/* SPDX-License-Identifier: LGPL-2.1-or-later */ /* * Copyright (C) 2021, Google Inc. * * camera_sensor_helper.cpp - Helper class that performs sensor-specific * parameter computations */ #include "camera_sensor_helper.h" #include #include /** * \file camera_sensor_helper.h * \brief Helper class that performs sensor-specific parameter computations * * Computation of sensor configuration parameters is a sensor specific * operation. Each CameraHelper derived class computes the value of * configuration parameters, for example the analogue gain value, using * sensor-specific functions and constants. * * Every subclass of CameraSensorHelper shall be registered with libipa using * the REGISTER_CAMERA_SENSOR_HELPER() macro. */ namespace libcamera { LOG_DEFINE_CATEGORY(CameraSensorHelper) namespace ipa { /** * \class CameraSensorHelper * \brief Base class for computing sensor tuning parameters using * sensor-specific constants * * Instances derived from CameraSensorHelper class are sensor-specific. * Each supported sensor will have an associated base class defined. */ /** * \brief Construct a CameraSensorHelper instance * * CameraSensorHelper derived class instances shall never be constructed * manually but always through the CameraSensorHelperFactoryBase::create() * function. */ /** * \brief Compute gain code from the analogue gain absolute value * \param[in] gain The real gain to pass * * This function aims to abstract the calculation of the gain letting the IPA * use the real gain for its estimations. * * \return The gain code to pass to V4L2 */ uint32_t CameraSensorHelper::gainCode(double gain) const { const AnalogueGainConstants &k = gainConstants_; switch (gainType_) { case AnalogueGainLinear: ASSERT(k.linear.m0 == 0 || k.linear.m1 == 0); return (k.linear.c0 - k.linear.c1 * gain) / (k.linear.m1 * gain - k.linear.m0); case AnalogueGainExponential: ASSERT(k.exp.a != 0 && k.exp.m != 0); return std::log2(gain / k.exp.a) / k.exp.m; default: ASSERT(false); return 0; } } /** * \brief Compute the real gain from the V4L2 subdev control gain code * \param[in] gainCode The V4L2 subdev control gain * * This function aims to abstract the calculation of the gain letting the IPA * use the real gain for its estimations. It is the counterpart of the function * CameraSensorHelper::gainCode. * * \return The real gain */ double CameraSensorHelper::gain(uint32_t gainCode) const { const AnalogueGainConstants &k = gainConstants_; double gain = static_cast(gainCode); switch (gainType_) { case AnalogueGainLinear: ASSERT(k.linear.m0 == 0 || k.linear.m1 == 0); return (k.linear.m0 * gain + k.linear.c0) / (k.linear.m1 * gain + k.linear.c1); case AnalogueGainExponential: ASSERT(k.exp.a != 0 && k.exp.m != 0); return k.exp.a * std::exp2(k.exp.m * gain); default: ASSERT(false); return 0.0; } } /** * \enum CameraSensorHelper::AnalogueGainType * \brief The gain calculation modes as defined by the MIPI CCS * * Describes the image sensor analogue gain capabilities. * Two modes are possible, depending on the sensor: Linear and Exponential. */ /** * \var CameraSensorHelper::AnalogueGainLinear * \brief Gain is computed using linear gain estimation * * The relationship between the integer gain parameter and the resulting gain * multiplier is given by the following equation: * * \f$gain=\frac{m0x+c0}{m1x+c1}\f$ * * Where 'x' is the gain control parameter, and m0, m1, c0 and c1 are * image-sensor-specific constants of the sensor. * These constants are static parameters, and for any given image sensor either * m0 or m1 shall be zero. * * The full Gain equation therefore reduces to either: * * \f$gain=\frac{c0}{m1x+c1}\f$ or \f$\frac{m0x+c0}{c1}\f$ */ /** * \var CameraSensorHelper::AnalogueGainExponential * \brief Gain is expressed using an exponential model * * The relationship between the integer gain parameter and the resulting gain * multiplier is given by the following equation: * * \f$gain = a \cdot 2^{m \cdot x}\f$ * * Where 'x' is the gain control parameter, and 'a' and 'm' are image * sensor-specific constants. * * This is a subset of the MIPI CCS exponential gain model with the linear * factor 'a' being a constant, but with the exponent being configurable * through the 'm' coefficient. * * When the gain is expressed in dB, 'a' is equal to 1 and 'm' to * \f$log_{2}{10^{\frac{1}{20}}}\f$. */ /** * \struct CameraSensorHelper::AnalogueGainLinearConstants * \brief Analogue gain constants for the linear gain model * * \var CameraSensorHelper::AnalogueGainLinearConstants::m0 * \brief Constant used in the linear gain coding/decoding * * \note Either m0 or m1 shall be zero. * * \var CameraSensorHelper::AnalogueGainLinearConstants::c0 * \brief Constant used in the linear gain coding/decoding * * \var CameraSensorHelper::AnalogueGainLinearConstants::m1 * \brief Constant used in the linear gain coding/decoding * * \note Either m0 or m1 shall be zero. * * \var CameraSensorHelper::AnalogueGainLinearConstants::c1 * \brief Constant used in the linear gain coding/decoding */ /** * \struct CameraSensorHelper::AnalogueGainExpConstants * \brief Analogue gain constants for the exponential gain model * * \var CameraSensorHelper::AnalogueGainExpConstants::a * \brief Constant used in the exponential gain coding/decoding * * \var CameraSensorHelper::AnalogueGainExpConstants::m * \brief Constant used in the exponential gain coding/decoding */ /** * \struct CameraSensorHelper::AnalogueGainConstants * \brief Analogue gain model constants * * This union stores the constants used to calculate the analogue gain. The * CameraSensorHelper::gainType_ variable selects which union member is valid. * * \var CameraSensorHelper::AnalogueGainConstants::linear * \brief Constants for the linear gain model * * \var CameraSensorHelper::AnalogueGainConstants::exp * \brief Constants for the exponential gain model */ /** * \var CameraSensorHelper::gainType_ * \brief The analogue gain model type */ /** * \var CameraSensorHelper::gainConstants_ * \brief The analogue gain parameters used for calculation * * The analogue gain is calculated through a formula, and its parameters are * sensor specific. Use this variable to store the values at init time. */ /** * \class CameraSensorHelperFactoryBase * \brief Base class for camera sensor helper factories * * The CameraSensorHelperFactoryBase class is the base of all specializations of * the CameraSensorHelperFactory class template. It implements the factory * registration, maintains a registry of factories, and provides access to the * registered factories. */ /** * \brief Construct a camera sensor helper factory base * \param[in] name Name of the camera sensor helper class * * Creating an instance of the factory base registers it with the global list of * factories, accessible through the factories() function. * * The factory \a name is used to look up factories and shall be unique. */ CameraSensorHelperFactoryBase::CameraSensorHelperFactoryBase(const std::string name) : name_(name) { registerType(this); } /** * \brief Create an instance of the CameraSensorHelper corresponding to * a named factory * \param[in] name Name of the factory * * \return A unique pointer to a new instance of the CameraSensorHelper subclass * corresponding to the named factory or a null pointer if no such factory * exists */ std::unique_ptr CameraSensorHelperFactoryBase::create(const std::string &name) { const std::vector &factories = CameraSensorHelperFactoryBase::factories(); for (const CameraSensorHelperFactoryBase *factory : factories) { if (name != factory->name_) continue; return factory->createInstance(); } return nullptr; } /** * \brief Add a camera sensor helper class to the registry * \param[in] factory Factory to use to construct the camera sensor helper * * The caller is responsible to guarantee the uniqueness of the camera sensor * helper name. */ void CameraSensorHelperFactoryBase::registerType(CameraSensorHelperFactoryBase *factory) { std::vector &factories = CameraSensorHelperFactoryBase::factories(); factories.push_back(factory); } /** * \brief Retrieve the list of all camera sensor helper factories * \return The list of camera sensor helper factories */ std::vector &CameraSensorHelperFactoryBase::factories() { /* * The static factories map is defined inside the function to ensure * it gets initialized on first use, without any dependency on link * order. */ static std::vector factories; return factories; } /** * \class CameraSensorHelperFactory * \brief Registration of CameraSensorHelperFactory classes and creation of instances * \tparam _Helper The camera sensor helper class type for this factory * * To facilitate discovery and instantiation of CameraSensorHelper classes, the * CameraSensorHelperFactory class implements auto-registration of camera sensor * helpers. Each CameraSensorHelper subclass shall register itself using the * REGISTER_CAMERA_SENSOR_HELPER() macro, which will create a corresponding * instance of a CameraSensorHelperFactory subclass and register it with the * static list of factories. */ /** * \fn CameraSensorHelperFactory::CameraSensorHelperFactory(const char *name) * \brief Construct a camera sensor helper factory * \param[in] name Name of the camera sensor helper class * * Creating an instance of the factory registers it with the global list of * factories, accessible through the CameraSensorHelperFactoryBase::factories() * function. * * The factory \a name is used to look up factories and shall be unique. */ /** * \fn CameraSensorHelperFactory::createInstance() const * \brief Create an instance of the CameraSensorHelper corresponding to the * factory * * \return A unique pointer to a newly constructed instance of the * CameraSensorHelper subclass corresponding to the factory */ /** * \def REGISTER_CAMERA_SENSOR_HELPER * \brief Register a camera sensor helper with the camera sensor helper factory * \param[in] name Sensor model name used to register the class * \param[in] helper Class name of CameraSensorHelper derived class to register * * Register a CameraSensorHelper subclass with the factory and make it available * to try and match sensors. */ /* ----------------------------------------------------------------------------- * Sensor-specific subclasses */ #ifndef __DOXYGEN__ /* * Helper function to compute the m parameter of the exponential gain model * when the gain code is expressed in dB. */ static constexpr double expGainDb(double step) { constexpr double log2_10 = 3.321928094887362; /* * The gain code is expressed in step * dB (e.g. in 0.1 dB steps): * * G_code = G_dB/step = 20/step*log10(G_linear) * * Inverting the formula, we get * * G_linear = 10^(step/20*G_code) = 2^(log2(10)*step/20*G_code) */ return log2_10 * step / 20; } class CameraSensorHelperAr0521 : public CameraSensorHelper { public: uint32_t gainCode(double gain) const override; double gain(uint32_t gainCode) const override; private: static constexpr double kStep_ = 16; }; uint32_t CameraSensorHelperAr0521::gainCode(double gain) const { gain = std::clamp(gain, 1.0, 15.5); unsigned int coarse = std::log2(gain); unsigned int fine = (gain / (1 << coarse) - 1) * kStep_; return (coarse << 4) | (fine & 0xf); } double CameraSensorHelperAr0521::gain(uint32_t gainCode) const { unsigned int coarse = gainCode >> 4; unsigned int fine = gainCode & 0xf; return (1 << coarse) * (1 + fine / kStep_); } REGISTER_CAMERA_SENSOR_HELPER("ar0521", CameraSensorHelperAr0521) class CameraSensorHelperImx219 : public CameraSensorHelper { public: CameraSensorHelperImx219() { gainType_ = AnalogueGainLinear; gainConstants_.linear = { 0, 256, -1, 256 }; } }; REGISTER_CAMERA_SENSOR_HELPER("imx219", CameraSensorHelperImx219) class CameraSensorHelperImx258 : public CameraSensorHelper { public: CameraSensorHelperImx258() { gainType_ = AnalogueGainLinear; gainConstants_.linear = { 0, 512, -1, 512 }; } }; REGISTER_CAMERA_SENSOR_HELPER("imx258", CameraSensorHelperImx258) class CameraSensorHelperImx290 : public CameraSensorHelper { public: CameraSensorHelperImx290() { gainType_ = AnalogueGainExponential; gainConstants_.exp = { 1.0, expGainDb(0.3) }; } }; REGISTER_CAMERA_SENSOR_HELPER("imx290", CameraSensorHelperImx290) class CameraSensorHelperImx296 : public CameraSensorHelper { public: CameraSensorHelperImx296() { gainType_ = AnalogueGainExponential; gainConstants_.exp = { 1.0, expGainDb(0.1) }; } }; REGISTER_CAMERA_SENSOR_HELPER("imx296", CameraSensorHelperImx296) class CameraSensorHelperImx327 : public CameraSensorHelperImx290 { }; REGISTER_CAMERA_SENSOR_HELPER("imx327", CameraSensorHelperImx327) class CameraSensorHelperImx477 : public CameraSensorHelper { public: CameraSensorHelperImx477() { gainType_ = AnalogueGainLinear; gainConstants_.linear = { 0, 1024, -1, 1024 }; } }; REGISTER_CAMERA_SENSOR_HELPER("imx477", CameraSensorHelperImx477) class CameraSensorHelperOv2685 : public CameraSensorHelper { public: CameraSensorHelperOv2685() { /* * The Sensor Manual doesn't appear to document the gain model. * This has been validated with some empirical testing only. */ gainType_ = AnalogueGainLinear; gainConstants_.linear = { 1, 0, 0, 128 }; } }; REGISTER_CAMERA_SENSOR_HELPER("ov2685", CameraSensorHelperOv2685) class CameraSensorHelperOv2740 : public CameraSensorHelper { public: CameraSensorHelperOv2740() { gainType_ = AnalogueGainLinear; gainConstants_.linear = { 1, 0, 0, 128 }; } }; REGISTER_CAMERA_SENSOR_HELPER("ov2740", CameraSensorHelperOv2740) class CameraSensorHelperOv4689 : public CameraSensorHelper { public: CameraSensorHelperOv4689() { gainType_ = AnalogueGainLinear; gainConstants_.linear = { 1, 0, 0, 128 }; } }; REGISTER_CAMERA_SENSOR_HELPER("ov4689", CameraSensorHelperOv4689) class CameraSensorHelperOv5640 : public CameraSensorHelper { public: CameraSensorHelperOv5640() { gainType_ = AnalogueGainLinear; gainConstants_.linear = { 1, 0, 0, 16 }; } }; REGISTER_CAMERA_SENSOR_HELPER("ov5640", CameraSensorHelperOv5640) class CameraSensorHelperOv5647 : public CameraSensorHelper { public: CameraSensorHelperOv5647() { gainType_ = AnalogueGainLinear; gainConstants_.linear = { 1, 0, 0, 16 }; } }; REGISTER_CAMERA_SENSOR_HELPER("ov5647", CameraSensorHelperOv5647) class CameraSensorHelperOv5670 : public CameraSensorHelper { public: CameraSensorHelperOv5670() { gainType_ = AnalogueGainLinear; gainConstants_.linear = { 1, 0, 0, 128 }; } }; REGISTER_CAMERA_SENSOR_HELPER("ov5670", CameraSensorHelperOv5670) class CameraSensorHelperOv5675 : public CameraSensorHelper { public: CameraSensorHelperOv5675() { gainType_ = AnalogueGainLinear; gainConstants_.linear = { 1, 0, 0, 128 }; } }; REGISTER_CAMERA_SENSOR_HELPER("ov5675", CameraSensorHelperOv5675) class CameraSensorHelperOv5693 : public CameraSensorHelper { public: CameraSensorHelperOv5693() { gainType_ = AnalogueGainLinear; gainConstants_.linear = { 1, 0, 0, 16 }; } }; REGISTER_CAMERA_SENSOR_HELPER("ov5693", CameraSensorHelperOv5693) class CameraSensorHelperOv64a40 : public CameraSensorHelper { public: CameraSensorHelperOv64a40() { gainType_ = AnalogueGainLinear; gainConstants_.linear = { 1, 0, 0, 128 }; } }; REGISTER_CAMERA_SENSOR_HELPER("ov64a40", CameraSensorHelperOv64a40) class CameraSensorHelperOv8858 : public CameraSensorHelper { public: CameraSensorHelperOv8858() { gainType_ = AnalogueGainLinear; /* * \todo Validate the selected 1/128 step value as it differs * from what the sensor manual describes. * * See: https://patchwork.linuxtv.org/project/linux-media/patch/20221106171129.166892-2-nicholas@rothemail.net/#142267 */ gainConstants_.linear = { 1, 0, 0, 128 }; } }; REGISTER_CAMERA_SENSOR_HELPER("ov8858", CameraSensorHelperOv8858) class CameraSensorHelperOv8865 : public CameraSensorHelper { public: CameraSensorHelperOv8865() { gainType_ = AnalogueGainLinear; gainConstants_.linear = { 1, 0, 0, 128 }; } }; REGISTER_CAMERA_SENSOR_HELPER("ov8865", CameraSensorHelperOv8865) class CameraSensorHelperOv13858 : public CameraSensorHelper { public: CameraSensorHelperOv13858() { gainType_ = AnalogueGainLinear; gainConstants_.linear = { 1, 0, 0, 128 }; } }; REGISTER_CAMERA_SENSOR_HELPER("ov13858", CameraSensorHelperOv13858) #endif /* __DOXYGEN__ */ } /* namespace ipa */ } /* namespace libcamera */ 352' href='#n352'>352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562