lua: add youtube-dl hook script

This merely adds the file without using it, for the sake of retaining
authorship information.

Signed-off-by: wm4 <wm4@nowhere>

player/lua/ytdl_hook.lua

@@ -0,0 +1,163 @@
+local utils = require 'mp.utils'
+local msg = require 'mp.msg'
+
+local ytdl = {
+    path = "youtube-dl",
+    minver = "2014.11.09",
+    vercheck = nil,
+}
+
+mp.add_hook("on_load", 10, function ()
+
+    local function exec(args)
+        local ret = utils.subprocess({args = args})
+        return ret.status, ret.stdout
+    end
+
+    local url = mp.get_property("stream-open-filename")
+
+    if (url:find("http://") == 1) or (url:find("https://") == 1)
+        or (url:find("ytdl://") == 1) then
+
+       -- check version of youtube-dl if not done yet
+        if (ytdl.vercheck == nil) then
+
+             -- check for youtube-dl in mpv's config dir
+            local ytdl_mcd = mp.find_config_file("youtube-dl")
+            if not (ytdl_mcd == nil) then
+                msg.verbose("found youtube-dl at: " .. ytdl_mcd)
+                ytdl.path = ytdl_mcd
+            end
+
+            msg.debug("checking ytdl version ...")
+            local es, version = exec({ytdl.path, "--version"})
+            if (es < 0) then
+                msg.warn("youtube-dl not found, not executable, or broken.")
+                ytdl.vercheck = false
+            elseif (version < ytdl.minver) then
+                msg.verbose("found youtube-dl version: " .. version)
+                msg.warn("Your version of youtube-dl is too old! "
+                    .. "You need at least version '"..ytdl.minver
+                    .. "', try running `youtube-dl -U`.")
+                ytdl.vercheck = false
+            else
+                msg.verbose("found youtube-dl version: " .. version)
+                ytdl.vercheck = true
+            end
+        end
+
+        if not (ytdl.vercheck) then
+            return
+        end
+
+        -- strip ytdl://
+        if (url:find("ytdl://") == 1) then
+            url = url:sub(8)
+        end
+
+        -- subformat workaround
+        local subformat = "srt"
+        if url:find("crunchyroll.com") then
+            subformat = "ass"
+        end
+
+        local es, json = exec({
+            ytdl.path, "-J", "--flat-playlist", "--all-subs",
+            "--sub-format", subformat, "--no-playlist", "--", url
+            })
+
+        if (es < 0) or (json == nil) or (json == "") then
+            msg.warn("youtube-dl failed, trying to play URL directly ...")
+            return
+        end
+
+        local json, err = utils.parse_json(json)
+
+        if (json == nil) then
+            msg.error("failed to parse JSON data: " .. err)
+            return
+        end
+
+        msg.info("youtube-dl succeeded!")
+
+        -- what did we get?
+        if not (json["direct"] == nil) and (json["direct"] == true) then
+            -- direct URL, nothing to do
+            msg.verbose("Got direct URL")
+            return
+        elseif not (json["_type"] == nil) and (json["_type"] == "playlist") then
+            -- a playlist
+
+            local playlist = "#EXTM3U\n"
+            for i, entry in pairs(json.entries) do
+                local site = entry.url
+
+                -- some extractors will still return the full info for
+                -- all clips in the playlist and the URL will point
+                -- directly to the file in that case, which we don't
+                -- want so get the webpage URL instead, which is what
+                -- we want
+                if not (entry["webpage_url"] == nil) then
+                    site = entry["webpage_url"]
+                end
+
+                playlist = playlist .. "ytdl://" .. site .. "\n"
+            end
+
+            mp.set_property("stream-open-filename", "memory://" .. playlist)
+
+        else -- probably a video
+            local streamurl = ""
+
+            -- DASH?
+            if not (json["requested_formats"] == nil) then
+                msg.info("NOTE: Using DASH, expect inaccurate duration.")
+                -- video url
+                streamurl = json["requested_formats"][1].url
+
+                -- audio url
+                mp.set_property("file-local-options/audio-file",
+                    json["requested_formats"][2].url)
+
+                -- workaround for slow startup (causes inaccurate duration)
+                mp.set_property("file-local-options/demuxer-lavf-o",
+                    "fflags=+ignidx")
+
+            elseif not (json.url == nil) then
+                -- normal video
+                streamurl = json.url
+            else
+                msg.error("No URL found in JSON data.")
+                return
+            end
+
+            msg.debug("streamurl: " .. streamurl)
+
+            mp.set_property("stream-open-filename", streamurl)
+
+            mp.set_property("file-local-options/media-title", json.title)
+
+            -- add subtitles
+            if not (json.subtitles == nil) then
+                for lang, script in pairs(json.subtitles) do
+                    msg.verbose("adding subtitle ["..lang.."]")
+
+                    local slang = lang
+                    if (lang:len() > 3) then
+                        slang = lang:sub(1,2)
+                    end
+
+                    mp.commandv("sub_add", "memory://"..script,
+                        "auto", lang.." "..subformat, slang)
+                end
+            end
+
+            -- for rtmp
+            if not (json.play_path == nil) then
+                mp.set_property("file-local-options/stream-lavf-o",
+                    "rtmp_tcurl=\""..streamurl..
+                    "\",rtmp_playpath=\""..json.play_path.."\"")
+            end
+        end
+    end
+end)