ADD file system event handling to monitor & allow for timestamp-based seeking

rewind/daemon.py

@@ -8,6 +8,8 @@ import subprocess
 
 from rewind.video import get_duration
 from rewind.paths import load_state, write_state, load_config
+from watchdog.observers import Observer
+from watchdog.events import FileSystemEventHandler
 
 INTERVAL = 10
 MAX_AGE_SECONDS = 60 * 60 * 1
@@ -49,14 +51,13 @@ def add_file_to_state(file_path: str) -> None:
     state = load_state()
     files = state.get("files", [])
 
-    # Update duration of last file if exists 
     if files and len(files) > 0:
         last_file = files[-1]
-        last_file["duration"] = get_duration(last_file["path"])
+        last_file["e_timestamp"] = datetime.datetime.now().timestamp()
 
     files.append({
         "path": file_path,
-        "duration": 0.0
+        "timestamp": datetime.datetime.now().timestamp(),
     })
 
     state["files"] = files
@@ -66,6 +67,12 @@ def handle_shutdown(signum, frame):
     global running
     running = False
 
+class Handler(FileSystemEventHandler):
+    def on_created(self, event):
+        if not event.is_directory and event.src_path.endswith(".ts"):
+            add_file_to_state(event.src_path)
+            print(f"Added new file to state: {event.src_path}")
+
 def main() -> None:
     signal.signal(signal.SIGINT, handle_shutdown)
     signal.signal(signal.SIGTERM, handle_shutdown)
@@ -75,29 +82,19 @@ def main() -> None:
 
     config = load_config()
     con = open_obs_connection(config["obs"]["host"], config["obs"]["port"], config["obs"]["password"])
-    if con is None:
-        return
+
     recording_dir = con.get_record_directory().record_directory
     start_recording(con)
-
     create_state_file()
 
-    current_files = os.listdir(recording_dir)
-
     try:
+        event_handler = Handler()
+        observer = Observer()
+        observer.schedule(event_handler, path=recording_dir, recursive=False)
+        observer.start()
+
         while running:
             cleanup_old_files(recording_dir, MAX_AGE_SECONDS)
-
-            new_files = os.listdir(recording_dir)
-            added_files = set(new_files) - set(current_files)
-
-            # Add new files to state
-            for filename in added_files:
-                file_path = os.path.join(recording_dir, filename)
-                add_file_to_state(file_path)
-                print(f"Added new file to state: {file_path}")
-
-            current_files = new_files
             time.sleep(INTERVAL)
     finally:
         stop_recording(con)

rewind/video.py

@@ -4,25 +4,53 @@ import datetime
 import subprocess
 from rewind.paths import load_state
 
+"""
+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 combine_last_x_ts_files(seconds: float, output_file: str) -> None:
-    ts_files = load_state().get("files", [])
-    ts_files[-1]["duration"] = get_duration(ts_files[-1]["path"])
+    ts_files = load_state()["files"]
 
-    total_duration = 0.0
-    files_to_include = []
+    files, start_offset, end_offset = get_ts_files(
+        datetime.datetime.now().timestamp() - seconds,
+        datetime.datetime.now().timestamp()
+    )
 
-    while ts_files and total_duration < seconds:
-        ts_file = ts_files.pop()
-        files_to_include.append(ts_file["path"])
-        total_duration += ts_file["duration"]
+    print(f"Combining files: {files} with start offset {start_offset} and end offset {end_offset}")
 
-    files_to_include.reverse()
     with open("file_list.txt", "w") as f:
-        for file_path in files_to_include:
+        for file_path in files:
             f.write(f"file '{file_path}'\n")
 
     subprocess.run(["ffmpeg", "-y", 
-                    "-ss", str(max(0, total_duration - seconds)),
+                    "-ss", str(start_offset),
                     "-f", "concat", "-safe", "0", "-i", 
                     "file_list.txt", 
                     "-c", "copy", 
@@ -43,4 +71,9 @@ def get_duration(file_path: str) -> float:
         stdout=subprocess.PIPE,
         stderr=subprocess.STDOUT
     )
+
+    # error checking
+    if result.returncode != 0:
+        raise RuntimeError(f"ffprobe failed for file {file_path}")
+
     return float(result.stdout)