refactor(daemon): use obs-events for file fetching

Instead of depending on watchdog, use the OBS event which is faster.

README.md

@@ -6,3 +6,9 @@ rewind is a lightweight, disk-backed replay recording tool for OBS that continuo
 2) Enable OBS websocket and take note of the host, port and password
 3) Setup config.toml with host, port, password info
 4) Run the daemon as a background service (rewind-daemon)
+
+# Why OBS?
+Instead of implementing a custom screen recorder, rewind uses OBS as the backend recorder. Rationale:
+  - Cross-platform video capture is complex (platform APIs, drivers, hardware acceleration, A/V sync).
+  - Implementing a custom recorder is out of scope and would duplicate mature functionality.
+  - OBS provides a stable, production-grade capture and segmentation pipeline.

pyproject.toml

@@ -7,7 +7,7 @@ requires-python = ">=3.9"
 
 dependencies = [
   "obsws-python",
-  "watchdog",
+  "tomli-w",
   "tqdm"
 ]
 

requirements.txt

@@ -1,4 +1,4 @@
 obsws-python==1.8.0
+tomli-w==1.1.0
 tqdm==4.67.2
-watchdog==6.0.0
 websocket-client==1.9.0

rewind/cli.py

@@ -3,14 +3,16 @@ import sys
 import argparse
 
 from rewind.core import clip, mark, save, print_markers
+from rewind.os.main import enable_autostart, disable_autostart, start_daemon, stop_daemon
+from rewind.config import Config
 
 def build_clip_parser(subparsers: argparse._SubParsersAction) -> None:
     clip_parser = subparsers.add_parser("clip", help="Clips the last 'x' seconds")
     clip_parser.add_argument(
         "-s", "--seconds",
         type=int,
-        default=30,
+        default=60,
-        help="Number of seconds to include in the clip (default: 30)"
+        help="Number of seconds to include in the clip (default: 60)"
     )
 
 def build_save_parser(subparsers: argparse._SubParsersAction) -> None:
@@ -34,13 +36,33 @@ def build_mark_parser(subparsers: argparse._SubParsersAction) -> None:
     mark_parser.add_argument(
         "-n", "--name",
         type=str,
-        required=True,
+        required=False,
         help="Name of the marker"
     )
 
 def build_list_parser(subparsers: argparse._SubParsersAction) -> None:
     list_parser = subparsers.add_parser("list", help="List all markers in the recording")
 
+def build_daemon_parser(subparsers: argparse._SubParsersAction) -> None:
+    daemon_parser = subparsers.add_parser("daemon", help="Control the rewind daemon")
+    daemon_sub = daemon_parser.add_subparsers(dest="daemon_command")
+    daemon_sub.add_parser("start", help="Start the daemon")
+    daemon_sub.add_parser("stop", help="Stop the daemon")
+    daemon_sub.add_parser("enable", help="Enable autostart for the daemon")
+    daemon_sub.add_parser("disable", help="Disable autostart for the daemon")
+
+
+def build_config_parser(subparsers: argparse._SubParsersAction) -> None:
+    config_parser = subparsers.add_parser("config", help="View or edit config values")
+    config_sub = config_parser.add_subparsers(dest="config_command")
+
+    get_parser = config_sub.add_parser("get", help="Print a single config value")
+    get_parser.add_argument("key", help="Dotted key, e.g. obs.host")
+
+    set_parser = config_sub.add_parser("set", help="Update a config value")
+    set_parser.add_argument("key", help="Dotted key, e.g. obs.host")
+    set_parser.add_argument("value", help="New value")
+
 def build_parser() -> argparse.ArgumentParser:
     parser = argparse.ArgumentParser(
         prog="rewind",
@@ -53,12 +75,15 @@ def build_parser() -> argparse.ArgumentParser:
     build_mark_parser(sub)
     build_list_parser(sub)
     build_save_parser(sub)
+    build_daemon_parser(sub)
+    build_config_parser(sub)
 
     return parser
 
 def main(argv=None) -> int:
     parser = build_parser()
     args = parser.parse_args(argv)
+    cfg = Config()
 
     try:
         if args.command == "clip":
@@ -69,6 +94,24 @@ def main(argv=None) -> int:
             print_markers()
         elif args.command == "save":
             save(args.start, args.end)
+        elif args.command == "daemon":
+            if args.daemon_command == "start":
+                start_daemon()
+            elif args.daemon_command == "stop":
+                stop_daemon()
+            elif args.daemon_command == "enable":
+                enable_autostart()
+            elif args.daemon_command == "disable":
+                disable_autostart()
+            else:
+                parser.error("Unknown daemon command: expected 'start' or 'stop'")
+        elif args.command == "config":
+            if args.config_command == "set":
+                cfg.set(args.key, args.value)
+            elif args.config_command == "get":
+                print(cfg.get(args.key))
+            else:
+                parser.error("Unknown config command: expected 'get' or 'set'")
         else:
             parser.error("Unknown command")
     except Exception as e:
@@ -78,4 +121,4 @@ def main(argv=None) -> int:
     return 0
 
 if __name__ == "__main__":
-    sys.exit(main())
+    sys.exit(main())

rewind/config.py

@@ -0,0 +1,89 @@
+#!/usr/bin/env python3
+import os
+import tomllib
+import tomli_w
+from pathlib import Path
+
+from rewind.paths import get_config_dir
+
+_CONFIG_NAME = "config.toml"
+_EXAMPLE_CONFIG = Path(__file__).parent / "example.config.toml"
+
+
+class Config:
+    def __init__(self):
+        self._config_dir = get_config_dir()
+        self._config_file = self._config_dir / _CONFIG_NAME
+        self._data = self._load()
+
+    # Private
+    def _load(self) -> dict:
+        if not self._config_file.exists():
+            self._config_dir.mkdir(parents=True, exist_ok=True)
+            self._config_file.write_text(_EXAMPLE_CONFIG.read_text())
+
+        with self._config_file.open("rb") as f:
+            return tomllib.load(f)
+
+    def _save(self) -> None:
+        with self._config_file.open("wb") as f:
+            tomli_w.dump(self._data, f)
+
+    # Public
+    def get_obs_host(self) -> str:
+        return self._data["obs"]["host"]
+
+    def set_obs_host(self, value: str) -> None:
+        self._data["obs"]["host"] = value
+        self._save()
+
+    def get_obs_port(self) -> int:
+        return self._data["obs"]["port"]
+
+    def set_obs_port(self, value: int) -> None:
+        self._data["obs"]["port"] = value
+        self._save()
+
+    def get_obs_password(self) -> str:
+        return self._data["obs"]["password"]
+
+    def set_obs_password(self, value: str) -> None:
+        self._data["obs"]["password"] = value
+        self._save()
+
+    def get_max_record_time(self) -> int:
+        return self._data["record"]["max_record_time"]
+
+    def set_max_record_time(self, value: int) -> None:
+        self._data["record"]["max_record_time"] = value
+        self._save()
+
+    def get_clip_output(self) -> str:
+        return os.path.expanduser(self._data["record"]["clip_output"])
+
+    def set_clip_output(self, value: str) -> None:
+        self._data["record"]["clip_output"] = value
+        self._save()
+
+    def get_vod_output(self) -> str:
+        return os.path.expanduser(self._data["record"]["vod_output"])
+
+    def set_vod_output(self, value: str) -> None:
+        self._data["record"]["vod_output"] = value
+        self._save()
+
+    def get(self, key: str) -> str:
+        section, _, field = key.partition(".")
+        try:
+            return str(self._data[section][field])
+        except KeyError:
+            raise KeyError(f"Unknown config key: {key!r}")
+
+    def set(self, key: str, value: str) -> None:
+        section, _, field = key.partition(".")
+        try:
+            current = self._data[section][field]
+        except KeyError:
+            raise KeyError(f"Unknown config key: {key!r}")
+        self._data[section][field] = type(current)(value)
+        self._save()

rewind/core.py

@@ -1,15 +1,18 @@
 #!/usr/bin/env python3
 import os
 import datetime
-import subprocess
-import json
 
-from rewind.state import load_state
+from rewind.config import Config
-from rewind.paths import load_config
+from rewind.media import get_ts_files, concat_ts_files
-from tqdm import tqdm
+from rewind.state import load_state, add_marker_to_state, remove_marker_from_state
+
+config = Config()
 
 def clip(seconds_from_end: float) -> None:
-    clip_output = os.path.expanduser(load_config()["record"]["clip_output"])
+    if seconds_from_end <= 0 or seconds_from_end > 600:
+        raise ValueError("Clip length must be positive and less than or equal to 10 minutes")
+
+    clip_output = config.get_clip_output()
     os.makedirs(clip_output, exist_ok=True)
 
     output_file_name = f"{datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S')}.mp4"
@@ -19,67 +22,49 @@ def clip(seconds_from_end: float) -> None:
     end_timestamp = datetime.datetime.now().timestamp()
     length = end_timestamp - start_timestamp
     
-    files, start_offset, end_offset = _get_ts_files(
+    ts_files = [f for f in load_state()["files"] if os.path.exists(f["path"])]
+    files, start_offset, end_offset = get_ts_files(
+        ts_files,
         start_timestamp,
         end_timestamp
     )
 
-    _concat_ts_files(files, start_offset, end_offset, length, output_path)
+    concat_ts_files(files, start_offset, end_offset, length, output_path)
     print(f"Created clip: {output_path}")
 
 def save(first_marker: str, second_marker: str):
-    vod_dir = os.path.expanduser(load_config()["record"]["vod_output"])
+    vod_dir = config.get_vod_output()
     os.makedirs(vod_dir, exist_ok=True)
 
     first_timestamp = get_marker_timestamp(first_marker)
     second_timestamp = get_marker_timestamp(second_marker)
 
-    output_file_name = f"{datetime.datetime.fromtimestamp(first_timestamp).strftime('%Y-%m-%d_%H:%M:%S')}-[{first_marker}-{second_marker}].mp4"
-    output_path = os.path.join(vod_dir, output_file_name)
-
     if first_timestamp >= second_timestamp:
         raise ValueError("First marker must be before second marker")
 
-    files, start_offset, end_offset = _get_ts_files(
+    output_file_name = f"{datetime.datetime.fromtimestamp(first_timestamp).strftime('%Y-%m-%d_%H:%M:%S')}-[{first_marker}-{second_marker}].mp4"
+    output_path = os.path.join(vod_dir, output_file_name)
+
+    ts_files = [f for f in load_state()["files"] if os.path.exists(f["path"])]
+
+    files, start_offset, end_offset = get_ts_files(
+        ts_files,
         first_timestamp,
         second_timestamp
     )
 
-    _concat_ts_files(files, start_offset, end_offset, second_timestamp - first_timestamp, output_path)
+    concat_ts_files(files, start_offset, end_offset, second_timestamp - first_timestamp, output_path)
     print(f"Created video file: {output_path}")
 
 def mark(name: str) -> None:
     if not name:
-        raise ValueError("Marker name cannot be empty")
+        name = datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S')
     
-    if marker_exists(name):
+    add_marker_to_state(name)
-        raise ValueError("Marker name already exists")
-    
-    # writes marker to json file (not state)
-    markers_file = os.path.join(os.path.dirname(__file__), "markers.json")
-    if os.path.exists(markers_file):
-        with open(markers_file, "r") as f:
-            markers = json.load(f)
-    else:
-        markers = []
-
-    markers.append({
-        "name": name,
-        "timestamp": datetime.datetime.now().timestamp()
-    })
-
-    with open(markers_file, "w") as f:
-        json.dump(markers, f, indent=4)
-
     print(f"Added marker: {name}")
 
 def get_marker_timestamp(name: str) -> float:
-    markers_file = os.path.join(os.path.dirname(__file__), "markers.json")
+    markers = load_state().get("markers", [])
-    if not os.path.exists(markers_file):
-        raise RuntimeError("No markers found")
-
-    with open(markers_file, "r") as f:
-        markers = json.load(f)
 
     for marker in markers:
         if marker["name"] == name:
@@ -88,144 +73,24 @@ def get_marker_timestamp(name: str) -> float:
     raise ValueError("Marker name does not exist")
 
 def print_markers() -> None:
-    markers_file = os.path.join(os.path.dirname(__file__), "markers.json")
+    markers = load_state().get("markers", [])
-    if not os.path.exists(markers_file):
-        print("No markers found.")
-        return
 
-    with open(markers_file, "r") as f:
+    if markers == []:
-        markers = json.load(f)
+        print("No markers exist.")
 
     for marker in markers:
         format_time = datetime.datetime.fromtimestamp(marker['timestamp']).strftime('%Y-%m-%d %H:%M:%S')
         print(f"{format_time} -> {marker['name']}")
         
 def remove_marker(name: str) -> None:
-    markers_file = os.path.join(os.path.dirname(__file__), "markers.json")
+    remove_marker_from_state(name)
-    if not os.path.exists(markers_file):
-        raise RuntimeError("No markers found")
-
-    with open(markers_file, "r") as f:
-        markers = json.load(f)
-
-    markers = [m for m in markers if m["name"] != name]
-
-    with open(markers_file, "w") as f:
-        json.dump(markers, f, indent=4)
-
     print(f"Removed marker: {name}")
 
 def marker_exists(name: str) -> bool:
-    markers_file = os.path.join(os.path.dirname(__file__), "markers.json")
+    markers = load_state().get("markers", [])
-    if not os.path.exists(markers_file):
-        return False
-
-    with open(markers_file, "r") as f:
-        markers = json.load(f)
 
     for marker in markers:
         if marker["name"] == name:
             return True
     
-    return False
+    return False
-
-"""
-Retrieves .ts files recorded between the specified timestamps.
-Returns a list of file paths and extra start and end offsets if needed.
-get_duration() is used as little as possible since it is slow.
-end_timestamp of a file is the start time of the next file.
-"""
-def _get_ts_files(start_timestamp: float, end_timestamp: float) -> tuple[list[str], float, float]:
-    ts_files = load_state()["files"]
-    selected_files = []
-    start_offset = 0.0
-    end_offset = 0.0
-
-    for i, file_info in enumerate(ts_files):
-        file_start = file_info["timestamp"]
-        file_end = ts_files[i + 1]["timestamp"] if i + 1 < len(ts_files) else get_duration(file_info["path"]) + file_start
-
-        if file_end <= start_timestamp:
-            continue
-        if file_start >= end_timestamp:
-            break
-
-        selected_files.append(file_info["path"])
-
-        if file_start <= start_timestamp < file_end:
-            start_offset = start_timestamp - file_start
-        if file_start < end_timestamp <= file_end:
-            end_offset = file_end - end_timestamp
-
-    return selected_files, start_offset, end_offset
-
-def _concat_ts_files(file_list: list[str], start_offset: float, end_offset: float, length: float, output_file: str) -> None:
-    with open("file_list.txt", "w") as f:
-        for file_path in file_list:
-            f.write(f"file '{file_path}'\n")
-
-    cmd = ["ffmpeg", "-y", "-hide_banner", "-loglevel", "error", "-nostats", "-progress", "pipe:1"]
-    if start_offset > 0:
-        cmd += ["-ss", str(start_offset)]
-    if end_offset > 0:
-        cmd += ["-t", str(length)]
-    cmd += ["-f", "concat", "-safe", "0", "-i", "file_list.txt", "-c", "copy"]
-    cmd.append(output_file)
-
-    process = subprocess.Popen(
-        cmd,
-        stdout=subprocess.PIPE,
-        stderr=subprocess.PIPE,
-        text=True,
-        bufsize=1,
-    )
-
-    init_ms_val = 0
-    init_ms_val_set = False
-
-    with tqdm(
-        total=length,
-        unit="s",
-        unit_scale=True,
-        unit_divisor=60,
-        desc="Processing",
-        leave=True,
-    ) as pbar:
-        for line in process.stdout:
-            line = line.strip()
-            
-
-            if line.startswith("out_time_ms="):
-                out_time_ms = int(line.split("=")[1])
-
-                if not init_ms_val_set:
-                    init_ms_val = out_time_ms
-                    init_ms_val_set = True
-                out_time_ms -= init_ms_val
-
-                seconds = abs(out_time_ms / 1_000_000)
-                pbar.n = min(seconds, length)
-                pbar.refresh()
-
-            elif line == "progress=end":
-                break
-
-    ret = process.wait()
-    os.remove("file_list.txt")
-
-    if ret != 0:
-        raise RuntimeError("ffmpeg failed")
-
-def get_duration(file_path: str) -> float:
-    result = subprocess.run(
-        ["ffprobe", "-v", "error", "-show_entries",
-         "format=duration", "-of",
-         "default=noprint_wrappers=1:nokey=1", file_path],
-        stdout=subprocess.PIPE,
-        stderr=subprocess.STDOUT
-    )
-
-    if result.returncode != 0:
-        raise RuntimeError(f"ffprobe failed for file {file_path}")
-
-    return float(result.stdout)

rewind/daemon.py

@@ -3,56 +3,52 @@ import os
 import datetime
 import time
 import obsws_python as obs
-import subprocess
 import logging
-import json
+import signal
-import shutil
 
-from watchdog.observers import Observer
+from rewind.paths import get_state_dir
-from watchdog.events import FileSystemEventHandler
+from rewind.config import Config
-from rewind.paths import load_config
 from rewind.core import mark, marker_exists, remove_marker
-from rewind.state import add_file_to_state, create_state_file_if_needed, cleanup_state_files
+from rewind.state import add_file_to_state, create_state_file_if_needed, cleanup_state
 
-INTERVAL = 10
 running = True
+LOG_FILE =  get_state_dir() / "daemon.log"
+INTERVAL = 10
+OBS_MAX_RETRIES = 5
 
 logger = logging.getLogger(__name__)
 logger.setLevel(logging.DEBUG)
-logging.basicConfig(format="%(levelname)s:%(name)s:%(message)s")
+logging.basicConfig(format="%(levelname)s:%(name)s:%(message)s", handlers=[logging.FileHandler(LOG_FILE), logging.StreamHandler()])
 logging.getLogger("obsws_python").setLevel(logging.CRITICAL)
 
-SENTINEL_FILE = os.path.expanduser("~/.config/obs-studio/.sentinel")
+def shutdown(signum, frame):
-OBS_MAX_RETRIES = 10
+    global running
+    logger.info(f"Received signal {signum}, shutting down cleanly")
+    running = False
 
-def open_obs():
+signal.signal(signal.SIGINT, shutdown)
-    kill_command = subprocess.run(['pkill', 'obs'])
+signal.signal(signal.SIGTERM, shutdown)
-    if kill_command.returncode not in [0, 1]:
-        raise SystemError("Could not kill existing OBS instance")
 
-    if os.path.exists(SENTINEL_FILE):
+def open_obs_connection(host: str, port: int, password: str, obs_max_retries: int) -> dict[str, obs.ReqClient | obs.EventClient]:
-        try:
+    req = None
-            shutil.rmtree(SENTINEL_FILE)
+    event = None
-            logger.info("Removed existing OBS .sentinel directory")
-        except Exception as e:
-            logger.error(f"Could not delete OBS .sentinel directory: {e}")
-
-    # Using and not checking OBS since it needs to be non-blocking
-    subprocess.Popen(["obs", "--minimize-to-tray"], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
-
-def open_obs_connection(host: str, port: int, password: str) -> obs.ReqClient:
-    con = None
     init_sleep = 1
 
-    for _ in range(OBS_MAX_RETRIES):
+    for _ in range(obs_max_retries):
         try:
-            con = obs.ReqClient(host=host, port=port, password=password)
+            req = obs.ReqClient(host=host, port=port, password=password)
+            event = obs.EventClient(host=host, port=port, password=password)
         except ConnectionRefusedError:
             logger.info("OBS WebSocket not ready, retrying...")
-
+        except obs.events.OBSSDKError:
-        if con:
+            raise RuntimeError("Check OBS credentials")
+            
+        if req and event:
             logger.info(f"Successfully connected to OBS at {host}:{port}")
-            return con
+            return {
+                "req": req,
+                "event": event
+            }
 
         time.sleep(init_sleep)
         init_sleep *= 2
@@ -83,58 +79,37 @@ def cleanup_physical_files(directory: str, max_age_seconds: int) -> None:
                 os.remove(file_path)
                 logger.info(f"Removed old file: {file_path}")
 
-def cleanup_markers(max_age_seconds: float) -> None:
+def on_record_file_changed(event) -> None:
-    markers_file = os.path.join(os.path.dirname(__file__), "markers.json")
+    new_file = event.new_output_path
-    if not os.path.exists(markers_file):
+    add_file_to_state(new_file)
-        return
-
-    with open(markers_file, "r") as f:
-        markers = json.load(f)
-
-    current_time = datetime.datetime.now().timestamp()
-    new_markers = [m for m in markers if current_time - m['timestamp'] <= max_age_seconds]
-
-    with open(markers_file, "w") as f:
-        json.dump(new_markers, f, indent=4)
-
-    if new_markers != markers:
-        logger.info(f"Cleaning up {len(markers)-len(new_markers)} markers")
-
-class Handler(FileSystemEventHandler):
-    def on_created(self, event):
-        if event.is_directory:
-            return
-        if not event.src_path.endswith(".ts"):
-            return
-        
-        add_file_to_state(event.src_path)
-        logger.info(f"Added new file to state: {event.src_path}")
 
 def main() -> None:
-    open_obs()
+    config = Config()
-    config = load_config()
+    obs_host = config.get_obs_host()
-    con = open_obs_connection(config["obs"]["host"], config["obs"]["port"], config["obs"]["password"])
+    obs_port = config.get_obs_port()
+    obs_password = config.get_obs_password()
 
-    recording_dir = con.get_record_directory().record_directory
+    connections = open_obs_connection(obs_host, obs_port, obs_password, OBS_MAX_RETRIES)
-    start_recording(con)
+    req_con = connections["req"]
+    event_con = connections["event"]
+
+    event_con.callback.register(on_record_file_changed)
+
+    recording_dir = req_con.get_record_directory().record_directory
+    start_recording(req_con)
 
     create_state_file_if_needed()
     create_initial_marker()
 
     try:
-        event_handler = Handler()
-        observer = Observer()
-        observer.schedule(event_handler, path=recording_dir, recursive=False)
-        observer.start()
-
         while running:
-            cleanup_physical_files(recording_dir, config["record"]["max_record_time"])
+            cleanup_physical_files(recording_dir, config.get_max_record_time())
-            cleanup_state_files()
+            cleanup_state(config.get_max_record_time())
-            cleanup_markers(config["record"]["max_record_time"])
             time.sleep(INTERVAL)
     finally:
-        stop_recording(con)
+        stop_recording(req_con)
-        con.disconnect()
+        event_con.disconnect()
+        req_con.disconnect()
         logger.info("Daemon stopped")
 
 if __name__ == "__main__":

rewind/example.config.toml

@@ -1,7 +1,7 @@
 [obs]
 host = "localhost"
 port = 4455
-password = "6BQWrpHLbyJxNLPJ"
+password = ""
 
 [record]
 max_record_time = 28800

rewind/media.py

@@ -0,0 +1,114 @@
+import os
+import subprocess
+import tempfile
+
+from rewind.state import load_state
+from tqdm import tqdm
+
+"""
+Retrieves .ts files recorded between the specified timestamps.
+Returns a list of file paths and extra start and end offsets if needed.
+get_duration() is used as little as possible since it is slow.
+end_timestamp of a file is the start time of the next file.
+"""
+def get_ts_files(
+        ts_files: list[dict],
+        start_timestamp: float, 
+        end_timestamp: float
+        ) -> tuple[list[str], float, float]:
+    selected_files = []
+    start_offset = 0.0
+    end_offset = 0.0
+
+    for i, file_info in enumerate(ts_files):
+        file_start = file_info["timestamp"]
+        file_end = ts_files[i + 1]["timestamp"] if i + 1 < len(ts_files) else get_duration(file_info["path"]) + file_start
+        
+        if file_end <= start_timestamp:
+            continue
+        if file_start >= end_timestamp:
+            break
+
+        selected_files.append(file_info["path"])
+
+        if file_start < start_timestamp:
+            start_offset = start_timestamp - file_start
+
+        if file_end >= end_timestamp:
+            end_offset = file_end - end_timestamp
+            break
+        
+    return selected_files, start_offset, end_offset
+
+def concat_ts_files(file_list: list[str], start_offset: float, end_offset: float, length: float, output_file: str) -> None:
+    tmp_file = tempfile.NamedTemporaryFile(mode="w", suffix=".txt", delete=False)
+    try:
+        for file_path in file_list:
+            tmp_file.write(f"file '{file_path}'\n")
+        tmp_file.close()
+
+        cmd = ["ffmpeg", "-y", "-hide_banner", "-loglevel", "error", "-nostats", "-progress", "pipe:1"]
+        if start_offset > 0:
+            cmd += ["-ss", str(start_offset)]
+        if end_offset > 0:
+            cmd += ["-t", str(length)]
+        cmd += ["-f", "concat", "-safe", "0", "-i", tmp_file.name, "-c", "copy"]
+        cmd.append(output_file)
+
+        process = subprocess.Popen(
+            cmd,
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE,
+            text=True,
+            bufsize=1,
+        )
+
+        init_ms_val = 0
+        init_ms_val_set = False
+
+        with tqdm(
+            total=length,
+            unit="s",
+            unit_scale=True,
+            unit_divisor=60,
+            desc="Processing",
+            leave=True,
+        ) as pbar:
+            for line in process.stdout:  # type: ignore[union-attr]
+                line = line.strip()
+
+                if line.startswith("out_time_ms="):
+                    out_time_ms = int(line.split("=")[1])
+
+                    if not init_ms_val_set:
+                        init_ms_val = out_time_ms
+                        init_ms_val_set = True
+                    out_time_ms -= init_ms_val
+
+                    seconds = abs(out_time_ms / 1_000_000)
+                    pbar.n = min(seconds, length)
+                    pbar.refresh()
+
+                elif line == "progress=end":
+                    break
+
+        ret = process.wait()
+        if ret != 0:
+            raise RuntimeError("ffmpeg failed")
+    finally:
+        os.unlink(tmp_file.name)
+
+def get_duration(file_path: str) -> float:
+    result = subprocess.run(
+        ["ffprobe", "-v", "error", "-show_entries",
+         "format=duration", "-of",
+         "default=noprint_wrappers=1:nokey=1", file_path],
+        stdout=subprocess.PIPE,
+        stderr=subprocess.PIPE,
+        text=True,
+    )
+
+    if result.returncode != 0:
+        raise RuntimeError(f"ffprobe failed for file {file_path}")
+
+    return float(result.stdout.strip())

rewind/os/backend.py

@@ -0,0 +1,15 @@
+class OSBackend:
+    def __init__(self, program_path: str):
+        self.program_path = program_path
+
+    def enable_autostart(self):
+        raise NotImplementedError("enable_autostart not implemented for this platform")
+
+    def disable_autostart(self):
+        raise NotImplementedError("disable_autostart not implemented for this platform")
+
+    def start_daemon(self):
+        raise NotImplementedError("start_daemon not implemented for this platform")
+
+    def stop_daemon(self):
+        raise NotImplementedError("stop_daemon not implemented for this platform")

rewind/os/linux.py

@@ -0,0 +1,80 @@
+import subprocess
+
+from pathlib import Path
+from rewind.os.backend import OSBackend
+
+class LinuxBackend(OSBackend):
+    def __init__(self, program_path: str):
+        super().__init__(program_path)
+
+    def _run(self, cmd: list[str]):
+        result = subprocess.run(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, text=True)
+        if result.returncode != 0:
+            raise RuntimeError(f"Command failed: {' '.join(cmd)}\n{result.stderr}")
+        return result
+
+    def _create_systemd_service(self):
+        systemd_dir = Path.home() / ".config/systemd/user"
+        systemd_dir.mkdir(parents=True, exist_ok=True)
+
+        obs_service = systemd_dir / "obs.service"
+        daemon_service = systemd_dir / "rewind-daemon.service"
+
+        obs_service.write_text("""[Unit]
+    Description=OBS Studio
+    After=graphical-session.target
+    Wants=graphical-session.target
+
+    [Service]
+    # Ensure OBS sentinel files are cleaned up before starting the daemon
+    ExecStartPre=-/usr/bin/rm -rf %h/.config/obs-studio/.sentinel
+    ExecStart=obs --minimize-to-tray
+    Restart=on-failure
+    RestartSec=3
+
+    [Install]
+    WantedBy=default.target
+    """)
+
+        daemon_service.write_text(f"""[Unit]
+    Description=Rewind Daemon
+    After=obs.service
+    Requires=obs.service
+
+    [Service]
+    ExecStart={self.program_path}
+    Restart=always
+    RestartSec=5
+    Environment=PYTHONUNBUFFERED=1
+
+    [Install]
+    WantedBy=default.target
+    """)
+
+    def enable_autostart(self):
+        self._create_systemd_service()
+        self._run(["systemctl", "--user", "daemon-reload"])
+
+        self._run(["systemctl", "--user", "enable", "obs.service"])
+        self._run(["systemctl", "--user", "enable", "rewind-daemon.service"])
+
+        print("Installed OBS + rewind-daemon via systemd")
+
+    def disable_autostart(self):
+        self._create_systemd_service()
+        self._run(["systemctl", "--user", "disable", "rewind-daemon.service"])
+        self._run(["systemctl", "--user", "disable", "obs.service"])
+
+        systemd_dir = Path.home() / ".config/systemd/user"
+        (systemd_dir / "rewind-daemon.service").unlink(missing_ok=True)
+        (systemd_dir / "obs.service").unlink(missing_ok=True)
+        self._run(["systemctl", "--user", "daemon-reload"])
+
+    def start_daemon(self):
+        self._create_systemd_service()
+        self._run(["systemctl", "--user", "start", "rewind-daemon.service"])
+
+    def stop_daemon(self):
+        self._create_systemd_service()
+        self._run(["systemctl", "--user", "stop", "rewind-daemon.service"])
+        self._run(["systemctl", "--user", "stop", "obs.service"])

rewind/os/main.py

@@ -0,0 +1,37 @@
+#!/usr/bin/env python3
+import platform
+import shutil
+
+from rewind.os.linux import LinuxBackend
+
+APP_NAME = "rewind-daemon"
+
+def _find_executable():
+    path = shutil.which(APP_NAME)
+    if not path:
+        raise RuntimeError(f"{APP_NAME} not found in PATH")
+    return path
+
+def _get_backend():
+    system = platform.system()
+    program_path = _find_executable()
+    if system == "Linux":
+        return LinuxBackend(program_path)
+    else:
+        raise RuntimeError(f"Autostart on OS {system} not compatible or not implemented")
+
+def enable_autostart():
+    backend = _get_backend()
+    backend.enable_autostart()
+    
+def disable_autostart():
+    backend = _get_backend()
+    backend.disable_autostart()
+
+def start_daemon():
+    backend = _get_backend()
+    backend.start_daemon()
+    
+def stop_daemon():
+    backend = _get_backend()
+    backend.stop_daemon()

rewind/paths.py

@@ -1,28 +1,65 @@
 #!/usr/bin/env python3
 import os
-import tomllib
+import platform
 from pathlib import Path
-from importlib import resources
 
 APP_NAME = "rewind"
-CONFIG_NAME = "config.toml"
-STATE_NAME = "state.json"
 
+def _create_dirs(path: Path) -> None:
+    if not path.exists():
+        path.mkdir(parents=True, exist_ok=True)
+
+"""
+Returns the path to the directory where config files should be stored, creating it if it doesn't exist.
+The location is determined based on the operating system:
+- Linux: Uses XDG_CONFIG_HOME environment variable or defaults to ~/.config/rewind
+- macOS: Uses ~/Library/Application Support/rewind
+- Windows: Uses APPDATA environment variable or defaults to %APPDATA%\rewind
+"""
 def get_config_dir() -> Path:
-    base = os.environ.get("XDG_CONFIG_HOME", Path.home() / ".config")
+    system = platform.system()
-    return Path(base) / APP_NAME
+    home = Path.home()
 
-def load_config() -> dict:
+    if system == "Linux":
-    config_dir = get_config_dir()
+        base = os.environ.get("XDG_CONFIG_HOME", home / ".config")
-    config_file = config_dir / CONFIG_NAME
+        path = Path(base) / APP_NAME
+        _create_dirs(path)
+        return path
+    elif system == "Darwin":
+        path = home / "Library" / "Application Support" / APP_NAME
+        _create_dirs(path)
+        return path
+    elif system == "Windows":
+        path = Path(os.environ.get("APPDATA", home / "AppData" / "Roaming")) / APP_NAME
+        _create_dirs(path)
+        return path
+    else:
+        raise OSError("Unsupported operating system")
 
-    # Create config directory if it doesn't exist and replace with default config
+"""
-    if not config_file.exists():
+Returns the path to the directory where state files should be stored, creating it if it doesn't exist.
-        config_dir.mkdir(parents=True, exist_ok=True)
+The location is determined based on the operating system:
-        with resources.open_text("rewind", CONFIG_NAME) as default_config:
+- Linux: Uses XDG_STATE_HOME environment variable or defaults to ~/.local/state/rewind
-            with config_file.open("w") as f:
+- macOS: Uses ~/Library/Application Support/rewind/state
-                f.write(default_config.read())
+- Windows: Uses LOCALAPPDATA environment variable or defaults to %LOCALAPPDATA%\rewind\state
+"""
+def get_state_dir() -> Path:
+    system = platform.system()
+    home = Path.home()
 
-    with config_file.open("rb") as f:
+    if system == "Linux":
-        return tomllib.load(f)
+        base = os.environ.get("XDG_STATE_HOME", home / ".local" / "state")
-        
+        path = Path(base) / APP_NAME
+        _create_dirs(path)
+        return path
+    elif system == "Darwin":
+        path = home / "Library" / "Application Support" / APP_NAME / "state"
+        _create_dirs(path)
+        return path
+    elif system == "Windows":
+        base = Path(os.environ.get("LOCALAPPDATA", home / "AppData" / "Local"))
+        path = base / APP_NAME / "state"
+        _create_dirs(path)
+        return path
+    else:
+        raise OSError("Unsupported operating system")

rewind/state.py

@@ -2,28 +2,34 @@
 import datetime
 import json
 import os
+import logging
 
 from pathlib import Path
+from rewind.paths import get_state_dir
+
+logger = logging.getLogger(__name__)
 
-APP_NAME = "rewind"
 STATE_NAME = "state.json"
-
+EMPTY_STATE = {
-def state_dir() -> Path:
+    "files": [],
-    base = os.path.expanduser("~/.local/share")
+    "markers": []
-    path = Path(base) / APP_NAME
+}
-    path.mkdir(parents=True, exist_ok=True)
-    return path
 
 def get_state_file_path() -> Path:
-    return state_dir() / STATE_NAME
+    return get_state_dir() / STATE_NAME
 
 def load_state() -> dict:
-    if not get_state_file_path().exists():
+    path = get_state_file_path()
-        return {"files": []}
+    if not path.exists():
-    with get_state_file_path().open() as f:
+        return {"files": [], "markers": []}
+
+    with path.open() as f:
         return json.load(f)
 
 def write_state(state: dict) -> None:
+    if "files" not in state or "markers" not in state:
+        raise ValueError("Invalid state configuration. State must contain 'files' and 'markers' keys.")
+
     tmp = get_state_file_path().with_suffix(".tmp")
     with tmp.open("w") as f:
         json.dump(state, f, indent=2)
@@ -31,25 +37,80 @@ def write_state(state: dict) -> None:
 
 def add_file_to_state(file_path: str) -> None:
     state = load_state()
-    files = state.get("files", [])
+    files = sorted(state.get("files", []), key=lambda f: f["timestamp"])
+
+    # Idempotency guard
+    existing_paths = {f["path"] for f in files}
+    if file_path in existing_paths:
+        return
 
     files.append({
         "path": file_path,
-        "timestamp": datetime.datetime.now().timestamp(),
+        "timestamp": datetime.datetime.now().timestamp()
     })
 
     state["files"] = files
     write_state(state)
 
-def cleanup_state_files() -> None:
+    logger.info(f"Added new file to state: {file_path}")
-    state = load_state()
+
-    files = state.get("files", [])
+def add_marker_to_state(marker_name: str) -> None:
+    state = load_state()
+    markers = state.get("markers", [])
+
+    existing_markers = {m["name"] for m in markers}
+    if marker_name in existing_markers:
+        raise ValueError("Marker already exists")
+    
+    markers.append({
+        "name": marker_name,
+        "timestamp": datetime.datetime.now().timestamp()
+    })
+
+    state["markers"] = markers
+    write_state(state)
+
+    logger.info(f"Added new marker to state: {marker_name}")
+
+def remove_marker_from_state(marker_name: str) -> None:
+    state = load_state()
+    markers = state.get("markers", [])
+    markers = [marker for marker in markers if marker["name"] != marker_name]
+
+    state["markers"] = markers
+    write_state(state)
+
+    logger.info(f"Removed marker from state: {marker_name}")
+
+def cleanup_state(max_age_seconds: float) -> None:
+    state = load_state()
+    now = datetime.datetime.now().timestamp()
+
+    files = state.get("files", [])
+    markers = state.get("markers", [])
+
+    # First filter by existence
+    files = [
+        f for f in files
+        if os.path.exists(f["path"])
+    ]
+
+    # Then filter by age
+    files = [
+        f for f in files
+        if now - f["timestamp"] <= max_age_seconds
+    ]
+
+    markers = [
+        m for m in markers
+        if now - m["timestamp"] <= max_age_seconds
+    ]
+
+    state["files"] = files
+    state["markers"] = markers
 
-    # Remove old files from state
-    state["files"] = [file for file in files if os.path.exists(file["path"])]
     write_state(state)
 
 def create_state_file_if_needed() -> None:
-    if not os.path.exists(get_state_file_path()):
+    if not get_state_file_path().exists():
-        state = {"files": []}
+        write_state(EMPTY_STATE.copy())
-        write_state(state)