diff options
Diffstat (limited to 'drivers/media/video/gspca/autogain_functions.c')
| -rw-r--r-- | drivers/media/video/gspca/autogain_functions.c | 178 |
1 files changed, 0 insertions, 178 deletions
diff --git a/drivers/media/video/gspca/autogain_functions.c b/drivers/media/video/gspca/autogain_functions.c deleted file mode 100644 index 67db674..0000000 --- a/drivers/media/video/gspca/autogain_functions.c +++ /dev/null @@ -1,178 +0,0 @@ -/* - * Functions for auto gain. - * - * Copyright (C) 2010-2012 Hans de Goede <hdegoede@redhat.com> - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA - */ -#include "gspca.h" - -/* auto gain and exposure algorithm based on the knee algorithm described here: - http://ytse.tricolour.net/docs/LowLightOptimization.html - - Returns 0 if no changes were made, 1 if the gain and or exposure settings - where changed. */ -int gspca_expo_autogain( - struct gspca_dev *gspca_dev, - int avg_lum, - int desired_avg_lum, - int deadzone, - int gain_knee, - int exposure_knee) -{ - s32 gain, orig_gain, exposure, orig_exposure; - int i, steps, retval = 0; - - if (v4l2_ctrl_g_ctrl(gspca_dev->autogain) == 0) - return 0; - - orig_gain = gain = v4l2_ctrl_g_ctrl(gspca_dev->gain); - orig_exposure = exposure = v4l2_ctrl_g_ctrl(gspca_dev->exposure); - - /* If we are of a multiple of deadzone, do multiple steps to reach the - desired lumination fast (with the risc of a slight overshoot) */ - steps = abs(desired_avg_lum - avg_lum) / deadzone; - - PDEBUG(D_FRAM, "autogain: lum: %d, desired: %d, steps: %d", - avg_lum, desired_avg_lum, steps); - - for (i = 0; i < steps; i++) { - if (avg_lum > desired_avg_lum) { - if (gain > gain_knee) - gain--; - else if (exposure > exposure_knee) - exposure--; - else if (gain > gspca_dev->gain->default_value) - gain--; - else if (exposure > gspca_dev->exposure->minimum) - exposure--; - else if (gain > gspca_dev->gain->minimum) - gain--; - else - break; - } else { - if (gain < gspca_dev->gain->default_value) - gain++; - else if (exposure < exposure_knee) - exposure++; - else if (gain < gain_knee) - gain++; - else if (exposure < gspca_dev->exposure->maximum) - exposure++; - else if (gain < gspca_dev->gain->maximum) - gain++; - else - break; - } - } - - if (gain != orig_gain) { - v4l2_ctrl_s_ctrl(gspca_dev->gain, gain); - retval = 1; - } - if (exposure != orig_exposure) { - v4l2_ctrl_s_ctrl(gspca_dev->exposure, exposure); - retval = 1; - } - - if (retval) - PDEBUG(D_FRAM, "autogain: changed gain: %d, expo: %d", - gain, exposure); - return retval; -} -EXPORT_SYMBOL(gspca_expo_autogain); - -/* Autogain + exposure algorithm for cameras with a coarse exposure control - (usually this means we can only control the clockdiv to change exposure) - As changing the clockdiv so that the fps drops from 30 to 15 fps for - example, will lead to a huge exposure change (it effectively doubles), - this algorithm normally tries to only adjust the gain (between 40 and - 80 %) and if that does not help, only then changes exposure. This leads - to a much more stable image then using the knee algorithm which at - certain points of the knee graph will only try to adjust exposure, - which leads to oscilating as one exposure step is huge. - - Returns 0 if no changes were made, 1 if the gain and or exposure settings - where changed. */ -int gspca_coarse_grained_expo_autogain( - struct gspca_dev *gspca_dev, - int avg_lum, - int desired_avg_lum, - int deadzone) -{ - s32 gain_low, gain_high, gain, orig_gain, exposure, orig_exposure; - int steps, retval = 0; - - if (v4l2_ctrl_g_ctrl(gspca_dev->autogain) == 0) - return 0; - - orig_gain = gain = v4l2_ctrl_g_ctrl(gspca_dev->gain); - orig_exposure = exposure = v4l2_ctrl_g_ctrl(gspca_dev->exposure); - - gain_low = (gspca_dev->gain->maximum - gspca_dev->gain->minimum) / - 5 * 2 + gspca_dev->gain->minimum; - gain_high = (gspca_dev->gain->maximum - gspca_dev->gain->minimum) / - 5 * 4 + gspca_dev->gain->minimum; - - /* If we are of a multiple of deadzone, do multiple steps to reach the - desired lumination fast (with the risc of a slight overshoot) */ - steps = (desired_avg_lum - avg_lum) / deadzone; - - PDEBUG(D_FRAM, "autogain: lum: %d, desired: %d, steps: %d", - avg_lum, desired_avg_lum, steps); - - if ((gain + steps) > gain_high && - exposure < gspca_dev->exposure->maximum) { - gain = gain_high; - gspca_dev->exp_too_low_cnt++; - gspca_dev->exp_too_high_cnt = 0; - } else if ((gain + steps) < gain_low && - exposure > gspca_dev->exposure->minimum) { - gain = gain_low; - gspca_dev->exp_too_high_cnt++; - gspca_dev->exp_too_low_cnt = 0; - } else { - gain += steps; - if (gain > gspca_dev->gain->maximum) - gain = gspca_dev->gain->maximum; - else if (gain < gspca_dev->gain->minimum) - gain = gspca_dev->gain->minimum; - gspca_dev->exp_too_high_cnt = 0; - gspca_dev->exp_too_low_cnt = 0; - } - - if (gspca_dev->exp_too_high_cnt > 3) { - exposure--; - gspca_dev->exp_too_high_cnt = 0; - } else if (gspca_dev->exp_too_low_cnt > 3) { - exposure++; - gspca_dev->exp_too_low_cnt = 0; - } - - if (gain != orig_gain) { - v4l2_ctrl_s_ctrl(gspca_dev->gain, gain); - retval = 1; - } - if (exposure != orig_exposure) { - v4l2_ctrl_s_ctrl(gspca_dev->exposure, exposure); - retval = 1; - } - - if (retval) - PDEBUG(D_FRAM, "autogain: changed gain: %d, expo: %d", - gain, exposure); - return retval; -} -EXPORT_SYMBOL(gspca_coarse_grained_expo_autogain); |