_.stride(size_.width, i, 1u);
-		const unsigned int planeSize =
-			stride * ((size_.height + vertSubSample - 1) / vertSubSample);
-
-		planes_[i] = libcamera::Span<uint8_t>(
-			static_cast<uint8_t *>(address) + offset, planeSize);
-
-		offset += planeSize;
+	planes_.reserve(planeInfo_.size());
+	for (const auto &info : planeInfo_) {
+		planes_.emplace_back(
+			static_cast<uint8_t *>(address) + info.offset, info.size);
 	}
 
 	return true;
-- 
2.33.0.rc2.250.ged5fa647cd-goog