[libcamera-devel] [PATCH v5] android: libyuv: Introduce PostProcessorYuv

[Hirokazu Honda]

This adds PostProcessorYuv. It supports NV12 buffer scaling
using libyuv.

Signed-off-by: Hirokazu Honda <hiroh at chromium.org>
Reviewed-by: Jacopo Mondi <jacopo at jmondi.org>

---
 src/android/meson.build                |   1 +
 src/android/yuv/post_processor_yuv.cpp | 145 +++++++++++++++++++++++++
 src/android/yuv/post_processor_yuv.h   |  42 +++++++
 3 files changed, 188 insertions(+)
 create mode 100644 src/android/yuv/post_processor_yuv.cpp
 create mode 100644 src/android/yuv/post_processor_yuv.h

diff --git a/src/android/meson.build b/src/android/meson.build
index 95d0f420..50481eeb 100644
--- a/src/android/meson.build
+++ b/src/android/meson.build
@@ -49,6 +49,7 @@ android_hal_sources = files([
     'jpeg/exif.cpp',
     'jpeg/post_processor_jpeg.cpp',
     'jpeg/thumbnailer.cpp',
+    'yuv/post_processor_yuv.cpp'
 ])

 android_camera_metadata_sources = files([
diff --git a/src/android/yuv/post_processor_yuv.cpp b/src/android/yuv/post_processor_yuv.cpp
new file mode 100644
index 00000000..aecb921f
--- /dev/null
+++ b/src/android/yuv/post_processor_yuv.cpp
@@ -0,0 +1,145 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2021, Google Inc.
+ *
+ * post_processor_yuv.cpp - Post Processor using libyuv
+ */
+
+#include "post_processor_yuv.h"
+
+#include <libyuv/scale.h>
+
+#include <libcamera/formats.h>
+#include <libcamera/geometry.h>
+#include <libcamera/internal/formats.h>
+#include <libcamera/internal/log.h>
+#include <libcamera/pixel_format.h>
+
+using namespace libcamera;
+
+LOG_DEFINE_CATEGORY(YUV)
+
+int PostProcessorYuv::configure(const StreamConfiguration &inCfg,
+				const StreamConfiguration &outCfg)
+{
+	if (inCfg.pixelFormat != outCfg.pixelFormat) {
+		LOG(YUV, Error) << "Pixel format conversion is not supported"
+				<< " (from " << inCfg.toString()
+				<< " to " << outCfg.toString() << ")";
+		return -EINVAL;
+	}
+
+	if (inCfg.size < outCfg.size) {
+		LOG(YUV, Error) << "Up-scaling is not supported"
+				<< " (from " << inCfg.toString()
+				<< " to " << outCfg.toString() << ")";
+		return -EINVAL;
+	}
+
+	if (inCfg.pixelFormat != formats::NV12) {
+		LOG(YUV, Error) << "Unsupported format " << inCfg.pixelFormat
+				<< " (only NV12 is supported)";
+		return -EINVAL;
+	}
+
+	calculateLengths(inCfg, outCfg);
+	return 0;
+}
+
+int PostProcessorYuv::process(const FrameBuffer &source,
+			      libcamera::MappedBuffer *destination,
+			      [[maybe_unused]] const CameraMetadata &requestMetadata,
+			      [[maybe_unused]] CameraMetadata *metadata)
+{
+	if (!isValidBuffers(source, *destination))
+		return -EINVAL;
+
+	const MappedFrameBuffer sourceMapped(&source, PROT_READ);
+	if (!sourceMapped.isValid()) {
+		LOG(YUV, Error) << "Failed to mmap camera frame buffer";
+		return -EINVAL;
+	}
+
+	int ret = libyuv::NV12Scale(sourceMapped.maps()[0].data(),
+				    sourceStride_[0],
+				    sourceMapped.maps()[1].data(),
+				    sourceStride_[1],
+				    sourceSize_.width, sourceSize_.height,
+				    destination->maps()[0].data(),
+				    destinationStride_[0],
+				    destination->maps()[1].data(),
+				    destinationStride_[1],
+				    destinationSize_.width,
+				    destinationSize_.height,
+				    libyuv::FilterMode::kFilterBilinear);
+	if (ret) {
+		LOG(YUV, Error) << "Failed NV12 scaling: " << ret;
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+bool PostProcessorYuv::isValidBuffers(const FrameBuffer &source,
+				      const libcamera::MappedBuffer &destination) const
+{
+	if (source.planes().size() != 2u) {
+		LOG(YUV, Error) << "Invalid number of source planes: "
+				<< source.planes().size();
+		return false;
+	}
+	if (destination.maps().size() != 2u) {
+		LOG(YUV, Error) << "Invalid number of destination planes: "
+				<< destination.maps().size();
+		return false;
+	}
+
+	if (source.planes()[0].length < sourceLength_[0] ||
+	    source.planes()[1].length < sourceLength_[1]) {
+		LOG(YUV, Error) << "The source planes lengths are too small"
+				<< ", actual size: {"
+				<< source.planes()[0].length << ", "
+				<< source.planes()[1].length << "}"
+				<< ", expected size: {"
+				<< sourceLength_[0] << ", "
+				<< sourceLength_[1] << "}";
+		return false;
+	}
+	if (destination.maps()[0].size() < destinationLength_[0] ||
+	    destination.maps()[1].size() < destinationLength_[1]) {
+		LOG(YUV, Error)
+			<< "The destination planes lengths are too small"
+			<< ", actual size: {" << destination.maps()[0].size()
+			<< ", " << destination.maps()[1].size() << "}"
+			<< ", expected size: {" << sourceLength_[0] << ", "
+			<< sourceLength_[1] << "}";
+		return false;
+	}
+
+	return true;
+}
+
+void PostProcessorYuv::calculateLengths(const StreamConfiguration &inCfg,
+					const StreamConfiguration &outCfg)
+{
+	ASSERT(inCfg.pixelFormat == formats::NV12);
+	ASSERT(outCfg.pixelFormat == formats::NV12);
+
+	sourceSize_ = inCfg.size;
+	destinationSize_ = outCfg.size;
+
+	const PixelFormatInfo &nv12Info = PixelFormatInfo::info(formats::NV12);
+	for (unsigned int i = 0; i < 2; i++) {
+		sourceStride_[i] = nv12Info.stride(sourceSize_.width, i, 1);
+		destinationStride_[i] = nv12Info.stride(destinationSize_.width, i, 1);
+
+		const unsigned int vertSubSample =
+			nv12Info.planes[i].verticalSubSampling;
+		sourceLength_[i] =
+			nv12Info.stride(sourceSize_.width, i, 1) *
+			((sourceSize_.height + vertSubSample - 1) / vertSubSample);
+		destinationLength_[i] =
+			nv12Info.stride(destinationSize_.width, i, 1) *
+			((destinationSize_.height + vertSubSample - 1) / vertSubSample);
+	}
+}
diff --git a/src/android/yuv/post_processor_yuv.h b/src/android/yuv/post_processor_yuv.h
new file mode 100644
index 00000000..c58b4cf7
--- /dev/null
+++ b/src/android/yuv/post_processor_yuv.h
@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2021, Google Inc.
+ *
+ * post_processor_yuv.h - Post Processor using libyuv
+ */
+#ifndef __ANDROID_POST_PROCESSOR_YUV_H__
+#define __ANDROID_POST_PROCESSOR_YUV_H__
+
+#include "../post_processor.h"
+
+#include <libcamera/geometry.h>
+
+class CameraDevice;
+
+class PostProcessorYuv : public PostProcessor
+{
+public:
+	PostProcessorYuv() = default;
+
+	int configure(const libcamera::StreamConfiguration &incfg,
+		      const libcamera::StreamConfiguration &outcfg) override;
+	int process(const libcamera::FrameBuffer &source,
+		    libcamera::MappedBuffer *destination,
+		    const CameraMetadata &requestMetadata,
+		    CameraMetadata *metadata) override;
+
+private:
+	bool isValidBuffers(const libcamera::FrameBuffer &source,
+			    const libcamera::MappedBuffer &destination) const;
+	void calculateLengths(const libcamera::StreamConfiguration &inCfg,
+			      const libcamera::StreamConfiguration &outCfg);
+
+	libcamera::Size sourceSize_;
+	libcamera::Size destinationSize_;
+	unsigned int sourceLength_[2] = {};
+	unsigned int destinationLength_[2] = {};
+	unsigned int sourceStride_[2] = {};
+	unsigned int destinationStride_[2] = {};
+};
+
+#endif /* __ANDROID_POST_PROCESSOR_YUV_H__ */
--
2.30.0.365.g02bc693789-goog