[libcamera-devel] [PATCH RFC 3/7] android: yuv: prepare support for other pixel formats

[Mattijs Korpershoek]

PostProcessorYuv assumes that both source and destination pixel formats
will always be formats::NV12.
This might change in the future, for example when doing pixel format
conversion via libyuv.

Add the necessary plumbing so that other formats can be added easily in
the future.

Also increase plane number to 3, since some YUV format [1] are
fully planar (and thus have 3 planes).

[1] https://docs.kernel.org/userspace-api/media/v4l/pixfmt-yuv-planar.html#fully-planar-yuv-formats
Signed-off-by: Mattijs Korpershoek <mkorpershoek at baylibre.com>
---
 src/android/yuv/post_processor_yuv.cpp | 26 +++++++++++++++-----------
 src/android/yuv/post_processor_yuv.h   | 12 ++++++++----
 2 files changed, 23 insertions(+), 15 deletions(-)

diff --git a/src/android/yuv/post_processor_yuv.cpp b/src/android/yuv/post_processor_yuv.cpp
index d58090db14ee..734bb85b7351 100644
--- a/src/android/yuv/post_processor_yuv.cpp
+++ b/src/android/yuv/post_processor_yuv.cpp
@@ -90,18 +90,18 @@ void PostProcessorYuv::process(Camera3RequestDescriptor::StreamBuffer *streamBuf
 bool PostProcessorYuv::isValidBuffers(const FrameBuffer &source,
 				      const CameraBuffer &destination) const
 {
-	if (source.planes().size() != 2) {
+	if (source.planes().size() != sourceNumPlanes_) {
 		LOG(YUV, Error) << "Invalid number of source planes: "
 				<< source.planes().size();
 		return false;
 	}
-	if (destination.numPlanes() != 2) {
+	if (destination.numPlanes() != destinationNumPlanes_) {
 		LOG(YUV, Error) << "Invalid number of destination planes: "
 				<< destination.numPlanes();
 		return false;
 	}
 
-	for (unsigned int i = 0; i < 2; i++) {
+	for (unsigned int i = 0; i < sourceNumPlanes_; i++) {
 		if (source.planes()[i].length < sourceLength_[i]) {
 			LOG(YUV, Error)
 				<< "The source planes lengths are too small, "
@@ -112,7 +112,7 @@ bool PostProcessorYuv::isValidBuffers(const FrameBuffer &source,
 			return false;
 		}
 	}
-	for (unsigned int i = 0; i < 2; i++) {
+	for (unsigned int i = 0; i < destinationNumPlanes_; i++) {
 		if (destination.plane(i).size() < destinationLength_[i]) {
 			LOG(YUV, Error)
 				<< "The destination planes lengths are too small, "
@@ -132,18 +132,22 @@ void PostProcessorYuv::calculateLengths(const StreamConfiguration &inCfg,
 {
 	sourceSize_ = inCfg.size;
 	destinationSize_ = outCfg.size;
+	sourceFormat_ = inCfg.pixelFormat;
+	destinationFormat_ = outCfg.pixelFormat;
 
-	const PixelFormatInfo &sourceInfo = PixelFormatInfo::info(formats::NV12);
-	for (unsigned int i = 0; i < 2; i++) {
+	const PixelFormatInfo &sourceInfo = PixelFormatInfo::info(sourceFormat_);
+	sourceNumPlanes_ = sourceInfo.numPlanes();
+	for (unsigned int i = 0; i < sourceInfo.numPlanes(); i++) {
 		sourceStride_[i] = inCfg.stride;
 		sourceLength_[i] = sourceInfo.planeSize(sourceSize_.height, i,
 							sourceStride_[i]);
 	}
 
-	const PixelFormatInfo &destinationInfo = PixelFormatInfo::info(formats::NV12);
-	for (unsigned int i = 0; i < 2; i++) {
-		destinationStride_[i] = sourceInfo.stride(destinationSize_.width, i, 1);
-		destinationLength_[i] = sourceInfo.planeSize(destinationSize_.height, i,
-							     destinationStride_[i]);
+	const PixelFormatInfo &destinationInfo = PixelFormatInfo::info(destinationFormat_);
+	destinationNumPlanes_ = destinationInfo.numPlanes();
+	for (unsigned int i = 0; i < destinationInfo.numPlanes(); i++) {
+		destinationStride_[i] = destinationInfo.stride(destinationSize_.width, i, 1);
+		destinationLength_[i] = destinationInfo.planeSize(destinationSize_.height, i,
+								  destinationStride_[i]);
 	}
 }
diff --git a/src/android/yuv/post_processor_yuv.h b/src/android/yuv/post_processor_yuv.h
index a7ac17c564b6..bfe35f46c6dc 100644
--- a/src/android/yuv/post_processor_yuv.h
+++ b/src/android/yuv/post_processor_yuv.h
@@ -28,8 +28,12 @@ private:
 
 	libcamera::Size sourceSize_;
 	libcamera::Size destinationSize_;
-	unsigned int sourceLength_[2] = {};
-	unsigned int destinationLength_[2] = {};
-	unsigned int sourceStride_[2] = {};
-	unsigned int destinationStride_[2] = {};
+	libcamera::PixelFormat sourceFormat_;
+	libcamera::PixelFormat destinationFormat_;
+	unsigned int sourceLength_[3] = {};
+	unsigned int destinationLength_[3] = {};
+	unsigned int sourceStride_[3] = {};
+	unsigned int destinationStride_[3] = {};
+	unsigned int sourceNumPlanes_;
+	unsigned int destinationNumPlanes_;
 };

-- 
2.41.0