some changes

.gitignore

@@ -1,4 +1,5 @@
 def
+data/
 *.egg-info/
 __pycache__/
 .venv/

cht/config.py

@@ -3,8 +3,9 @@ from pathlib import Path
 APP_ID = "com.cht.StreamAgent"
 APP_NAME = "CHT"
 
-# Default session data location
+# Default session data location — in project dir for easy clearing
-DATA_DIR = Path.home() / ".local" / "share" / "cht"
+PROJECT_DIR = Path(__file__).resolve().parent.parent
+DATA_DIR = PROJECT_DIR / "data"
 SESSIONS_DIR = DATA_DIR / "sessions"
 
 # Stream defaults

cht/stream/ffmpeg.py

@@ -1,17 +1,13 @@
 """
 Thin wrapper around ffmpeg-python for building and running ffmpeg pipelines.
 
-All ffmpeg command construction goes through this module so manager.py
+All ffmpeg command construction goes through this module.
-and other consumers never build raw CLI arg lists.
-
 Uses ffmpeg-python's own run/run_async for subprocess management.
 """
 
 import logging
-import os
 import signal
 import subprocess
-from pathlib import Path
 
 import ffmpeg
 
@@ -20,84 +16,37 @@ log = logging.getLogger(__name__)
 GLOBAL_ARGS = ("-hide_banner", "-loglevel", "warning")
 
 
-def receive_to_pipe(stream_url, segment_dir=None, segment_duration=60):
+def receive_and_record(stream_url, output_path):
-    """Receive mpegts stream and pipe to stdout for mpv.
+    """Receive mpegts stream and write to a single growing file.
 
-    If segment_dir is provided, also saves segments to disk.
+    mpv reads this file for DVR-style playback.
-    Uses pipe (not fifo) so OS kernel buffers prevent blocking.
+    ffmpeg scene detection runs on this file for frame extraction.
+    Audio is preserved in the recording (muxed mpegts).
     """
     stream = ffmpeg.input(stream_url, fflags="nobuffer", flags="low_delay")
-
-    out_pipe = ffmpeg.output(stream, "pipe:", c="copy", f="mpegts")
-
-    if segment_dir:
-        out_segments = ffmpeg.output(
-            stream,
-            str(segment_dir / "segment_%04d.ts"),
-            c="copy",
-            f="segment",
-            segment_time=segment_duration,
-            reset_timestamps=1,
-        )
-        return ffmpeg.merge_outputs(out_pipe, out_segments).global_args(*GLOBAL_ARGS)
-
-    return out_pipe.global_args(*GLOBAL_ARGS)
-
-
-def receive_and_segment(stream_url, segment_dir, segment_duration=60):
-    """Receive mpegts stream and save as segmented .ts files."""
-    stream = ffmpeg.input(stream_url, fflags="nobuffer", flags="low_delay")
     return (
-        ffmpeg.output(
+        ffmpeg.output(stream, str(output_path), c="copy", f="mpegts")
-            stream,
-            str(segment_dir / "segment_%04d.ts"),
-            c="copy",
-            f="segment",
-            segment_time=segment_duration,
-            reset_timestamps=1,
-        )
         .global_args(*GLOBAL_ARGS)
     )
 
 
-def receive_and_segment_with_monitor(stream_url, segment_dir, fifo_path, segment_duration=60):
-    """Receive stream, save segments AND tee to a named pipe for monitoring."""
-    if not fifo_path.exists():
-        os.mkfifo(str(fifo_path))
-
-    stream = ffmpeg.input(stream_url, fflags="nobuffer", flags="low_delay")
-
-    out_segments = ffmpeg.output(
-        stream,
-        str(segment_dir / "segment_%04d.ts"),
-        c="copy",
-        f="segment",
-        segment_time=segment_duration,
-        reset_timestamps=1,
-    )
-
-    out_monitor = ffmpeg.output(
-        stream,
-        str(fifo_path),
-        c="copy",
-        f="mpegts",
-    )
-
-    return ffmpeg.merge_outputs(out_segments, out_monitor).global_args(*GLOBAL_ARGS)
-
-
 def extract_scene_frames(input_path, output_dir, scene_threshold=0.3,
-                         max_interval=30, start_number=1):
+                         max_interval=30, start_number=1, start_time=0.0):
     """Extract frames from a file on scene change.
 
     Uses ffmpeg select filter with scene detection and a max-interval fallback.
-    Returns (stdout bytes, stderr bytes) for timestamp parsing.
+    start_time: skip to this position before processing (avoids re-scanning).
+    Returns (stdout, stderr) as decoded strings for timestamp parsing.
     """
     select_expr = (
         f"gt(scene,{scene_threshold})"
         f"+gte(t-prev_selected_t,{max_interval})"
     )
-    stream = ffmpeg.input(str(input_path))
+    input_opts = {}
+    if start_time > 0:
+        input_opts["ss"] = str(start_time)
+
+    stream = ffmpeg.input(str(input_path), **input_opts)
     stream = stream.filter("select", select_expr).filter("showinfo")
 
     output = (
@@ -116,23 +65,6 @@ def extract_scene_frames(input_path, output_dir, scene_threshold=0.3,
     return stdout.decode("utf-8", errors="replace"), stderr.decode("utf-8", errors="replace")
 
 
-def extract_audio_pcm(input_path):
-    """Extract audio as 16kHz mono PCM wav, returning an output node for piping."""
-    stream = ffmpeg.input(str(input_path))
-    return (
-        ffmpeg.output(
-            stream.audio,
-            "pipe:",
-            vn=None,
-            acodec="pcm_s16le",
-            ar=16000,
-            ac=1,
-            f="wav",
-        )
-        .global_args(*GLOBAL_ARGS)
-    )
-
-
 def run_async(output_node, pipe_stdout=False, pipe_stderr=False):
     """Start an ffmpeg pipeline asynchronously via ffmpeg-python's run_async."""
     log.info("run_async: %s", " ".join(output_node.compile()))

cht/stream/manager.py

@@ -1,14 +1,15 @@
 """
 StreamManager: orchestrates ffmpeg pipelines for receiving, recording,
-frame extraction, and audio extraction from a muxed mpegts/TCP stream.
+and frame extraction from a muxed mpegts/TCP stream.
 
-All data goes to disk. UI reads from disk.
+Architecture:
-All ffmpeg commands go through cht.stream.ffmpeg module.
+  sender → TCP:4444 → ffmpeg (writes growing recording.ts)
+                               └→ mpv plays recording.ts (DVR: live edge + scrub)
+                               └→ ffmpeg scene detection (periodic on recording)
 """
 
 import json
 import logging
-import os
 import re
 import time
 from pathlib import Path
@@ -17,7 +18,6 @@ from threading import Thread
 from cht.config import (
     STREAM_HOST,
     STREAM_PORT,
-    SEGMENT_DURATION,
     SCENE_THRESHOLD,
     MAX_FRAME_INTERVAL,
     SESSIONS_DIR,
@@ -52,10 +52,129 @@ class StreamManager:
     def stream_url(self):
         return f"tcp://{STREAM_HOST}:{STREAM_PORT}?listen"
 
-    def start_all(self):
+    @property
-        self.setup_dirs()
+    def recording_path(self):
-        self.start_recorder()
+        return self.stream_dir / "recording.ts"
-        self.start_frame_extractor()
+
+    # -- Recording --
+
+    def start_recorder(self):
+        """Start ffmpeg to receive TCP stream and write to recording.ts."""
+        node = ff.receive_and_record(self.stream_url, self.recording_path)
+        proc = ff.run_async(node, pipe_stderr=True)
+        self._procs["recorder"] = proc
+        log.info("Recorder started: pid=%s url=%s → %s", proc.pid, self.stream_url, self.recording_path)
+        self._start_stderr_reader("recorder", proc)
+
+    # -- Scene detection --
+
+    def start_scene_detector(self):
+        """Periodically run ffmpeg scene detection on the growing recording.
+
+        Tracks how far we've processed to avoid re-scanning from the start.
+        """
+        log.info("Starting scene detector (threshold=%.2f, interval=%ds)",
+                 SCENE_THRESHOLD, MAX_FRAME_INTERVAL)
+
+        def _detect():
+            last_processed_size = 0
+            processed_duration = 0.0  # seconds already processed
+            frame_count = 0
+
+            while "stop" not in self._stop_flags:
+                time.sleep(10)
+                if not self.recording_path.exists():
+                    continue
+                size = self.recording_path.stat().st_size
+                if size <= last_processed_size or size < 100_000:
+                    continue
+
+                log.info("Recording grew: %d → %d bytes, scanning from %.1fs",
+                         last_processed_size, size, processed_duration)
+                last_processed_size = size
+
+                try:
+                    new_count, new_duration = self._extract_new_frames(
+                        self.recording_path,
+                        start_time=processed_duration,
+                        start_number=frame_count + 1,
+                    )
+                    if new_count > 0:
+                        frame_count += new_count
+                        log.info("Found %d new frames (total: %d)", new_count, frame_count)
+                    if new_duration > processed_duration:
+                        processed_duration = new_duration
+                except Exception as e:
+                    log.error("Scene detection failed: %s", e)
+
+            log.info("Scene detector stopped")
+
+        t = Thread(target=_detect, daemon=True, name="scene_detector")
+        t.start()
+        self._threads["scene_detector"] = t
+
+    def _extract_new_frames(self, path, start_time=0.0, start_number=1):
+        """Extract scene-change frames starting from a given timestamp.
+
+        Returns (new_frame_count, max_timestamp_seen).
+        """
+        existing_before = set(f.name for f in self.frames_dir.glob("F*.jpg"))
+
+        try:
+            _stdout, stderr = ff.extract_scene_frames(
+                path,
+                self.frames_dir,
+                scene_threshold=SCENE_THRESHOLD,
+                max_interval=MAX_FRAME_INTERVAL,
+                start_number=start_number,
+                start_time=start_time,
+            )
+        except Exception as e:
+            log.error("ffmpeg scene extraction error: %s", e)
+            return 0, start_time
+
+        if stderr:
+            for line in stderr.splitlines()[:5]:
+                log.debug("[scene_detect:stderr] %s", line)
+
+        # Parse timestamps and update index
+        max_ts = start_time
+        new_count = 0
+        index_path = self.frames_dir / "index.json"
+        if index_path.exists():
+            with open(index_path) as f:
+                index = json.load(f)
+        else:
+            index = []
+
+        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:
+                    index.append({
+                        "id": frame_id,
+                        "timestamp": pts_time,
+                        "path": str(frame_path),
+                        "sent_to_agent": False,
+                    })
+                    log.info("Indexed frame %s at pts=%.2f", frame_id, pts_time)
+                    new_count += 1
+                    if pts_time > max_ts:
+                        max_ts = pts_time
+                    frame_num += 1
+
+        with open(index_path, "w") as f:
+            json.dump(index, f, indent=2)
+
+        return new_count, max_ts
+
+    # -- Lifecycle --
 
     def stop_all(self):
         log.info("Stopping all processes...")
@@ -66,44 +185,7 @@ class StreamManager:
         self._procs.clear()
         log.info("All processes stopped")
 
-    def start_recorder(self):
-        node = ff.receive_and_segment(
-            self.stream_url, self.stream_dir, SEGMENT_DURATION,
-        )
-        proc = ff.run_async(node, pipe_stderr=True)
-        self._procs["recorder"] = proc
-        log.info("Recorder started: pid=%s url=%s", proc.pid, self.stream_url)
-        self._start_stderr_reader("recorder", proc)
-
-    def start_receiver_pipe(self):
-        """Receive stream, pipe stdout to mpv, save segments to disk."""
-        self.setup_dirs()
-        node = ff.receive_to_pipe(
-            self.stream_url,
-            segment_dir=self.stream_dir,
-            segment_duration=SEGMENT_DURATION,
-        )
-        proc = ff.run_async(node, pipe_stdout=True, pipe_stderr=True)
-        self._procs["receiver"] = proc
-        log.info("Receiver started: pid=%s url=%s (pipe + segments)", proc.pid, self.stream_url)
-        self._start_stderr_reader("receiver", proc)
-        return proc
-
-    def start_recorder_with_monitor(self):
-        self.setup_dirs()
-        fifo_path = self.session_dir / "monitor.pipe"
-
-        node = ff.receive_and_segment_with_monitor(
-            self.stream_url, self.stream_dir, fifo_path, SEGMENT_DURATION,
-        )
-        proc = ff.run_async(node, pipe_stderr=True)
-        self._procs["recorder"] = proc
-        log.info("Recorder+monitor started: pid=%s url=%s fifo=%s", proc.pid, self.stream_url, fifo_path)
-        self._start_stderr_reader("recorder", proc)
-        return fifo_path
-
     def _start_stderr_reader(self, name, proc):
-        """Read stderr from a process in a thread and log it."""
         def _read():
             try:
                 for line in proc.stderr:
@@ -117,116 +199,3 @@ class StreamManager:
 
         t = Thread(target=_read, daemon=True, name=f"{name}_stderr")
         t.start()
-
-    def start_frame_extractor_on_recording(self, recording_path):
-        """Extract frames periodically from a growing recording file."""
-        log.info("Starting frame extractor on recording: %s", recording_path)
-        self._recording_path = recording_path
-        self._start_recording_frame_watcher()
-
-    def _start_recording_frame_watcher(self):
-        def _watch():
-            last_size = 0
-            log.info("Recording frame watcher running, watching %s", self._recording_path)
-            while "stop" not in self._stop_flags:
-                if self._recording_path.exists():
-                    size = self._recording_path.stat().st_size
-                    if size > last_size and size > 100_000:  # wait for some data
-                        log.info("Recording grew: %d -> %d bytes, extracting frames", last_size, size)
-                        last_size = size
-                        self._extract_frames_from_file(self._recording_path)
-                time.sleep(10)  # check every 10s
-            log.info("Recording frame watcher stopped")
-
-        t = Thread(target=_watch, daemon=True, name="recording_frame_watcher")
-        t.start()
-        self._threads["recording_frame_watcher"] = t
-
-    def start_frame_extractor(self):
-        log.info("Starting frame watcher...")
-        self._start_frame_watcher()
-
-    def _start_frame_watcher(self):
-        def _watch():
-            seen = set()
-            log.info("Frame watcher running, watching %s", self.stream_dir)
-            while "stop" not in self._stop_flags:
-                segments = sorted(self.stream_dir.glob("segment_*.ts"))
-                for seg in segments:
-                    if seg.name not in seen and seg.stat().st_size > 0:
-                        seen.add(seg.name)
-                        log.info("New segment found: %s (%d bytes)", seg.name, seg.stat().st_size)
-                        self._extract_frames_from_file(seg)
-                time.sleep(2)
-            log.info("Frame watcher stopped")
-
-        t = Thread(target=_watch, daemon=True, name="frame_watcher")
-        t.start()
-        self._threads["frame_watcher"] = t
-
-    def _extract_frames_from_file(self, segment_path):
-        existing = list(self.frames_dir.glob("F*.jpg"))
-        start_num = len(existing) + 1
-        log.info("Extracting frames from %s (start_num=%d)", segment_path.name, start_num)
-
-        try:
-            _stdout, stderr = ff.extract_scene_frames(
-                segment_path,
-                self.frames_dir,
-                scene_threshold=SCENE_THRESHOLD,
-                max_interval=MAX_FRAME_INTERVAL,
-                start_number=start_num,
-            )
-            if stderr:
-                for line in stderr.splitlines()[:10]:
-                    log.debug("[frame_extract:stderr] %s", line)
-            self._parse_frame_timestamps(stderr, start_num)
-            new_frames = list(self.frames_dir.glob("F*.jpg"))
-            log.info("Frame extraction done: %d new frames", len(new_frames) - len(existing))
-        except Exception as e:
-            log.error("Frame extraction failed for %s: %s", segment_path.name, e)
-
-    def _parse_frame_timestamps(self, stderr_output, start_num):
-        index_path = self.frames_dir / "index.json"
-        if index_path.exists():
-            with open(index_path) as f:
-                index = json.load(f)
-        else:
-            index = []
-
-        frame_num = start_num
-        for line in stderr_output.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():
-                    index.append({
-                        "id": frame_id,
-                        "timestamp": pts_time,
-                        "path": str(frame_path),
-                        "sent_to_agent": False,
-                    })
-                    log.info("Indexed frame %s at pts=%.2f", frame_id, pts_time)
-                    frame_num += 1
-
-        with open(index_path, "w") as f:
-            json.dump(index, f, indent=2)
-
-    def start_audio_extractor(self):
-        """Will be implemented in Phase 3."""
-        pass
-
-    def get_ffplay_cmd(self):
-        fifo_path = self.session_dir / "monitor.pipe"
-        return [
-            "ffplay",
-            "-hwaccel", "cuda",
-            "-fflags", "nobuffer",
-            "-flags", "low_delay",
-            "-framedrop",
-            "-i", str(fifo_path),
-        ], fifo_path

cht/ui/monitor.py

@@ -1,97 +1,193 @@
 """
-MonitorWidget: mpv-based live stream monitor embedded in GTK4.
+MonitorWidget: mpv-based stream monitor embedded in GTK4 via OpenGL.
 
-Uses libmpv's OpenGL render API + Gtk.GLArea for proper embedding.
+Supports DVR-style playback of a growing recording file:
-No X11 wid hacks — renders directly to a GL texture in the GTK layout.
+  - Follows live edge by default
-Works on both X11 and Wayland.
+  - Slider scrubs video + audio together
+  - Can capture frame at current cursor position
 """
 
+import ctypes
 import logging
 
 import gi
 gi.require_version("Gtk", "4.0")
-from gi.repository import Gtk, GLib, Gdk
+from gi.repository import Gtk, GLib
 
 from cht.ui.mpv import Player
 
 log = logging.getLogger(__name__)
 
+# Cache libGL reference
+_libGL = ctypes.cdll.LoadLibrary("libGL.so.1")
+GL_DRAW_FRAMEBUFFER_BINDING = 0x8CA6
+
 
 class MonitorWidget(Gtk.Box):
-    """Widget that embeds mpv video via OpenGL into the GTK4 layout."""
+    """Embedded mpv video player with DVR controls."""
 
     def __init__(self, **kwargs):
         super().__init__(orientation=Gtk.Orientation.VERTICAL, **kwargs)
         self._player = None
+        self._following_live = True
+        self._slider_updating = False
 
+        # GL area for video
         self._gl_area = Gtk.GLArea()
         self._gl_area.set_hexpand(True)
         self._gl_area.set_vexpand(True)
         self._gl_area.set_auto_render(False)
         self._gl_area.set_has_depth_buffer(False)
         self._gl_area.set_has_stencil_buffer(False)
-
         self._gl_area.connect("realize", self._on_realize)
         self._gl_area.connect("unrealize", self._on_unrealize)
         self._gl_area.connect("render", self._on_render)
-
         self.append(self._gl_area)
-        log.info("MonitorWidget initialized (GLArea)")
+
+        # Slider for scrubbing (shared timeline for video + audio)
+        slider_box = Gtk.Box(orientation=Gtk.Orientation.HORIZONTAL, spacing=4)
+        slider_box.set_margin_start(4)
+        slider_box.set_margin_end(4)
+        slider_box.set_margin_bottom(2)
+
+        self._time_label = Gtk.Label(label="00:00")
+        self._time_label.set_width_chars(6)
+        slider_box.append(self._time_label)
+
+        self._slider = Gtk.Scale(orientation=Gtk.Orientation.HORIZONTAL)
+        self._slider.set_hexpand(True)
+        self._slider.set_range(0, 1)
+        self._slider.set_draw_value(False)
+        self._slider.connect("value-changed", self._on_slider_changed)
+        slider_box.append(self._slider)
+
+        self._duration_label = Gtk.Label(label="00:00")
+        self._duration_label.set_width_chars(6)
+        slider_box.append(self._duration_label)
+
+        self._live_btn = Gtk.Button(label="LIVE")
+        self._live_btn.add_css_class("suggested-action")
+        self._live_btn.connect("clicked", self._on_live_clicked)
+        slider_box.append(self._live_btn)
+
+        self.append(slider_box)
+
+        # Update slider position periodically
+        GLib.timeout_add(500, self._update_slider)
+
+        log.info("MonitorWidget initialized (GLArea + slider)")
+
+    # -- GL callbacks --
 
     def _on_realize(self, gl_area):
-        """GL context is ready — initialize mpv's render context."""
         log.info("GLArea realized")
         gl_area.make_current()
         if gl_area.get_error():
             log.error("GLArea error: %s", gl_area.get_error())
-            return
 
     def _on_unrealize(self, gl_area):
-        """Clean up mpv render context."""
         log.info("GLArea unrealized")
-        if self._player:
+        self.stop()
-            self._player.terminate()
-            self._player = None
 
     def _on_render(self, gl_area, gl_context):
-        """Render mpv's current frame to the GLArea."""
         if not self._player:
             return True
 
-        # Get the default FBO that GTK4 GLArea renders to
-        fbo = gl_area.get_buffer() if hasattr(gl_area, 'get_buffer') else 0
         width = gl_area.get_width()
         height = gl_area.get_height()
 
-        # GTK4 GLArea uses its own FBO, get it from GL state
-        import ctypes
         fbo_id = ctypes.c_int(0)
-        gl = ctypes.cdll.LoadLibrary("libGL.so.1")
+        _libGL.glGetIntegerv(GL_DRAW_FRAMEBUFFER_BINDING, ctypes.byref(fbo_id))
-        gl.glGetIntegerv(0x8CA6, ctypes.byref(fbo_id))  # GL_DRAW_FRAMEBUFFER_BINDING
 
         self._player.render(fbo_id.value, width, height)
         return True
 
     def _on_mpv_update(self):
-        """Called by mpv when a new frame is ready. Triggers re-render."""
         GLib.idle_add(self._gl_area.queue_render)
 
-    def start_stream(self, source, record_path=None):
+    # -- Slider --
-        """Start playing from a URL and optionally record to disk.
+
+    def _on_slider_changed(self, slider):
+        if self._slider_updating or not self._player:
+            return
+        pos = slider.get_value()
+        self._player.seek(pos)
+        self._following_live = False
+        self._live_btn.remove_css_class("suggested-action")
+
+    def _on_live_clicked(self, button):
+        if self._player and self._player.duration:
+            self._player.seek(self._player.duration - 0.5)
+            self._following_live = True
+            self._live_btn.add_css_class("suggested-action")
+
+    def _update_slider(self):
+        if not self._player:
+            return True
+
+        pos = self._player.time_pos
+        dur = self._player.duration
+        if pos is not None and dur is not None and dur > 0:
+            self._slider_updating = True
+            self._slider.set_range(0, dur)
+            self._slider.set_value(pos)
+            self._slider_updating = False
+
+            self._time_label.set_text(self._fmt_time(pos))
+            self._duration_label.set_text(self._fmt_time(dur))
+
+            # Auto-follow live edge: if at EOF or falling behind, reload
+            if self._following_live:
+                if self._player.idle or dur - pos > 3:
+                    self._reload_live()
+
+        return True  # keep timer running
+
+    def _reload_live(self):
+        """Reload the growing file and seek to near-end (live edge)."""
+        if not self._player or not self._recording_path:
+            return
+        self._player.play(str(self._recording_path))
+        # Small delay then seek to end
+        GLib.timeout_add(500, self._seek_to_end_once)
+
+    @staticmethod
+    def _fmt_time(seconds):
+        m, s = divmod(int(seconds), 60)
+        h, m = divmod(m, 60)
+        if h:
+            return f"{h}:{m:02d}:{s:02d}"
+        return f"{m:02d}:{s:02d}"
+
+    # -- Public API --
+
+    def _seek_to_end_once(self):
+        if self._player and self._player.duration:
+            self._player.seek(self._player.duration - 0.5)
+        return False  # don't repeat
+
+    def start_recording(self, recording_path):
+        """Start DVR-style playback of a growing recording file.
 
         Args:
-            source: TCP URL (tcp://...), file path, etc.
+            recording_path: path to the .ts file being written by ffmpeg
-            record_path: if set, mpv dumps the raw stream to this file
         """
+        self._recording_path = recording_path
         self._gl_area.make_current()
 
-        self._player = Player(record_path=record_path)
+        self._player = Player()
         self._player.init_gl(update_callback=self._on_mpv_update)
-        self._player.play(source)
+        self._player.play_file(recording_path)
-        log.info("Monitor streaming from: %s (record=%s)", source, record_path)
+        self._following_live = True
+        self._live_btn.add_css_class("suggested-action")
+        log.info("Monitor playing recording: %s", recording_path)
+
+    def screenshot(self, path):
+        """Capture frame at current cursor position."""
+        if self._player:
+            self._player.screenshot(path)
 
     def stop(self):
-        """Stop playback and release mpv."""
         if self._player:
             log.info("Stopping monitor")
             self._player.terminate()

cht/ui/mpv.py

@@ -2,7 +2,10 @@
 MPV wrapper using python-mpv (libmpv bindings) with OpenGL render API.
 
 Renders video frames to an OpenGL context provided by GTK4's GLArea.
-No subprocess calls, no X11 wid hacks.
+Supports DVR-style playback of a growing recording file:
+  - Follow live edge (default)
+  - Scrub back to any point
+  - Audio + video synced via single slider
 """
 
 import ctypes
@@ -30,40 +33,50 @@ _get_proc_address = _make_get_proc_address()
 
 
 class Player:
-    """Wraps a libmpv player with OpenGL render context for GTK4 embedding."""
+    """Wraps a libmpv player with OpenGL render context for GTK4 embedding.
 
-    def __init__(self, record_path=None):
+    Designed for DVR-style playback of a growing file:
+    - play_file() opens the recording and seeks to end (live edge)
+    - seek() scrubs to any position (audio + video move together)
+    - time_pos / duration track playback state for the slider
+    """
+
+    def __init__(self):
         opts = {
             "input_default_bindings": False,
             "input_vo_keyboard": False,
             "osc": False,
-            "profile": "low-latency",
-            "cache": "no",
-            "untimed": True,
-            "demuxer_thread": "no",
-            "demuxer_lavf_o": "fflags=+nobuffer",
-            "video_sync": "display-desync",
             "vo": "libmpv",
             "hwdec": "auto",
+            "video_sync": "display-desync",
+            # DVR: keep alive at EOF, wait for more data
+            "keep_open": "yes",
+            "demuxer_max_bytes": "500MiB",
+            "demuxer_readahead_secs": "5",
+            # Allow re-reading growing file
+            "demuxer_cache_wait": True,
         }
-        if record_path:
-            opts["stream_record"] = str(record_path)
-            log.info("mpv will record stream to: %s", record_path)
 
-        log.info("Creating mpv player (OpenGL render mode)")
+        log.info("Creating mpv player (OpenGL render, DVR mode)")
-        self._player = libmpv.MPV(**opts)
+        self._player = libmpv.MPV(log_handler=self._mpv_log, loglevel="v", **opts)
         self._ctx = None
         self._update_callback = None
         log.info("mpv player created")
 
+    @staticmethod
+    def _mpv_log(loglevel, component, message):
+        msg = f"[mpv/{component}] {message.strip()}"
+        if loglevel in ("fatal", "error"):
+            log.error(msg)
+        elif loglevel == "warn":
+            log.warning(msg)
+        else:
+            log.debug(msg)
+
     def init_gl(self, update_callback):
         """Initialize the OpenGL render context.
 
-        Must be called from a thread with an active GL context (e.g. GLArea realize).
+        Must be called with an active GL context.
-
-        Args:
-            update_callback: called by mpv when a new frame is ready to render.
-                             Should trigger a GLArea queue_render().
         """
         self._update_callback = update_callback
         self._ctx = libmpv.MpvRenderContext(
@@ -73,41 +86,40 @@ class Player:
                 "get_proc_address": _get_proc_address,
             },
         )
-        # Keep reference to prevent GC of the ctypes callback
         self._get_proc_address_ref = _get_proc_address
         self._ctx.update_cb = self._on_mpv_update
         log.info("mpv OpenGL render context initialized")
 
     def _on_mpv_update(self):
-        """Called by mpv from any thread when a new frame is available."""
         if self._update_callback:
             self._update_callback()
 
     def render(self, fbo, width, height):
-        """Render the current frame to the given OpenGL FBO.
+        """Render current frame to the given OpenGL FBO."""
-
-        Call from the GLArea render signal handler.
-        """
         if self._ctx:
             self._ctx.render(
                 flip_y=True,
-                opengl_fbo={
+                opengl_fbo={"fbo": fbo, "w": width, "h": height},
-                    "fbo": fbo,
-                    "w": width,
-                    "h": height,
-                },
             )
 
     def play(self, source):
-        """Play from a file path or URL."""
+        """Play from any source (URL, file path)."""
         log.info("mpv play: %s", source)
         self._player.play(str(source))
 
-    def play_fd(self, fd):
+    def play_file(self, path):
-        """Play from a raw file descriptor."""
+        """Play a recording file, seeking to the end (live edge)."""
-        source = f"fd://{fd}"
+        log.info("mpv play_file (DVR): %s", path)
-        log.info("mpv play from fd: %s", source)
+        self._player.play(str(path))
-        self._player.play(source)
+        # Seek to end once playback starts
+        self._player.observe_property("duration", self._seek_to_live_once)
+
+    def _seek_to_live_once(self, name, value):
+        """Seek to live edge once duration is known, then stop observing."""
+        if value and value > 1:
+            log.info("Seeking to live edge: %.1fs", value)
+            self._player.seek(value - 0.5, reference="absolute")
+            self._player.unobserve_property("duration", self._seek_to_live_once)
 
     def pause(self):
         self._player.pause = True
@@ -120,13 +132,18 @@ class Player:
         return self._player.pause
 
     def seek(self, seconds):
-        """Seek to absolute position in seconds."""
+        """Seek to absolute position. Audio + video move together."""
         self._player.seek(seconds, reference="absolute")
 
     def seek_relative(self, seconds):
         """Seek relative to current position."""
         self._player.seek(seconds, reference="relative")
 
+    def screenshot(self, path):
+        """Save current frame as an image file."""
+        self._player.screenshot_to_file(str(path), includes="video")
+        log.debug("Screenshot saved: %s", path)
+
     def stop(self):
         log.info("mpv stop")
         self._player.stop()

cht/window.py

@@ -1,9 +1,12 @@
+import json
 import logging
+from pathlib import Path
 
 import gi
 gi.require_version("Gtk", "4.0")
 gi.require_version("Adw", "1")
-from gi.repository import Gtk, Adw, GLib, Pango
+gi.require_version("GdkPixbuf", "2.0")
+from gi.repository import Gtk, Adw, GLib, Pango, GdkPixbuf
 
 from cht.config import APP_NAME
 from cht.ui.monitor import MonitorWidget
@@ -72,16 +75,32 @@ class ChtWindow(Adw.ApplicationWindow):
         log.info("Session: %s", self._stream_mgr.session_id)
         self._stream_mgr.setup_dirs()
 
-        # mpv listens on TCP directly (lowest latency, like def scripts)
+        # 1. ffmpeg receives TCP and writes growing recording.ts
-        # and records the raw stream to disk for frame extraction
+        self._stream_mgr.start_recorder()
-        stream_url = self._stream_mgr.stream_url
+        log.info("Recorder started, waiting for sender...")
-        record_path = self._stream_mgr.stream_dir / "recording.ts"
-        log.info("Starting mpv on %s, recording to %s", stream_url, record_path)
-        self._monitor.start_stream(stream_url, record_path=record_path)
-        log.info("Monitor started, waiting for sender...")
 
-        self._stream_mgr.start_frame_extractor_on_recording(record_path)
+        # 2. mpv plays the recording file (DVR: live edge + scrub)
-        log.info("Frame extractor started")
+        # Small delay to let ffmpeg create the file
+        GLib.timeout_add(2000, self._start_playback)
+
+        # 3. ffmpeg scene detection runs periodically on the recording
+        self._stream_mgr.start_scene_detector()
+        log.info("Scene detector started")
+
+        # 4. Poll for new frames and show thumbnails
+        self._known_frames = set()
+        GLib.timeout_add(3000, self._poll_frames)
+
+    def _start_playback(self):
+        """Start mpv playback once recording file exists."""
+        if self._stream_mgr and self._stream_mgr.recording_path.exists():
+            size = self._stream_mgr.recording_path.stat().st_size
+            if size > 10_000:
+                self._monitor.start_recording(self._stream_mgr.recording_path)
+                log.info("Playback started")
+                return False  # stop timer
+        log.info("Waiting for recording data...")
+        return True  # retry
 
     def _stop_stream(self):
         log.info("Stopping stream...")
@@ -279,13 +298,55 @@ class ChtWindow(Adw.ApplicationWindow):
         end_iter = buf.get_end_iter()
         buf.insert(end_iter, f"[{entry_id}] {text}\n")
 
-    def add_frame_thumbnail(self, frame_id, pixbuf):
+    def _poll_frames(self):
+        """Check for new extracted frames and add thumbnails."""
+        if not self._stream_mgr:
+            return False
+
+        index_path = self._stream_mgr.frames_dir / "index.json"
+        if not index_path.exists():
+            return True
+
+        try:
+            with open(index_path) as f:
+                index = json.load(f)
+        except (json.JSONDecodeError, IOError):
+            return True
+
+        for entry in index:
+            fid = entry["id"]
+            if fid in self._known_frames:
+                continue
+            fpath = Path(entry["path"])
+            if not fpath.exists():
+                continue
+
+            self._known_frames.add(fid)
+            try:
+                pixbuf = GdkPixbuf.Pixbuf.new_from_file_at_scale(
+                    str(fpath), 160, 90, True
+                )
+                self._add_frame_thumbnail(fid, pixbuf, entry.get("timestamp"))
+            except Exception as e:
+                log.warning("Failed to load thumbnail for %s: %s", fid, e)
+
+        return True  # keep polling
+
+    def _add_frame_thumbnail(self, frame_id, pixbuf, timestamp=None):
+        box = Gtk.Box(orientation=Gtk.Orientation.VERTICAL, spacing=1)
+
         img = Gtk.Image.new_from_pixbuf(pixbuf)
-        overlay = Gtk.Overlay()
+        box.append(img)
-        overlay.set_child(img)
+
-        label = Gtk.Label(label=frame_id)
+        label_text = frame_id
-        label.set_halign(Gtk.Align.START)
+        if timestamp is not None:
-        label.set_valign(Gtk.Align.END)
+            m, s = divmod(int(timestamp), 60)
+            label_text = f"{frame_id} [{m:02d}:{s:02d}]"
+
+        label = Gtk.Label(label=label_text)
         label.add_css_class("caption")
-        overlay.add_overlay(label)
+        label.set_ellipsize(Pango.EllipsizeMode.END)
-        self._frames_flow.append(overlay)
+        box.append(label)
+
+        self._frames_flow.append(box)
+        log.info("Added thumbnail: %s", frame_id)

pyproject.toml

@@ -10,6 +10,8 @@ requires-python = ">=3.13"
 dependencies = [
     "ffmpeg-python",
     "python-mpv",
+    "Pillow",
+    "numpy",
 ]
 
 [tool.setuptools.packages.find]

tests/test_ffmpeg.py

@@ -1,9 +1,7 @@
 """Tests for cht.stream.ffmpeg — pipeline construction and execution."""
 
-import os
 import signal
 import subprocess
-from pathlib import Path
 from unittest.mock import patch, MagicMock
 
 import pytest
@@ -12,76 +10,43 @@ import ffmpeg as ffmpeg_lib
 from cht.stream import ffmpeg as ff
 
 
-class TestReceiveAndSegment:
+class TestReceiveAndRecord:
     def test_compiles_to_valid_cmd(self, tmp_path):
-        node = ff.receive_and_segment(
+        node = ff.receive_and_record(
-            "tcp://0.0.0.0:4444?listen", tmp_path, segment_duration=30
+            "tcp://0.0.0.0:4444?listen", tmp_path / "recording.ts"
         )
         cmd = node.compile()
         cmd_str = " ".join(str(c) for c in cmd)
-
         assert cmd[0] == "ffmpeg"
         assert "tcp://0.0.0.0:4444?listen" in cmd_str
-        assert "segment" in cmd_str
+        assert "recording.ts" in cmd_str
-        assert str(tmp_path / "segment_%04d.ts") in cmd_str
 
     def test_input_has_low_latency_flags(self, tmp_path):
-        node = ff.receive_and_segment("tcp://0.0.0.0:4444?listen", tmp_path)
+        node = ff.receive_and_record(
+            "tcp://0.0.0.0:4444?listen", tmp_path / "rec.ts"
+        )
         cmd_str = " ".join(str(c) for c in node.compile())
         assert "nobuffer" in cmd_str
         assert "low_delay" in cmd_str
 
     def test_copy_codec(self, tmp_path):
-        node = ff.receive_and_segment("tcp://0.0.0.0:4444?listen", tmp_path)
+        node = ff.receive_and_record(
+            "tcp://0.0.0.0:4444?listen", tmp_path / "rec.ts"
+        )
         assert "copy" in node.compile()
 
     def test_has_global_args(self, tmp_path):
-        node = ff.receive_and_segment("tcp://0.0.0.0:4444?listen", tmp_path)
+        node = ff.receive_and_record(
-        cmd = node.compile()
+            "tcp://0.0.0.0:4444?listen", tmp_path / "rec.ts"
-        assert "-hide_banner" in cmd
-
-
-class TestReceiveAndSegmentWithMonitor:
-    def test_creates_fifo(self, tmp_path):
-        fifo = tmp_path / "monitor.pipe"
-        ff.receive_and_segment_with_monitor(
-            "tcp://0.0.0.0:4444?listen", tmp_path, fifo
-        )
-        assert fifo.exists()
-
-    def test_does_not_recreate_existing_fifo(self, tmp_path):
-        fifo = tmp_path / "monitor.pipe"
-        os.mkfifo(str(fifo))
-        inode_before = fifo.stat().st_ino
-        ff.receive_and_segment_with_monitor(
-            "tcp://0.0.0.0:4444?listen", tmp_path, fifo
-        )
-        assert fifo.stat().st_ino == inode_before
-
-    def test_has_two_outputs(self, tmp_path):
-        fifo = tmp_path / "monitor.pipe"
-        node = ff.receive_and_segment_with_monitor(
-            "tcp://0.0.0.0:4444?listen", tmp_path, fifo
-        )
-        cmd_str = " ".join(str(c) for c in node.compile())
-        assert "segment_%04d.ts" in cmd_str
-        assert "monitor.pipe" in cmd_str
-
-    def test_both_outputs_use_copy(self, tmp_path):
-        fifo = tmp_path / "monitor.pipe"
-        node = ff.receive_and_segment_with_monitor(
-            "tcp://0.0.0.0:4444?listen", tmp_path, fifo
-        )
-        cmd = node.compile()
-        assert cmd.count("copy") >= 2
-
-    def test_has_global_args(self, tmp_path):
-        fifo = tmp_path / "monitor.pipe"
-        node = ff.receive_and_segment_with_monitor(
-            "tcp://0.0.0.0:4444?listen", tmp_path, fifo
         )
         assert "-hide_banner" in node.compile()
 
+    def test_mpegts_format(self, tmp_path):
+        node = ff.receive_and_record(
+            "tcp://0.0.0.0:4444?listen", tmp_path / "rec.ts"
+        )
+        assert "mpegts" in node.compile()
+
 
 class TestExtractSceneFrames:
     def test_compiles_select_filter(self, tmp_path):
@@ -113,32 +78,12 @@ class TestExtractSceneFrames:
         assert stderr == "err"
 
 
-class TestExtractAudioPcm:
-    def test_compiles_audio_extraction(self, tmp_path):
-        node = ff.extract_audio_pcm(tmp_path / "test.ts")
-        cmd_str = " ".join(str(c) for c in node.compile())
-        assert "pcm_s16le" in cmd_str
-        assert "16000" in cmd_str
-        assert "pipe:" in cmd_str
-        assert "wav" in cmd_str
-
-    def test_has_global_args(self, tmp_path):
-        node = ff.extract_audio_pcm(tmp_path / "test.ts")
-        assert "-hide_banner" in node.compile()
-
-
 class TestRunAsync:
-    @patch("ffmpeg.run_async")
+    def test_compiles_valid_command(self, tmp_path):
-    def test_delegates_to_ffmpeg_python(self, mock_run_async, tmp_path):
+        node = ff.receive_and_record("tcp://0.0.0.0:4444?listen", tmp_path / "rec.ts")
-        node = ffmpeg_lib.input("test").output("out")
+        cmd = node.compile()
-        ff.run_async(node)
+        assert cmd[0] == "ffmpeg"
-        # ffmpeg-python's run_async is called on the node
+        assert "tcp://0.0.0.0:4444?listen" in " ".join(cmd)
-        # Our function calls node.run_async() which is the bound method
-
-    @patch("ffmpeg.run_async")
-    def test_passes_pipe_flags(self, mock_run_async, tmp_path):
-        node = ffmpeg_lib.input("test").output("out")
-        ff.run_async(node, pipe_stdout=True, pipe_stderr=True)
 
 
 class TestStopProc:

tests/test_manager.py

@@ -1,10 +1,8 @@
 """Tests for cht.stream.manager — StreamManager orchestration."""
 
 import json
-import os
 import time
-from pathlib import Path
+from unittest.mock import patch, MagicMock
-from unittest.mock import patch, MagicMock, call
 
 import pytest
 
@@ -13,7 +11,6 @@ from cht.stream.manager import StreamManager
 
 @pytest.fixture
 def manager(tmp_path):
-    """StreamManager with session dir in tmp_path."""
     with patch("cht.stream.manager.SESSIONS_DIR", tmp_path):
         mgr = StreamManager(session_id="test_session")
         yield mgr
@@ -24,7 +21,7 @@ class TestInit:
     def test_session_id_default(self, tmp_path):
         with patch("cht.stream.manager.SESSIONS_DIR", tmp_path):
             mgr = StreamManager()
-            assert mgr.session_id  # should be a timestamp string
+            assert mgr.session_id
 
     def test_session_id_custom(self, manager):
         assert manager.session_id == "test_session"
@@ -54,44 +51,29 @@ class TestStreamUrl:
         assert "listen" in manager.stream_url
 
 
+class TestRecordingPath:
+    def test_is_in_stream_dir(self, manager):
+        assert manager.recording_path.parent == manager.stream_dir
+        assert manager.recording_path.name == "recording.ts"
+
+
 class TestStartRecorder:
     @patch("cht.stream.manager.ff.run_async")
-    @patch("cht.stream.manager.ff.receive_and_segment")
+    @patch("cht.stream.manager.ff.receive_and_record")
-    def test_calls_ffmpeg_module(self, mock_segment, mock_async, manager):
+    def test_calls_ffmpeg_module(self, mock_record, mock_async, manager):
         manager.setup_dirs()
         mock_node = MagicMock()
-        mock_segment.return_value = mock_node
+        mock_record.return_value = mock_node
 
         manager.start_recorder()
 
-        mock_segment.assert_called_once_with(
+        mock_record.assert_called_once_with(
-            manager.stream_url, manager.stream_dir, 60,
+            manager.stream_url, manager.recording_path,
         )
         mock_async.assert_called_once_with(mock_node, pipe_stderr=True)
         assert "recorder" in manager._procs
 
 
-class TestStartRecorderWithMonitor:
-    @patch("cht.stream.manager.ff.run_async")
-    @patch("cht.stream.manager.ff.receive_and_segment_with_monitor")
-    def test_creates_fifo_and_starts(self, mock_monitor, mock_async, manager):
-        mock_node = MagicMock()
-        mock_monitor.return_value = mock_node
-
-        fifo = manager.start_recorder_with_monitor()
-
-        assert fifo == manager.session_dir / "monitor.pipe"
-        mock_monitor.assert_called_once()
-        mock_async.assert_called_once_with(mock_node, pipe_stderr=True)
-
-    @patch("cht.stream.manager.ff.run_async")
-    @patch("cht.stream.manager.ff.receive_and_segment_with_monitor")
-    def test_setup_dirs_called(self, mock_monitor, mock_async, manager):
-        mock_monitor.return_value = MagicMock()
-        manager.start_recorder_with_monitor()
-        assert manager.stream_dir.is_dir()
-
-
 class TestStopAll:
     @patch("cht.stream.manager.ff.stop_proc")
     def test_stops_all_procs(self, mock_stop, manager):
@@ -109,162 +91,89 @@ class TestStopAll:
         assert "stop" in manager._stop_flags
 
 
-class TestParseFrameTimestamps:
+class TestExtractNewFrames:
-    def test_parses_showinfo_output(self, manager):
-        manager.setup_dirs()
-        # Create fake frame files
-        for i in range(1, 4):
-            (manager.frames_dir / f"F{i:04d}.jpg").touch()
-
-        stderr = (
-            "[Parsed_showinfo_1 @ 0x1234] n:0 pts:1000 pts_time:10.5 other stuff\n"
-            "some other line\n"
-            "[Parsed_showinfo_1 @ 0x1234] n:1 pts:2000 pts_time:20.0 other stuff\n"
-            "[Parsed_showinfo_1 @ 0x1234] n:2 pts:3000 pts_time:35.7 other stuff\n"
-        )
-
-        manager._parse_frame_timestamps(stderr, start_num=1)
-
-        index_path = manager.frames_dir / "index.json"
-        assert index_path.exists()
-
-        with open(index_path) as f:
-            index = json.load(f)
-
-        assert len(index) == 3
-        assert index[0]["id"] == "F0001"
-        assert index[0]["timestamp"] == 10.5
-        assert index[0]["sent_to_agent"] is False
-        assert index[1]["id"] == "F0002"
-        assert index[1]["timestamp"] == 20.0
-        assert index[2]["id"] == "F0003"
-        assert index[2]["timestamp"] == 35.7
-
-    def test_appends_to_existing_index(self, manager):
-        manager.setup_dirs()
-        index_path = manager.frames_dir / "index.json"
-
-        # Pre-existing index
-        existing = [{"id": "F0001", "timestamp": 5.0, "path": "/old", "sent_to_agent": True}]
-        with open(index_path, "w") as f:
-            json.dump(existing, f)
-
-        # New frame
-        (manager.frames_dir / "F0002.jpg").touch()
-        stderr = "[Parsed_showinfo_1 @ 0x1] n:0 pts:100 pts_time:15.0 stuff\n"
-        manager._parse_frame_timestamps(stderr, start_num=2)
-
-        with open(index_path) as f:
-            index = json.load(f)
-
-        assert len(index) == 2
-        assert index[0]["id"] == "F0001"  # preserved
-        assert index[1]["id"] == "F0002"  # new
-
-    def test_skips_missing_frame_files(self, manager):
-        manager.setup_dirs()
-        # Don't create the frame file
-        stderr = "[Parsed_showinfo_1 @ 0x1] n:0 pts:100 pts_time:10.0 stuff\n"
-        manager._parse_frame_timestamps(stderr, start_num=1)
-
-        index_path = manager.frames_dir / "index.json"
-        with open(index_path) as f:
-            index = json.load(f)
-        assert len(index) == 0
-
-    def test_ignores_non_showinfo_lines(self, manager):
-        manager.setup_dirs()
-        (manager.frames_dir / "F0001.jpg").touch()
-
-        stderr = (
-            "frame=  100 fps=30 q=28.0 size=    1024kB\n"
-            "video:500kB audio:200kB subtitle:0kB other streams:0kB\n"
-        )
-        manager._parse_frame_timestamps(stderr, start_num=1)
-
-        index_path = manager.frames_dir / "index.json"
-        with open(index_path) as f:
-            index = json.load(f)
-        assert len(index) == 0
-
-
-class TestExtractFramesFromFile:
     @patch("cht.stream.manager.ff.extract_scene_frames")
-    def test_calls_ffmpeg_with_correct_args(self, mock_extract, manager):
+    def test_calls_ffmpeg_with_start_time(self, mock_extract, manager):
         manager.setup_dirs()
-        seg = manager.stream_dir / "segment_0001.ts"
+        rec = manager.recording_path
-        seg.touch()
+        rec.touch()
 
         mock_extract.return_value = ("", "")
-        manager._extract_frames_from_file(seg)
+        manager._extract_new_frames(rec, start_time=10.0, start_number=5)
 
         mock_extract.assert_called_once_with(
-            seg,
+            rec,
             manager.frames_dir,
             scene_threshold=0.3,
             max_interval=30,
-            start_number=1,
+            start_number=5,
+            start_time=10.0,
         )
 
     @patch("cht.stream.manager.ff.extract_scene_frames")
-    def test_continues_numbering(self, mock_extract, manager):
+    def test_indexes_new_frames(self, mock_extract, manager):
         manager.setup_dirs()
-        # Pre-existing frames
+        rec = manager.recording_path
+        rec.touch()
+
+        # Simulate ffmpeg creating a frame file during extraction
+        def create_frame_and_return(*args, **kwargs):
             (manager.frames_dir / "F0001.jpg").touch()
-        (manager.frames_dir / "F0002.jpg").touch()
+            return ("", "[Parsed_showinfo_1 @ 0x1] n:0 pts:1000 pts_time:10.5 stuff\n")
 
-        seg = manager.stream_dir / "segment_0002.ts"
+        mock_extract.side_effect = create_frame_and_return
-        seg.touch()
 
-        mock_extract.return_value = ("", "")
+        count, max_ts = manager._extract_new_frames(rec, start_number=1)
-        manager._extract_frames_from_file(seg)
+        assert count == 1
+        assert max_ts == 10.5
 
-        assert mock_extract.call_args.kwargs["start_number"] == 3
+        index_path = manager.frames_dir / "index.json"
+        with open(index_path) as f:
+            index = json.load(f)
+        assert len(index) == 1
+        assert index[0]["id"] == "F0001"
+        assert index[0]["timestamp"] == 10.5
 
     @patch("cht.stream.manager.ff.extract_scene_frames")
     def test_handles_ffmpeg_failure(self, mock_extract, manager):
         manager.setup_dirs()
-        seg = manager.stream_dir / "segment_0001.ts"
+        rec = manager.recording_path
-        seg.touch()
+        rec.touch()
 
         mock_extract.side_effect = RuntimeError("ffmpeg died")
-        # Should not raise
+        count, max_ts = manager._extract_new_frames(rec)
-        manager._extract_frames_from_file(seg)
+        assert count == 0
 
-
-class TestFrameWatcher:
     @patch("cht.stream.manager.ff.extract_scene_frames")
-    def test_detects_new_segments(self, mock_extract, manager):
+    def test_skips_preexisting_frames(self, mock_extract, manager):
+        manager.setup_dirs()
+        rec = manager.recording_path
+        rec.touch()
+
+        # Pre-existing frame
+        (manager.frames_dir / "F0001.jpg").touch()
+
+        # ffmpeg "creates" no new files, just returns showinfo for existing
+        stderr = "[Parsed_showinfo_1 @ 0x1] n:0 pts:100 pts_time:5.0 stuff\n"
+        mock_extract.return_value = ("", stderr)
+
+        count, _ = manager._extract_new_frames(rec, start_number=1)
+        # F0001 already existed before extraction, should not be counted
+        assert count == 0
+
+
+class TestSceneDetector:
+    @patch("cht.stream.manager.ff.extract_scene_frames")
+    def test_detects_growing_file(self, mock_extract, manager):
         manager.setup_dirs()
         mock_extract.return_value = ("", "")
 
-        manager.start_frame_extractor()
+        # Create recording with some data
+        rec = manager.recording_path
+        rec.write_bytes(b"\x00" * 200_000)
 
-        # Create a segment file
+        manager.start_scene_detector()
-        seg = manager.stream_dir / "segment_0001.ts"
+        time.sleep(12)  # wait for one cycle
-        seg.write_bytes(b"\x00" * 100)
-
-        # Wait for watcher to pick it up
-        time.sleep(3)
         manager.stop_all()
 
         mock_extract.assert_called()
-
-    @patch("cht.stream.manager.ff.extract_scene_frames")
-    def test_skips_already_seen(self, mock_extract, manager):
-        manager.setup_dirs()
-        mock_extract.return_value = ("", "")
-
-        # Pre-create segment
-        seg = manager.stream_dir / "segment_0001.ts"
-        seg.write_bytes(b"\x00" * 100)
-
-        manager.start_frame_extractor()
-        time.sleep(3)
-        call_count = mock_extract.call_count
-
-        # Wait another cycle — should not re-process
-        time.sleep(3)
-        manager.stop_all()
-
-        assert mock_extract.call_count == call_count