[libcamera-devel] [PATCH v1 11/14] ipa: raspberrypi: First version of autofocus algorithm using PDAF
Kieran Bingham
kieran.bingham at ideasonboard.com
Thu Jan 19 14:00:15 CET 2023
Hi Nick, Naush,
I was soo close to merging this series in one... but alas there's a minor
compiler issue in this one.
Quoting Naushir Patuck via libcamera-devel (2023-01-19 10:45:41)
> From: Nick Hollinghurst <nick.hollinghurst at raspberrypi.com>
>
> Provide the first version of the Raspberry Pi autofocus algorithm. This
> implementation uses a hybrid of contrast detect autofocus (CDAF) and phase
> detect autofocus (PDAF) statistics. PDAF is always preferred over CDAF due to
> having less "hunting" behavior.
>
> Signed-off-by: Nick Hollinghurst <nick.hollinghurst at raspberrypi.com>
> Signed-off-by: Naushir Patuck <naush at raspberrypi.com>
> Reviewed-by: Naushir Patuck <naush at raspberrypi.com>
> Reviewed-by: David Plowman <david.plowman at raspberrypi.com>
> ---
> src/ipa/raspberrypi/controller/rpi/af.cpp | 755 ++++++++++++++++++++++
> src/ipa/raspberrypi/controller/rpi/af.h | 153 +++++
> src/ipa/raspberrypi/meson.build | 1 +
> 3 files changed, 909 insertions(+)
> create mode 100644 src/ipa/raspberrypi/controller/rpi/af.cpp
> create mode 100644 src/ipa/raspberrypi/controller/rpi/af.h
>
> diff --git a/src/ipa/raspberrypi/controller/rpi/af.cpp b/src/ipa/raspberrypi/controller/rpi/af.cpp
> new file mode 100644
> index 000000000000..7e2e8961085a
> --- /dev/null
> +++ b/src/ipa/raspberrypi/controller/rpi/af.cpp
> @@ -0,0 +1,755 @@
> +/* SPDX-License-Identifier: BSD-2-Clause */
> +/*
> + * Copyright (C) 2022-2023, Raspberry Pi Ltd
> + *
> + * af.cpp - Autofocus control algorithm
> + */
> +
> +#include "af.h"
> +
> +#include <iomanip>
> +#include <math.h>
> +#include <stdlib.h>
> +
> +#include <libcamera/base/log.h>
> +
> +#include <libcamera/control_ids.h>
> +
> +using namespace RPiController;
> +using namespace libcamera;
> +
> +LOG_DEFINE_CATEGORY(RPiAf)
> +
> +#define NAME "rpi.af"
> +
> +/*
> + * Default values for parameters. All may be overridden in the tuning file.
> + * Many of these values are sensor- or module-dependent; the defaults here
> + * assume IMX708 in a Raspberry Pi V3 camera with the standard lens.
> + *
> + * Here all focus values are in dioptres (1/m). They are converted to hardware
> + * units when written to status.lensSetting or returned from setLensPosition().
> + *
> + * Gain and delay values are relative to the update rate, since much (not all)
> + * of the delay is in the sensor and (for CDAF) ISP, not the lens mechanism;
> + * but note that algorithms are updated at no more than 30 Hz.
> + */
> +
> +Af::RangeDependentParams::RangeDependentParams()
> + : focusMin(0.0),
> + focusMax(12.0),
> + focusDefault(1.0)
> +{
> +}
> +
> +Af::SpeedDependentParams::SpeedDependentParams()
> + : stepCoarse(1.0),
> + stepFine(0.25),
> + contrastRatio(0.75),
> + pdafGain(-0.02),
> + pdafSquelch(0.125),
> + maxSlew(2.0),
> + pdafFrames(20),
> + dropoutFrames(6),
> + stepFrames(4)
> +{
> +}
> +
> +Af::CfgParams::CfgParams()
> + : confEpsilon(8),
> + confThresh(16),
> + confClip(512),
> + skipFrames(5),
> + map()
> +{
> +}
> +
> +template<typename T>
> +static void readNumber(T &dest, const libcamera::YamlObject ¶ms, char const *name)
> +{
> + auto value = params[name].get<T>();
> + if (value)
> + dest = *value;
> + else
> + LOG(RPiAf, Warning) << "Missing parameter \"" << name << "\"";
> +}
> +
> +void Af::RangeDependentParams::read(const libcamera::YamlObject ¶ms)
> +{
> +
> + readNumber<double>(focusMin, params, "min");
> + readNumber<double>(focusMax, params, "max");
> + readNumber<double>(focusDefault, params, "default");
> +}
> +
> +void Af::SpeedDependentParams::read(const libcamera::YamlObject ¶ms)
> +{
> + readNumber<double>(stepCoarse, params, "step_coarse");
> + readNumber<double>(stepFine, params, "step_fine");
> + readNumber<double>(contrastRatio, params, "contrast_ratio");
> + readNumber<double>(pdafGain, params, "pdaf_gain");
> + readNumber<double>(pdafSquelch, params, "pdaf_squelch");
> + readNumber<double>(maxSlew, params, "max_slew");
> + readNumber<uint32_t>(pdafFrames, params, "pdaf_frames");
> + readNumber<uint32_t>(dropoutFrames, params, "dropout_frames");
> + readNumber<uint32_t>(stepFrames, params, "step_frames");
> +}
> +
> +int Af::CfgParams::read(const libcamera::YamlObject ¶ms)
> +{
> + if (params.contains("ranges")) {
> + auto &rr = params["ranges"];
> +
> + if (rr.contains("normal"))
> + ranges[AfRangeNormal].read(rr["normal"]);
> + else
> + LOG(RPiAf, Warning) << "Missing range \"normal\"";
> +
> + ranges[AfRangeMacro] = ranges[AfRangeNormal];
> + if (rr.contains("macro"))
> + ranges[AfRangeMacro].read(rr["macro"]);
> +
> + ranges[AfRangeFull].focusMin = std::min(ranges[AfRangeNormal].focusMin,
> + ranges[AfRangeMacro].focusMin);
> + ranges[AfRangeFull].focusMax = std::max(ranges[AfRangeNormal].focusMax,
> + ranges[AfRangeMacro].focusMax);
> + ranges[AfRangeFull].focusDefault = ranges[AfRangeNormal].focusDefault;
> + if (rr.contains("full"))
> + ranges[AfRangeFull].read(rr["full"]);
> + } else
> + LOG(RPiAf, Warning) << "No ranges defined";
> +
> + if (params.contains("speeds")) {
> + auto &ss = params["speeds"];
> +
> + if (ss.contains("normal"))
> + speeds[AfSpeedNormal].read(ss["normal"]);
> + else
> + LOG(RPiAf, Warning) << "Missing speed \"normal\"";
> +
> + speeds[AfSpeedFast] = speeds[AfSpeedNormal];
> + if (ss.contains("fast"))
> + speeds[AfSpeedFast].read(ss["fast"]);
> + } else
> + LOG(RPiAf, Warning) << "No speeds defined";
> +
> + readNumber<uint32_t>(confEpsilon, params, "conf_epsilon");
> + readNumber<uint32_t>(confThresh, params, "conf_thresh");
> + readNumber<uint32_t>(confClip, params, "conf_clip");
> + readNumber<uint32_t>(skipFrames, params, "skip_frames");
> +
> + if (params.contains("map"))
> + map.read(params["map"]);
> + else
> + LOG(RPiAf, Warning) << "No map defined";
> +
> + return 0;
> +}
> +
> +void Af::CfgParams::initialise()
> +{
> + if (map.empty()) {
> + /* Default mapping from dioptres to hardware setting */
> + static constexpr double DefaultMapX0 = 0.0;
> + static constexpr double DefaultMapY0 = 445.0;
> + static constexpr double DefaultMapX1 = 15.0;
> + static constexpr double DefaultMapY1 = 925.0;
> +
> + map.append(DefaultMapX0, DefaultMapY0);
> + map.append(DefaultMapX1, DefaultMapY1);
> +
> + LOG(RPiAf, Warning) << "af.map is not defined, ";
> + }
> +}
> +
> +/* Af Algorithm class */
> +
> +Af::Af(Controller *controller)
> + : AfAlgorithm(controller),
> + cfg_(),
> + range_(AfRangeNormal),
> + speed_(AfSpeedNormal),
> + mode_(AfAlgorithm::AfModeManual),
> + pauseFlag_(false),
> + sensorSize_{ 0, 0 },
> + useWeights_(false),
> + phaseWeights_{},
> + contrastWeights_{},
> + scanState_(ScanState::Idle),
> + initted_(false),
> + ftarget_(-1.0),
> + fsmooth_(-1.0),
> + prevContrast_(0.0),
> + skipCount_(0),
> + stepCount_(0),
> + dropCount_(0),
> + scanMaxContrast_(0.0),
> + scanMinContrast_(1.0e9),
> + scanData_(),
> + reportState_(AfState::Idle)
> +{
> + scanData_.reserve(24);
> +}
> +
> +Af::~Af()
> +{
> +}
> +
> +char const *Af::name() const
> +{
> + return NAME;
> +}
> +
> +int Af::read(const libcamera::YamlObject ¶ms)
> +{
> + return cfg_.read(params);
> +}
> +
> +void Af::initialise()
> +{
> + cfg_.initialise();
> +}
> +
> +void Af::switchMode(CameraMode const &cameraMode, [[maybe_unused]] Metadata *metadata)
> +{
> + (void)metadata;
> + sensorSize_.width = cameraMode.sensorWidth;
> + sensorSize_.height = cameraMode.sensorHeight;
> +
> + if (scanState_ >= ScanState::Coarse && scanState_ < ScanState::Settle) {
> + /*
> + * If a scan was in progress, re-start it, as CDAF statistics
> + * may have changed. Though if the application is just about
> + * to take a still picture, this will not help...
> + */
> + startProgrammedScan();
> + }
> + skipCount_ = cfg_.skipFrames;
> +}
> +
> +bool Af::getPhase(PdafData const &data, double &phase, double &conf) const
> +{
> + static const uint8_t defaultWeights[PDAF_DATA_ROWS][PDAF_DATA_COLS] = {
> + { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
> + { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
> + { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
> + { 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0 },
> + { 0, 0, 0, 0, 2, 4, 4, 4, 4, 4, 4, 2, 0, 0, 0, 0 },
> + { 0, 0, 0, 0, 2, 4, 4, 4, 4, 4, 4, 2, 0, 0, 0, 0 },
> + { 0, 0, 0, 0, 2, 4, 4, 4, 4, 4, 4, 2, 0, 0, 0, 0 },
> + { 0, 0, 0, 0, 2, 4, 4, 4, 4, 4, 4, 2, 0, 0, 0, 0 },
> + { 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0 },
> + { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
> + { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
> + { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }
> + };
> + int32_t sumW = 0;
> + int32_t sumWc = 0;
> + int32_t sumWcp = 0;
> + auto wgts = useWeights_ ? phaseWeights_ : defaultWeights;
> +
> + for (unsigned i = 0; i < PDAF_DATA_ROWS; ++i) {
> + for (unsigned j = 0; j < PDAF_DATA_COLS; ++j) {
> + if (wgts[i][j]) {
> + uint32_t c = data.conf[i][j];
> + if (c >= cfg_.confThresh) {
> + if (c > cfg_.confClip)
> + c = cfg_.confClip;
> + sumWc += wgts[i][j] * (int32_t)c;
> + c -= (cfg_.confThresh >> 1);
> + sumWcp += wgts[i][j] * data.phase[i][j] * (int32_t)c;
> + }
> + sumW += wgts[i][j];
> + }
> + }
> + }
> +
> + if (sumWc > 0) {
> + phase = (double)sumWcp / (double)sumWc;
> + conf = (double)sumWc / (double)sumW;
> + return true;
> + } else {
> + phase = 0.0;
> + conf = 0.0;
> + return false;
> + }
> +}
> +
> +void Af::doPDAF(double phase, double conf)
> +{
> + /* Apply loop gain */
> + phase *= cfg_.speeds[speed_].pdafGain;
> +
> + if (mode_ == AfModeContinuous) {
> + /*
> + * PDAF in Continuous mode. Scale down lens movement when
> + * delta is small or confidence is low, to suppress wobble.
> + */
> + if (std::abs(phase) < cfg_.speeds[speed_].pdafSquelch) {
> + double a = phase / cfg_.speeds[speed_].pdafSquelch;
> + phase *= a * a;
> + }
> + phase *= conf / (conf + cfg_.confEpsilon);
> + } else {
> + /*
> + * PDAF in triggered-auto mode. Allow early termination when
> + * phase delta is small; scale down lens movements towards
> + * the end of the sequence, to ensure a stable image.
> + */
> + if (stepCount_ >= cfg_.speeds[speed_].stepFrames) {
> + if (std::abs(phase) < cfg_.speeds[speed_].pdafSquelch)
> + stepCount_ = cfg_.speeds[speed_].stepFrames;
> + } else
> + phase *= stepCount_ / cfg_.speeds[speed_].stepFrames;
> + }
> +
> + /* Apply slew rate limit. Report failure if out of bounds. */
> + if (phase < -cfg_.speeds[speed_].maxSlew) {
> + phase = -cfg_.speeds[speed_].maxSlew;
> + reportState_ = (ftarget_ <= cfg_.ranges[range_].focusMin) ? AfState::Failed
> + : AfState::Scanning;
> + } else if (phase > cfg_.speeds[speed_].maxSlew) {
> + phase = cfg_.speeds[speed_].maxSlew;
> + reportState_ = (ftarget_ >= cfg_.ranges[range_].focusMax) ? AfState::Failed
> + : AfState::Scanning;
> + } else
> + reportState_ = AfState::Focused;
> +
> + ftarget_ = fsmooth_ + phase;
> +}
> +
> +bool Af::earlyTerminationByPhase(double phase)
> +{
> + if (scanData_.size() > 0 &&
> + scanData_[scanData_.size() - 1].conf >= cfg_.confEpsilon) {
> + double oldFocus = scanData_[scanData_.size() - 1].focus;
> + double oldPhase = scanData_[scanData_.size() - 1].phase;
> +
> + /*
> + * Check that the gradient is finite and has the expected sign;
> + * Interpolate/extrapolate the lens position for zero phase.
> + * Check that the extrapolation is well-conditioned.
> + */
> + if ((ftarget_ - oldFocus) * (phase - oldPhase) > 0.0) {
> + double param = phase / (phase - oldPhase);
> + if (-3.0 <= param && param <= 3.5) {
> + ftarget_ += param * (oldFocus - ftarget_);
> + LOG(RPiAf, Debug) << "ETBP: param=" << param;
> + return true;
> + }
> + }
> + }
> +
> + return false;
> +}
> +
> +double Af::findPeak(unsigned i) const
> +{
> + double f = scanData_[i].focus;
> +
> + if (i > 0 && i + 1 < scanData_.size()) {
> + double dropLo = scanData_[i].contrast - scanData_[i - 1].contrast;
> + double dropHi = scanData_[i].contrast - scanData_[i + 1].contrast;
> + if (dropLo < dropHi) {
> + double param = 0.3125 * (1.0 - dropLo / dropHi) * (1.6 - dropLo / dropHi);
> + f += param * (scanData_[i - 1].focus - f);
> + } else if (dropHi < dropLo) {
> + double param = 0.3125 * (1.0 - dropHi / dropLo) * (1.6 - dropHi / dropLo);
> + f += param * (scanData_[i + 1].focus - f);
> + }
> + }
> +
> + LOG(RPiAf, Debug) << "FindPeak: " << f;
> + return f;
> +}
> +
> +void Af::doScan(double contrast, double phase, double conf)
> +{
> + /* Record lens position, contrast and phase values for the current scan */
> + if (scanData_.empty() || contrast > scanMaxContrast_) {
> + scanMaxContrast_ = contrast;
> + scanMaxIndex_ = scanData_.size();
> + }
> + if (contrast < scanMinContrast_)
> + scanMinContrast_ = contrast;
> + scanData_.emplace_back(ScanRecord{ ftarget_, contrast, phase, conf });
> +
> + if (scanState_ == ScanState::Coarse) {
> + if (ftarget_ >= cfg_.ranges[range_].focusMax ||
> + contrast < cfg_.speeds[speed_].contrastRatio * scanMaxContrast_) {
> + /*
> + * Finished course scan, or termination based on contrast.
> + * Jump to just after max contrast and start fine scan.
> + */
> + ftarget_ = std::min(ftarget_, findPeak(scanMaxIndex_) +
> + 2.0 * cfg_.speeds[speed_].stepFine);
> + scanState_ = ScanState::Fine;
> + scanData_.clear();
> + } else
> + ftarget_ += cfg_.speeds[speed_].stepCoarse;
> + } else { /* ScanState::Fine */
> + if (ftarget_ <= cfg_.ranges[range_].focusMin || scanData_.size() >= 5 ||
> + contrast < cfg_.speeds[speed_].contrastRatio * scanMaxContrast_) {
> + /*
> + * Finished fine scan, or termination based on contrast.
> + * Use quadratic peak-finding to find best contrast position.
> + */
> + ftarget_ = findPeak(scanMaxIndex_);
> + scanState_ = ScanState::Settle;
> + } else
> + ftarget_ -= cfg_.speeds[speed_].stepFine;
> + }
> +
> + stepCount_ = (ftarget_ == fsmooth_) ? 0 : cfg_.speeds[speed_].stepFrames;
> +}
> +
> +void Af::doAF(double contrast, double phase, double conf)
> +{
> + /* Skip frames at startup and after mode change */
> + if (skipCount_ > 0) {
> + LOG(RPiAf, Debug) << "SKIP";
> + skipCount_--;
> + return;
> + }
> +
> + if (scanState_ == ScanState::Pdaf) {
> + /*
> + * Use PDAF closed-loop control whenever available, in both CAF
> + * mode and (for a limited number of iterations) when triggered.
> + * If PDAF fails (due to poor contrast, noise or large defocus),
> + * fall back to a CDAF-based scan. To avoid "nuisance" scans,
> + * scan only after a number of frames with low PDAF confidence.
> + */
> + if (conf > (dropCount_ ? cfg_.confEpsilon : 0.0)) {
> + doPDAF(phase, conf);
> + if (stepCount_ > 0)
> + stepCount_--;
> + else if (mode_ != AfModeContinuous)
> + scanState_ = ScanState::Idle;
> + dropCount_ = 0;
> + } else if (++dropCount_ == cfg_.speeds[speed_].dropoutFrames)
> + startProgrammedScan();
> + } else if (scanState_ >= ScanState::Coarse && fsmooth_ == ftarget_) {
> + /*
> + * Scanning sequence. This means PDAF has become unavailable.
> + * Allow a delay between steps for CDAF FoM statistics to be
> + * updated, and a "settling time" at the end of the sequence.
> + * [A coarse or fine scan can be abandoned if two PDAF samples
> + * allow direct interpolation of the zero-phase lens position.]
> + */
> + if (stepCount_ > 0)
> + stepCount_--;
> + else if (scanState_ == ScanState::Settle) {
> + if (prevContrast_ >= cfg_.speeds[speed_].contrastRatio * scanMaxContrast_ &&
> + scanMinContrast_ <= cfg_.speeds[speed_].contrastRatio * scanMaxContrast_)
> + reportState_ = AfState::Focused;
> + else
> + reportState_ = AfState::Failed;
> + if (mode_ == AfModeContinuous && !pauseFlag_ &&
> + cfg_.speeds[speed_].dropoutFrames > 0)
> + scanState_ = ScanState::Pdaf;
> + else
> + scanState_ = ScanState::Idle;
> + scanData_.clear();
> + } else if (conf >= cfg_.confEpsilon && earlyTerminationByPhase(phase)) {
> + scanState_ = ScanState::Settle;
> + stepCount_ = (mode_ == AfModeContinuous) ? 0
> + : cfg_.speeds[speed_].stepFrames;
> + } else
> + doScan(contrast, phase, conf);
> + }
> +}
> +
> +void Af::updateLensPosition()
> +{
> + if (mode_ != AfModeManual) {
> + ftarget_ = std::clamp(ftarget_,
> + cfg_.ranges[range_].focusMin,
> + cfg_.ranges[range_].focusMax);
> + }
> +
> + /* \todo Add a clip for manual lens position to be within the PWL limits. */
> +
> + if (initted_) {
> + /* from a known lens position: apply slew rate limit */
> + fsmooth_ = std::clamp(ftarget_,
> + fsmooth_ - cfg_.speeds[speed_].maxSlew,
> + fsmooth_ + cfg_.speeds[speed_].maxSlew);
> + } else {
> + /* from an unknown position: go straight to target, but add delay */
> + fsmooth_ = ftarget_;
> + initted_ = true;
> + skipCount_ = cfg_.skipFrames;
> + }
> +}
> +
> +/*
> + * PDAF phase data are available in prepare(), but CDAF statistics are not
> + * available until process(). We are gambling on the availability of PDAF.
> + * To expedite feedback control using PDAF, issue the V4L2 lens control from
> + * prepare(). Conversely, during scans, we must allow an extra frame delay
> + * between steps, to retrieve CDAF statistics from the previous process()
> + * so we can terminate the scan early without having to change our minds.
> + */
> +
> +void Af::prepare(Metadata *imageMetadata)
> +{
> + if (initted_) {
> + /* Get PDAF from the embedded metadata, and run AF algorithm core */
> + PdafData data;
> + double phase = 0.0, conf = 0.0;
> + double oldFt = ftarget_;
> + double oldFs = fsmooth_;
> + ScanState oldSs = scanState_;
> + uint32_t oldSt = stepCount_;
> + if (imageMetadata->get("pdaf.data", data) == 0)
> + getPhase(data, phase, conf);
> + doAF(prevContrast_, phase, conf);
> + updateLensPosition();
> + LOG(RPiAf, Debug) << std::fixed << std::setprecision(2)
> + << static_cast<unsigned int>(reportState_)
> + << " sst" << static_cast<unsigned int>(oldSs)
> + << "->" << static_cast<unsigned int>(scanState_)
> + << " stp" << oldSt << "->" << stepCount_
> + << " ft" << oldFt << "->" << ftarget_
> + << " fs" << oldFs << "->" << fsmooth_
> + << " cont=" << (int)prevContrast_
> + << " phase=" << (int)phase << " conf=" << (int)conf;
> + }
> +
> + /* Report status and produce new lens setting */
> + AfStatus status;
> + if (pauseFlag_)
> + status.pauseState = (scanState_ == ScanState::Idle) ? AfPauseState::Paused
> + : AfPauseState::Pausing;
> + else
> + status.pauseState = AfPauseState::Running;
> +
> + if (mode_ == AfModeAuto && scanState_ != ScanState::Idle)
> + status.state = AfState::Scanning;
> + else
> + status.state = reportState_;
> + status.lensSetting = initted_ ? std::optional<int>(cfg_.map.eval(fsmooth_))
> + : std::nullopt;
> + imageMetadata->set("af.status", status);
> +}
> +
> +double Af::getContrast(struct bcm2835_isp_stats_focus const focus_stats[FOCUS_REGIONS]) const
> +{
> + uint32_t totW = 0, totWc = 0;
> +
> + if (useWeights_) {
> + for (unsigned i = 0; i < FOCUS_REGIONS; ++i) {
> + unsigned w = contrastWeights_[i];
> + totW += w;
> + totWc += w * (focus_stats[i].contrast_val[1][1] >> 10);
> + }
> + }
> + if (totW == 0) {
> + totW = 2;
> + totWc = (focus_stats[5].contrast_val[1][1] >> 10) +
> + (focus_stats[6].contrast_val[1][1] >> 10);
> + }
> +
> + return (double)totWc / (double)totW;
> +}
> +
> +void Af::process(StatisticsPtr &stats, [[maybe_unused]] Metadata *imageMetadata)
> +{
> + (void)imageMetadata;
> + prevContrast_ = getContrast(stats->focus_stats);
> +}
> +
> +/* Controls */
> +
> +void Af::setRange(AfRange r)
> +{
> + LOG(RPiAf, Debug) << "setRange: " << (unsigned)r;
> + if (r < AfAlgorithm::AfRangeMax)
> + range_ = r;
> +}
> +
> +void Af::setSpeed(AfSpeed s)
> +{
> + LOG(RPiAf, Debug) << "setSpeed: " << (unsigned)s;
> + if (s < AfAlgorithm::AfSpeedMax) {
> + if (scanState_ == ScanState::Pdaf &&
> + cfg_.speeds[s].pdafFrames > cfg_.speeds[speed_].pdafFrames)
> + stepCount_ += cfg_.speeds[s].pdafFrames - cfg_.speeds[speed_].pdafFrames;
> + speed_ = s;
> + }
> +}
> +
> +void Af::setMetering(bool mode)
> +{
> + useWeights_ = mode;
> +}
> +
> +void Af::setWindows(libcamera::Span<libcamera::Rectangle const> const &wins)
> +{
> + /*
> + * Here we just merge all of the given windows, weighted by area.
> + * If there are more than 15 overlapping windows, overflow can occur.
> + * TODO: A better approach might be to find the phase in each window
> + * and choose either the closest or the highest-confidence one?
> + *
> + * Using mostly "int" arithmetic, because Rectangle has signed x, y
> + */
> + ASSERT(sensorSize_.width > 0 && sensorSize_.height > 0);
> + int gridY = (int)(sensorSize_.height / PDAF_DATA_ROWS);
> + int gridX = (int)(sensorSize_.width / PDAF_DATA_COLS);
> + int gridA = gridY * gridX;
> +
> + for (int i = 0; i < PDAF_DATA_ROWS; ++i)
> + std::fill(phaseWeights_[i], phaseWeights_[i] + PDAF_DATA_COLS, 0);
> + std::fill(contrastWeights_, contrastWeights_ + FOCUS_REGIONS, 0);
> +
> + for (auto &w : wins) {
> + for (int i = 0; i < PDAF_DATA_ROWS; ++i) {
> + int y0 = std::max(gridY * i, w.y);
> + int y1 = std::min(gridY * (i + 1), w.y + (int)(w.height));
> + if (y0 >= y1)
> + continue;
> + y1 -= y0;
> + for (int j = 0; j < PDAF_DATA_COLS; ++j) {
> + int x0 = std::max(gridX * j, w.x);
> + int x1 = std::min(gridX * (j + 1), w.x + (int)(w.width));
> + if (x0 >= x1)
> + continue;
> + int a = y1 * (x1 - x0);
> + a = (16 * a + gridA - 1) / gridA;
> + phaseWeights_[i][j] += a;
> + contrastWeights_[4 * ((3 * i) / PDAF_DATA_ROWS) + ((4 * j) / PDAF_DATA_COLS)] += a;
> + }
> + }
> + }
> +}
> +
> +bool Af::setLensPosition(double dioptres, int *hwpos)
> +{
> + bool changed = false;
> +
> + if (mode_ == AfModeManual) {
> + LOG(RPiAf, Debug) << "setLensPosition: " << dioptres;
> + changed = !(initted_ && fsmooth_ == dioptres);
> + ftarget_ = dioptres;
> + updateLensPosition();
> + }
> +
> + if (hwpos)
> + *hwpos = cfg_.map.eval(fsmooth_);
> +
> + return changed;
> +}
> +
> +std::optional<double> Af::getLensPosition() const
> +{
> + /*
> + * \todo We ought to perform some precise timing here to determine
> + * the current lens position.
> + */
> + return initted_ ? std::optional<double>(fsmooth_) : std::nullopt;
> +}
> +
> +void Af::startCAF()
> +{
> + /* Try PDAF if the tuning file permits it for CAF; else CDAF */
> + if (cfg_.speeds[speed_].dropoutFrames > 0) {
> + if (!initted_) {
> + ftarget_ = cfg_.ranges[range_].focusDefault;
> + updateLensPosition();
> + }
> + scanState_ = ScanState::Pdaf;
> + scanData_.clear();
> + dropCount_ = 0;
> + reportState_ = AfState::Scanning;
> + } else {
> + startProgrammedScan();
> + }
> +}
> +
> +void Af::startProgrammedScan()
> +{
> + ftarget_ = cfg_.ranges[range_].focusMin;
> + updateLensPosition();
> + scanState_ = ScanState::Coarse;
> + scanMaxContrast_ = 0.0;
> + scanMinContrast_ = 1.0e9;
> + scanMaxIndex_ = 0;
> + scanData_.clear();
> + stepCount_ = cfg_.speeds[speed_].stepFrames;
> + reportState_ = AfState::Scanning;
> +}
> +
> +void Af::goIdle()
> +{
> + scanState_ = ScanState::Idle;
> + reportState_ = AfState::Idle;
> + scanData_.clear();
> +}
> +
> +void Af::cancelScan()
> +{
> + LOG(RPiAf, Debug) << "cancelScan";
> + if (mode_ == AfModeAuto)
> + goIdle();
> +}
> +
> +void Af::triggerScan()
> +{
> + LOG(RPiAf, Debug) << "triggerScan";
> + if (mode_ == AfModeAuto && scanState_ == ScanState::Idle) {
> + /* Try PDAF if the tuning file permits it for Auto; else CDAF */
> + if (cfg_.speeds[speed_].pdafFrames > 0 && cfg_.speeds[speed_].dropoutFrames > 0) {
> + if (!initted_) {
> + ftarget_ = cfg_.ranges[range_].focusDefault;
> + updateLensPosition();
> + }
> + stepCount_ = cfg_.speeds[speed_].pdafFrames;
> + scanState_ = ScanState::Pdaf;
> + dropCount_ = 0;
> + } else
> + startProgrammedScan();
> + reportState_ = AfState::Scanning;
> + }
> +}
> +
> +void Af::setMode(AfAlgorithm::AfMode mode)
> +{
> + LOG(RPiAf, Debug) << "setMode: " << (unsigned)mode;
> + if (mode_ != mode) {
> + mode_ = mode;
> + pauseFlag_ = false;
> + if (mode == AfModeContinuous)
> + startCAF();
> + else if (mode != AfModeAuto)
> + goIdle();
> + }
> +}
> +
> +AfAlgorithm::AfMode Af::getMode() const
> +{
> + return mode_;
> +}
> +
> +void Af::pause(AfAlgorithm::AfPause pause)
> +{
> + LOG(RPiAf, Debug) << "pause: " << (unsigned)pause;
> + if (mode_ == AfModeContinuous) {
> + if (pause == AfPauseResume && pauseFlag_) {
> + startCAF();
> + pauseFlag_ = false;
> + } else if (pause != AfPauseResume && !pauseFlag_) {
> + if (pause == AfPauseImmediate || scanState_ == ScanState::Pdaf)
> + goIdle();
> + pauseFlag_ = true;
> + }
> + }
> +}
> +
> +// Register algorithm with the system.
> +static Algorithm *create(Controller *controller)
> +{
> + return (Algorithm *)new Af(controller);
> +}
> +static RegisterAlgorithm reg(NAME, &create);
> diff --git a/src/ipa/raspberrypi/controller/rpi/af.h b/src/ipa/raspberrypi/controller/rpi/af.h
> new file mode 100644
> index 000000000000..0431bd70ae29
> --- /dev/null
> +++ b/src/ipa/raspberrypi/controller/rpi/af.h
> @@ -0,0 +1,153 @@
> +/* SPDX-License-Identifier: BSD-2-Clause */
> +/*
> + * Copyright (C) 2022-2023, Raspberry Pi Ltd
> + *
> + * af.h - Autofocus control algorithm
> + */
> +#pragma once
> +
> +#include "../af_algorithm.h"
> +#include "../af_status.h"
> +#include "../pdaf_data.h"
> +#include "../pwl.h"
> +
> +/*
> + * This algorithm implements a hybrid of CDAF and PDAF, favouring PDAF.
> + *
> + * Whenever PDAF is available, it is used in a continuous feedback loop.
> + * When triggered in auto mode, we simply enable AF for a limited number
> + * of frames (it may terminate early if the delta becomes small enough).
> + *
> + * When PDAF confidence is low (due e.g. to low contrast or extreme defocus)
> + * or PDAF data are absent, fall back to CDAF with a programmed scan pattern.
> + * A coarse and fine scan are performed, using ISP's CDAF focus FoM to
> + * estimate the lens position with peak contrast. This is slower due to
> + * extra latency in the ISP, and requires a settling time between steps.
> + *
> + * Some hysteresis is applied to the switch between PDAF and CDAF, to avoid
> + * "nuisance" scans. During each interval where PDAF is not working, only
> + * ONE scan will be performed; CAF cannot track objects using CDAF alone.
> + *
> + * This algorithm is unrelated to "rpi.focus" which merely reports CDAF FoM.
> + */
> +
> +namespace RPiController {
> +
> +class Af : public AfAlgorithm
> +{
> +public:
> + Af(Controller *controller = NULL);
> + ~Af();
> + char const *name() const override;
> + int read(const libcamera::YamlObject ¶ms) override;
> + void initialise() override;
> +
> + /* IPA calls */
> + void switchMode(CameraMode const &cameraMode, Metadata *metadata) override;
> + void prepare(Metadata *imageMetadata) override;
> + void process(StatisticsPtr &stats, Metadata *imageMetadata) override;
> +
> + /* controls */
> + void setRange(AfRange range) override;
> + void setSpeed(AfSpeed speed) override;
> + void setMetering(bool use_windows) override;
> + void setWindows(libcamera::Span<libcamera::Rectangle const> const &wins) override;
> + void setMode(AfMode mode) override;
> + AfMode getMode() const override;
> + bool setLensPosition(double dioptres, int32_t *hwpos) override;
> + std::optional<double> getLensPosition() const override;
> + void triggerScan() override;
> + void cancelScan() override;
> + void pause(AfPause pause) override;
> +
> +private:
> + enum class ScanState {
> + Idle,
> + Pdaf,
> + Coarse,
> + Fine,
> + Settle
> + };
> +
> + struct RangeDependentParams {
> + double focusMin; /* lower (far) limit in dipotres */
> + double focusMax; /* upper (near) limit in dioptres */
> + double focusDefault; /* default setting ("hyperfocal") */
> +
> + RangeDependentParams();
> + void read(const libcamera::YamlObject ¶ms);
> + };
> +
> + struct SpeedDependentParams {
> + double stepCoarse; /* used for scans */
> + double stepFine; /* used for scans */
> + double contrastRatio; /* used for scan termination and reporting */
> + double pdafGain; /* coefficient for PDAF feedback loop */
> + double pdafSquelch; /* PDAF stability parameter (device-specific) */
> + double maxSlew; /* limit for lens movement per frame */
> + uint32_t pdafFrames; /* number of iterations when triggered */
> + uint32_t dropoutFrames; /* number of non-PDAF frames to switch to CDAF */
> + uint32_t stepFrames; /* frames to skip in between steps of a scan */
> +
> + SpeedDependentParams();
> + void read(const libcamera::YamlObject ¶ms);
> + };
> +
> + struct CfgParams {
> + RangeDependentParams ranges[AfRangeMax];
> + SpeedDependentParams speeds[AfSpeedMax];
> + uint32_t confEpsilon; /* PDAF hysteresis threshold (sensor-specific) */
> + uint32_t confThresh; /* PDAF confidence cell min (sensor-specific) */
> + uint32_t confClip; /* PDAF confidence cell max (sensor-specific) */
> + uint32_t skipFrames; /* frames to skip at start or modeswitch */
> + Pwl map; /* converts dioptres -> lens driver position */
> +
> + CfgParams();
> + int read(const libcamera::YamlObject ¶ms);
> + void initialise();
> + };
> +
> + struct ScanRecord {
> + double focus;
> + double contrast;
> + double phase;
> + double conf;
> + };
> +
> + bool getPhase(PdafData const &data, double &phase, double &conf) const;
> + double getContrast(struct bcm2835_isp_stats_focus const focus_stats[FOCUS_REGIONS]) const;
> + void doPDAF(double phase, double conf);
> + bool earlyTerminationByPhase(double phase);
> + void doScan(double contrast, double phase, double conf);
> + double findPeak(unsigned index) const;
> + void doAF(double contrast, double phase, double conf);
> + void updateLensPosition();
> + void startProgrammedScan();
> + void startCAF();
> + void goIdle();
> +
> + /* Configuration and settings */
> + CfgParams cfg_;
> + AfRange range_;
> + AfSpeed speed_;
> + AfMode mode_;
> + bool pauseFlag_;
> + libcamera::Size sensorSize_;
> + bool useWeights_;
> + uint8_t phaseWeights_[PDAF_DATA_ROWS][PDAF_DATA_COLS];
> + uint16_t contrastWeights_[FOCUS_REGIONS];
> +
> + /* Working state. */
> + ScanState scanState_;
> + bool initted_;
> + double ftarget_, fsmooth_;
> + double prevContrast_;
> + bool pdafSeen_;
This pdafSeen_ variable is unused and gets noticed by Clang.
FAILED: src/ipa/raspberrypi/ipa_rpi.so.p/controller_rpi_af.cpp.o
clang++-11 -Isrc/ipa/raspberrypi/ipa_rpi.so.p -Isrc/ipa/raspberrypi -I../../../src/libcamera/src/ipa/raspberrypi -Iinclude -I../../../src/libcamera/include -Isrc/ipa -I../../../src/libcamera/src/ipa -I../../../src/libcamera/src/ipa/raspberrypi/controller -Iinclude/libcamera/ipa -Iinclude/libcamera -fcolor-diagnostics -D_FILE_OFFSET_BITS=64 -Wall -Winvalid-pch -Wnon-virtual-dtor -Wextra -Werror -std=c++17 -O0 -g -Wextra-semi -Wthread-safety -Wshadow -include /home/kbingham/iob/libcamera/ci/integrator/builds/build-matrix/clang-11/config.h -Wno-c99-designator -fPIC -DLIBCAMERA_BASE_PRIVATE -MD -MQ src/ipa/raspberrypi/ipa_rpi.so.p/controller_rpi_af.cpp.o -MF src/ipa/raspberrypi/ipa_rpi.so.p/controller_rpi_af.cpp.o.d -o src/ipa/raspberrypi/ipa_rpi.so.p/controller_rpi_af.cpp.o -c ../../../src/libcamera/src/ipa/raspberrypi/controller/rpi/af.cpp
In file included from ../../../src/libcamera/src/ipa/raspberrypi/controller/rpi/af.cpp:8:
../../../src/libcamera/src/ipa/raspberrypi/controller/rpi/af.h:145:7: error: private field 'pdafSeen_' is not used [-Werror,-Wunused-private-field]
bool pdafSeen_;
^
1 error generated.
As this is a single line to remove, and I don't think that's
controversial - I think that could be fixed while applying if you're ok
with that.
--
Kieran
> + unsigned skipCount_, stepCount_, dropCount_;
> + unsigned scanMaxIndex_;
> + double scanMaxContrast_, scanMinContrast_;
> + std::vector<ScanRecord> scanData_;
> + AfState reportState_;
> +};
> +
> +} // namespace RPiController
> diff --git a/src/ipa/raspberrypi/meson.build b/src/ipa/raspberrypi/meson.build
> index 517d815bb98c..4e2689536257 100644
> --- a/src/ipa/raspberrypi/meson.build
> +++ b/src/ipa/raspberrypi/meson.build
> @@ -27,6 +27,7 @@ rpi_ipa_sources = files([
> 'controller/controller.cpp',
> 'controller/histogram.cpp',
> 'controller/algorithm.cpp',
> + 'controller/rpi/af.cpp',
> 'controller/rpi/alsc.cpp',
> 'controller/rpi/awb.cpp',
> 'controller/rpi/sharpen.cpp',
> --
> 2.25.1
>
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