blob: 1ea2c8988cb5c9f01dec39297f00f96e796d0e6e [file] [log] [blame]
/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
* Copyright (C) 2020, Google Inc.
*
* ipu3.cpp - IPU3 Image Processing Algorithms
*/
#include <algorithm>
#include <array>
#include <cmath>
#include <limits>
#include <map>
#include <memory>
#include <stdint.h>
#include <utility>
#include <vector>
#include <linux/intel-ipu3.h>
#include <linux/v4l2-controls.h>
#include <libcamera/base/log.h>
#include <libcamera/base/utils.h>
#include <libcamera/control_ids.h>
#include <libcamera/framebuffer.h>
#include <libcamera/ipa/ipa_interface.h>
#include <libcamera/ipa/ipa_module_info.h>
#include <libcamera/ipa/ipu3_ipa_interface.h>
#include <libcamera/request.h>
#include "libcamera/internal/mapped_framebuffer.h"
#include "algorithms/af.h"
#include "algorithms/agc.h"
#include "algorithms/algorithm.h"
#include "algorithms/awb.h"
#include "algorithms/blc.h"
#include "algorithms/tone_mapping.h"
#include "libipa/camera_sensor_helper.h"
/* Minimum grid width, expressed as a number of cells */
static constexpr uint32_t kMinGridWidth = 16;
/* Maximum grid width, expressed as a number of cells */
static constexpr uint32_t kMaxGridWidth = 80;
/* Minimum grid height, expressed as a number of cells */
static constexpr uint32_t kMinGridHeight = 16;
/* Maximum grid height, expressed as a number of cells */
static constexpr uint32_t kMaxGridHeight = 60;
/* log2 of the minimum grid cell width and height, in pixels */
static constexpr uint32_t kMinCellSizeLog2 = 3;
/* log2 of the maximum grid cell width and height, in pixels */
static constexpr uint32_t kMaxCellSizeLog2 = 6;
namespace libcamera {
LOG_DEFINE_CATEGORY(IPAIPU3)
using namespace std::literals::chrono_literals;
namespace ipa::ipu3 {
/**
* \brief The IPU3 IPA implementation
*
* The IPU3 Pipeline defines an IPU3-specific interface for communication
* between the PipelineHandler and the IPA module.
*
* We extend the IPAIPU3Interface to implement our algorithms and handle events
* from the IPU3 PipelineHandler to satisfy requests from the application.
*
* At initialisation time, a CameraSensorHelper is instantiated to support
* camera-specific calculations, while the default controls are computed, and
* the algorithms are constructed and placed in an ordered list.
*
* The IPU3 ImgU operates with a grid layout to divide the overall frame into
* rectangular cells of pixels. When the IPA is configured, we determine the
* best grid for the statistics based on the pipeline handler Bayer Down Scaler
* output size.
*
* Two main events are then handled to operate the IPU3 ImgU by populating its
* parameter buffer, and adapting the settings of the sensor attached to the
* IPU3 CIO2 through sensor-specific V4L2 controls.
*
* When the event \a EventFillParams occurs we populate the ImgU parameter
* buffer with settings to configure the device in preparation for handling the
* frame queued in the Request.
*
* When the frame has completed processing, the ImgU will generate a statistics
* buffer which is given to the IPA as part of the \a EventStatReady event. At
* this event we run the algorithms to parse the statistics and cache any
* results for the next \a EventFillParams event.
*
* The individual algorithms are split into modular components that are called
* iteratively to allow them to process statistics from the ImgU in a defined
* order.
*
* The current implementation supports three core algorithms:
* - Automatic white balance (AWB)
* - Automatic gain and exposure control (AGC)
* - Black level correction (BLC)
* - Tone mapping (Gamma)
*
* AWB is implemented using a Greyworld algorithm, and calculates the red and
* blue gains to apply to generate a neutral grey frame overall.
*
* AGC is handled by calculating a histogram of the green channel to estimate an
* analogue gain and shutter time which will provide a well exposed frame. A
* low-pass IIR filter is used to smooth the changes to the sensor to reduce
* perceivable steps.
*
* The tone mapping algorithm provides a gamma correction table to improve the
* contrast of the scene.
*
* The black level compensation algorithm subtracts a hardcoded black level from
* all pixels.
*
* The IPU3 ImgU has further processing blocks to support image quality
* improvements through bayer and temporal noise reductions, however those are
* not supported in the current implementation, and will use default settings as
* provided by the kernel driver.
*
* Demosaicing is operating with the default parameters and could be further
* optimised to provide improved sharpening coefficients, checker artifact
* removal, and false color correction.
*
* Additional image enhancements can be made by providing lens and
* sensor-specific tuning to adapt for Black Level compensation (BLC), Lens
* shading correction (SHD) and Color correction (CCM).
*/
class IPAIPU3 : public IPAIPU3Interface
{
public:
int init(const IPASettings &settings,
const IPACameraSensorInfo &sensorInfo,
const ControlInfoMap &sensorControls,
ControlInfoMap *ipaControls) override;
int start() override;
void stop() override;
int configure(const IPAConfigInfo &configInfo,
ControlInfoMap *ipaControls) override;
void mapBuffers(const std::vector<IPABuffer> &buffers) override;
void unmapBuffers(const std::vector<unsigned int> &ids) override;
void processEvent(const IPU3Event &event) override;
private:
void updateControls(const IPACameraSensorInfo &sensorInfo,
const ControlInfoMap &sensorControls,
ControlInfoMap *ipaControls);
void updateSessionConfiguration(const ControlInfoMap &sensorControls);
void processControls(unsigned int frame, const ControlList &controls);
void fillParams(unsigned int frame, ipu3_uapi_params *params);
void parseStatistics(unsigned int frame,
int64_t frameTimestamp,
const ipu3_uapi_stats_3a *stats);
void setControls(unsigned int frame);
void calculateBdsGrid(const Size &bdsOutputSize);
std::map<unsigned int, MappedFrameBuffer> buffers_;
ControlInfoMap sensorCtrls_;
ControlInfoMap lensCtrls_;
IPACameraSensorInfo sensorInfo_;
/* Camera sensor controls. */
uint32_t defVBlank_;
uint32_t exposure_;
uint32_t minExposure_;
uint32_t maxExposure_;
uint32_t gain_;
uint32_t minGain_;
uint32_t maxGain_;
/* Interface to the Camera Helper */
std::unique_ptr<CameraSensorHelper> camHelper_;
/* Maintain the algorithms used by the IPA */
std::list<std::unique_ptr<ipa::ipu3::Algorithm>> algorithms_;
/* Local parameter storage */
struct IPAContext context_;
};
/**
* \brief Compute IPASessionConfiguration using the sensor information and the
* sensor V4L2 controls
*/
void IPAIPU3::updateSessionConfiguration(const ControlInfoMap &sensorControls)
{
const ControlInfo &v4l2Exposure = sensorControls.find(V4L2_CID_EXPOSURE)->second;
int32_t minExposure = v4l2Exposure.min().get<int32_t>();
int32_t maxExposure = v4l2Exposure.max().get<int32_t>();
const ControlInfo &v4l2Gain = sensorControls.find(V4L2_CID_ANALOGUE_GAIN)->second;
int32_t minGain = v4l2Gain.min().get<int32_t>();
int32_t maxGain = v4l2Gain.max().get<int32_t>();
/*
* When the AGC computes the new exposure values for a frame, it needs
* to know the limits for shutter speed and analogue gain.
* As it depends on the sensor, update it with the controls.
*
* \todo take VBLANK into account for maximum shutter speed
*/
context_.configuration.agc.minShutterSpeed = minExposure * context_.configuration.sensor.lineDuration;
context_.configuration.agc.maxShutterSpeed = maxExposure * context_.configuration.sensor.lineDuration;
context_.configuration.agc.minAnalogueGain = camHelper_->gain(minGain);
context_.configuration.agc.maxAnalogueGain = camHelper_->gain(maxGain);
}
/**
* \brief Compute camera controls using the sensor information and the sensor
* V4L2 controls
*
* Some of the camera controls are computed by the pipeline handler, some others
* by the IPA module which is in charge of handling, for example, the exposure
* time and the frame duration.
*
* This function computes:
* - controls::ExposureTime
* - controls::FrameDurationLimits
*/
void IPAIPU3::updateControls(const IPACameraSensorInfo &sensorInfo,
const ControlInfoMap &sensorControls,
ControlInfoMap *ipaControls)
{
ControlInfoMap::Map controls{};
double lineDuration = context_.configuration.sensor.lineDuration.get<std::micro>();
/*
* Compute exposure time limits by using line length and pixel rate
* converted to microseconds. Use the V4L2_CID_EXPOSURE control to get
* exposure min, max and default and convert it from lines to
* microseconds.
*/
const ControlInfo &v4l2Exposure = sensorControls.find(V4L2_CID_EXPOSURE)->second;
int32_t minExposure = v4l2Exposure.min().get<int32_t>() * lineDuration;
int32_t maxExposure = v4l2Exposure.max().get<int32_t>() * lineDuration;
int32_t defExposure = v4l2Exposure.def().get<int32_t>() * lineDuration;
controls[&controls::ExposureTime] = ControlInfo(minExposure, maxExposure,
defExposure);
/*
* Compute the frame duration limits.
*
* The frame length is computed assuming a fixed line length combined
* with the vertical frame sizes.
*/
const ControlInfo &v4l2HBlank = sensorControls.find(V4L2_CID_HBLANK)->second;
uint32_t hblank = v4l2HBlank.def().get<int32_t>();
uint32_t lineLength = sensorInfo.outputSize.width + hblank;
const ControlInfo &v4l2VBlank = sensorControls.find(V4L2_CID_VBLANK)->second;
std::array<uint32_t, 3> frameHeights{
v4l2VBlank.min().get<int32_t>() + sensorInfo.outputSize.height,
v4l2VBlank.max().get<int32_t>() + sensorInfo.outputSize.height,
v4l2VBlank.def().get<int32_t>() + sensorInfo.outputSize.height,
};
std::array<int64_t, 3> frameDurations;
for (unsigned int i = 0; i < frameHeights.size(); ++i) {
uint64_t frameSize = lineLength * frameHeights[i];
frameDurations[i] = frameSize / (sensorInfo.pixelRate / 1000000U);
}
controls[&controls::FrameDurationLimits] = ControlInfo(frameDurations[0],
frameDurations[1],
frameDurations[2]);
*ipaControls = ControlInfoMap(std::move(controls), controls::controls);
}
/**
* \brief Initialize the IPA module and its controls
*
* This function receives the camera sensor information from the pipeline
* handler, computes the limits of the controls it handles and returns
* them in the \a ipaControls output parameter.
*/
int IPAIPU3::init(const IPASettings &settings,
const IPACameraSensorInfo &sensorInfo,
const ControlInfoMap &sensorControls,
ControlInfoMap *ipaControls)
{
camHelper_ = CameraSensorHelperFactory::create(settings.sensorModel);
if (camHelper_ == nullptr) {
LOG(IPAIPU3, Error)
<< "Failed to create camera sensor helper for "
<< settings.sensorModel;
return -ENODEV;
}
/* Clean context */
context_ = {};
context_.configuration.sensor.lineDuration = sensorInfo.lineLength * 1.0s / sensorInfo.pixelRate;
/* Construct our Algorithms */
algorithms_.push_back(std::make_unique<algorithms::Af>());
algorithms_.push_back(std::make_unique<algorithms::Agc>());
algorithms_.push_back(std::make_unique<algorithms::Awb>());
algorithms_.push_back(std::make_unique<algorithms::BlackLevelCorrection>());
algorithms_.push_back(std::make_unique<algorithms::ToneMapping>());
/* Initialize controls. */
updateControls(sensorInfo, sensorControls, ipaControls);
return 0;
}
/**
* \brief Perform any processing required before the first frame
*/
int IPAIPU3::start()
{
/*
* Set the sensors V4L2 controls before the first frame to ensure that
* we have an expected and known configuration from the start.
*/
setControls(0);
return 0;
}
/**
* \brief Ensure that all processing has completed
*/
void IPAIPU3::stop()
{
}
/**
* \brief Calculate a grid for the AWB statistics
*
* This function calculates a grid for the AWB algorithm in the IPU3 firmware.
* Its input is the BDS output size calculated in the ImgU.
* It is limited for now to the simplest method: find the lesser error
* with the width/height and respective log2 width/height of the cells.
*
* \todo The frame is divided into cells which can be 8x8 => 64x64.
* As a smaller cell improves the algorithm precision, adapting the
* x_start and y_start parameters of the grid would provoke a loss of
* some pixels but would also result in more accurate algorithms.
*/
void IPAIPU3::calculateBdsGrid(const Size &bdsOutputSize)
{
Size best;
Size bestLog2;
/* Set the BDS output size in the IPAConfiguration structure */
context_.configuration.grid.bdsOutputSize = bdsOutputSize;
uint32_t minError = std::numeric_limits<uint32_t>::max();
for (uint32_t shift = kMinCellSizeLog2; shift <= kMaxCellSizeLog2; ++shift) {
uint32_t width = std::clamp(bdsOutputSize.width >> shift,
kMinGridWidth,
kMaxGridWidth);
width = width << shift;
uint32_t error = utils::abs_diff(width, bdsOutputSize.width);
if (error >= minError)
continue;
minError = error;
best.width = width;
bestLog2.width = shift;
}
minError = std::numeric_limits<uint32_t>::max();
for (uint32_t shift = kMinCellSizeLog2; shift <= kMaxCellSizeLog2; ++shift) {
uint32_t height = std::clamp(bdsOutputSize.height >> shift,
kMinGridHeight,
kMaxGridHeight);
height = height << shift;
uint32_t error = utils::abs_diff(height, bdsOutputSize.height);
if (error >= minError)
continue;
minError = error;
best.height = height;
bestLog2.height = shift;
}
struct ipu3_uapi_grid_config &bdsGrid = context_.configuration.grid.bdsGrid;
bdsGrid.x_start = 0;
bdsGrid.y_start = 0;
bdsGrid.width = best.width >> bestLog2.width;
bdsGrid.block_width_log2 = bestLog2.width;
bdsGrid.height = best.height >> bestLog2.height;
bdsGrid.block_height_log2 = bestLog2.height;
/* The ImgU pads the lines to a multiple of 4 cells. */
context_.configuration.grid.stride = utils::alignUp(bdsGrid.width, 4);
LOG(IPAIPU3, Debug) << "Best grid found is: ("
<< (int)bdsGrid.width << " << " << (int)bdsGrid.block_width_log2 << ") x ("
<< (int)bdsGrid.height << " << " << (int)bdsGrid.block_height_log2 << ")";
}
/**
* \brief Configure the IPU3 IPA
* \param[in] configInfo The IPA configuration data, received from the pipeline
* handler
* \param[in] ipaControls The IPA controls to update
*
* Calculate the best grid for the statistics based on the pipeline handler BDS
* output, and parse the minimum and maximum exposure and analogue gain control
* values.
*
* \todo Document what the BDS is, ideally in a block diagram of the ImgU.
*
* All algorithm modules are called to allow them to prepare the
* \a IPASessionConfiguration structure for the \a IPAContext.
*/
int IPAIPU3::configure(const IPAConfigInfo &configInfo,
ControlInfoMap *ipaControls)
{
if (configInfo.sensorControls.empty()) {
LOG(IPAIPU3, Error) << "No sensor controls provided";
return -ENODATA;
}
sensorInfo_ = configInfo.sensorInfo;
lensCtrls_ = configInfo.lensControls;
/*
* Compute the sensor V4L2 controls to be used by the algorithms and
* to be set on the sensor.
*/
sensorCtrls_ = configInfo.sensorControls;
const auto itExp = sensorCtrls_.find(V4L2_CID_EXPOSURE);
if (itExp == sensorCtrls_.end()) {
LOG(IPAIPU3, Error) << "Can't find exposure control";
return -EINVAL;
}
const auto itGain = sensorCtrls_.find(V4L2_CID_ANALOGUE_GAIN);
if (itGain == sensorCtrls_.end()) {
LOG(IPAIPU3, Error) << "Can't find gain control";
return -EINVAL;
}
const auto itVBlank = sensorCtrls_.find(V4L2_CID_VBLANK);
if (itVBlank == sensorCtrls_.end()) {
LOG(IPAIPU3, Error) << "Can't find VBLANK control";
return -EINVAL;
}
minExposure_ = itExp->second.min().get<int32_t>();
maxExposure_ = itExp->second.max().get<int32_t>();
exposure_ = minExposure_;
minGain_ = itGain->second.min().get<int32_t>();
maxGain_ = itGain->second.max().get<int32_t>();
gain_ = minGain_;
defVBlank_ = itVBlank->second.def().get<int32_t>();
calculateBdsGrid(configInfo.bdsOutputSize);
/* Clean frameContext at each reconfiguration. */
context_.frameContext = {};
/* Update the camera controls using the new sensor settings. */
updateControls(sensorInfo_, sensorCtrls_, ipaControls);
/* Update the IPASessionConfiguration using the sensor settings. */
updateSessionConfiguration(sensorCtrls_);
for (auto const &algo : algorithms_) {
int ret = algo->configure(context_, configInfo);
if (ret)
return ret;
}
return 0;
}
/**
* \brief Map the parameters and stats buffers allocated in the pipeline handler
* \param[in] buffers The buffers to map
*/
void IPAIPU3::mapBuffers(const std::vector<IPABuffer> &buffers)
{
for (const IPABuffer &buffer : buffers) {
const FrameBuffer fb(buffer.planes);
buffers_.emplace(buffer.id,
MappedFrameBuffer(&fb, MappedFrameBuffer::MapFlag::ReadWrite));
}
}
/**
* \brief Unmap the parameters and stats buffers
* \param[in] ids The IDs of the buffers to unmap
*/
void IPAIPU3::unmapBuffers(const std::vector<unsigned int> &ids)
{
for (unsigned int id : ids) {
auto it = buffers_.find(id);
if (it == buffers_.end())
continue;
buffers_.erase(it);
}
}
/**
* \brief Process an event generated by the pipeline handler
* \param[in] event The event sent from pipeline handler
*
* The expected event handling over the lifetime of a Request has
* the following sequence:
*
* - EventProcessControls : Handle controls from a new Request
* - EventFillParams : Prepare the ISP to process the Request
* - EventStatReady : Process statistics after ISP completion
*/
void IPAIPU3::processEvent(const IPU3Event &event)
{
switch (event.op) {
case EventProcessControls: {
processControls(event.frame, event.controls);
break;
}
case EventFillParams: {
auto it = buffers_.find(event.bufferId);
if (it == buffers_.end()) {
LOG(IPAIPU3, Error) << "Could not find param buffer!";
return;
}
Span<uint8_t> mem = it->second.planes()[0];
ipu3_uapi_params *params =
reinterpret_cast<ipu3_uapi_params *>(mem.data());
fillParams(event.frame, params);
break;
}
case EventStatReady: {
auto it = buffers_.find(event.bufferId);
if (it == buffers_.end()) {
LOG(IPAIPU3, Error) << "Could not find stats buffer!";
return;
}
Span<uint8_t> mem = it->second.planes()[0];
const ipu3_uapi_stats_3a *stats =
reinterpret_cast<ipu3_uapi_stats_3a *>(mem.data());
int32_t exposure = event.sensorControls.get(V4L2_CID_EXPOSURE).get<int32_t>();
int32_t gain = event.sensorControls.get(V4L2_CID_ANALOGUE_GAIN).get<int32_t>();
context_.frameContext.sensor.exposure = exposure;
context_.frameContext.sensor.gain = camHelper_->gain(gain);
parseStatistics(event.frame, event.frameTimestamp, stats);
break;
}
default:
LOG(IPAIPU3, Error) << "Unknown event " << event.op;
break;
}
}
/**
* \brief Process a control list for a request from the application
* \param[in] frame The number of the frame which will be processed next
* \param[in] controls The controls for the \a frame
*
* Parse the request to handle any IPA-managed controls that were set from the
* application such as manual sensor settings.
*/
void IPAIPU3::processControls([[maybe_unused]] unsigned int frame,
[[maybe_unused]] const ControlList &controls)
{
/* \todo Start processing for 'frame' based on 'controls'. */
}
/**
* \brief Fill the ImgU parameter buffer for the next frame
* \param[in] frame The number of the latest frame processed
* \param[out] params The parameter buffer to fill
*
* Algorithms are expected to fill the IPU3 parameter buffer for the next
* frame given their most recent processing of the ImgU statistics.
*/
void IPAIPU3::fillParams(unsigned int frame, ipu3_uapi_params *params)
{
/*
* The incoming params buffer may contain uninitialised data, or the
* parameters of previously queued frames. Clearing the entire buffer
* may be an expensive operation, and the kernel will only read from
* structures which have their associated use-flag set.
*
* It is the responsibility of the algorithms to set the use flags
* accordingly for any data structure they update during prepare().
*/
params->use = {};
for (auto const &algo : algorithms_)
algo->prepare(context_, params);
IPU3Action op;
op.op = ActionParamFilled;
queueFrameAction.emit(frame, op);
}
/**
* \brief Process the statistics generated by the ImgU
* \param[in] frame The number of the latest frame processed
* \param[in] frameTimestamp The current frame timestamp
* \param[in] stats The IPU3 statistics and ISP results
*
* Parse the most recently processed image statistics from the ImgU. The
* statistics are passed to each algorithm module to run their calculations and
* update their state accordingly.
*/
void IPAIPU3::parseStatistics(unsigned int frame,
[[maybe_unused]] int64_t frameTimestamp,
const ipu3_uapi_stats_3a *stats)
{
double lineDuration = context_.configuration.sensor.lineDuration.get<std::micro>();
ControlList ctrls(controls::controls);
for (auto const &algo : algorithms_)
algo->process(context_, stats);
setControls(frame);
/* \todo Use VBlank value calculated from each frame exposure. */
int64_t frameDuration = (defVBlank_ + sensorInfo_.outputSize.height) * lineDuration;
ctrls.set(controls::FrameDuration, frameDuration);
ctrls.set(controls::AnalogueGain, context_.frameContext.sensor.gain);
ctrls.set(controls::ColourTemperature, context_.frameContext.awb.temperatureK);
ctrls.set(controls::ExposureTime, context_.frameContext.sensor.exposure * lineDuration);
/*
* \todo The Metadata provides a path to getting extended data
* out to the application. Further data such as a simplifed Histogram
* might have value to be exposed, however such data may be
* difficult to report in a generically parsable way and we
* likely want to avoid putting platform specific metadata in.
*/
IPU3Action op;
op.op = ActionMetadataReady;
op.controls = ctrls;
queueFrameAction.emit(frame, op);
}
/**
* \brief Handle sensor controls for a given \a frame number
* \param[in] frame The frame on which the sensor controls should be set
*
* Send the desired sensor control values to the pipeline handler to request
* that they are applied on the camera sensor.
*/
void IPAIPU3::setControls(unsigned int frame)
{
IPU3Action op;
op.op = ActionSetSensorControls;
exposure_ = context_.frameContext.agc.exposure;
gain_ = camHelper_->gainCode(context_.frameContext.agc.gain);
ControlList ctrls(sensorCtrls_);
ctrls.set(V4L2_CID_EXPOSURE, static_cast<int32_t>(exposure_));
ctrls.set(V4L2_CID_ANALOGUE_GAIN, static_cast<int32_t>(gain_));
op.sensorControls = ctrls;
ControlList lensCtrls(lensCtrls_);
lensCtrls.set(V4L2_CID_FOCUS_ABSOLUTE,
static_cast<int32_t>(context_.frameContext.af.focus));
op.lensControls = lensCtrls;
queueFrameAction.emit(frame, op);
}
} /* namespace ipa::ipu3 */
/**
* \brief External IPA module interface
*
* The IPAModuleInfo is required to match an IPA module construction against the
* intented pipeline handler with the module. The API and pipeline handler
* versions must match the corresponding IPA interface and pipeline handler.
*
* \sa struct IPAModuleInfo
*/
extern "C" {
const struct IPAModuleInfo ipaModuleInfo = {
IPA_MODULE_API_VERSION,
1,
"PipelineHandlerIPU3",
"ipu3",
};
/**
* \brief Create an instance of the IPA interface
*
* This function is the entry point of the IPA module. It is called by the IPA
* manager to create an instance of the IPA interface for each camera. When
* matched against with a pipeline handler, the IPAManager will construct an IPA
* instance for each associated Camera.
*/
IPAInterface *ipaCreate()
{
return new ipa::ipu3::IPAIPU3();
}
}
} /* namespace libcamera */