[libcamera-devel] [PATCH v7 2/3] libcamera: raspberrypi: Add control of sensor vblanking

Naushir Patuck naush at raspberrypi.com
Fri Dec 11 15:03:25 CET 2020


Hi David,



On Fri, 11 Dec 2020 at 13:58, David Plowman <david.plowman at raspberrypi.com>
wrote:

> Hi Naush
>
> Thanks for the revised patch!
>
> On Fri, 11 Dec 2020 at 13:35, Naushir Patuck <naush at raspberrypi.com>
> wrote:
> >
> > Add support for setting V4L2_CID_VBLANK appropriately when setting
> > V4L2_CID_EXPOSURE. This will allow adaptive framerates during
> > viewfinder use cases (e.g. when the exposure time goes above 33ms, we
> > can reduce the framerate to lower than 30fps).
> >
> > The minimum and maximum frame durations are provided via libcamera
> > controls, and will prioritise exposure time limits over any AGC request.
> >
> > V4L2_CID_VBLANK is controlled through the staggered writer, just like
> > the exposure and gain controls.
> >
> > Signed-off-by: Naushir Patuck <naush at raspberrypi.com>
> > ---
> >  include/libcamera/ipa/raspberrypi.h           |  1 +
> >  src/ipa/raspberrypi/cam_helper.cpp            | 35 +++++++++++++++-
> >  src/ipa/raspberrypi/cam_helper.hpp            | 15 ++++++-
> >  src/ipa/raspberrypi/cam_helper_imx219.cpp     | 13 +++++-
> >  src/ipa/raspberrypi/cam_helper_imx477.cpp     | 11 ++++-
> >  src/ipa/raspberrypi/cam_helper_ov5647.cpp     | 11 ++++-
> >  src/ipa/raspberrypi/raspberrypi.cpp           | 42 ++++++++++++++++---
> >  .../pipeline/raspberrypi/raspberrypi.cpp      |  3 +-
> >  8 files changed, 118 insertions(+), 13 deletions(-)
> >
> > diff --git a/include/libcamera/ipa/raspberrypi.h
> b/include/libcamera/ipa/raspberrypi.h
> > index 01fe5abc..160ca681 100644
> > --- a/include/libcamera/ipa/raspberrypi.h
> > +++ b/include/libcamera/ipa/raspberrypi.h
> > @@ -65,6 +65,7 @@ static const ControlInfoMap Controls = {
> >         { &controls::Sharpness, ControlInfo(0.0f, 16.0f, 1.0f) },
> >         { &controls::ColourCorrectionMatrix, ControlInfo(-16.0f, 16.0f)
> },
> >         { &controls::ScalerCrop, ControlInfo(Rectangle{},
> Rectangle(65535, 65535, 65535, 65535), Rectangle{}) },
> > +       { &controls::FrameDurations, ControlInfo(1.0e3f, 1.0e9f) },
>
> Just wondering whether it looks a bit strange to initialise explicitly
> with floats now that they're int64_t, though I guess it makes no real
> difference...
>

This is wrong!  I forgot to update this bit of code, thanks for spotting
that!


>
> But other than this tiny thing:
>
> Reviewed-by: David Plowman <david.plowman at raspberrypi.com>
> Tested-by: David Plowman <david.plowman at raspberrypi.com>
>
> Thanks!
> David
>
> >  };
> >
> >  } /* namespace RPi */
> > diff --git a/src/ipa/raspberrypi/cam_helper.cpp
> b/src/ipa/raspberrypi/cam_helper.cpp
> > index c8ac3232..7fd3e7f6 100644
> > --- a/src/ipa/raspberrypi/cam_helper.cpp
> > +++ b/src/ipa/raspberrypi/cam_helper.cpp
> > @@ -34,8 +34,10 @@ CamHelper *CamHelper::Create(std::string const
> &cam_name)
> >         return nullptr;
> >  }
> >
> > -CamHelper::CamHelper(MdParser *parser)
> > -       : parser_(parser), initialized_(false)
> > +CamHelper::CamHelper(MdParser *parser, unsigned int maxFrameLength,
> > +                    unsigned int frameIntegrationDiff)
> > +       : parser_(parser), initialized_(false),
> maxFrameLength_(maxFrameLength),
> > +         frameIntegrationDiff_(frameIntegrationDiff)
> >  {
> >  }
> >
> > @@ -56,6 +58,35 @@ double CamHelper::Exposure(uint32_t exposure_lines)
> const
> >         return exposure_lines * mode_.line_length / 1000.0;
> >  }
> >
> > +uint32_t CamHelper::GetVBlanking(double &exposure, double
> minFrameDuration,
> > +                                double maxFrameDuration) const
> > +{
> > +       uint32_t frameLengthMin, frameLengthMax, vblank;
> > +       uint32_t exposureLines = ExposureLines(exposure);
> > +
> > +       assert(initialized_);
> > +
> > +       /*
> > +        * Clip frame length by the frame duration range and the maximum
> allowable
> > +        * value in the sensor, given by maxFrameLength_.
> > +        */
> > +       frameLengthMin = std::clamp<uint32_t>(1e3 * minFrameDuration /
> mode_.line_length,
> > +                                             mode_.height,
> maxFrameLength_);
> > +       frameLengthMax = std::clamp<uint32_t>(1e3 * maxFrameDuration /
> mode_.line_length,
> > +                                             mode_.height,
> maxFrameLength_);
> > +       /*
> > +        * Limit the exposure to the maximum frame duration requested,
> and
> > +        * re-calculate if it has been clipped.
> > +        */
> > +       exposureLines = std::min(frameLengthMax - frameIntegrationDiff_,
> exposureLines);
> > +       exposure = Exposure(exposureLines);
> > +
> > +       /* Limit the vblank to the range allowed by the frame length
> limits. */
> > +       vblank = std::clamp(exposureLines + frameIntegrationDiff_,
> > +                           frameLengthMin, frameLengthMax) -
> mode_.height;
> > +       return vblank;
> > +}
> > +
> >  void CamHelper::SetCameraMode(const CameraMode &mode)
> >  {
> >         mode_ = mode;
> > diff --git a/src/ipa/raspberrypi/cam_helper.hpp
> b/src/ipa/raspberrypi/cam_helper.hpp
> > index 044c2866..b1739a57 100644
> > --- a/src/ipa/raspberrypi/cam_helper.hpp
> > +++ b/src/ipa/raspberrypi/cam_helper.hpp
> > @@ -62,12 +62,15 @@ class CamHelper
> >  {
> >  public:
> >         static CamHelper *Create(std::string const &cam_name);
> > -       CamHelper(MdParser *parser);
> > +       CamHelper(MdParser *parser, unsigned int maxFrameLength,
> > +                 unsigned int frameIntegrationDiff);
> >         virtual ~CamHelper();
> >         void SetCameraMode(const CameraMode &mode);
> >         MdParser &Parser() const { return *parser_; }
> >         uint32_t ExposureLines(double exposure_us) const;
> >         double Exposure(uint32_t exposure_lines) const; // in us
> > +       virtual uint32_t GetVBlanking(double &exposure_us, double
> minFrameDuration,
> > +                                     double maxFrameDuration) const;
> >         virtual uint32_t GainCode(double gain) const = 0;
> >         virtual double Gain(uint32_t gain_code) const = 0;
> >         virtual void GetDelays(int &exposure_delay, int &gain_delay)
> const;
> > @@ -76,10 +79,20 @@ public:
> >         virtual unsigned int HideFramesModeSwitch() const;
> >         virtual unsigned int MistrustFramesStartup() const;
> >         virtual unsigned int MistrustFramesModeSwitch() const;
> > +
> >  protected:
> >         MdParser *parser_;
> >         CameraMode mode_;
> > +
> > +private:
> >         bool initialized_;
> > +       /* Largest possible frame length, in units of lines. */
> > +       unsigned int maxFrameLength_;
> > +       /*
> > +        * 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
> > diff --git a/src/ipa/raspberrypi/cam_helper_imx219.cpp
> b/src/ipa/raspberrypi/cam_helper_imx219.cpp
> > index db8ab879..8688ec09 100644
> > --- a/src/ipa/raspberrypi/cam_helper_imx219.cpp
> > +++ b/src/ipa/raspberrypi/cam_helper_imx219.cpp
> > @@ -49,13 +49,22 @@ public:
> >         double Gain(uint32_t gain_code) const override;
> >         unsigned int MistrustFramesModeSwitch() const override;
> >         bool SensorEmbeddedDataPresent() const override;
> > +
> > +private:
> > +       /*
> > +        * Smallest difference between the frame length and integration
> time,
> > +        * in units of lines.
> > +        */
> > +       static constexpr int frameIntegrationDiff = 4;
> > +       /* Largest possible frame length, in units of lines. */
> > +       static constexpr int maxFrameLength = 0xffff;
> >  };
> >
> >  CamHelperImx219::CamHelperImx219()
> >  #if ENABLE_EMBEDDED_DATA
> > -       : CamHelper(new MdParserImx219())
> > +       : CamHelper(new MdParserImx219(), maxFrameLength,
> frameIntegrationDiff)
> >  #else
> > -       : CamHelper(new MdParserRPi())
> > +       : CamHelper(new MdParserRPi(), maxFrameLength,
> frameIntegrationDiff)
> >  #endif
> >  {
> >  }
> > diff --git a/src/ipa/raspberrypi/cam_helper_imx477.cpp
> b/src/ipa/raspberrypi/cam_helper_imx477.cpp
> > index 0e896ac7..53961310 100644
> > --- a/src/ipa/raspberrypi/cam_helper_imx477.cpp
> > +++ b/src/ipa/raspberrypi/cam_helper_imx477.cpp
> > @@ -38,10 +38,19 @@ public:
> >         uint32_t GainCode(double gain) const override;
> >         double Gain(uint32_t gain_code) const override;
> >         bool SensorEmbeddedDataPresent() const override;
> > +
> > +private:
> > +       /*
> > +        * Smallest difference between the frame length and integration
> time,
> > +        * in units of lines.
> > +        */
> > +       static constexpr int frameIntegrationDiff = 22;
> > +       /* Largest possible frame length, in units of lines. */
> > +       static constexpr int maxFrameLength = 0xffdc;
> >  };
> >
> >  CamHelperImx477::CamHelperImx477()
> > -       : CamHelper(new MdParserImx477())
> > +       : CamHelper(new MdParserImx477(), maxFrameLength,
> frameIntegrationDiff)
> >  {
> >  }
> >
> > diff --git a/src/ipa/raspberrypi/cam_helper_ov5647.cpp
> b/src/ipa/raspberrypi/cam_helper_ov5647.cpp
> > index dc5d8275..7630c127 100644
> > --- a/src/ipa/raspberrypi/cam_helper_ov5647.cpp
> > +++ b/src/ipa/raspberrypi/cam_helper_ov5647.cpp
> > @@ -22,6 +22,15 @@ public:
> >         unsigned int HideFramesModeSwitch() const override;
> >         unsigned int MistrustFramesStartup() const override;
> >         unsigned int MistrustFramesModeSwitch() const override;
> > +
> > +private:
> > +       /*
> > +        * Smallest difference between the frame length and integration
> time,
> > +        * in units of lines.
> > +        */
> > +       static constexpr int frameIntegrationDiff = 4;
> > +       /* Largest possible frame length, in units of lines. */
> > +       static constexpr int maxFrameLength = 0xffff;
> >  };
> >
> >  /*
> > @@ -30,7 +39,7 @@ public:
> >   */
> >
> >  CamHelperOv5647::CamHelperOv5647()
> > -       : CamHelper(new MdParserRPi())
> > +       : CamHelper(new MdParserRPi(), maxFrameLength,
> frameIntegrationDiff)
> >  {
> >  }
> >
> > diff --git a/src/ipa/raspberrypi/raspberrypi.cpp
> b/src/ipa/raspberrypi/raspberrypi.cpp
> > index 60cfdc27..f6d2b543 100644
> > --- a/src/ipa/raspberrypi/raspberrypi.cpp
> > +++ b/src/ipa/raspberrypi/raspberrypi.cpp
> > @@ -58,6 +58,8 @@ namespace libcamera {
> >  /* Configure the sensor with these values initially. */
> >  constexpr double DefaultAnalogueGain = 1.0;
> >  constexpr unsigned int DefaultExposureTime = 20000;
> > +constexpr double defaultMinFrameDuration = 1e6 / 30.0;
> > +constexpr double defaultMaxFrameDuration = 1e6 / 0.01;
> >
> >  LOG_DEFINE_CATEGORY(IPARPI)
> >
> > @@ -145,6 +147,9 @@ private:
> >         /* LS table allocation passed in from the pipeline handler. */
> >         FileDescriptor lsTableHandle_;
> >         void *lsTable_;
> > +
> > +       /* Frame duration (1/fps) given in microseconds. */
> > +       double minFrameDuration_, maxFrameDuration_;
> >  };
> >
> >  int IPARPi::init(const IPASettings &settings)
> > @@ -266,7 +271,8 @@ void IPARPi::configure(const CameraSensorInfo
> &sensorInfo,
> >                 sensorMetadata = helper_->SensorEmbeddedDataPresent();
> >
> >                 result->data.push_back(gainDelay);
> > -               result->data.push_back(exposureDelay);
> > +               result->data.push_back(exposureDelay); /* FOR EXPOSURE
> ctrl */
> > +               result->data.push_back(exposureDelay); /* For VBLANK
> ctrl */
> >                 result->data.push_back(sensorMetadata);
> >
> >                 result->operation |= RPi::IPA_CONFIG_STAGGERED_WRITE;
> > @@ -335,6 +341,8 @@ void IPARPi::configure(const CameraSensorInfo
> &sensorInfo,
> >                 AgcStatus agcStatus;
> >                 agcStatus.shutter_time = DefaultExposureTime;
> >                 agcStatus.analogue_gain = DefaultAnalogueGain;
> > +               minFrameDuration_ = defaultMinFrameDuration;
> > +               maxFrameDuration_ = defaultMaxFrameDuration;
> >                 applyAGC(&agcStatus, ctrls);
> >
> >                 result->controls.emplace_back(ctrls);
> > @@ -712,6 +720,18 @@ void IPARPi::queueRequest(const ControlList
> &controls)
> >                         break;
> >                 }
> >
> > +               case controls::FRAME_DURATIONS: {
> > +                       auto frameDurations = ctrl.second.get<Span<const
> int64_t>>();
> > +
> > +                       /* This will be applied once AGC recalculations
> occur. */
> > +                       minFrameDuration_ = frameDurations[0] ?
> frameDurations[0] : defaultMinFrameDuration;
> > +                       maxFrameDuration_ = frameDurations[1] ?
> frameDurations[1] : defaultMaxFrameDuration;
> > +                       libcameraMetadata_.set(controls::FrameDurations,
> > +                                              {
> static_cast<int64_t>(minFrameDuration_),
> > +
> static_cast<int64_t>(maxFrameDuration_) });
> > +                       break;
> > +               }
> > +
> >                 default:
> >                         LOG(IPARPI, Warning)
> >                                 << "Ctrl " << controls::controls.at
> (ctrl.first)->name()
> > @@ -882,7 +902,12 @@ void IPARPi::applyAWB(const struct AwbStatus
> *awbStatus, ControlList &ctrls)
> >  void IPARPi::applyAGC(const struct AgcStatus *agcStatus, ControlList
> &ctrls)
> >  {
> >         int32_t gainCode = helper_->GainCode(agcStatus->analogue_gain);
> > -       int32_t exposureLines =
> helper_->ExposureLines(agcStatus->shutter_time);
> > +
> > +       /* GetVBlanking might clip exposure time to the fps limits. */
> > +       double exposure = agcStatus->shutter_time;
> > +       int32_t vblanking = helper_->GetVBlanking(exposure,
> minFrameDuration_,
> > +                                                 maxFrameDuration_);
> > +       int32_t exposureLines = helper_->ExposureLines(exposure);
> >
> >         if (unicamCtrls_.find(V4L2_CID_ANALOGUE_GAIN) ==
> unicamCtrls_.end()) {
> >                 LOG(IPARPI, Error) << "Can't find analogue gain control";
> > @@ -894,13 +919,20 @@ void IPARPi::applyAGC(const struct AgcStatus
> *agcStatus, ControlList &ctrls)
> >                 return;
> >         }
> >
> > -       LOG(IPARPI, Debug) << "Applying AGC Exposure: " <<
> agcStatus->shutter_time
> > -                          << " (Shutter lines: " << exposureLines << ")
> Gain: "
> > +       LOG(IPARPI, Debug) << "Applying AGC Exposure: " << exposure
> > +                          << " (Shutter lines: " << exposureLines << ",
> AGC requested "
> > +                          << agcStatus->shutter_time << ") Gain: "
> >                            << agcStatus->analogue_gain << " (Gain Code: "
> >                            << gainCode << ")";
> >
> > -       ctrls.set(V4L2_CID_ANALOGUE_GAIN, gainCode);
> > +       /*
> > +        * Due to the behavior of V4L2, the current value of VBLANK
> could clip the
> > +        * exposure time without us knowing. The next time though this
> function should
> > +        * clip exposure correctly.
> > +        */
> > +       ctrls.set(V4L2_CID_VBLANK, vblanking);
> >         ctrls.set(V4L2_CID_EXPOSURE, exposureLines);
> > +       ctrls.set(V4L2_CID_ANALOGUE_GAIN, gainCode);
> >  }
> >
> >  void IPARPi::applyDG(const struct AgcStatus *dgStatus, ControlList
> &ctrls)
> > diff --git a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> > index 2ec1f6e7..13349f31 100644
> > --- a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> > +++ b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> > @@ -1221,7 +1221,8 @@ int RPiCameraData::configureIPA(const
> CameraConfiguration *config)
> >                 if (!staggeredCtrl_) {
> >                         staggeredCtrl_.init(unicam_[Unicam::Image].dev(),
> >                                             { { V4L2_CID_ANALOGUE_GAIN,
> result.data[resultIdx++] },
> > -                                             { V4L2_CID_EXPOSURE,
> result.data[resultIdx++] } });
> > +                                             { V4L2_CID_EXPOSURE,
> result.data[resultIdx++] },
> > +                                             { V4L2_CID_VBLANK,
> result.data[resultIdx++] } });
> >                         sensorMetadata_ = result.data[resultIdx++];
> >                 }
> >         }
> > --
> > 2.25.1
> >
> > _______________________________________________
> > libcamera-devel mailing list
> > libcamera-devel at lists.libcamera.org
> > https://lists.libcamera.org/listinfo/libcamera-devel
>
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