[libcamera-devel] [PATCH v3 3/3] android: camera_device: Reorder configurations before requesting

[Hirokazu Honda]

This reorders Camera3Configs before executing
CameraConfiguration::validate() to make it easier for the Camera
to satisfy the Android framework request.
---
 src/android/camera_device.cpp | 104 +++++++++++++++++++++++++++++++++-
 1 file changed, 102 insertions(+), 2 deletions(-)

diff --git a/src/android/camera_device.cpp b/src/android/camera_device.cpp
index b7bf3d88..dcba4e7d 100644
--- a/src/android/camera_device.cpp
+++ b/src/android/camera_device.cpp
@@ -9,6 +9,7 @@
 #include "camera_ops.h"
 #include "post_processor.h"

+#include <optional>
 #include <sys/mman.h>
 #include <tuple>
 #include <vector>
@@ -27,6 +28,8 @@

 using namespace libcamera;

+LOG_DECLARE_CATEGORY(HAL)
+
 namespace {

 /*
@@ -140,9 +143,104 @@ struct Camera3StreamConfig {
 	std::vector<CameraStream::Type> types;
 	StreamConfiguration config;
 };
-} /* namespace */

-LOG_DECLARE_CATEGORY(HAL)
+/*
+ * Reorder the configurations so that CameraDevice can accept them as much as
+ * possible. The sort rule is as follows.
+ * 1.) The configuration for NV12 request whose resolution is the largest.
+ * 2.) The configuration for JPEG request.
+ * 3.) Others. Larger resolutions and different formats are put earlier.
+ */
+std::vector<Camera3StreamConfig> sortCamera3StreamConfigs(
+	std::vector<Camera3StreamConfig> unsortedStreamConfigs,
+	const camera3_stream_t *jpegStream) {
+	const size_t unsortedStreamConfigsSize = unsortedStreamConfigs.size();
+	std::optional<Camera3StreamConfig> streamConfigForJpeg = std::nullopt;
+	if (jpegStream) {
+		for (auto it = unsortedStreamConfigs.begin();
+		     it != unsortedStreamConfigs.end(); it++) {
+			const auto &streams = it->streams;
+			if (std::find(streams.begin(), streams.end(),
+				      jpegStream) != streams.end()) {
+				streamConfigForJpeg = *it;
+				unsortedStreamConfigs.erase(it);
+				break;
+			}
+		}
+                if (!streamConfigForJpeg)
+                  LOG(HAL, Fatal) << "No Camera3StreamConfig is found for Jpeg";
+	}
+
+	std::map<uint32_t, std::vector<Camera3StreamConfig>> formatToConfigs;
+	for (const auto &streamConfig : unsortedStreamConfigs) {
+		const StreamConfiguration &config = streamConfig.config;
+		formatToConfigs[config.pixelFormat].push_back(streamConfig);
+
+	}
+	for (auto& [format, streamConfigs] : formatToConfigs) {
+		/* Sorted by resolution. Smaller is put first. */
+		std::sort(streamConfigs.begin(), streamConfigs.end(),
+			  [](const auto &streamConfigA, const auto &streamConfigB) {
+				  const Size &sizeA = streamConfigA.config.size;
+				  const Size &sizeB = streamConfigB.config.size;
+                                  return sizeA < sizeB;
+			  });
+	}
+
+	std::vector<Camera3StreamConfig> sortedStreamConfigs;
+        sortedStreamConfigs.reserve(unsortedStreamConfigsSize);
+	/*
+	 * NV12 is the most prioritized format. Put the configuration with NV12
+	 * and the largest resolution first.
+	 */
+	const auto nv12Stream = formatToConfigs.find(formats::NV12);
+	if (nv12Stream != formatToConfigs.end()) {
+		auto &nv12StreamConfigs = nv12Stream->second;
+		const Size &nv12LargestSize = nv12StreamConfigs.back().config.size;
+		/*
+		 * If JPEG will be created from NV12 and the size is larger than
+		 * the largest NV12 configurations, then put the NV12
+		 * configuration for JPEG first.
+		 */
+		if (streamConfigForJpeg &&
+		    streamConfigForJpeg->config.pixelFormat == formats::NV12) {
+			const Size &nv12SizeForJpeg = streamConfigForJpeg->config.size;
+			if (nv12LargestSize < nv12SizeForJpeg) {
+				sortedStreamConfigs.push_back(*streamConfigForJpeg);
+				streamConfigForJpeg = std::nullopt;
+			}
+		}
+		sortedStreamConfigs.push_back(nv12StreamConfigs.back());
+		nv12StreamConfigs.pop_back();
+	}
+
+	/* If the configuration for JPEG is there, then put it. */
+	if (streamConfigForJpeg) {
+		sortedStreamConfigs.push_back(*streamConfigForJpeg);
+		streamConfigForJpeg = std::nullopt;
+	}
+
+	/*
+	 * Put configurations with different formats and larger resolutions
+	 * earlier.
+	 */
+	while (!formatToConfigs.empty()) {
+		for (auto it = formatToConfigs.begin(); it != formatToConfigs.end();) {
+			auto& streamConfigs = it->second;
+			if (streamConfigs.empty()) {
+				it = formatToConfigs.erase(it);
+				continue;
+			}
+			sortedStreamConfigs.push_back(streamConfigs.back());
+			streamConfigs.pop_back();
+			it++;
+		}
+	}
+	assert(sortedStreamConfigs.size() == unsortedStreamConfigsSize);
+
+	return sortedStreamConfigs;
+}
+} /* namespace */

 MappedCamera3Buffer::MappedCamera3Buffer(const buffer_handle_t camera3buffer,
 					 int flags)
@@ -1333,6 +1431,8 @@ int CameraDevice::configureStreams(camera3_stream_configuration_t *stream_list)
 		streamConfigs[index].types.push_back(type);
 	}

+	streamConfigs = sortCamera3StreamConfigs(std::move(streamConfigs),
+						  jpegStream);
 	for (const auto &streamConfig : streamConfigs) {
 		config_->addConfiguration(streamConfig.config);
 		for (size_t i = 0; i < streamConfig.streams.size(); ++i) {
--
2.29.2.576.ga3fc446d84-goog