[libcamera-devel] [PATCH/RFC 08/12] libcamera: stream: Add StreamFormats

Laurent Pinchart laurent.pinchart at ideasonboard.com
Sat May 18 01:06:17 CEST 2019


From: Niklas Söderlund <niklas.soderlund at ragnatech.se>

Add a StreamFormats which describes all the formats a stream can
support. The object does not collect any formation itself but can
simplify users interaction with formats as it's able to translate a
stream format range into discrete steps.

Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
---
 include/libcamera/stream.h |  30 ++++++
 src/libcamera/stream.cpp   | 191 +++++++++++++++++++++++++++++++++++++
 2 files changed, 221 insertions(+)

diff --git a/include/libcamera/stream.h b/include/libcamera/stream.h
index 47c007ed52e2..138ed649ba8c 100644
--- a/include/libcamera/stream.h
+++ b/include/libcamera/stream.h
@@ -7,6 +7,7 @@
 #ifndef __LIBCAMERA_STREAM_H__
 #define __LIBCAMERA_STREAM_H__
 
+#include <map>
 #include <string>
 #include <vector>
 
@@ -39,6 +40,35 @@ enum StreamRole {
 	Viewfinder,
 };
 
+class StreamFormats
+{
+public:
+	struct Range {
+		Size min;
+		Size max;
+		unsigned int stepWidth;
+		unsigned int stepHeight;
+	};
+
+	StreamFormats() {}
+
+	StreamFormats(const std::map<unsigned int, Range> &rangeSizes)
+		: rangeSizes_(rangeSizes) {}
+
+	StreamFormats(const std::map<unsigned int, std::vector<Size>> &discreteSizes)
+		: discreteSizes_(discreteSizes) {}
+
+	std::vector<unsigned int> formats() const;
+	std::vector<Size> sizes(unsigned int pixelformat) const;
+
+	bool isRange() const { return !rangeSizes_.empty(); }
+	Range range(unsigned int pixelformat) const;
+
+private:
+	std::map<unsigned int, std::vector<Size>> discreteSizes_;
+	std::map<unsigned int, Range> rangeSizes_;
+};
+
 using StreamRoles = std::vector<StreamRole>;
 
 class Stream
diff --git a/src/libcamera/stream.cpp b/src/libcamera/stream.cpp
index 0c59a31a3a05..e82fa8143b8f 100644
--- a/src/libcamera/stream.cpp
+++ b/src/libcamera/stream.cpp
@@ -7,6 +7,7 @@
 
 #include <libcamera/stream.h>
 
+#include <algorithm>
 #include <iomanip>
 #include <sstream>
 
@@ -122,6 +123,196 @@ std::string StreamConfiguration::toString() const
  * \brief A vector of StreamRole
  */
 
+/**
+ * \class StreamFormats
+ * \brief Hold information about supported stream formats
+ *
+ * The StreamFormats class holds information about pixel formats and frame
+ * sizes a stream supports. The class groups size information by the pixel
+ * format which can produce it. There are two types of size information which
+ * can be described in the StreamFormats object discrete and range sizes.
+ *
+ * The discrete sizes are a list of fixed sizes of the only resolutions the
+ * stream can produce. While the range description contains a max and min
+ * size together with a stepping. The range information can either be consumed
+ * raw which allows users to calculate a size which the stream could support
+ * or be accessed thru the sizes() helper which will compute a list of common
+ * discrete sizes which can be produced within the range.
+ */
+
+/**
+ * \class StreamFormats::Range
+ * \brief Hold information about stream format range
+ */
+
+/**
+ * \var StreamFormats::Range::min
+ * \brief Range minimum size
+ */
+
+/**
+ * \var StreamFormats::Range::max
+ * \brief Range maximum size
+ */
+
+/**
+ * \var StreamFormats::Range::stepWidth
+ * \brief Range width step length in pixels
+ */
+
+/**
+ * \var StreamFormats::Range::stepHeight
+ * \brief Range height step length in pixels
+ */
+
+/**
+ * \fn StreamFormats::StreamFormats(const std::map< unsigned int, Range > &rangeSizes)
+ * \brief Constrict a ranged based StreamFormats object
+ * \param[in] rangeSizes A map of pixel format to a ranged description
+ * \sa StreamFormats::Range
+ */
+
+/**
+ * \fn StreamFormats::StreamFormats(const std::map< unsigned int, std::vector< Size >> &discreteSizes)
+ * \brief Constrict a discrete based StreamFormats object
+ * \param[in] discreteSizes A map of pixel format to a list of frame sizes
+ */
+
+/**
+ * \brief Retrive a list of pixel formats supported by the stram
+ * \returns A list of pixel formats
+ */
+std::vector<unsigned int> StreamFormats::formats() const
+{
+	std::vector<unsigned int> formats;
+
+	if (isRange()) {
+		for (auto const &it : rangeSizes_)
+			formats.push_back(it.first);
+	} else {
+		for (auto const &it : discreteSizes_)
+			formats.push_back(it.first);
+	}
+
+	return formats;
+}
+
+/**
+ * \brief Retrive a list of frame sizes
+ * \param[in] pixelformat Pixel format to retrive sizes for
+ * \returns A list of frame sizes
+ */
+std::vector<Size> StreamFormats::sizes(unsigned int pixelformat) const
+{
+	std::vector<Size> sizes;
+
+	/*
+	 * Sizes to try and extract from ranges.
+	 * \todo Verify list of resolutions are good
+	 */
+	static const std::vector<Size> rangeDescreteSizes = {
+		Size(160, 120),
+		Size(240, 160),
+		Size(320, 240),
+		Size(400, 240),
+		Size(480, 320),
+		Size(640, 360),
+		Size(640, 480),
+		Size(720, 480),
+		Size(720, 576),
+		Size(768, 480),
+		Size(800, 600),
+		Size(854, 480),
+		Size(960, 540),
+		Size(960, 640),
+		Size(1024, 576),
+		Size(1024, 600),
+		Size(1024, 768),
+		Size(1152, 864),
+		Size(1280, 1024),
+		Size(1280, 1080),
+		Size(1280, 720),
+		Size(1280, 800),
+		Size(1360, 768),
+		Size(1366, 768),
+		Size(1400, 1050),
+		Size(1440, 900),
+		Size(1536, 864),
+		Size(1600, 1200),
+		Size(1600, 900),
+		Size(1680, 1050),
+		Size(1920, 1080),
+		Size(1920, 1200),
+		Size(2048, 1080),
+		Size(2048, 1152),
+		Size(2048, 1536),
+		Size(2160, 1080),
+		Size(2560, 1080),
+		Size(2560, 1440),
+		Size(2560, 1600),
+		Size(2560, 2048),
+		Size(2960, 1440),
+		Size(3200, 1800),
+		Size(3200, 2048),
+		Size(3200, 2400),
+		Size(3440, 1440),
+		Size(3840, 1080),
+		Size(3840, 1600),
+		Size(3840, 2160),
+		Size(3840, 2400),
+		Size(4096, 2160),
+		Size(5120, 2160),
+		Size(5120, 2880),
+		Size(7680, 4320),
+	};
+
+	if (!isRange()) {
+		auto const &it = discreteSizes_.find(pixelformat);
+		if (it == discreteSizes_.end())
+			return {};
+		sizes = it->second;
+	} else {
+		Range limit = range(pixelformat);
+
+		for (const Size &size : rangeDescreteSizes) {
+			if (size.width < limit.min.width ||
+			    size.width > limit.max.width ||
+			    size.height < limit.min.height ||
+			    size.height > limit.max.height ||
+			    size.width % limit.stepWidth ||
+			    size.height % limit.stepHeight)
+				continue;
+
+			sizes.push_back(size);
+		}
+	}
+
+	std::sort(sizes.begin(), sizes.end());
+
+	return sizes;
+}
+
+/**
+ * \fn StreamFormats::isRange()
+ * \brief Check if the StreamFormat is a range description
+ * \returns True if the description is a range, false otherwise
+ */
+
+/**
+ * \brief Retrive the range description
+ * \param[in] pixelformat Pixel format to retrive description for
+ * \returns The range description
+ */
+StreamFormats::Range StreamFormats::range(unsigned int pixelformat) const
+{
+	auto const it = rangeSizes_.find(pixelformat);
+
+	if (it == rangeSizes_.end())
+		return {};
+
+	return it->second;
+}
+
 /**
  * \class Stream
  * \brief Video stream for a camera
-- 
Regards,

Laurent Pinchart



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