fix(v4l2):: show bool controls and fix control name mismatch with Motion (#3391)

v4l2-ctl reports bool controls without min/max, so they were filtered
out before reaching the UI and never rendered as a checkbox. Capture
the control type from the parenthesized field and default bool
controls to min=0 and max=1.

Control values also often never reached the camera. Motion matches
video_params entries against the driver's raw control name, which
v4l2-ctl never prints: it collapses runs of non-alphanumeric
characters into underscores, so "White Balance, Automatic" is shown as
"white_balance_automatic". That substitution cannot be reversed, and
on a typical UVC webcam it breaks every control whose driver name is
more than one word -- half of them on the camera this was found on.

Write the control ID instead, in Motion's own "ID%08d" format, which
Motion builds and matches on in video_v4l2.c. IDs are stable UAPI
constants, whereas control names have changed between kernel versions.

Matching by ID also survives Motion upgrades: 5.x made name matching
case-sensitive, breaking even the single-word names that work on 4.6.

Existing configs with plain names are read back unchanged and migrate
to IDs on the next save.

Author: Marijn0

motioneye/config.py

@@ -1120,12 +1120,16 @@ def motion_camera_ui_to_dict(ui, prev_config=None):
         threshold = int(float(ui['frame_change_threshold']) * width * height / 100)
 
         if proto == 'v4l2':
-            # video controls
-            vid_control_params = (
-                ('{}={}'.format(n, c['value']))
-                for n, c in list(ui['video_controls'].items())
-            )
-            data['vid_control_params'] = ','.join(vid_control_params)
+            # video controls, control_id is the ID Motion actually matches against (see v4l2-ctl --list-ctrls)
+            video_controls = v4l2ctl.list_ctrls(prev_config.get('videodevice', ''))
+            if video_controls:
+                vid_control_params = (
+                    '{}={}'.format(
+                        video_controls.get(n, {}).get('control_id', n), c['value']
+                    )
+                    for n, c in list(ui['video_controls'].items())
+                )
+                data['vid_control_params'] = ','.join(vid_control_params)
 
     else:  # assuming netcam
         if match(
@@ -1682,6 +1686,12 @@ def motion_camera_dict_to_ui(data):  # noqa: C901
         ui['resolution'] = str(data['width']) + 'x' + str(data['height'])
 
         video_controls = v4l2ctl.list_ctrls(data['videodevice'])
+
+        # video_params is keyed by control_id, map it back to our UI name
+        name_by_control_id = {
+            c.get('control_id', n): n for n, c in video_controls.items()
+        }
+
         video_controls = [
             (n, c)
             for (n, c) in list(video_controls.items())
@@ -1701,6 +1711,7 @@ def motion_camera_dict_to_ui(data):  # noqa: C901
             else:
                 continue  # ignore any other kind of param
 
+            name = name_by_control_id.get(name, name)
             vid_control_values[name] = value
 
         ui['video_controls'] = {

motioneye/controls/v4l2ctl.py

@@ -179,14 +179,30 @@ def list_ctrls(device):
         if not line:
             continue
 
-        match = re.match(r'^\s*(\w+)\s+([a-f0-9x\s]+)?\(\w+\)\s*:\s*(.+)\s*', line)
+        match = re.match(r'^\s*(\w+)\s+([a-f0-9x\s]+)?\((\w+)\)\s*:\s*(.+)\s*', line)
         if not match:
             continue
 
-        control, _, properties = match.groups()
+        control, id_hex, ctrl_type, properties = match.groups()
         properties = dict(
             [v.split('=', 1) for v in properties.split(' ') if v.count('=')]
         )
+        if ctrl_type == 'bool':
+            # v4l2-ctl --list-ctrls gives no min/max for bool controls, so set them here
+            properties.setdefault('min', '0')
+            properties.setdefault('max', '1')
+
+        # Motion matches controls by ID. We use ID because the driver's raw
+        # name doesn't always match the name v4l2-ctl gives (e.g. driver:
+        # "White Balance, Automatic" vs. v4l2-ctl: "white_balance_automatic")
+        if id_hex:
+            try:
+                properties['control_id'] = f'ID{int(id_hex, 16):08d}'
+            except ValueError:
+                logging.warning(
+                    f'could not parse v4l2 control id "{id_hex}" for "{control}"'
+                )
+
         controls[control] = properties
 
     _ctrls_cache[device] = controls