""" StreamManager: orchestrates ffmpeg for recording and scene detection. Architecture: sender → TCP:4444 → ffmpeg (writes recording.ts) recording.ts → mpv (plays via Timeline) recording.ts → ffmpeg scene detection (periodic, incremental) """ import json import logging import re import time from pathlib import Path from threading import Thread from cht.config import ( STREAM_HOST, STREAM_PORT, RELAY_PORT, SCENE_THRESHOLD, SESSIONS_DIR, ) from cht.stream import ffmpeg as ff log = logging.getLogger(__name__) class StreamManager: def __init__(self, session_id=None): if session_id is None: session_id = time.strftime("%Y%m%d_%H%M%S") self.session_id = session_id self.session_dir = SESSIONS_DIR / session_id self.stream_dir = self.session_dir / "stream" self.frames_dir = self.session_dir / "frames" self.transcript_dir = self.session_dir / "transcript" self.agent_dir = self.session_dir / "agent" self._procs = {} self._threads = {} self._stop_flags = set() log.info("Session: %s", session_id) def setup_dirs(self): for d in (self.stream_dir, self.frames_dir, self.transcript_dir, self.agent_dir): d.mkdir(parents=True, exist_ok=True) @property def stream_url(self): return f"tcp://{STREAM_HOST}:{STREAM_PORT}?listen" @property def relay_url(self): return f"udp://127.0.0.1:{RELAY_PORT}" @property def recording_path(self): return self.stream_dir / "recording.mkv" # -- Recording -- def start_recorder(self): """Start ffmpeg to receive TCP stream, write to MKV, and relay to UDP.""" node = ff.receive_record_and_relay(self.stream_url, self.recording_path, self.relay_url) proc = ff.run_async(node, pipe_stderr=True) self._procs["recorder"] = proc log.info("Recorder: pid=%s → %s", proc.pid, self.recording_path) self._start_stderr_reader("recorder", proc) # -- Scene Detection -- def start_scene_detector(self, on_new_frames=None): """Periodically run scene detection on new portions of the recording. Args: on_new_frames: callback(list of {id, timestamp, path}) for new frames """ self._on_new_frames = on_new_frames def _detect(): processed_time = 0.0 frame_count = 0 while "stop" not in self._stop_flags: time.sleep(5) if not self.recording_path.exists(): continue size = self.recording_path.stat().st_size if size < 100_000: continue # Get current duration. Use a 6s safety margin — MKV tail can # be corrupt for several seconds after the last flush, causing # ffmpeg to crash even with a 3s margin. safe_duration = self._estimate_safe_duration() if safe_duration is None or safe_duration <= processed_time + 8: continue # Process from last checkpoint to safe point process_to = safe_duration - 6 # 6s safety margin for MKV tail if process_to <= processed_time: continue log.info("Scene detection: %.1fs → %.1fs", processed_time, process_to) new_frames = self._detect_scenes( start_time=processed_time, end_time=process_to, start_number=frame_count + 1, ) if new_frames: frame_count += len(new_frames) log.info("Found %d new scene frames (total: %d)", len(new_frames), frame_count) if self._on_new_frames: self._on_new_frames(new_frames) processed_time = process_to log.info("Scene detector stopped") t = Thread(target=_detect, daemon=True, name="scene_detector") t.start() self._threads["scene_detector"] = t def _estimate_safe_duration(self): """Estimate recording duration. Uses ffprobe, falls back to file size.""" try: import ffmpeg as ffmpeg_lib info = ffmpeg_lib.probe(str(self.recording_path)) dur = float(info.get("format", {}).get("duration", 0)) if dur > 0: return dur except Exception: pass # Fallback: rough estimate from file size (~500kbit/s typical for this stream) try: size = self.recording_path.stat().st_size return size / 65_000 # ~500kbps → 62.5 KB/s except Exception: return None def _detect_scenes(self, start_time, end_time, start_number): """Run ffmpeg scene detection on a time range. Returns list of new frame entries.""" duration = end_time - start_time existing_before = set(f.name for f in self.frames_dir.glob("F*.jpg")) try: _stdout, stderr = ff.extract_scene_frames( self.recording_path, self.frames_dir, scene_threshold=SCENE_THRESHOLD, start_number=start_number, start_time=start_time, duration=duration, ) except Exception as e: log.error("Scene detection failed: %s", e) return [] # Parse new frames from showinfo output new_frames = [] index_path = self.frames_dir / "index.json" index = json.loads(index_path.read_text()) if index_path.exists() else [] frame_num = start_number for line in stderr.splitlines(): if "showinfo" not in line: continue pts_match = re.search(r"pts_time:\s*([\d.]+)", line) if pts_match: pts_time = float(pts_match.group(1)) frame_id = f"F{frame_num:04d}" frame_path = self.frames_dir / f"{frame_id}.jpg" if frame_path.exists() and frame_path.name not in existing_before: entry = { "id": frame_id, "timestamp": pts_time, "path": str(frame_path), "sent_to_agent": False, } index.append(entry) new_frames.append(entry) frame_num += 1 index_path.write_text(json.dumps(index, indent=2)) return new_frames # -- Lifecycle -- def stop_all(self): log.info("Stopping all...") self._stop_flags.add("stop") for name, proc in self._procs.items(): log.info("Stopping %s", name) ff.stop_proc(proc) self._procs.clear() def _start_stderr_reader(self, name, proc): def _read(): for line in proc.stderr: text = line.decode("utf-8", errors="replace").rstrip() if text: log.debug("[%s] %s", name, text) log.info("[%s] exited: %s", name, proc.poll()) Thread(target=_read, daemon=True, name=f"{name}_stderr").start()