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-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 @@ | |||
1 | /* | ||
2 | * Auto gain algorithm for camera's with a coarse exposure control | ||
3 | * | ||
4 | * Copyright (C) 2010 Hans de Goede <hdegoede@redhat.com> | ||
5 | * | ||
6 | * This program is free software; you can redistribute it and/or modify | ||
7 | * it under the terms of the GNU General Public License as published by | ||
8 | * the Free Software Foundation; either version 2 of the License, or | ||
9 | * (at your option) any later version. | ||
10 | * | ||
11 | * This program is distributed in the hope that it will be useful, | ||
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
14 | * GNU General Public License for more details. | ||
15 | * | ||
16 | * You should have received a copy of the GNU General Public License | ||
17 | * along with this program; if not, write to the Free Software | ||
18 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | ||
19 | */ | ||
20 | |||
21 | /* Autogain + exposure algorithm for cameras with a coarse exposure control | ||
22 | (usually this means we can only control the clockdiv to change exposure) | ||
23 | As changing the clockdiv so that the fps drops from 30 to 15 fps for | ||
24 | example, will lead to a huge exposure change (it effectively doubles), | ||
25 | this algorithm normally tries to only adjust the gain (between 40 and | ||
26 | 80 %) and if that does not help, only then changes exposure. This leads | ||
27 | to a much more stable image then using the knee algorithm which at | ||
28 | certain points of the knee graph will only try to adjust exposure, | ||
29 | which leads to oscilating as one exposure step is huge. | ||
30 | |||
31 | Note this assumes that the sd struct for the cam in question has | ||
32 | exp_too_high_cnt and exp_too_high_cnt int members for use by this function. | ||
33 | |||
34 | Returns 0 if no changes were made, 1 if the gain and or exposure settings | ||
35 | where changed. */ | ||
36 | static int gspca_coarse_grained_expo_autogain(struct gspca_dev *gspca_dev, | ||
37 | int avg_lum, int desired_avg_lum, int deadzone) | ||
38 | { | ||
39 | int i, steps, gain, orig_gain, exposure, orig_exposure; | ||
40 | int gain_low, gain_high; | ||
41 | const struct ctrl *gain_ctrl = NULL; | ||
42 | const struct ctrl *exposure_ctrl = NULL; | ||
43 | struct sd *sd = (struct sd *) gspca_dev; | ||
44 | int retval = 0; | ||
45 | |||
46 | for (i = 0; i < gspca_dev->sd_desc->nctrls; i++) { | ||
47 | if (gspca_dev->ctrl_dis & (1 << i)) | ||
48 | continue; | ||
49 | if (gspca_dev->sd_desc->ctrls[i].qctrl.id == V4L2_CID_GAIN) | ||
50 | gain_ctrl = &gspca_dev->sd_desc->ctrls[i]; | ||
51 | if (gspca_dev->sd_desc->ctrls[i].qctrl.id == V4L2_CID_EXPOSURE) | ||
52 | exposure_ctrl = &gspca_dev->sd_desc->ctrls[i]; | ||
53 | } | ||
54 | if (!gain_ctrl || !exposure_ctrl) { | ||
55 | PDEBUG(D_ERR, "Error: gspca_coarse_grained_expo_autogain " | ||
56 | "called on cam without gain or exposure"); | ||
57 | return 0; | ||
58 | } | ||
59 | |||
60 | if (gain_ctrl->get(gspca_dev, &gain) || | ||
61 | exposure_ctrl->get(gspca_dev, &exposure)) | ||
62 | return 0; | ||
63 | |||
64 | orig_gain = gain; | ||
65 | orig_exposure = exposure; | ||
66 | gain_low = | ||
67 | (gain_ctrl->qctrl.maximum - gain_ctrl->qctrl.minimum) / 5 * 2; | ||
68 | gain_low += gain_ctrl->qctrl.minimum; | ||
69 | gain_high = | ||
70 | (gain_ctrl->qctrl.maximum - gain_ctrl->qctrl.minimum) / 5 * 4; | ||
71 | gain_high += gain_ctrl->qctrl.minimum; | ||
72 | |||
73 | /* If we are of a multiple of deadzone, do multiple steps to reach the | ||
74 | desired lumination fast (with the risc of a slight overshoot) */ | ||
75 | steps = (desired_avg_lum - avg_lum) / deadzone; | ||
76 | |||
77 | PDEBUG(D_FRAM, "autogain: lum: %d, desired: %d, steps: %d", | ||
78 | avg_lum, desired_avg_lum, steps); | ||
79 | |||
80 | if ((gain + steps) > gain_high && | ||
81 | sd->exposure < exposure_ctrl->qctrl.maximum) { | ||
82 | gain = gain_high; | ||
83 | sd->exp_too_low_cnt++; | ||
84 | } else if ((gain + steps) < gain_low && | ||
85 | sd->exposure > exposure_ctrl->qctrl.minimum) { | ||
86 | gain = gain_low; | ||
87 | sd->exp_too_high_cnt++; | ||
88 | } else { | ||
89 | gain += steps; | ||
90 | if (gain > gain_ctrl->qctrl.maximum) | ||
91 | gain = gain_ctrl->qctrl.maximum; | ||
92 | else if (gain < gain_ctrl->qctrl.minimum) | ||
93 | gain = gain_ctrl->qctrl.minimum; | ||
94 | sd->exp_too_high_cnt = 0; | ||
95 | sd->exp_too_low_cnt = 0; | ||
96 | } | ||
97 | |||
98 | if (sd->exp_too_high_cnt > 3) { | ||
99 | exposure--; | ||
100 | sd->exp_too_high_cnt = 0; | ||
101 | } else if (sd->exp_too_low_cnt > 3) { | ||
102 | exposure++; | ||
103 | sd->exp_too_low_cnt = 0; | ||
104 | } | ||
105 | |||
106 | if (gain != orig_gain) { | ||
107 | gain_ctrl->set(gspca_dev, gain); | ||
108 | retval = 1; | ||
109 | } | ||
110 | if (exposure != orig_exposure) { | ||
111 | exposure_ctrl->set(gspca_dev, exposure); | ||
112 | retval = 1; | ||
113 | } | ||
114 | |||
115 | return retval; | ||
116 | } | ||