diff options
Diffstat (limited to 'drivers/media/video/gspca/coarse_expo_autogain.h')
| -rw-r--r-- | drivers/media/video/gspca/coarse_expo_autogain.h | 116 |
1 files changed, 0 insertions, 116 deletions
diff --git a/drivers/media/video/gspca/coarse_expo_autogain.h b/drivers/media/video/gspca/coarse_expo_autogain.h deleted file mode 100644 index 1cb9d941eaf6..000000000000 --- a/drivers/media/video/gspca/coarse_expo_autogain.h +++ /dev/null @@ -1,116 +0,0 @@ -/* - * Auto gain algorithm for camera's with a coarse exposure control - * - * Copyright (C) 2010 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 - */ - -/* 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. - - Note this assumes that the sd struct for the cam in question has - exp_too_high_cnt and exp_too_high_cnt int members for use by this function. - - Returns 0 if no changes were made, 1 if the gain and or exposure settings - where changed. */ -static int gspca_coarse_grained_expo_autogain(struct gspca_dev *gspca_dev, - int avg_lum, int desired_avg_lum, int deadzone) -{ - int i, steps, gain, orig_gain, exposure, orig_exposure; - int gain_low, gain_high; - const struct ctrl *gain_ctrl = NULL; - const struct ctrl *exposure_ctrl = NULL; - struct sd *sd = (struct sd *) gspca_dev; - int retval = 0; - - for (i = 0; i < gspca_dev->sd_desc->nctrls; i++) { - if (gspca_dev->ctrl_dis & (1 << i)) - continue; - if (gspca_dev->sd_desc->ctrls[i].qctrl.id == V4L2_CID_GAIN) - gain_ctrl = &gspca_dev->sd_desc->ctrls[i]; - if (gspca_dev->sd_desc->ctrls[i].qctrl.id == V4L2_CID_EXPOSURE) - exposure_ctrl = &gspca_dev->sd_desc->ctrls[i]; - } - if (!gain_ctrl || !exposure_ctrl) { - PDEBUG(D_ERR, "Error: gspca_coarse_grained_expo_autogain " - "called on cam without gain or exposure"); - return 0; - } - - if (gain_ctrl->get(gspca_dev, &gain) || - exposure_ctrl->get(gspca_dev, &exposure)) - return 0; - - orig_gain = gain; - orig_exposure = exposure; - gain_low = - (gain_ctrl->qctrl.maximum - gain_ctrl->qctrl.minimum) / 5 * 2; - gain_low += gain_ctrl->qctrl.minimum; - gain_high = - (gain_ctrl->qctrl.maximum - gain_ctrl->qctrl.minimum) / 5 * 4; - gain_high += gain_ctrl->qctrl.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 && - sd->exposure < exposure_ctrl->qctrl.maximum) { - gain = gain_high; - sd->exp_too_low_cnt++; - } else if ((gain + steps) < gain_low && - sd->exposure > exposure_ctrl->qctrl.minimum) { - gain = gain_low; - sd->exp_too_high_cnt++; - } else { - gain += steps; - if (gain > gain_ctrl->qctrl.maximum) - gain = gain_ctrl->qctrl.maximum; - else if (gain < gain_ctrl->qctrl.minimum) - gain = gain_ctrl->qctrl.minimum; - sd->exp_too_high_cnt = 0; - sd->exp_too_low_cnt = 0; - } - - if (sd->exp_too_high_cnt > 3) { - exposure--; - sd->exp_too_high_cnt = 0; - } else if (sd->exp_too_low_cnt > 3) { - exposure++; - sd->exp_too_low_cnt = 0; - } - - if (gain != orig_gain) { - gain_ctrl->set(gspca_dev, gain); - retval = 1; - } - if (exposure != orig_exposure) { - exposure_ctrl->set(gspca_dev, exposure); - retval = 1; - } - - return retval; -} |