Add script: savepoints

2 files changed, 118 insertions, 0 deletions

diff --git a/README.adoc b/README.adoc
index d44dfc6..d0f1b14 100644
--- a/README.adoc
+++ b/README.adoc
@@ -1,10 +1,13 @@
 = mpv scripts by Arjun Satarkar
 :toc:
 
+Assume these are compatible only with Unix-like systems by default; examination of the code will often suggest relatively minor modifications needed to support Windows. If this is relevant to your use case, feel free to open an issue or pull request.
+
 == Scripts
 
 * *mpvclip.* Clip sections of video with ffmpeg. Allows choosing CRF/two-pass target size, with sensible defaults. As of 2025-03-01, requires recent mpv git master build.
 * *get_subtitle.* Copy the text of the current subtitle line to the clipboard. Relies on `https://github.com/astrand/xclip[+xclip+`] to function.
+* *savepoints.* Save the current video timestamp to disk, and easily jump between all savepoints set for a particular video.
 
 == Copying
 
diff --git a/savepoints/main.lua b/savepoints/main.lua
new file mode 100644
index 0000000..13a2415
--- /dev/null
+++ b/savepoints/main.lua
@@ -0,0 +1,115 @@
+--[[
+mpv scripts - savepoints
+Copyright (C) 2025-present Arjun Satarkar
+
+This program is free software: you can redistribute it and/or modify it under
+the terms of the GNU General Public License version 3.
+
+This program is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+FOR A PARTICULAR PURPOSE. See the GNU General Public License version 3 for
+more details.
+]]
+
+local input = require("mp.input")
+local utils = require("mp.utils")
+
+local home_dir = os.getenv("HOME")
+local savepoints_dir = utils.join_path(home_dir, "mpv-savepoints")
+
+local savepoints = {}
+local savepoints_hms = {}
+
+local function bsearch_next_index(arr, val, past_end)
+    local low = 1
+    local high = #arr + (past_end and 1 or 0)
+
+    while true do
+        if high <= low then
+            return high
+        end
+        local i = math.floor((high + low) / 2)
+        if arr[i] <= val then
+            low = i + 1
+        else
+            high = i
+        end
+    end
+end
+
+local function to_hms(pos)
+    local hours = math.floor(pos / (60 * 60))
+    local minutes = math.floor((pos / 60) % 60)
+    local seconds = math.floor(pos % 60)
+    local milliseconds = math.floor(pos % 1 * 1000)
+
+    return ("%02d:%02d:%02d.%03d"):format(hours, minutes, seconds, milliseconds)
+end
+
+local function cache_savepoint(pos)
+    local i = bsearch_next_index(savepoints, pos, true)
+    table.insert(savepoints, i, pos)
+    table.insert(savepoints_hms, i, to_hms(pos))
+end
+
+local function open_savepoint_file(mode)
+    return io.open(utils.join_path(savepoints_dir, mp.get_property("filename") .. ".txt"), mode)
+end
+
+local function load_savepoints()
+    if next(savepoints) ~= nil then
+        return
+    end
+
+    mp.command_native({
+        name = "subprocess",
+        args = { "mkdir", "-p", savepoints_dir },
+        playback_only = false
+    })
+
+    local file = open_savepoint_file("r")
+    if file then
+        for line in file:lines() do
+            table.insert(savepoints, tonumber(line))
+        end
+        table.sort(savepoints)
+        for _, v in ipairs(savepoints) do
+            table.insert(savepoints_hms, to_hms(v))
+        end
+        file:close()
+    end
+end
+
+local function add_savepoint()
+    load_savepoints()
+
+    local file = open_savepoint_file("a")
+    if file then
+        local pos_str = mp.get_property("time-pos/full")
+        local pos = tonumber(pos_str)
+        cache_savepoint(pos)
+        file:write(pos_str .. "\n")
+        file:close()
+    end
+end
+
+local function jump_to_savepoint()
+    load_savepoints()
+
+    if next(savepoints) == nil then
+        mp.osd_message("No savepoints for this file!")
+        return
+    end
+
+    input.select({
+        prompt = "Jump to savepoint:",
+        items = savepoints_hms,
+        default_item = bsearch_next_index(savepoints, tonumber(mp.get_property("time-pos/full"))),
+        submit = function(i)
+            mp.commandv("seek", tostring(savepoints[i]), "absolute+exact")
+        end
+    })
+end
+
+mp.add_key_binding("a", "add-savepoint", add_savepoint)
+mp.add_key_binding("ctrl+a", "jump-to-savepoint", jump_to_savepoint)