Hi Sylwester, On Wed January 23 2013 23:21:57 Sylwester Nawrocki wrote: > This patch adds a helper function that allows to modify range, > i.e. minimum, maximum, step and default value of a v4l2 control, > after the control has been created and initialized. This is helpful > in situations when range of a control depends on user configurable > parameters, e.g. camera sensor absolute exposure time depending on > an output image resolution and frame rate. > > v4l2_ctrl_modify_range() function allows to modify range of an > INTEGER, BOOL, MENU, INTEGER_MENU and BITMASK type controls. > > Based on a patch from Hans Verkuil http://patchwork.linuxtv.org/patch/8654. > > Signed-off-by: Sylwester Nawrocki <sylvester.nawrocki@xxxxxxxxx> > Acked-by: Hans Verkuil <hans.verkuil@xxxxxxxxx> I've been playing around with this a bit, using this vivi patch: diff --git a/drivers/media/platform/vivi.c b/drivers/media/platform/vivi.c index c46d2e8..85bc314 100644 --- a/drivers/media/platform/vivi.c +++ b/drivers/media/platform/vivi.c @@ -1093,6 +1093,15 @@ static int vidioc_s_input(struct file *file, void *priv, unsigned int i) return 0; dev->input = i; + /* + * Modify the brightness range depending on the input. + * This makes it easy to use vivi to test if applications can + * handle control range modifications and is also how this is + * typically used in practice as different inputs may be hooked + * up to different receivers with different control ranges. + */ + v4l2_ctrl_modify_range(dev->brightness, + 128 * i, 255 + 128 * i, 1, 127 + 128 * i); precalculate_bars(dev); precalculate_line(dev); return 0; And it made me wonder if it wouldn't be more sensible if modify_range would also update the current value to the new default value? You get weird effects otherwise where the new value is clamped to either the minimum or maximum value if the current value falls outside the new range. Regards, Hans PS: qv4l2 has been updated to support range update events. -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
