From 79a834f24c6e5094876b57973f7900401ec4683f Mon Sep 17 00:00:00 2001 From: David Plowman Date: Sat, 1 Aug 2020 09:01:51 +0100 Subject: libcamera: ipa: raspberrypi: ALSC: Improve behaviour when camera mode changes Now that we stop the asynchronous thread on a SwitchMode, we would do better to regenerate all the tables if the new camera mode crops in a significantly different way to the old one. A few minor tweaks make sense along with this: * Reset the lambda values when we reset everything. It wouldn't make sense to re-start with the old mode's values. * Use the last recorded colour temperature to generate new tables rather than any default value. * Set the frame "phase" counter to ensure the adaptive procedure will run asap. Signed-off-by: David Plowman Reviewed-by: Laurent Pinchart Signed-off-by: Laurent Pinchart Reviewed-by: Naushir Patuck --- src/ipa/raspberrypi/controller/rpi/alsc.cpp | 54 ++++++++++++++++++++--------- 1 file changed, 37 insertions(+), 17 deletions(-) (limited to 'src') diff --git a/src/ipa/raspberrypi/controller/rpi/alsc.cpp b/src/ipa/raspberrypi/controller/rpi/alsc.cpp index 4df99347..9df713a3 100644 --- a/src/ipa/raspberrypi/controller/rpi/alsc.cpp +++ b/src/ipa/raspberrypi/controller/rpi/alsc.cpp @@ -166,11 +166,8 @@ void Alsc::Initialise() RPI_LOG("Alsc"); frame_count2_ = frame_count_ = frame_phase_ = 0; first_time_ = true; - // Initialise the lambdas. Each call to Process then restarts from the - // previous results. Also initialise the previous frame tables to the - // same harmless values. - for (int i = 0; i < XY; i++) - lambda_r_[i] = lambda_b_[i] = 1.0; + ct_ = config_.default_ct; + // The lambdas are initialised in the SwitchMode. } void Alsc::waitForAysncThread() @@ -185,31 +182,53 @@ void Alsc::waitForAysncThread() } } +static bool compare_modes(CameraMode const &cm0, CameraMode const &cm1) +{ + // Return true if the modes crop from the sensor significantly differently. + int left_diff = abs(cm0.crop_x - cm1.crop_x); + int top_diff = abs(cm0.crop_y - cm1.crop_y); + int right_diff = fabs(cm0.crop_x + cm0.scale_x * cm0.width - + cm1.crop_x - cm1.scale_x * cm1.width); + int bottom_diff = fabs(cm0.crop_y + cm0.scale_y * cm0.height - + cm1.crop_y - cm1.scale_y * cm1.height); + // These thresholds are a rather arbitrary amount chosen to trigger + // when carrying on with the previously calculated tables might be + // worse than regenerating them (but without the adaptive algorithm). + int threshold_x = cm0.sensor_width >> 4; + int threshold_y = cm0.sensor_height >> 4; + return left_diff > threshold_x || right_diff > threshold_x || + top_diff > threshold_y || bottom_diff > threshold_y; +} + void Alsc::SwitchMode(CameraMode const &camera_mode, Metadata *metadata) { (void)metadata; + // We're going to start over with the tables if there's any "significant" + // change. + bool reset_tables = first_time_ || compare_modes(camera_mode_, camera_mode); + // Ensure the other thread isn't running while we do this. waitForAysncThread(); - // There's a bit of a question what we should do if the "crop" of the - // camera mode has changed. Should we effectively reset the algorithm - // and start over? camera_mode_ = camera_mode; // We must resample the luminance table like we do the others, but it's // fixed so we can simply do it up front here. resample_cal_table(config_.luminance_lut, camera_mode_, luminance_table_); - if (first_time_) { - // On the first time, arrange for something sensible in the - // initial tables. Construct the tables for some default colour - // temperature. This echoes the code in doAlsc, without the - // adaptive algorithm. + if (reset_tables) { + // Upon every "table reset", arrange for something sensible to be + // generated. Construct the tables for the previous recorded colour + // temperature. In order to start over from scratch we initialise + // the lambdas, but the rest of this code then echoes the code in + // doAlsc, without the adaptive algorithm. + for (int i = 0; i < XY; i++) + lambda_r_[i] = lambda_b_[i] = 1.0; double cal_table_r[XY], cal_table_b[XY], cal_table_tmp[XY]; - get_cal_table(4000, config_.calibrations_Cr, cal_table_tmp); + get_cal_table(ct_, config_.calibrations_Cr, cal_table_tmp); resample_cal_table(cal_table_tmp, camera_mode_, cal_table_r); - get_cal_table(4000, config_.calibrations_Cb, cal_table_tmp); + get_cal_table(ct_, config_.calibrations_Cb, cal_table_tmp); resample_cal_table(cal_table_tmp, camera_mode_, cal_table_b); compensate_lambdas_for_cal(cal_table_r, lambda_r_, async_lambda_r_); @@ -220,6 +239,7 @@ void Alsc::SwitchMode(CameraMode const &camera_mode, Metadata *metadata) config_.luminance_strength); memcpy(prev_sync_results_, sync_results_, sizeof(prev_sync_results_)); + frame_phase_ = config_.frame_period; // run the algo again asap first_time_ = false; } } @@ -265,8 +285,8 @@ void Alsc::restartAsync(StatisticsPtr &stats, Metadata *image_metadata) { RPI_LOG("Starting ALSC thread"); // Get the current colour temperature. It's all we need from the - // metadata. - ct_ = get_ct(image_metadata, config_.default_ct); + // metadata. Default to the last CT value (which could be the default). + ct_ = get_ct(image_metadata, ct_); // We have to copy the statistics here, dividing out our best guess of // the LSC table that the pipeline applied to them. AlscStatus alsc_status; -- cgit v1.2.1