[libcamera-devel] [PATCH v4 4/5] ipa: raspberrypi: Pass the maximum allowable shutter speed into the AGC
Laurent Pinchart
laurent.pinchart at ideasonboard.com
Thu Feb 4 21:59:06 CET 2021
Hi Naush,
Thank you for the patch.
On Fri, Jan 29, 2021 at 11:16:15AM +0000, Naushir Patuck wrote:
> In order to provide an optimal split between shutter speed and gain, the
> AGC must know the maximum allowable shutter speed, as limited by the
> maximum frame duration (either application provided or the default).
>
> Add a new API function, SetMaxShutter, to the AgcAlgorithm class. The
> IPA provides the the maximum shutter speed for AGC calculations.
s/the the/the/
> This applies to both the manual and auto AGC modes.
>
> Signed-off-by: Naushir Patuck <naush at raspberrypi.com>
> Reviewed-by: David Plowman <david.plowman at raspberrypi.com>
> Reviewed-by: Jacopo Mondi <jacopo at jmondi.org>
> ---
> .../raspberrypi/controller/agc_algorithm.hpp | 1 +
> src/ipa/raspberrypi/controller/rpi/agc.cpp | 48 +++++++++++++------
> src/ipa/raspberrypi/controller/rpi/agc.hpp | 3 ++
> src/ipa/raspberrypi/raspberrypi.cpp | 12 +++++
> 4 files changed, 49 insertions(+), 15 deletions(-)
>
> diff --git a/src/ipa/raspberrypi/controller/agc_algorithm.hpp b/src/ipa/raspberrypi/controller/agc_algorithm.hpp
> index 981f1de2f0e4..f97deb0fca59 100644
> --- a/src/ipa/raspberrypi/controller/agc_algorithm.hpp
> +++ b/src/ipa/raspberrypi/controller/agc_algorithm.hpp
> @@ -19,6 +19,7 @@ public:
> virtual void SetEv(double ev) = 0;
> virtual void SetFlickerPeriod(double flicker_period) = 0;
> virtual void SetFixedShutter(double fixed_shutter) = 0; // microseconds
> + virtual void SetMaxShutter(double max_shutter) = 0; // microseconds
> virtual void SetFixedAnalogueGain(double fixed_analogue_gain) = 0;
> virtual void SetMeteringMode(std::string const &metering_mode_name) = 0;
> virtual void SetExposureMode(std::string const &exposure_mode_name) = 0;
> diff --git a/src/ipa/raspberrypi/controller/rpi/agc.cpp b/src/ipa/raspberrypi/controller/rpi/agc.cpp
> index eddd1684da12..0023d50029f1 100644
> --- a/src/ipa/raspberrypi/controller/rpi/agc.cpp
> +++ b/src/ipa/raspberrypi/controller/rpi/agc.cpp
> @@ -157,7 +157,7 @@ Agc::Agc(Controller *controller)
> frame_count_(0), lock_count_(0),
> last_target_exposure_(0.0),
> ev_(1.0), flicker_period_(0.0),
> - fixed_shutter_(0), fixed_analogue_gain_(0.0)
> + max_shutter_(0), fixed_shutter_(0), fixed_analogue_gain_(0.0)
> {
> memset(&awb_, 0, sizeof(awb_));
> // Setting status_.total_exposure_value_ to zero initially tells us
> @@ -227,11 +227,16 @@ void Agc::SetFlickerPeriod(double flicker_period)
> flicker_period_ = flicker_period;
> }
>
> +void Agc::SetMaxShutter(double max_shutter)
> +{
> + max_shutter_ = max_shutter;
> +}
> +
> void Agc::SetFixedShutter(double fixed_shutter)
> {
> fixed_shutter_ = fixed_shutter;
> // Set this in case someone calls Pause() straight after.
> - status_.shutter_time = fixed_shutter;
> + status_.shutter_time = clipShutter(fixed_shutter_);
> }
>
> void Agc::SetFixedAnalogueGain(double fixed_analogue_gain)
> @@ -261,7 +266,8 @@ void Agc::SwitchMode([[maybe_unused]] CameraMode const &camera_mode,
> {
> housekeepConfig();
>
> - if (fixed_shutter_ != 0.0 && fixed_analogue_gain_ != 0.0) {
> + double fixed_shutter = clipShutter(fixed_shutter_);
> + if (fixed_shutter != 0.0 && fixed_analogue_gain_ != 0.0) {
> // We're going to reset the algorithm here with these fixed values.
>
> fetchAwbStatus(metadata);
> @@ -269,14 +275,14 @@ void Agc::SwitchMode([[maybe_unused]] CameraMode const &camera_mode,
> ASSERT(min_colour_gain != 0.0);
>
> // This is the equivalent of computeTargetExposure and applyDigitalGain.
> - target_.total_exposure_no_dg = fixed_shutter_ * fixed_analogue_gain_;
> + target_.total_exposure_no_dg = fixed_shutter * fixed_analogue_gain_;
> target_.total_exposure = target_.total_exposure_no_dg / min_colour_gain;
>
> // Equivalent of filterExposure. This resets any "history".
> filtered_ = target_;
>
> // Equivalent of divideUpExposure.
> - filtered_.shutter = fixed_shutter_;
> + filtered_.shutter = fixed_shutter;
> filtered_.analogue_gain = fixed_analogue_gain_;
> } else if (status_.total_exposure_value) {
> // On a mode switch, it's possible the exposure profile could change,
> @@ -290,7 +296,7 @@ void Agc::SwitchMode([[maybe_unused]] CameraMode const &camera_mode,
> // for any that weren't set.
>
> // Equivalent of divideUpExposure.
> - filtered_.shutter = fixed_shutter_ ? fixed_shutter_ : config_.default_exposure_time;
> + filtered_.shutter = fixed_shutter ? fixed_shutter : config_.default_exposure_time;
> filtered_.analogue_gain = fixed_analogue_gain_ ? fixed_analogue_gain_ : config_.default_analogue_gain;
> }
>
> @@ -403,7 +409,8 @@ void Agc::housekeepConfig()
> {
> // First fetch all the up-to-date settings, so no one else has to do it.
> status_.ev = ev_;
> - status_.fixed_shutter = fixed_shutter_;
> + double fixed_shutter = clipShutter(fixed_shutter_);
> + status_.fixed_shutter = fixed_shutter;
You could write
status_.fixed_shutter = clipShutter(fixed_shutter_);
> status_.fixed_analogue_gain = fixed_analogue_gain_;
> status_.flicker_period = flicker_period_;
> LOG(RPiAgc, Debug) << "ev " << status_.ev << " fixed_shutter "
> @@ -582,13 +589,15 @@ void Agc::computeTargetExposure(double gain)
> target_.total_exposure = current_.total_exposure_no_dg * gain;
> // The final target exposure is also limited to what the exposure
> // mode allows.
> + double max_shutter = status_.fixed_shutter != 0.0
> + ? status_.fixed_shutter
> + : exposure_mode_->shutter.back();
The indentation is a bit weird, how about this ?
double max_shutter = status_.fixed_shutter != 0.0
? status_.fixed_shutter
: exposure_mode_->shutter.back();
Those are minor issues,
Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
If you're fine with these changes, there's no need to resent, I'll fix
when applying.
> + max_shutter = clipShutter(max_shutter);
> double max_total_exposure =
> - (status_.fixed_shutter != 0.0
> - ? status_.fixed_shutter
> - : exposure_mode_->shutter.back()) *
> + max_shutter *
> (status_.fixed_analogue_gain != 0.0
> - ? status_.fixed_analogue_gain
> - : exposure_mode_->gain.back());
> + ? status_.fixed_analogue_gain
> + : exposure_mode_->gain.back());
> target_.total_exposure = std::min(target_.total_exposure,
> max_total_exposure);
> }
> @@ -671,6 +680,7 @@ void Agc::divideUpExposure()
> shutter_time = status_.fixed_shutter != 0.0
> ? status_.fixed_shutter
> : exposure_mode_->shutter[0];
> + shutter_time = clipShutter(shutter_time);
> analogue_gain = status_.fixed_analogue_gain != 0.0
> ? status_.fixed_analogue_gain
> : exposure_mode_->gain[0];
> @@ -678,14 +688,15 @@ void Agc::divideUpExposure()
> for (unsigned int stage = 1;
> stage < exposure_mode_->gain.size(); stage++) {
> if (status_.fixed_shutter == 0.0) {
> - if (exposure_mode_->shutter[stage] *
> - analogue_gain >=
> + double stage_shutter =
> + clipShutter(exposure_mode_->shutter[stage]);
> + if (stage_shutter * analogue_gain >=
> exposure_value) {
> shutter_time =
> exposure_value / analogue_gain;
> break;
> }
> - shutter_time = exposure_mode_->shutter[stage];
> + shutter_time = stage_shutter;
> }
> if (status_.fixed_analogue_gain == 0.0) {
> if (exposure_mode_->gain[stage] *
> @@ -740,6 +751,13 @@ void Agc::writeAndFinish(Metadata *image_metadata, bool desaturate)
> << " analogue gain " << filtered_.analogue_gain;
> }
>
> +double Agc::clipShutter(double shutter)
> +{
> + if (max_shutter_)
> + shutter = std::min(shutter, max_shutter_);
> + return shutter;
> +}
> +
> // Register algorithm with the system.
> static Algorithm *Create(Controller *controller)
> {
> diff --git a/src/ipa/raspberrypi/controller/rpi/agc.hpp b/src/ipa/raspberrypi/controller/rpi/agc.hpp
> index 05c334e4a1de..0427fb59ec1b 100644
> --- a/src/ipa/raspberrypi/controller/rpi/agc.hpp
> +++ b/src/ipa/raspberrypi/controller/rpi/agc.hpp
> @@ -78,6 +78,7 @@ public:
> unsigned int GetConvergenceFrames() const override;
> void SetEv(double ev) override;
> void SetFlickerPeriod(double flicker_period) override;
> + void SetMaxShutter(double max_shutter) override; // microseconds
> void SetFixedShutter(double fixed_shutter) override; // microseconds
> void SetFixedAnalogueGain(double fixed_analogue_gain) override;
> void SetMeteringMode(std::string const &metering_mode_name) override;
> @@ -100,6 +101,7 @@ private:
> void filterExposure(bool desaturate);
> void divideUpExposure();
> void writeAndFinish(Metadata *image_metadata, bool desaturate);
> + double clipShutter(double shutter);
> AgcMeteringMode *metering_mode_;
> AgcExposureMode *exposure_mode_;
> AgcConstraintMode *constraint_mode_;
> @@ -126,6 +128,7 @@ private:
> std::string constraint_mode_name_;
> double ev_;
> double flicker_period_;
> + double max_shutter_;
> double fixed_shutter_;
> double fixed_analogue_gain_;
> };
> diff --git a/src/ipa/raspberrypi/raspberrypi.cpp b/src/ipa/raspberrypi/raspberrypi.cpp
> index e4911b734e20..8c0e699184f6 100644
> --- a/src/ipa/raspberrypi/raspberrypi.cpp
> +++ b/src/ipa/raspberrypi/raspberrypi.cpp
> @@ -1006,6 +1006,18 @@ void IPARPi::applyFrameDurations(double minFrameDuration, double maxFrameDuratio
> libcameraMetadata_.set(controls::FrameDurations,
> { static_cast<int64_t>(minFrameDuration_),
> static_cast<int64_t>(maxFrameDuration_) });
> +
> + /*
> + * Calculate the maximum exposure time possible for the AGC to use.
> + * GetVBlanking() will update maxShutter with the largest exposure
> + * value possible.
> + */
> + double maxShutter = std::numeric_limits<double>::max();
> + helper_->GetVBlanking(maxShutter, minFrameDuration_, maxFrameDuration_);
> +
> + RPiController::AgcAlgorithm *agc = dynamic_cast<RPiController::AgcAlgorithm *>(
> + controller_.GetAlgorithm("agc"));
> + agc->SetMaxShutter(maxShutter);
> }
>
> void IPARPi::applyAGC(const struct AgcStatus *agcStatus, ControlList &ctrls)
--
Regards,
Laurent Pinchart
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