libv4l: autogain tweaks

-Take a bit larger steps when modifying very fine grain controls, even when
 steps < 3
-Don't do step multiplication when changing exposure in the exposure low
 range

Signed-off-by: Hans de Goede <hdegoede@redhat.com>

diff --git a/lib/libv4lconvert/processing/autogain.c b/lib/libv4lconvert/processing/autogain.c
index 56d5703..c6866d6 100644 (file)
--- a/lib/libv4lconvert/processing/autogain.c
+++ b/lib/libv4lconvert/processing/autogain.c
@@ -42,16 +42,20 @@ static int autogain_active(struct v4lprocessing_data *data)
 
 /* Adjust ctrl value with steps steps, while not crossing limit */
 static void autogain_adjust(struct v4l2_queryctrl *ctrl, int *value,
-               int steps, int limit)
+               int steps, int limit, int accel)
 {
        int ctrl_range = (ctrl->maximum - ctrl->minimum) / ctrl->step;
 
-       /* If we are of 3 * deadzone or more, and we have a very fine grained
+       /* If we are of 3 * deadzone or more, and we have a fine grained
           control, take larger steps, otherwise we take ages to get to the
-          right setting point. We use 256 as tripping point for determineing fine
-          grained controls here, as avg_lum has a range of 0 - 255. */
-       if (abs(steps) >= 3 && ctrl_range > 256)
+          right setting point. We use 256 as tripping point for determining
+          fine grained controls here, as avg_lum has a range of 0 - 255. */
+       if (accel && abs(steps) >= 3 && ctrl_range > 256)
                *value += steps * ctrl->step * (ctrl_range / 256);
+        /* If we are of by less then 3, but have a very finegrained control
+           still speed things up a bit */
+       else if (accel && ctrl_range > 1024)
+               *value += steps * ctrl->step * (ctrl_range / 1024);
        else
                *value += steps * ctrl->step;
 
@@ -150,28 +154,38 @@ static int autogain_calculate_lookup_tables(
 
        if (steps < 0) {
                if (exposure > expoctrl.default_value)
-                       autogain_adjust(&expoctrl, &exposure, steps, expoctrl.default_value);
+                       autogain_adjust(&expoctrl, &exposure, steps,
+                                       expoctrl.default_value, 1);
                else if (gain > gainctrl.default_value)
-                       autogain_adjust(&gainctrl, &gain, steps, gainctrl.default_value);
+                       autogain_adjust(&gainctrl, &gain, steps,
+                                       gainctrl.default_value, 1);
                else if (exposure > exposure_low)
-                       autogain_adjust(&expoctrl, &exposure, steps, exposure_low);
+                       autogain_adjust(&expoctrl, &exposure, steps,
+                                       exposure_low, 1);
                else if (gain > gainctrl.minimum)
-                       autogain_adjust(&gainctrl, &gain, steps, gainctrl.minimum);
+                       autogain_adjust(&gainctrl, &gain, steps,
+                                       gainctrl.minimum, 1);
                else if (exposure > expoctrl.minimum)
-                       autogain_adjust(&expoctrl, &exposure, steps, expoctrl.minimum);
+                       autogain_adjust(&expoctrl, &exposure, steps,
+                                       expoctrl.minimum, 0);
                else
                        steps = 0;
        } else {
                if (exposure < exposure_low)
-                       autogain_adjust(&expoctrl, &exposure, steps, exposure_low);
+                       autogain_adjust(&expoctrl, &exposure, steps,
+                                       exposure_low, 0);
                else if (gain < gainctrl.default_value)
-                       autogain_adjust(&gainctrl, &gain, steps, gainctrl.default_value);
+                       autogain_adjust(&gainctrl, &gain, steps,
+                                       gainctrl.default_value, 1);
                else if (exposure < expoctrl.default_value)
-                       autogain_adjust(&expoctrl, &exposure, steps, expoctrl.default_value);
+                       autogain_adjust(&expoctrl, &exposure, steps,
+                                       expoctrl.default_value, 1);
                else if (gain < gainctrl.maximum)
-                       autogain_adjust(&gainctrl, &gain, steps, gainctrl.maximum);
+                       autogain_adjust(&gainctrl, &gain, steps,
+                                       gainctrl.maximum, 1);
                else if (exposure < expoctrl.maximum)
-                       autogain_adjust(&expoctrl, &exposure, steps, expoctrl.maximum);
+                       autogain_adjust(&expoctrl, &exposure, steps,
+                                       expoctrl.maximum, 1);
                else
                        steps = 0;
        }