Keep one long-lived yt-dlp worker process instead of spawning per call

server/ytdlp-worker.py

@@ -0,0 +1,53 @@
+#!/usr/bin/env python3
+"""ytdlp-worker.py - one long-lived yt-dlp process answering many requests.
+
+Spawning yt-dlp per call pays Python start-up + extractor import every time.
+This worker imports yt_dlp ONCE and runs each request's argv in-process
+through the CLI's own entry point (yt_dlp._real_main), so config files such
+as /etc/yt-dlp.conf and everything else the command line sets up apply.
+
+Protocol (newline-delimited JSON):
+  stdin : {"id": <int>, "args": [<yt-dlp argv>...]}
+  stdout: {"id": <int>, "code": <int>, "out": "<captured stdout>", "err": "<stderr tail>"}
+Only for calls whose result is printed to stdout (-J, --dump-json, --version).
+Usage: python3 ytdlp-worker.py <path-to-yt-dlp-zipapp-or-empty>
+"""
+import io, json, sys, contextlib
+
+if len(sys.argv) > 1 and sys.argv[1]:
+    sys.path.insert(0, sys.argv[1])   # the yt-dlp release binary is a zipapp
+import yt_dlp  # noqa: E402
+
+proto_out = sys.stdout
+sys.stdout = io.StringIO()            # nothing may leak onto the protocol pipe
+
+def run(args):
+    out, err = io.StringIO(), io.StringIO()
+    code = 0
+    with contextlib.redirect_stdout(out), contextlib.redirect_stderr(err):
+        try:
+            # The CLI's own entry point (not parse_options + YoutubeDL): it also
+            # sets up what the command line does (JS challenge solving, plugins,
+            # post-processing defaults). A bare YoutubeDL got "Sign in to
+            # confirm you're not a bot" where the CLI succeeded.
+            ret = yt_dlp._real_main(args)
+            code = ret[0] if isinstance(ret, tuple) else (ret or 0)
+        except SystemExit as e:
+            code = e.code if isinstance(e.code, int) else 1
+        except Exception as e:  # report, never die
+            err.write(f"ERROR: {e}\n")
+            code = 1
+    return code, out.getvalue(), err.getvalue()[-8000:]
+
+for line in sys.stdin:
+    line = line.strip()
+    if not line:
+        continue
+    try:
+        req = json.loads(line)
+        code, out, err = run([str(a) for a in req.get("args", [])])
+        resp = {"id": req.get("id"), "code": code, "out": out, "err": err}
+    except Exception as e:
+        resp = {"id": None, "code": 1, "out": "", "err": f"worker: {e}"}
+    proto_out.write(json.dumps(resp) + "\n")
+    proto_out.flush()