[libcamera-devel] [PATCH v2 10/16] libcamera: stream: Add StreamFormats
Niklas Söderlund
niklas.soderlund at ragnatech.se
Wed Jun 12 02:43:53 CEST 2019
Add a StreamFormats class which describes all the formats a stream can
support. The object does not collect any formation itself but can
simplify user interactions with formats as it's able to translate a
stream format range into discrete list and a discrete list to a range.
Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
---
include/libcamera/stream.h | 16 +++
src/libcamera/stream.cpp | 228 +++++++++++++++++++++++++++++++++++++
2 files changed, 244 insertions(+)
diff --git a/include/libcamera/stream.h b/include/libcamera/stream.h
index e38c0e7e827d5888..48daf5ac23f55d85 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>
@@ -18,6 +19,21 @@ namespace libcamera {
class Camera;
class Stream;
+class StreamFormats
+{
+public:
+ StreamFormats();
+ StreamFormats(const std::map<unsigned int, std::vector<SizeRange>> &formats);
+
+ std::vector<unsigned int> pixelformats() const;
+ std::vector<Size> sizes(unsigned int pixelformat) const;
+
+ SizeRange range(unsigned int pixelformat) const;
+
+private:
+ std::map<unsigned int, std::vector<SizeRange>> formats_;
+};
+
struct StreamConfiguration {
StreamConfiguration()
: stream_(nullptr)
diff --git a/src/libcamera/stream.cpp b/src/libcamera/stream.cpp
index 0c59a31a3a0501d3..52340c2644aac8d8 100644
--- a/src/libcamera/stream.cpp
+++ b/src/libcamera/stream.cpp
@@ -7,9 +7,13 @@
#include <libcamera/stream.h>
+#include <algorithm>
+#include <climits>
#include <iomanip>
#include <sstream>
+#include "log.h"
+
/**
* \file stream.h
* \brief Video stream for a Camera
@@ -32,6 +36,230 @@
namespace libcamera {
+LOG_DEFINE_CATEGORY(Stream)
+
+/**
+ * \class StreamFormats
+ * \brief Hold information about supported stream formats
+ *
+ * The StreamFormats class holds information about the pixel formats and frame
+ * sizes a stream supports. The class groups size information by the pixel
+ * format which can produce it.
+ *
+ * There are two ways to examine the size information, as a range or as a list
+ * of discrete sizes. When sizes are viewed as a range it describes the minimum
+ * and maximum width and height values. There is a possibility to supplement the
+ * range description with a horizontal and vertical step. The step describes the
+ * size in pixels from the minimum with/height.
+ *
+ * When sizes are viewed as a list of discrete sizes they describe exact
+ * dimensions which can be selected and used.
+ *
+ * Pipeline handlers can create StreamFormats describing each pixel format using
+ * either a range or a list of discrete sizes. The StreamFormats class attempts
+ * to translate between the two different ways to view them. The translations
+ * are performed as:
+ *
+ * - If a pixel format is described as a list of discrete sizes then a range is
+ * created by taking the minimum and maximum width/height in the list. The
+ * step information is not recreated and is set to 0 to indicate it is
+ * generated.
+ *
+ * - If a pixel format is described as a range then a list of discrete sizes
+ * which fits inside that range are selected from a list of common sizes. The
+ * step information is taken into consideration when generating the sizes.
+ *
+ * Applications examining sizes as a range with step values of 0 shall be
+ * aware that the range are generated from a list of discrete sizes and there
+ * could be a large quantity of possible Size combinations which may not
+ * be supported by the Stream.
+ *
+ * All sizes retrieved from StreamFormats shall be treated as advisory and no
+ * size shall be considered to be supported until its been verified using
+ * CameraConfiguration::validate().
+ */
+
+/**
+ * \brief Construct a empty StreamFormats object
+ */
+StreamFormats::StreamFormats()
+{
+}
+
+/**
+ * \brief Construct a StreamFormats object
+ * \param[in] formats A map of pixel formats to a sizes description
+ */
+StreamFormats::StreamFormats(const std::map<unsigned int, std::vector<SizeRange>> &formats)
+ : formats_(formats)
+{
+}
+
+/**
+ * \brief Retrieve the list of supported pixel formats
+ * \returns The list of supported pixel formats
+ */
+std::vector<unsigned int> StreamFormats::pixelformats() const
+{
+ std::vector<unsigned int> formats;
+
+ for (auto const &it : formats_)
+ formats.push_back(it.first);
+
+ return formats;
+}
+
+/**
+ * \brief Retrieve the list of frame sizes
+ * \param[in] pixelformat Pixel format to retrieve sizes for
+ *
+ * If the sizes described for \a pixelformat are discrete they are returned
+ * directly. If the size described is a range a list of discrete sizes are
+ * computed from a set list of common resolutions which fits inside the
+ * described range. When computing the discrete list step values are considered
+ * but there are no guarantees that all sizes computed are supported.
+ *
+ * \returns List description of frame sizes
+ */
+std::vector<Size> StreamFormats::sizes(unsigned int pixelformat) const
+{
+ /*
+ * Sizes to try and extract from ranges.
+ * \todo Verify list of resolutions are good, current list compiled
+ * from v4l2 documentation and source code as well as lists of
+ * common frame sizes.
+ */
+ static const std::vector<Size> rangeDiscreteSizes = {
+ 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),
+ };
+ std::vector<Size> sizes;
+
+ /* Make sure pixel format exists. */
+ auto const &it = formats_.find(pixelformat);
+ if (it == formats_.end())
+ return {};
+
+ /* Try creating a list of discrete sizes. */
+ const std::vector<SizeRange> &ranges = it->second;
+ bool discrete = true;
+ for (const SizeRange &range : ranges) {
+ if (range.min != range.max) {
+ discrete = false;
+ break;
+ }
+ sizes.emplace_back(range.min);
+ }
+
+ /* If discrete not possible generate from range. */
+ if (!discrete) {
+ if (ranges.size() != 1) {
+ LOG(Stream, Error) << "Range format is ambiguous";
+ return {};
+ }
+
+ const SizeRange &limit = ranges.front();
+ sizes.clear();
+
+ for (const Size &size : rangeDiscreteSizes)
+ if (limit.contains(size))
+ sizes.push_back(size);
+ }
+
+ std::sort(sizes.begin(), sizes.end());
+
+ return sizes;
+}
+
+/**
+ * \brief Retrieve the frame size range
+ * \param[in] pixelformat Pixel format to retrieve range for
+ *
+ * If the size described for \a pixelformat is a range the range is returned
+ * directly. If the sizes described are a list of discrete sizes a range is
+ * computed from the minimum and maxim sizes in the list. The step values of
+ * a computed range is set to 0 to indicate that the range is generated and
+ * that the full range may not supported.
+ *
+ * \returns Range description of frame size
+ */
+SizeRange StreamFormats::range(unsigned int pixelformat) const
+{
+ auto const it = formats_.find(pixelformat);
+ if (it == formats_.end())
+ return {};
+
+ const std::vector<SizeRange> &ranges = it->second;
+ if (ranges.size() == 1)
+ return ranges[0];
+
+ LOG(Stream, Debug) << "Building range from discrete";
+ SizeRange range(UINT_MAX, UINT_MAX, 0, 0);
+ for (const SizeRange &limit : ranges) {
+ if (limit.min < range.min)
+ range.min = limit.min;
+
+ if (limit.max > range.max)
+ range.max = limit.max;
+ }
+
+ range.hStep = 0;
+ range.vStep = 0;
+
+ return range;
+}
+
/**
* \struct StreamConfiguration
* \brief Configuration parameters for a stream
--
2.21.0
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