Hello Laurie,
On Wed, 5 Aug 2020 21:42:18 +0100
Laurence Tratt <[email protected]> wrote:
> Following Marcus's commit of video(1) changes, the attached patch
> crudely solves the "-c output is misleading for
> white_balance_temperature" because we conflate
> auto_white_balance_temperature and white_balance_temperature (which
> are two separate UVC controls) into one control in video(1).
>
> With this patch we can tell people if white_balance_temperature is
> being automatically controlled or not:
>
> $ video white_balance_temperature=6500
> white_balance_temperature: 4000 -> 6500
> $ obj/video -c
> brightness=128
> contrast=32
> saturation=64
> hue=0
> gamma=120
> sharpness=2
> white_balance_temperature=6500
> $ obj/video -d
> $ obj/video -c
> brightness=128
> contrast=32
> saturation=64
> hue=0
> gamma=120
> sharpness=2
> white_balance_temperature=auto
>
> This patch raises several questions:
>
> 1) At the moment the only "auto" control we have is
> white_balance_temperature. If we gain control of
> zoom/pan/exposure (etc), it might be worth breaking out the common
> "auto" functionality?
For now how about adding the according auto control id to our dev_ctrls
structure? In a next step we could change
dev_set_ctrl_auto_white_balance() to become a generic function
dev_set_ctrl_auto() available for all auto controls.
> 2) Arguably the first command should look like:
> $ video white_balance_temperature=6500
> white_balance_temperature: auto -> 6500
I agree that feels more natural. Added in the below diff.
> 3) The output of "video -dv" is very different to "video -c": I
> suspect the former should look more like the latter for consistency.
Lets look at this separately.
> 4) "video -dc" doesn't seem to reset auto_white_balance_temperature?
Agree that combination should work - Will check it later.
>
> Laurie
Marcus
Index: video.c
===================================================================
RCS file: /cvs/xenocara/app/video/video.c,v
retrieving revision 1.33
diff -u -p -u -p -r1.33 video.c
--- video.c 5 Aug 2020 11:34:00 -0000 1.33
+++ video.c 8 Aug 2020 12:28:33 -0000
@@ -94,6 +94,7 @@ struct dev_ctrls {
char *name;
int supported;
int id;
+ int id_auto;
int def;
int min;
int max;
@@ -101,24 +102,25 @@ struct dev_ctrls {
int cur;
} ctrls[] = {
#define CTRL_BRIGHTNESS 0
- { "brightness", 0, V4L2_CID_BRIGHTNESS, 0, 0, 0, 0, 0 },
+ { "brightness", 0, V4L2_CID_BRIGHTNESS, 0, 0, 0, 0, 0, 0 },
#define CTRL_CONTRAST 1
- { "contrast", 0, V4L2_CID_CONTRAST, 0, 0, 0, 0, 0 },
+ { "contrast", 0, V4L2_CID_CONTRAST, 0, 0, 0, 0, 0, 0 },
#define CTRL_SATURATION 2
- { "saturation", 0, V4L2_CID_SATURATION, 0, 0, 0, 0, 0 },
+ { "saturation", 0, V4L2_CID_SATURATION, 0, 0, 0, 0, 0, 0 },
#define CTRL_HUE 3
- { "hue", 0, V4L2_CID_HUE, 0, 0, 0, 0, 0 },
+ { "hue", 0, V4L2_CID_HUE, 0, 0, 0, 0, 0, 0 },
#define CTRL_GAIN 4
- { "gain", 0, V4L2_CID_GAIN, 0, 0, 0, 0, 0 },
+ { "gain", 0, V4L2_CID_GAIN, 0, 0, 0, 0, 0, 0 },
#define CTRL_GAMMA 5
- { "gamma", 0, V4L2_CID_GAMMA, 0, 0, 0, 0, 0 },
+ { "gamma", 0, V4L2_CID_GAMMA, 0, 0, 0, 0, 0, 0 },
#define CTRL_SHARPNESS 6
- { "sharpness", 0, V4L2_CID_SHARPNESS, 0, 0, 0, 0, 0 },
+ { "sharpness", 0, V4L2_CID_SHARPNESS, 0, 0, 0, 0, 0, 0 },
#define CTRL_WHITE_BALANCE_TEMPERATURE 7
{ "white_balance_temperature",
- 0, V4L2_CID_WHITE_BALANCE_TEMPERATURE, 0, 0, 0, 0, 0 },
+ 0, V4L2_CID_WHITE_BALANCE_TEMPERATURE,
+ V4L2_CID_AUTO_WHITE_BALANCE, 0, 0, 0, 0, 0 },
#define CTRL_LAST 8
- { NULL, 0, 0, 0, 0, 0, 0, 0 }
+ { NULL, 0, 0, 0, 0, 0, 0, 0, 0 }
};
/* frame dimensions */
@@ -218,6 +220,7 @@ int dev_init(struct video *);
int dev_set_ctrl_abs(struct video *vid, int, int);
void dev_set_ctrl_rel(struct video *, int, int);
void dev_set_ctrl_auto_white_balance(struct video *, int, int);
+int dev_get_ctrl_auto(struct video *, int);
void dev_reset_ctrls(struct video *);
int parse_ctrl(struct video *, int, char **);
@@ -1102,6 +1105,24 @@ dev_set_ctrl_auto_white_balance(struct v
}
}
+int
+dev_get_ctrl_auto(struct video *vid, int ctrl)
+{
+ struct dev *d = &vid->dev;
+ struct v4l2_control control;
+
+ if (!ctrls[ctrl].id_auto)
+ return 0;
+
+ control.id = ctrls[ctrl].id_auto;
+ if (ioctl(d->fd, VIDIOC_G_CTRL, &control) != 0) {
+ warn("VIDIOC_G_CTRL");
+ return 0;
+ }
+
+ return (control.value);
+}
+
void
dev_reset_ctrls(struct video *vid)
{
@@ -1195,7 +1216,12 @@ dev_dump_query_ctrls(struct video *vid)
return;
for (i = 0; i < CTRL_LAST; i++) {
- if (ctrls[i].supported)
+ if (!ctrls[i].supported)
+ continue;
+
+ if (dev_get_ctrl_auto(vid, i))
+ fprintf(stderr, "%s=auto\n", ctrls[i].name);
+ else
fprintf(stderr, "%s=%d\n", ctrls[i].name, ctrls[i].cur);
}
}
@@ -1253,7 +1279,7 @@ dev_init(struct video *vid)
int
parse_ctrl(struct video *vid, int argc, char **argv)
{
- int i, val_old, val_new;
+ int i, val_old, auto_old, val_new;
char *p;
const char *errstr;
@@ -1296,9 +1322,17 @@ parse_ctrl(struct video *vid, int argc,
return 0;
}
val_old = ctrls[i].cur;
- if (dev_set_ctrl_abs(vid, i, val_new) == 0)
- fprintf(stderr, "%s: %d -> %d\n",
- ctrls[i].name, val_old, ctrls[i].cur);
+ auto_old = dev_get_ctrl_auto(vid, i);
+ if (dev_set_ctrl_abs(vid, i, val_new) == 0) {
+ if (auto_old) {
+ fprintf(stderr, "%s: auto -> %d\n",
+ ctrls[i].name, ctrls[i].cur);
+ } else {
+ fprintf(stderr, "%s: %d -> %d\n",
+ ctrls[i].name, val_old,
+ ctrls[i].cur);
+ }
+ }
break;
}
if (i == CTRL_LAST)
