mpv: sane-sysvol: monitor pipewire for changes and relay that to uosc

it's a one-way volume control, but that's a start

TODO.md

@@ -1,10 +1,14 @@
 ## BUGS
+- Signal restart loop drains battery
+  - decrease s6 restart time?
+- mpv `player-mode=pseudo-gui` swallows all loggin
 - ringer (i.e. dino incoming call) doesn't prevent moby from sleeping
 - sway mouse/kb hotplug doesn't work
 - `nix` operations from lappy hang when `desko` is unreachable
   - could at least direct the cache to `http://desko-hn:5001`
 
 ## REFACTORING:
+- REMOVE DEPRECATED `crypt` from sftpgo_auth_hook
 - consolidate ~/dev and ~/ref
   - ~/dev becomes a link to ~/ref/cat/mine
 - fold hosts/common/home/ssh.nix -> hosts/common/users/colin.nix

hosts/common/programs/mpv/default.nix

@@ -91,48 +91,22 @@ let
            local last_up = cursor.last_event['primary_up'] or { time = 0 }
            if cursor.hover_raw or last_down.time >= last_up.time then cursor:move(mouse.x, mouse.y) end"
 
-      ### patch so that the volume control corresponds to `ao-volume`, i.e. the system-wide volume.
+      ### patch so that uosc volume control is routed to sane-sysvol.
       ### this is particularly nice for moby, because it avoids the awkwardness that system volume
       ### is hard to adjust while screen is on.
-      ### note that only under alsa (`-ao=alsa`) does `ao-volume` actually correspond to system volume.
+      ### previously i used ao-volume instead of sane-sysvol: but that forced `ao=alsa`
+      ### and came with heavy perf penalties (especially when adjusting the volume)
       substituteInPlace src/uosc/main.lua \
         --replace-fail \
-          "mp.observe_property('volume', 'number', create_state_setter('volume'))" \
-          "mp.observe_property('volume', 'number', update_ao_volume)"
+          "mp.observe_property('volume'" \
+          "mp.observe_property('user-data/sane-sysvol/volume'"
       substituteInPlace src/uosc/elements/Volume.lua \
-        --replace-fail "mp.commandv('set', 'volume'" "mp.commandv('set', 'ao-volume'" \
-        --replace-fail "mp.set_property_native('volume'" "mp.set_property('ao-volume'"
-
-      # `ao-volume` isn't actually an observable property.
-      # as of 2024/03/02, they *may* be working on that:
-      # - <https://github.com/mpv-player/mpv/pull/13604#issuecomment-1971665736>
-      # in the meantime, just query the volume every tick (i.e. frame).
-      # alternative is mpv's JSON IPC feature, where i could notify its socket whenever pipewire volume changes.
-      cat <<EOF >> src/uosc/main.lua
-      function update_ao_volume(_, vol)
-        if vol == nil then
-          -- vol will be nil if called manually, instead of via observe_property
-          vol = mp.get_property('ao-volume')
-        end
-        if vol == nil then
-          vol = 0
-        else
-          vol = tonumber(vol)
-        end
-
-        if vol ~= state.volume then
-          set_state('volume', vol)
-          request_render()
-        end
-      end
-      -- tick seems to occur on every redraw (even when volume is hidden).
-      -- in practice: for every new frame of the source, or whenever the cursor is moved.
-      mp.register_event('tick', update_ao_volume)
-      -- if paused and cursor isn't moving, then `tick` isn't called. fallback to a timer.
-      mp.add_periodic_timer(2, update_ao_volume)
-      -- invoke immediately to ensure state.volume is non-nil
-      update_ao_volume()
-      EOF
+        --replace-fail \
+          "mp.commandv('set', 'volume'" \
+          "mp.set_property_native('user-data/sane-sysvol/volume'" \
+        --replace-fail \
+          "mp.set_property_native('volume'" \
+          "mp.set_property_native('user-data/sane-sysvol/volume'"
     '';
   });
   mpv-unwrapped = pkgs.mpv-unwrapped.overrideAttrs (upstream: {
@@ -148,7 +122,7 @@ let
 in
 {
   sane.programs.mpv = {
-    packageUnwrapped = pkgs.wrapMpv mpv-unwrapped {
+    packageUnwrapped = pkgs.wrapMpv (mpv-unwrapped.override { lua = pkgs.luajit; }) {
       scripts = [
         pkgs.mpvScripts.mpris
         pkgs.mpvScripts.mpv-playlistmanager
@@ -216,7 +190,9 @@ in
       # for `watch_later`
       ".local/state/mpv"
     ];
-    fs.".config/mpv/scripts/sane/main.lua".symlink.target = ./sane-main.lua;
+    fs.".config/mpv/scripts/sane-cast/main.lua".symlink.target = ./sane-cast-main.lua;
+    fs.".config/mpv/scripts/sane-sysvol/main.lua".symlink.target = ./sane-sysvol/main.lua;
+    fs.".config/mpv/scripts/sane-sysvol/non_blocking_popen.lua".symlink.target = ./sane-sysvol/non_blocking_popen.lua;
     fs.".config/mpv/input.conf".symlink.target = ./input.conf;
     fs.".config/mpv/mpv.conf".symlink.target = ./mpv.conf;
     fs.".config/mpv/script-opts/osc.conf".symlink.target = ./osc.conf;

hosts/common/programs/mpv/input.conf

@@ -31,7 +31,7 @@ ctrl+s      async screenshot                       #! Utils > Screenshot
 alt+i       script-binding uosc/keybinds           #! Utils > Key bindings
 O           script-binding uosc/show-in-directory  #! Utils > Show in directory
 #           script-binding uosc/open-config-directory #! Utils > Open config directory
-ctrl+r      script-binding sane/blast              #! Audiocast
-ctrl+t      script-binding sane/go2tv-video        #! Cast
-#           script-binding sane/go2tv-stream       #! Cast (...) > Stream
-#           script-binding sane/go2tv-gui          #! Cast (...) > GUI
+ctrl+r      script-binding sane-cast/blast              #! Audiocast
+ctrl+t      script-binding sane-cast/go2tv-video        #! Cast
+#           script-binding sane-cast/go2tv-stream       #! Cast (...) > Stream
+#           script-binding sane-cast/go2tv-gui          #! Cast (...) > GUI

hosts/common/programs/mpv/sane-sysvol/main.lua

@@ -0,0 +1,240 @@
+msg = require('mp.msg')
+msg.trace('sane-sysvol: load: begin')
+
+non_blocking_popen = require("non_blocking_popen")
+
+RD_SIZE = 4096
+
+function startswith(superstring, substring)
+  return superstring:sub(1, substring:len()) == substring
+end
+function strip_prefix(superstring, substring)
+  return superstring:sub(substring:len())
+end
+
+function ltrim(s)
+  -- remove all leading whitespace from `s`
+  local i = 1
+  while s:sub(i, i) == " " or s:sub(i, i) == "\t" do
+    i = i + 1
+  end
+  return s:sub(i)
+end
+
+function subprocess(args)
+  mp.command_native({
+    name = "subprocess",
+    args = args,
+    -- these arguments below probably don't matter: copied from sane-cast
+    detach = false,
+    capture_stdout = false,
+    capture_stderr = false,
+    passthrough_stdin = false,
+    playback_only = false,
+  })
+end
+
+function sysvol_new()
+  return {
+    -- sysvol is pipewire-native volume
+    -- it's the cube of the equivalent 0-100% value represented inside mpv
+    sysvol = nil,
+    change_sysvol = function(self, mpv_vol)
+      -- called when mpv wants to set the system-wide volume
+      if mpv_vol == nil then
+        return
+      end
+
+      local old_mpv_vol = nil
+      if self.sysvol ~= nil then
+        old_mpv_vol = 100 * self.sysvol^(1/3)
+      end
+      if old_mpv_vol ~= nil and math.floor(old_mpv_vol) == math.floor(mpv_vol) then
+        return
+      end
+
+      local volstr = tostring(mpv_vol) .. "%"
+      msg.debug("setting system-wide volume:", volstr)
+      self.sysvol = (0.01*mpv_vol)^3
+      subprocess({
+        "wpctl",
+        "set-volume",
+        "@DEFAULT_AUDIO_SINK@",
+        volstr
+      })
+    end,
+    on_sysvol_change = function(self, sysvol)
+      if sysvol == nil then
+        return
+      end
+      -- called when the pipewire system volume is changed (either by us, or an external application)
+      local new_mpv_vol = 100 * sysvol^(1/3)
+      local old_mpv_vol = nil
+      if self.sysvol ~= nil then
+        old_mpv_vol = 100 * self.sysvol^(1/3)
+      end
+
+      if old_mpv_vol ~= nil and math.abs(new_mpv_vol - old_mpv_vol) < 1.0 then
+        msg.debug("NOT announcing volume change to mpv (because it was what triggered the change):", old_mpv_vol, new_mpv_vol)
+        return
+      end
+
+      self.sysvol = sysvol
+      msg.debug("announcing volume change to mpv:", old_mpv_vol, new_mpv_vol)
+      mp.set_property_native("user-data/sane-sysvol/volume", new_mpv_vol)
+    end
+  }
+end
+
+function pwmon_parser_new()
+  return {
+    -- volume: pipewire-native volume. usually 0.0 - 1.0, but can go higher (e.g. 3.25)
+    -- `wpctl get-volume` and this volume are related, in that the volume reported by
+    -- wpctl is the cube-root of this one.
+    volume = {}, -- object-id (number) -> volume (number)
+    mute = {}, -- object-id (number) -> mute (bool)
+    last_audio_device_id = nil, -- TODO: might not actually be necessary
+
+    -- parser state:
+    in_changed = false,
+    changed_id = nil,
+    in_device = false,
+    in_direction = false,
+    in_output = false,
+    in_vol = false,
+    in_mute = false,
+
+    feed_line = function(self, line)
+      line = ltrim(line)
+      if startswith(line, "changed:") then
+        self.in_changed = true
+        self.changed_id = nil
+        self.in_device = false
+        self.in_direction = false
+        self.in_output = false
+        self.in_vol = false
+        self.in_mute = false
+        self.in_properties = false
+      elseif startswith(line, "added:") or startswith(line, "removed:") then
+        self.in_changed = false
+        self.changed_id = nil
+        self.in_device = false
+        self.in_direction = false
+        self.in_output = false
+        self.in_vol = false
+        self.in_mute = false
+        self.in_properties = false
+      elseif startswith(line, "id: ") and self.in_changed then
+        if self.changed_id == nil then
+          self.changed_id = tonumber(strip_prefix(line, "id: "))
+          msg.debug("changed_id:", self.changed_id)
+        end
+      elseif startswith(line, "type: ") and self.in_changed then
+        self.in_device = startswith(line, "type: PipeWire:Interface:Device")
+        msg.trace("parsed type:", line, self.in_device)
+      elseif startswith(line, "Prop: ") and self.in_changed and self.in_device then
+        self.in_direction = startswith(line, "Prop: key Spa:Pod:Object:Param:Route:direction")
+        if self.in_direction then
+          self.in_output = false
+        end
+        -- which of the *Volumes params we read is unclear.
+        -- alternative to this is to just detect the change, and then cal wpctl get-volume @DEFAULT_AUDIO_SINK@
+        self.in_vol = startswith(line, "Prop: key Spa:Pod:Object:Param:Props:channelVolumes")
+        self.in_mute = startswith(line, "Prop: key Spa:Pod:Object:Param:Props:softMute")
+        msg.trace("parsed `Prop:`", line, self.in_vol)
+      elseif line:find("Spa:Enum:Direction:Output", 1, true) and self.in_direction then
+        self.in_output = true
+      elseif startswith(line, "Float ") and self.in_changed and self.in_device and self.in_output and self.in_vol then
+        value = tonumber(strip_prefix(line, "Float "))
+        self:feed_volume(value)
+      elseif startswith(line, "Bool ") and self.in_changed and self.in_device and self.in_output and self.in_mute then
+        value = tonumber(strip_prefix(line, "Bool ")) == "true"
+        self:feed_mute(value)
+      elseif startswith(line, "properties:") and self.in_changed and self.in_device then
+        self.in_properties = true
+      elseif line == 'media.class = "Audio/Device"' and self.in_changed and self.in_device and self.in_properties then
+        self.last_audio_device_id = self.changed_id
+        msg.debug("last_audio_device_id:", self.changed_id)
+      end
+    end,
+
+    feed_volume = function(self, vol)
+      msg.debug("volume:", self.changed_id, vol)
+      self.volume[self.changed_id] = vol
+    end,
+    feed_mute = function(self, mute)
+      msg.debug("mute:", self.changed_id, mute)
+      self.mute[self.changed_id] = mute
+    end,
+    get_effective_volume = function(self, id)
+      if id == nil then
+        id = self.last_audio_device_id
+      end
+
+      if self.mute[id] then
+        return 0
+      else
+        return self.volume[id]
+      end
+    end
+  }
+end
+
+function pwmon_new()
+  return {
+    -- non_blocking_popen handle for the pw-mon process
+    -- which can be periodically read and parsed to detect volume changes
+    handle = non_blocking_popen.non_blocking_popen("pw-mon", RD_SIZE),
+    stdout_unparsed = "",
+    pwmon_parser = pwmon_parser_new(),
+    service = function(self)
+      -- do a single non-blocking read, and parse the result
+      -- in the *rare* case in which more than RD_SIZE data is ready, we service that remaining data on the next call
+      local buf, res = self.handle:read(RD_SIZE)
+      if res == "closed" then
+        msg.debug("pw-mon unexpectedly closed!")
+      end
+      if buf ~= nil then
+        self.stdout_unparsed = self.stdout_unparsed .. buf
+        self:consume_stdout()
+      end
+    end,
+    consume_stdout = function(self)
+      local idx_newline, next_newline = 0, 0
+      while next_newline ~= nil do
+        next_newline = self.stdout_unparsed:find("\n", idx_newline + 1, true)
+        if next_newline ~= nil then
+          self:ingest_line(self.stdout_unparsed:sub(idx_newline + 1, next_newline - 1))
+          idx_newline = next_newline
+        end
+      end
+      self.stdout_unparsed = self.stdout_unparsed:sub(idx_newline + 1)
+    end,
+    ingest_line = function(self, line)
+      msg.trace("pw-mon:", line)
+      local old_vol = self.pwmon_parser:get_effective_volume()
+      self.pwmon_parser:feed_line(line)
+      local new_vol = self.pwmon_parser:get_effective_volume()
+      if new_vol ~= old_vol then
+        msg.debug("pipewire volume change:", old_vol, new_vol)
+        mp.set_property_native("user-data/sane-sysvol/pw-mon-volume", new_vol)
+      end
+    end
+  }
+end
+
+
+mp.set_property_native("user-data/sane-sysvol/volume", 0)
+
+local sysvol = sysvol_new()
+mp.observe_property("user-data/sane-sysvol/volume", "native", function(_, val)
+  sysvol:change_sysvol(val)
+end)
+mp.observe_property("user-data/sane-sysvol/pw-mon-volume", "native", function(_, val)
+  sysvol:on_sysvol_change(val)
+end)
+
+local pwmon = pwmon_new()
+mp.register_event('tick', function() pwmon:service() end)
+
+msg.trace("sane-sysvol: load: complete")

hosts/common/programs/mpv/sane-sysvol/non_blocking_popen.lua

@@ -0,0 +1,80 @@
+-- source: <https://gist.github.com/max1220/c19ccd4d90ed32d41b879eba727cbcbd>
+-- requires: luajit
+--
+-- Implements a basic binding for popen that allows non-blocking reads
+-- returned "file" table only supports :read(with an optional size argument, no mode etc.) and :close
+local function non_blocking_popen(cmd, read_buffer_size)
+	local ffi = require("ffi")
+
+	-- C functions that we need
+	ffi.cdef([[
+		void* popen(const char* cmd, const char* mode);
+		int pclose(void* stream);
+		int fileno(void* stream);
+		int fcntl(int fd, int cmd, int arg);
+		int *__errno_location ();
+		ssize_t read(int fd, void* buf, size_t count);
+	]])
+	
+	-- you can compile a simple C programm to find these values(Or look in the headers)
+	local F_SETFL = 4
+	local O_NONBLOCK = 2048
+	local EAGAIN = 11
+	
+	-- this "array" holds the errno variable
+	local _errno = ffi.C.__errno_location()
+
+	-- the buffer for reading from the process
+	local read_buffer_size = tonumber(read_buffer_size) or 2048
+	local read_buffer = ffi.new('uint8_t[?]',read_buffer_size)
+
+	-- get a FILE* for our command
+	local file = assert(ffi.C.popen(cmd, "r"))
+	
+	-- turn the FILE* to a fd(int) for fcntl
+	local fd = ffi.C.fileno(file)
+	
+	-- set non-blocking mode for read
+	assert(ffi.C.fcntl(fd, F_SETFL, O_NONBLOCK)==0, "fcntl failed")
+
+	-- close the process, prevent reading, allow garbage colletion
+	function file_close(self)
+		ffi.C.pclose(file)
+		self.read_buffer = nil
+		read_buffer = nil
+		self.read = function() return nil, "closed"end
+	end
+
+	-- read up to size bytes from the process. Returns data(string) and number of bytes read if successfull,
+	-- nil, "EAGAIN" if there is no data aviable, and
+	-- nil, "closed" if the process has ended
+	local read = ffi.C.read
+	function file_read(self, size)
+		local _size = math.min(read_buffer_size, size)
+		while true do
+			local nbytes = read(fd,read_buffer,_size)
+			if nbytes > 0 then
+				local data = ffi.string(read_buffer, nbytes)
+				return data, nbytes
+			elseif (nbytes == -1) and (_errno[0] == EAGAIN) then
+				return nil, "EAGAIN"
+			else
+				file_close(self)
+				return nil, "closed"
+			end
+		end
+	end
+
+	return {
+		_fd = fd,
+		_file = file,
+		_read_buffer = read_buffer,
+		_read_buffer_size = read_buffer_size,
+		read = file_read,
+		close = file_close
+	}
+end
+
+return {
+	non_blocking_popen = non_blocking_popen
+}