diff options
Diffstat (limited to 'src/ipa/raspberrypi/controller/rpi/agc.cpp')
| -rw-r--r-- | src/ipa/raspberrypi/controller/rpi/agc.cpp | 74 |
1 files changed, 58 insertions, 16 deletions
diff --git a/src/ipa/raspberrypi/controller/rpi/agc.cpp b/src/ipa/raspberrypi/controller/rpi/agc.cpp index 4cf98e66..2533727e 100644 --- a/src/ipa/raspberrypi/controller/rpi/agc.cpp +++ b/src/ipa/raspberrypi/controller/rpi/agc.cpp @@ -145,6 +145,9 @@ void AgcConfig::Read(boost::property_tree::ptree const ¶ms) fast_reduce_threshold = params.get<double>("fast_reduce_threshold", 0.4); base_ev = params.get<double>("base_ev", 1.0); + // Start with quite a low value as ramping up is easier than ramping down. + default_exposure_time = params.get<double>("default_exposure_time", 1000); + default_analogue_gain = params.get<double>("default_analogue_gain", 1.0); } Agc::Agc(Controller *controller) @@ -220,14 +223,42 @@ void Agc::SetConstraintMode(std::string const &constraint_mode_name) void Agc::SwitchMode([[maybe_unused]] CameraMode const &camera_mode, Metadata *metadata) { - // On a mode switch, it's possible the exposure profile could change, - // so we run through the dividing up of exposure/gain again and - // write the results into the metadata we've been given. - if (status_.total_exposure_value) { - housekeepConfig(); + housekeepConfig(); + + if (fixed_shutter_ != 0.0 && fixed_analogue_gain_ != 0.0) { + // We're going to reset the algorithm here with these fixed values. + + fetchAwbStatus(metadata); + double min_colour_gain = std::min({ awb_.gain_r, awb_.gain_g, awb_.gain_b, 1.0 }); + 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 = 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_.analogue_gain = fixed_analogue_gain_; + } else if (status_.total_exposure_value) { + // On a mode switch, it's possible the exposure profile could change, + // or a fixed exposure/gain might be set so we divide up the exposure/ + // gain again, but we don't change any target values. divideUpExposure(); - writeAndFinish(metadata, false); + } else { + // We come through here on startup, when at least one of the shutter + // or gain has not been fixed. We must still write those values out so + // that they will be applied immediately. We supply some arbitrary defaults + // for any that weren't set. + + // Equivalent of divideUpExposure. + filtered_.shutter = fixed_shutter_ ? fixed_shutter_ : config_.default_exposure_time; + filtered_.analogue_gain = fixed_analogue_gain_ ? fixed_analogue_gain_ : config_.default_analogue_gain; } + + writeAndFinish(metadata, false); } void Agc::Prepare(Metadata *image_metadata) @@ -472,20 +503,31 @@ void Agc::computeGain(bcm2835_isp_stats *statistics, Metadata *image_metadata, void Agc::computeTargetExposure(double gain) { - // The statistics reflect the image without digital gain, so the final - // total exposure we're aiming for is: - target_.total_exposure = current_.total_exposure_no_dg * gain; - // The final target exposure is also limited to what the exposure - // mode allows. - double max_total_exposure = - (status_.fixed_shutter != 0.0 + if (status_.fixed_shutter != 0.0 && status_.fixed_analogue_gain != 0.0) { + // When ag and shutter are both fixed, we need to drive the + // total exposure so that we end up with a digital gain of at least + // 1/min_colour_gain. Otherwise we'd desaturate channels causing + // white to go cyan or magenta. + double min_colour_gain = std::min({ awb_.gain_r, awb_.gain_g, awb_.gain_b, 1.0 }); + ASSERT(min_colour_gain != 0.0); + target_.total_exposure = + status_.fixed_shutter * status_.fixed_analogue_gain / min_colour_gain; + } else { + // The statistics reflect the image without digital gain, so the final + // total exposure we're aiming for is: + target_.total_exposure = current_.total_exposure_no_dg * gain; + // The final target exposure is also limited to what the exposure + // mode allows. + double max_total_exposure = + (status_.fixed_shutter != 0.0 ? status_.fixed_shutter : exposure_mode_->shutter.back()) * - (status_.fixed_analogue_gain != 0.0 + (status_.fixed_analogue_gain != 0.0 ? status_.fixed_analogue_gain : exposure_mode_->gain.back()); - target_.total_exposure = std::min(target_.total_exposure, - max_total_exposure); + target_.total_exposure = std::min(target_.total_exposure, + max_total_exposure); + } LOG(RPiAgc, Debug) << "Target total_exposure " << target_.total_exposure; } |