[libcamera-devel] [RFC PATCH] android: camera_device: Reorder configurations given by a HAL client

[Hirokazu Honda]

Reorder configurations given by a HAL client in configureStreams()
so that CameraDevice and pipeline handlers can accept them as much
as possible.

Signed-off-by: Hirokazu Honda <hiroh at chromium.org>
---
 src/android/camera_device.cpp | 108 +++++++++++++++++++++++++++++++++-
 src/android/camera_device.h   |   3 +-
 2 files changed, 109 insertions(+), 2 deletions(-)

diff --git a/src/android/camera_device.cpp b/src/android/camera_device.cpp
index ca60f51..eee7248 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 <string.h>
 #include <sys/mman.h>
 #include <tuple>
 #include <vector>
@@ -132,6 +133,16 @@ const std::map<int, const Camera3Format> camera3FormatsMap = {

 LOG_DECLARE_CATEGORY(HAL)

+void printStreamList(const camera3_stream_configuration_t& streamList) {
+	LOG(HAL, Error) << "num_streams=" << streamList.num_streams;
+	for (unsigned int i = 0; i < streamList.num_streams; i++) {
+		const auto* stream = streamList.streams[i];
+		LOG(HAL, Error) << i << ": width=" << stream->width
+				<< ", height=" << stream->height
+				<< ", format=" << stream->format;
+	}
+}
+
 MappedCamera3Buffer::MappedCamera3Buffer(const buffer_handle_t camera3buffer,
 					 int flags)
 {
@@ -1188,7 +1199,7 @@ const camera_metadata_t *CameraDevice::constructDefaultRequestSettings(int type)
 	return requestTemplate->get();
 }

-PixelFormat CameraDevice::toPixelFormat(int format)
+PixelFormat CameraDevice::toPixelFormat(int format) const
 {
 	/* Translate Android format code to libcamera pixel format. */
 	auto it = formatsMap_.find(format);
@@ -1201,6 +1212,97 @@ PixelFormat CameraDevice::toPixelFormat(int format)
 	return it->second;
 }

+int CameraDevice::sortStreamConfig(camera3_stream_configuration_t* streamList) const
+{
+	std::map<uint32_t, std::vector<const camera3_stream_t*>> streamMap;
+	for (unsigned int i = 0; i < streamList->num_streams; ++i) {
+		const camera3_stream_t* stream = streamList->streams[i];
+		PixelFormat format = toPixelFormat(stream->format);
+		if (!format.isValid())
+			return -EINVAL;
+		streamMap[format.fourcc()].push_back(stream);
+	}
+	std::vector<uint32_t> formats;
+	for (auto& s: streamMap) {
+		formats.push_back(s.first);
+		auto& streams = s.second;
+		/* Sorted by resolution. Smaller is put first. */
+		std::sort(streams.begin(), streams.end(),
+			  [](const camera3_stream_t* streamA,
+			     const camera3_stream_t* streamB) {
+				  if (streamA->width != streamB->width)
+					  return streamA->width < streamB->width;
+				  return streamA->height < streamB->height;
+			  });
+	}
+
+	if (streamMap.find(formats::MJPEG) != streamMap.end() &&
+	    streamMap[formats::MJPEG].size() > 1) {
+		LOG(HAL, Error) << "Multiple JPEG streams are not supported";
+		return -EINVAL;
+	}
+
+	std::vector<const camera3_stream_t*> sortedStreams;
+	/*
+	 * NV12 is the most prioritized format. Put the configuration with NV12
+	 * and the largest resolution first.
+	 */
+	auto nv12StreamsIt = streamMap.find(formats::NV12);
+	if (nv12StreamsIt != streamMap.end()) {
+		auto& nv12Streams = nv12StreamsIt->second;
+		const camera3_stream_t* nv12Stream = nv12Streams.back();
+		sortedStreams.push_back(nv12Stream);
+		nv12Streams.pop_back();
+	}
+
+	/*
+	 * If JPEG is there, then put the JPEG configuration second and a
+	 * configuration whose specified stream the JPEG is encoded from third
+	 * if there is.
+	 */
+	auto jpegStreamsIt = streamMap.find(formats::MJPEG);
+	if (jpegStreamsIt != streamMap.end()) {
+		auto& jpegStreams = jpegStreamsIt->second;
+		const camera3_stream_t* jpegStream = jpegStreams[0];
+		sortedStreams.push_back(jpegStream);
+		streamMap.erase(jpegStreamsIt);
+		if (nv12StreamsIt != streamMap.end()) {
+			auto& nv12Streams = nv12StreamsIt->second;
+			auto nv12StreamForJpegIt =
+				std::find_if(nv12Streams.begin(),
+					     nv12Streams.end(),
+					     [&jpegStream](const auto* nv12Stream) {
+						     return nv12Stream->width == jpegStream->width && nv12Stream->height == jpegStream->height;
+					     });
+			if (nv12StreamForJpegIt != nv12Streams.end()) {
+				sortedStreams.push_back(*nv12StreamForJpegIt);
+				nv12Streams.erase(nv12StreamForJpegIt);
+			}
+		}
+	}
+
+	/*
+	 * Put configurations with different formats and larger resolutions
+	 * earlier.
+	 */
+	while (!streamMap.empty()) {
+		for (auto it = streamMap.begin(); it != streamMap.end();) {
+			auto& streams = it->second;
+			if (streams.empty()) {
+				it = streamMap.erase(it);
+				continue;
+			}
+			sortedStreams.push_back(streams.back());
+			streams.pop_back();
+		}
+	}
+
+	assert(sortedStreams.size() == streamList->num_streams);
+	memcpy(streamList->streams, sortedStreams.data(),
+	       sizeof(camera3_stream_t*) * streamList->num_streams);
+	return 0;
+}
+
 /*
  * Inspect the stream_list to produce a list of StreamConfiguration to
  * be use to configure the Camera.
@@ -1225,6 +1327,10 @@ int CameraDevice::configureStreams(camera3_stream_configuration_t *stream_list)
 	streams_.clear();
 	streams_.reserve(stream_list->num_streams);

+	printStreamList(*stream_list);
+	sortStreamConfig(stream_list);
+	printStreamList(*stream_list);
+
 	/* First handle all non-MJPEG streams. */
 	camera3_stream_t *jpegStream = nullptr;
 	for (unsigned int i = 0; i < stream_list->num_streams; ++i) {
diff --git a/src/android/camera_device.h b/src/android/camera_device.h
index fd08738..f8dc28b 100644
--- a/src/android/camera_device.h
+++ b/src/android/camera_device.h
@@ -104,7 +104,8 @@ private:
 	void notifyShutter(uint32_t frameNumber, uint64_t timestamp);
 	void notifyError(uint32_t frameNumber, camera3_stream_t *stream);
 	CameraMetadata *requestTemplatePreview();
-	libcamera::PixelFormat toPixelFormat(int format);
+	libcamera::PixelFormat toPixelFormat(int format) const;
+	int sortStreamConfig(camera3_stream_configuration_t* streamList) const;
 	std::unique_ptr<CameraMetadata> getResultMetadata(int frame_number,
 							  int64_t timestamp);

--
2.29.0.rc2.309.g374f81d7ae-goog