Update

pipewire/.config/wireplumber/scripts/lib/monitor-utils.lua

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+-- WirePlumber
+
+-- Copyright © 2023 Collabora Ltd.
+--    @author Ashok Sidipotu <ashok.sidipotu@collabora.com>
+
+-- SPDX-License-Identifier: MIT
+
+-- Script is a Lua Module of monitor Lua utility functions
+
+log = Log.open_topic ("s-monitors-utils")
+
+local mutils = {
+  cam_data = {}
+}
+
+-- finds out if any of the managed objects(nodes of a device or devices of
+-- device enumerator) has duplicate values
+function mutils.find_duplicate (parent, id, property, value)
+  for i = 0, id - 1, 1 do
+    local obj = parent:get_managed_object (i)
+    if obj and obj.properties[property] == value then
+      return true
+    end
+  end
+  return false
+end
+
+function get_cam_data(self, dev_id)
+  if not self.cam_data[dev_id] then
+    self.cam_data[dev_id] = {}
+    self.cam_data[dev_id]["libcamera"] = {}
+    self.cam_data[dev_id]["v4l2"] = {}
+  end
+  return self.cam_data[dev_id]
+end
+
+function parse_devids_get_cam_data(self, devids)
+  local dev_ids_json = Json.Raw(devids)
+  local dev_ids_table = {}
+
+  if dev_ids_json:is_array() then
+    dev_ids_table = dev_ids_json:parse()
+  else
+    -- to maintain the backward compatibility with earlier pipewire versions.
+    for dev_id_str in devids:gmatch("%S+") do
+      local dev_id = tonumber(dev_id_str)
+      if dev_id then
+        table.insert(dev_ids_table, dev_id)
+      end
+    end
+  end
+
+  local dev_num = nil
+  -- `device.devids` is a json array of device numbers
+  for _, dev_id_str in ipairs(dev_ids_table) do
+    local dev_id = tonumber(dev_id_str)
+    if not dev_id then
+      log:notice ("invalid device number")
+      return
+    end
+
+    log:debug ("Working on device " .. dev_id)
+    local dev_cam_data = get_cam_data (self, dev_id)
+    if not dev_num then
+      dev_num = dev_id
+      if #dev_ids_table > 1 then
+        -- libcam node can some times use more tha one V4L2 devices, in this
+        -- case, return the first device id and mark rest of the them as peers
+        -- to the first one.
+        log:debug ("Device " .. dev_id .. " uses multi V4L2 devices")
+        dev_cam_data.uses_multi_v4l2_devices = true
+      end
+    else
+      log:debug ("Device " .. dev_id .. " is peer to " .. dev_num)
+      dev_cam_data.peer_id = dev_num
+    end
+  end
+
+  if dev_num then
+    return self.cam_data[dev_num], dev_num
+  end
+end
+
+function mutils.clear_cam_data (self, dev_num)
+  local dev_cam_data = self.cam_data[dev_num]
+  if not dev_cam_data then
+    return
+  end
+
+  if dev_cam_data.uses_multi_v4l2_devices then
+    for dev_id, cam_data_ in pairs(self.cam_data) do
+      if cam_data_.peer_id == dev_num then
+        log:debug("clear " .. dev_id .. " it is peer to " .. dev_num)
+        self.cam_data[dev_id] = nil
+      end
+    end
+  end
+
+  self.cam_data[dev_num] = nil
+end
+
+function mutils.create_cam_node(self, dev_num)
+  local api = nil
+  local cam_data = get_cam_data (self, dev_num)
+
+  if cam_data["v4l2"].enum_status and cam_data["libcamera"].enum_status then
+    if cam_data.uses_multi_v4l2_devices then
+      api = "libcamera"
+    elseif cam_data.peer_id ~= nil then
+      -- no need to create node for peer
+      log:notice ("timer expired for peer device " .. dev_num)
+      return
+    elseif cam_data.is_device_uvc then
+      api = "v4l2"
+    else
+      api = "libcamera"
+    end
+  else
+    api = cam_data["v4l2"].enum_status and "v4l2" or "libcamera"
+  end
+
+  log:info (string.format ("create \"%s\" node for device:%s", api,
+    cam_data.dev_path))
+
+  source = source or Plugin.find ("standard-event-source")
+  local e = source:call ("create-event", "create-" .. api .. "-device-node",
+    cam_data[api].parent, nil)
+  e:set_data ("factory", cam_data[api].factory)
+  e:set_data ("node-properties", cam_data[api].properties)
+  e:set_data ("node-sub-id", cam_data[api].id)
+
+  EventDispatcher.push_event (e)
+
+  self:clear_cam_data (dev_num)
+end
+
+-- arbitrates between v4l2 and libcamera on who gets to create the device node
+-- for a device, logic is based on the device number of the device given by both
+-- the parties.
+function mutils.register_cam_node (self, parent, id, factory, properties)
+  local api = properties["device.api"]
+  local dev_ids = properties["device.devids"]
+  log:debug(api .. " reported " .. dev_ids)
+
+  local cam_data, dev_num = parse_devids_get_cam_data(self, dev_ids)
+
+  if not cam_data then
+    log:notice (string.format ("device numbers invalid for %s device:%s",
+      api, properties["device.name"]))
+    return false
+  end
+
+  -- only v4l2 can give this info
+  if properties["api.v4l2.cap.driver"] == "uvcvideo" then
+    log:debug ("Device " .. dev_num .. " is a UVC device")
+    cam_data.is_device_uvc = true
+  end
+
+  -- only v4l2 can give this info
+  if properties["api.v4l2.path"] then
+    cam_data.dev_path = properties["api.v4l2.path"]
+  end
+
+  local cam_api_data = cam_data[api]
+  cam_api_data.enum_status = true
+
+  -- cache info, it comes handy when creating node
+  cam_api_data.parent = parent
+  cam_api_data.id = id
+  cam_api_data.name = properties["device.name"]
+  cam_api_data.factory = factory
+  cam_api_data.properties = properties
+
+  local other_api = api == "v4l2" and "libcamera" or "v4l2"
+  if cam_api_data.enum_status and not cam_data[other_api].enum_status then
+    log:trace (string.format ("\"%s\" armed a timer for %d", api, dev_num))
+    cam_data.source = Core.timeout_add (
+      Settings.get_int ("monitor.camera-discovery-timeout"), function()
+        log:trace (string.format ("\"%s\" armed timer expired for %d", api, dev_num))
+        self:create_cam_node (dev_num)
+        cam_data.source = nil
+      end)
+  elseif cam_data.source then
+    log:trace (string.format ("\"%s\" disarmed timer for %d", api, dev_num))
+    cam_data.source:destroy ()
+    cam_data.source = nil
+    self:create_cam_node (dev_num)
+  else
+    log:notice (string.format ("\"%s\" calling after timer expiry for %d:%s%s",
+      api, dev_num, cam_data.dev_path,
+      (cam_data.is_device_uvc and "(uvc)" or "")))
+  end
+
+  return true
+end
+
+return mutils