/* SPDX-License-Identifier: BSD-2-Clause */ /* * Copyright (C) 2019, Raspberry Pi Ltd * * cam_helper.h - helper class providing camera information */ #pragma once #include <memory> #include <string> #include <libcamera/base/span.h> #include <libcamera/base/utils.h> #include "camera_mode.h" #include "controller/controller.h" #include "controller/metadata.h" #include "md_parser.h" #include "libcamera/internal/v4l2_videodevice.h" namespace RPiController { /* * The CamHelper class provides a number of facilities that anyone trying * to drive a camera will need to know, but which are not provided by the * standard driver framework. Specifically, it provides: * * A "CameraMode" structure to describe extra information about the chosen * mode of the driver. For example, how it is cropped from the full sensor * area, how it is scaled, whether pixels are averaged compared to the full * resolution. * * The ability to convert between number of lines of exposure and actual * exposure time, and to convert between the sensor's gain codes and actual * gains. * * A function to return the number of frames of delay between updating exposure, * analogue gain and vblanking, and for the changes to take effect. For many * sensors these take the values 2, 1 and 2 respectively, but sensors that are * different will need to over-ride the default function provided. * * A function to query if the sensor outputs embedded data that can be parsed. * * A function to return the sensitivity of a given camera mode. * * A parser to parse the embedded data buffers provided by some sensors (for * example, the imx219 does; the ov5647 doesn't). This allows us to know for * sure the exposure and gain of the frame we're looking at. CamHelper * provides functions for converting analogue gains to and from the sensor's * native gain codes. * * Finally, a set of functions that determine how to handle the vagaries of * different camera modules on start-up or when switching modes. Some * modules may produce one or more frames that are not yet correctly exposed, * or where the metadata may be suspect. We have the following functions: * HideFramesStartup(): Tell the pipeline handler not to return this many * frames at start-up. This can also be used to hide initial frames * while the AGC and other algorithms are sorting themselves out. * HideFramesModeSwitch(): Tell the pipeline handler not to return this * many frames after a mode switch (other than start-up). Some sensors * may produce innvalid frames after a mode switch; others may not. * MistrustFramesStartup(): At start-up a sensor may return frames for * which we should not run any control algorithms (for example, metadata * may be invalid). * MistrustFramesModeSwitch(): The number of frames, after a mode switch * (other than start-up), for which control algorithms should not run * (for example, metadata may be unreliable). */ class CamHelper { public: static CamHelper *create(std::string const &camName); CamHelper(std::unique_ptr<MdParser> parser, unsigned int frameIntegrationDiff); virtual ~CamHelper(); void setCameraMode(const CameraMode &mode); virtual void prepare(libcamera::Span<const uint8_t> buffer, Metadata &metadata); virtual void process(StatisticsPtr &stats, Metadata &metadata); virtual uint32_t exposureLines(libcamera::utils::Duration exposure) const; virtual libcamera::utils::Duration exposure(uint32_t exposureLines) const; virtual uint32_t getVBlanking(libcamera::utils::Duration &exposure, libcamera::utils::Duration minFrameDuration, libcamera::utils::Duration maxFrameDuration) const; virtual uint32_t gainCode(double gain) const = 0; virtual double gain(uint32_t gainCode) const = 0; virtual void getDelays(int &exposureDelay, int &gainDelay, int &vblankDelay) const; virtual bool sensorEmbeddedDataPresent() const; virtual double getModeSensitivity(const CameraMode &mode) const; virtual unsigned int hideFramesStartup() const; virtual unsigned int hideFramesModeSwitch() const; virtual unsigned int mistrustFramesStartup() const; virtual unsigned int mistrustFramesModeSwitch() const; protected: void parseEmbeddedData(libcamera::Span<const uint8_t> buffer, Metadata &metadata); virtual void populateMetadata(const MdParser::RegisterMap ®isters, Metadata &metadata) const; std::unique_ptr<MdParser> parser_; CameraMode mode_; private: bool initialized_; /* * Smallest difference between the frame length and integration time, * in units of lines. */ unsigned int frameIntegrationDiff_; }; /* * This is for registering camera helpers with the system, so that the * CamHelper::Create function picks them up automatically. */ typedef CamHelper *(*CamHelperCreateFunc)(); struct RegisterCamHelper { RegisterCamHelper(char const *camName, CamHelperCreateFunc createFunc); }; } /* namespace RPi */