stats: change the way toggling/oneshot works internally

Previously multiple timers were used to realize oneshot, toggling
(redrawing) and page keybindings. The oneshot case in particular also
relied on mp.osd_message to display text only for a given duration.
This was changed to only use one timer in total now. Because now each
case has a defined "start" and "end" point (including oneshot)
mp.set_osd_ass() can be used to print stats as well. This is currently
optional and has to be activated using the config option
persistent_overlay=true.

One shortcoming: oneshot and toggling are mutual exclusive right now.
Previously you could enter toggling while oneshot stats were shown,
this is not possible anymore to reduce the number of cases to be
considered. This can be added later on if desired.

player/lua/stats.lua

@@ -21,6 +21,7 @@ local o = {
     duration = 4,
     redraw_delay = 1,                -- acts as duration in the toggling case
     ass_formatting = true,
+    persistent_overlay = false,      -- whether the stats can be overwritten by other output
     print_perfdata_passes = false,   -- when true, print the full information about all passes
     filter_params_max_length = 100,  -- a filter list longer than this many characters will be shown one filter per line instead
     debug = false,
@@ -79,18 +80,14 @@ local min = math.min
 
 -- Function used to record performance data
 local recorder = nil
--- Timer used for toggling
+-- Timer used for redrawing (toggling) and clearing the screen (oneshot)
-local toggle_timer = nil
+local display_timer = nil
--- Timer used to remove forced keybindings
-local binding_timer = nil
 -- Current page and <page key>:<page function> mappings
 local curr_page = o.key_page_1
 local pages = {}
-
 -- Save these sequences locally as we'll need them a lot
 local ass_start = mp.get_property_osd("osd-ass-cc/0")
 local ass_stop = mp.get_property_osd("osd-ass-cc/1")
-
 -- Ring buffers for the values used to construct a graph.
 -- .pos denotes the current position, .len the buffer length
 -- .max is the max value in the corresponding buffer
@@ -99,7 +96,6 @@ local function init_buffers()
     vsratio_buf = {0, pos = 1, len = 50, max = 0}
     vsjitter_buf = {0, pos = 1, len = 50, max = 0}
 end
-
 -- Save all properties known to this version of mpv
 local property_list = {}
 for p in string.gmatch(mp.get_property("property-list"), "([^,]+)") do property_list[p] = true end
@@ -121,7 +117,7 @@ end
 
 
 local function set_ASS(b)
-    if not o.use_ass then
+    if not o.use_ass or o.persistent_overlay then
         return ""
     end
     return b and ass_start or ass_stop
@@ -150,7 +146,8 @@ local function text_style()
     if o.custom_header and o.custom_header ~= "" then
         return set_ASS(true) .. o.custom_header
     else
-        return format("%s{\\r}{\\an7}{\\fs%d}{\\fn%s}{\\bord%f}{\\3c&H%s&}{\\1c&H%s&}{\\alpha&H%s&}{\\xshad%f}{\\yshad%f}{\\4c&H%s&}",
+        return format("%s{\\r}{\\an7}{\\fs%d}{\\fn%s}{\\bord%f}{\\3c&H%s&}" ..
+                      "{\\1c&H%s&}{\\alpha&H%s&}{\\xshad%f}{\\yshad%f}{\\4c&H%s&}",
                       set_ASS(true), o.font_size, o.font, o.border_size,
                       o.border_color, o.font_color, o.alpha, o.shadow_x_offset,
                       o.shadow_y_offset, o.shadow_color)
@@ -176,7 +173,9 @@ end
 
 
 local function has_ansi()
-    local is_windows = type(package) == 'table' and type(package.config) == 'string' and package.config:sub(1,1) == '\\'
+    local is_windows = type(package) == 'table'
+        and type(package.config) == 'string'
+        and package.config:sub(1, 1) == '\\'
     if is_windows then
         return os.getenv("ANSICON")
     end
@@ -309,7 +308,8 @@ local function append_perfdata(s, dedicated_page)
         return format("{\\b%d}%02d%%{\\b0}", w, i * 100)
     end
 
-    s[#s+1] = format("%s%s%s%s{\\fs%s}%s{\\fs%s}", dedicated_page and "" or o.nl, dedicated_page and "" or o.indent,
+    s[#s+1] = format("%s%s%s%s{\\fs%s}%s{\\fs%s}",
+                     dedicated_page and "" or o.nl, dedicated_page and "" or o.indent,
                      b("Frame Timings:"), o.prefix_sep, o.font_size * 0.66,
                      "(last/average/peak  μs)", o.font_size)
 
@@ -368,7 +368,7 @@ local function append_display_sync(s)
     append_property(s, "vo-delayed-frame-count", {prefix="Delayed:", nl=""})
 
     -- As we need to plot some graphs we print jitter and ratio on their own lines
-    if toggle_timer:is_enabled() and (o.plot_vsync_ratio or o.plot_vsync_jitter) and o.use_ass then
+    if not display_timer.oneshot and (o.plot_vsync_ratio or o.plot_vsync_jitter) and o.use_ass then
         local ratio_graph = ""
         local jitter_graph = ""
         if o.plot_vsync_ratio then
@@ -459,13 +459,12 @@ local function add_video(s)
     end
 
     if append_property(s, "video-codec", {prefix=o.nl .. o.nl .. "Video:", nl="", indent=""}) then
-        append_property(s, "hwdec-current",
+        append_property(s, "hwdec-current", {prefix="(hwdec:", nl="", indent=" ",
-                        {prefix="(hwdec:", nl="", indent=" ",
+                         no_prefix_markup=true, suffix=")"}, {no=true, [""]=true})
-                         no_prefix_markup=true, suffix=")"},
-                        {no=true, [""]=true})
     end
     append_property(s, "avsync", {prefix="A-V:"})
-    if append_property(s, compat("decoder-frame-drop-count"), {prefix="Dropped Frames:", suffix=" (decoder)"}) then
+    if append_property(s, compat("decoder-frame-drop-count"),
+                       {prefix="Dropped Frames:", suffix=" (decoder)"}) then
         append_property(s, compat("frame-drop-count"), {suffix=" (output)", nl="", indent=""})
     end
     if append_property(s, "display-fps", {prefix="Display FPS:", suffix=" (specified)"}) then
@@ -526,7 +525,7 @@ local function add_audio(s)
 end
 
 
--- Determine whether ASS formatting shall/can be used
+-- Determine whether ASS formatting shall/can be used and set formatting sequences
 local function eval_ass_formatting()
     o.use_ass = o.ass_formatting and has_vo_window()
     if o.use_ass then
@@ -584,38 +583,13 @@ local function filter_stats()
 end
 
 
--- Call the function for `page` and print it to OSD
+-- Current page and <page key>:<page function> mapping
-local function print_page(page, duration)
+curr_page = o.key_page_1
-    mp.osd_message(pages[page].f(), duration or o.duration)
+pages = {
-end
+    [o.key_page_1] = { f = default_stats, desc = "Default" },
-
+    [o.key_page_2] = { f = vo_stats, desc = "Extended Frame Timings" },
-
+    [o.key_page_3] = { f = filter_stats, desc = "Dummy" },
--- Add keybindings for every page
+}
-local function add_page_bindings()
-    local function a(k)
-        return function()
-            -- In single invocation case we need to reset the timer because
-            -- stats are printed again for o.duration
-            if not toggle_timer:is_enabled() then
-                binding_timer:kill()
-                binding_timer:resume()
-            end
-            curr_page = k
-            print_page(k, toggle_timer:is_enabled() and o.redraw_delay + 1 or nil)
-        end
-    end
-
-    for k, _ in pairs(pages) do
-        mp.add_forced_key_binding(k, k, a(k), {repeatable=true})
-    end
-end
-
-
-local function remove_page_bindings()
-    for k, _ in pairs(pages) do
-        mp.remove_key_binding(k)
-    end
-end
 
 
 -- Returns a function to record vsratio/jitter with the specified `skip` value
@@ -652,80 +626,109 @@ local function record_data(skip)
 end
 
 
-local function toggle_stats()
+-- Call the function for `page` and print it to OSD
-    -- Disable
+local function print_page(page)
-    if toggle_timer:is_enabled() then
+    if o.persistent_overlay then
+        mp.set_osd_ass(0, 0, pages[page].f())
+    else
+        mp.osd_message(pages[page].f(), display_timer.oneshot and o.duration or o.redraw_delay + 1)
+    end
+end
+
+
+local function clear_screen()
+    if o.persistent_overlay then mp.set_osd_ass(0, 0, "") else mp.osd_message("", 0) end
+end
+
+
+-- Add keybindings for every page
+local function add_page_bindings()
+    local function a(k)
+        return function()
+            curr_page = k
+            print_page(k)
+            if display_timer.oneshot then display_timer:kill() ; display_timer:resume() end
+        end
+    end
+    for k, _ in pairs(pages) do
+        mp.add_forced_key_binding(k, k, a(k), {repeatable=true})
+    end
+end
+
+
+-- Remove keybindings for every page
+local function remove_page_bindings()
+    for k, _ in pairs(pages) do
+        mp.remove_key_binding(k)
+    end
+end
+
+
+local function process_key_binding(oneshot)
+    -- Stats are already being displayed
+    if display_timer:is_enabled() then
+        -- Previous and current keys were oneshot -> restart timer
+        if display_timer.oneshot and oneshot then
+            display_timer:kill()
+            print_page(curr_page)
+            display_timer:resume()
+        -- Previous and current keys were toggling -> end toggling
+        elseif not display_timer.oneshot and not oneshot then
+            display_timer:kill()
+            clear_screen()
+            remove_page_bindings()
             if recorder then
                 mp.unregister_event(recorder)
                 recorder = nil
             end
-        toggle_timer:kill()
+        end
-        mp.osd_message("", 0)   -- clear the screen
+    -- No stats are being displayed yet
-        remove_page_bindings()
-    -- Enable
     else
-        if o.plot_vsync_jitter or o.plot_vsync_ratio then
+        if not oneshot and (o.plot_vsync_jitter or o.plot_vsync_ratio) then
             recorder = record_data(o.skip_frames)
             mp.register_event("tick", recorder)
         end
+        display_timer:kill()
+        display_timer.oneshot = oneshot
+        display_timer.timeout = oneshot and o.duration or o.redraw_delay
         add_page_bindings()
-        toggle_timer:resume()
+        print_page(curr_page)
-        print_page(curr_page, o.redraw_delay + 1)
+        display_timer:resume()
     end
 end
 
 
-local function oneshot_stats(page)
+-- Create the timer used for redrawing (toggling) or clearing the screen (oneshot)
-    -- Ignore single invocations while stats are toggled
+-- The duration here is not important and always set in process_key_binding()
-    if toggle_timer:is_enabled() then
+display_timer = mp.add_periodic_timer(o.duration,
-        return
-    end
-    binding_timer:kill()
-    binding_timer:resume()
-    add_page_bindings()
-    print_page(page or curr_page)
-end
-
-
--- Current page and <page key>:<page function> mapping
-curr_page = o.key_page_1
-pages = {
-    [o.key_page_1] = { f = default_stats, desc = "Default" },
-    [o.key_page_2] = { f = vo_stats, desc = "Extended Frame Timings" },
-    [o.key_page_3] = { f = filter_stats, desc = "Dummy" },
-}
-
-
--- Create timer used for toggling, pause it immediately
-toggle_timer = mp.add_periodic_timer(o.redraw_delay, function() print_page(curr_page, o.redraw_delay + 1) end)
-toggle_timer:kill()
-
--- Create timer used to remove forced key bindings, only in the "single invocation" case
-binding_timer = mp.add_periodic_timer(o.duration,
     function()
-        if not toggle_timer:is_enabled() then
+        if display_timer.oneshot then
-            remove_page_bindings()
+            display_timer:kill() ; clear_screen() ; remove_page_bindings()
+        else
+            print_page(curr_page)
         end
     end)
-binding_timer.oneshot = true
+display_timer:kill()
-binding_timer:kill()
 
 -- Single invocation key binding
-mp.add_key_binding(o.key_oneshot, "display-stats", oneshot_stats, {repeatable=true})
+mp.add_key_binding(o.key_oneshot, "display-stats", function() process_key_binding(true) end,
+    {repeatable=true})
+
+-- Toggling key binding
+mp.add_key_binding(o.key_toggle, "display-stats-toggle", function() process_key_binding(false) end,
+    {repeatable=false})
 
 -- Single invocation bindings without key, can be used in input.conf to create
 -- bindings for a specific page: "e script-binding stats/display-page-2"
 for k, _ in pairs(pages) do
-    mp.add_key_binding(nil, "display-page-" .. k, function() oneshot_stats(k) end, {repeatable=true})
+    mp.add_key_binding(nil, "display-page-" .. k, function() process_key_binding(true) end,
+        {repeatable=true})
 end
 
--- Toggling key binding
-mp.add_key_binding(o.key_toggle, "display-stats-toggle", toggle_stats, {repeatable=false})
-
 -- Reprint stats immediately when VO was reconfigured, only when toggled
 mp.register_event("video-reconfig",
     function()
-            if toggle_timer:is_enabled() then
+        if display_timer:is_enabled() then
-                print_page(curr_page, o.redraw_delay + 1)
+            print_page(curr_page)
         end
     end)