Files
bambuddy/backend/app/services/layer_timelapse.py
T
CarlandClaude Sonnet 5 24863203fb fix(camera): sweep orphaned timelapse session directories on startup
_active_sessions is in-memory only, so a process restart mid-print
loses track of any active layer-timelapse session without ever calling
cancel_session()/cleanup() - the frames directory (and, if stitching
had already produced output before the restart, a stray
timelapse_<session_id>.mp4) are then orphaned on disk permanently, with
no equivalent to the ffmpeg orphan janitor to reap them.

Confirmed live: 38MB of exactly this leftover on the OrangePi after
several restarts during this week's testing, including two corrupt
48-byte .mp4s from stitches that got interrupted mid-write.

Adds cleanup_orphaned_timelapse_sessions(), run once at startup: for
each printer_id under timelapse_frames/, remove any frame directory or
stitched-output file that doesn't match that printer's current active
session (if any) and is older than a defensive margin (5 min default).
A restart-recovered print never gets a new timelapse session either
(#1353's _maybe_start_layer_timelapse only fires on fresh PRINT_START
events), so nothing orphaned here can ever be resumed - safe to always
remove once it's old enough not to be a startup race.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-07-30 17:25:25 +01:00

370 lines
13 KiB
Python

"""Layer-based timelapse for external cameras.
Captures a frame on each layer change and stitches them into a video on print completion.
"""
import asyncio
import logging
import shutil
import time
from dataclasses import dataclass, field
from datetime import datetime
from pathlib import Path
from backend.app.core.config import settings
from backend.app.services.external_camera import capture_frame
logger = logging.getLogger(__name__)
# Active timelapse sessions: {printer_id: TimelapseSession}
_active_sessions: dict[int, "TimelapseSession"] = {}
def get_ffmpeg_path() -> str | None:
"""Get the path to ffmpeg executable."""
# Try shutil.which first
path = shutil.which("ffmpeg")
if path:
return path
# Check common locations (systemd services may have limited PATH)
for common_path in ["/usr/bin/ffmpeg", "/usr/local/bin/ffmpeg", "/opt/homebrew/bin/ffmpeg"]:
if Path(common_path).exists():
return common_path
return None
@dataclass
class TimelapseSession:
"""Active timelapse recording session."""
printer_id: int
archive_id: int | None
camera_url: str
camera_type: str
snapshot_url: str | None = None # Optional single-frame override; #1177
last_layer: int = -1
frame_count: int = 0
session_id: str = field(default_factory=lambda: datetime.now().strftime("%Y%m%d_%H%M%S"))
frames_dir: Path = field(init=False)
def __post_init__(self):
self.frames_dir = settings.base_dir / "timelapse_frames" / str(self.printer_id) / self.session_id
self.frames_dir.mkdir(parents=True, exist_ok=True)
logger.info("Created timelapse session %s for printer %s", self.session_id, self.printer_id)
async def capture_layer(self, layer_num: int) -> bool:
"""Capture frame if layer changed.
Args:
layer_num: Current layer number from printer
Returns:
True if frame was captured, False otherwise
"""
# Only capture if layer increased
if layer_num <= self.last_layer:
return False
self.last_layer = layer_num
try:
# Reuse the live view's frame instead of opening a second handle on
# a single-reader device (#2707). Unguarded, a print watched from
# start to finish recorded zero successful layer captures, and the
# stitched video came out empty or badly truncated.
from backend.app.api.routes.camera import live_frame_for_capture
defer, buffered = live_frame_for_capture(self.printer_id)
if defer:
if not buffered:
# Viewer attached but nothing buffered yet: skip this layer
# rather than compete and kick them off (#1348).
logger.debug(
"Skipping layer %s for printer %s: viewer attached, no buffered frame yet",
layer_num,
self.printer_id,
)
return False
frame_data = buffered
else:
frame_data = await capture_frame(self.camera_url, self.camera_type, snapshot_url=self.snapshot_url)
if frame_data:
frame_path = self.frames_dir / f"layer_{layer_num:05d}.jpg"
await asyncio.to_thread(frame_path.write_bytes, frame_data)
self.frame_count += 1
logger.debug(
"Captured layer %s for printer %s (frame %s)", layer_num, self.printer_id, self.frame_count
)
return True
else:
logger.warning("Failed to capture frame for layer %s", layer_num)
return False
except Exception as e:
logger.error("Error capturing timelapse frame: %s", e)
return False
async def stitch(self, output_path: Path, fps: int = 30) -> bool:
"""Create MP4 from captured frames using ffmpeg.
Args:
output_path: Path for output video file
fps: Frames per second for output video
Returns:
True if stitching succeeded, False otherwise
"""
if self.frame_count == 0:
logger.warning("No frames to stitch")
return False
ffmpeg = get_ffmpeg_path()
if not ffmpeg:
logger.error("ffmpeg not found - required for timelapse stitching")
return False
# Find all frame files and create a sequential list
# This handles gaps in layer numbers (e.g., if some captures failed)
frame_files = sorted(self.frames_dir.glob("layer_*.jpg"))
if not frame_files:
logger.warning("No frame files found in timelapse directory")
return False
# Create a concat file listing all frames
concat_file = self.frames_dir / "frames.txt"
try:
with open(concat_file, "w") as f:
for frame in frame_files:
# Each frame shown for 1/fps duration
f.write(f"file '{frame.name}'\n")
f.write(f"duration {1.0 / fps}\n")
# Add last frame again (required by concat demuxer)
if frame_files:
f.write(f"file '{frame_files[-1].name}'\n")
except Exception as e:
logger.error("Failed to create concat file: %s", e)
return False
# Use ffmpeg concat demuxer for variable-gap frame sequences
cmd = [
ffmpeg,
"-y", # Overwrite output
"-f",
"concat",
"-safe",
"0",
"-i",
str(concat_file),
"-c:v",
"libx264",
"-pix_fmt",
"yuv420p",
"-preset",
"medium",
"-crf",
"23",
str(output_path),
]
try:
process = await asyncio.create_subprocess_exec(
*cmd,
stdout=asyncio.subprocess.PIPE,
stderr=asyncio.subprocess.PIPE,
cwd=str(self.frames_dir), # Run in frames dir so relative paths work
)
stdout, stderr = await asyncio.wait_for(process.communicate(), timeout=300)
if process.returncode != 0:
logger.error("ffmpeg timelapse stitch failed: %s", stderr.decode()[:500])
return False
logger.info("Created timelapse video: %s (%s frames)", output_path, self.frame_count)
return True
except TimeoutError:
logger.error("Timelapse stitching timed out")
if process:
process.kill()
return False
except Exception as e:
logger.error("Timelapse stitch failed: %s", e)
return False
def cleanup(self):
"""Remove temporary frames directory."""
try:
if self.frames_dir.exists():
shutil.rmtree(self.frames_dir, ignore_errors=True)
logger.info("Cleaned up timelapse frames for session %s", self.session_id)
except Exception as e:
logger.warning("Failed to cleanup timelapse frames: %s", e)
def start_session(
printer_id: int,
archive_id: int | None,
url: str,
cam_type: str,
snapshot_url: str | None = None,
) -> TimelapseSession:
"""Start new timelapse session for a printer.
Args:
printer_id: The printer ID
archive_id: Associated print archive ID (optional)
url: External camera URL
cam_type: Camera type ("mjpeg", "rtsp", "snapshot")
snapshot_url: Optional single-frame URL override; when set, layer captures
fetch from it directly instead of opening the live stream. #1177.
Returns:
The new TimelapseSession
"""
# Cancel any existing session
cancel_session(printer_id)
session = TimelapseSession(
printer_id=printer_id,
archive_id=archive_id,
camera_url=url,
camera_type=cam_type,
snapshot_url=snapshot_url,
)
_active_sessions[printer_id] = session
logger.info("Started timelapse session for printer %s", printer_id)
return session
def get_session(printer_id: int) -> TimelapseSession | None:
"""Get active timelapse session for a printer."""
return _active_sessions.get(printer_id)
async def on_layer_change(printer_id: int, layer_num: int):
"""Called on layer change - captures frame if session active.
Args:
printer_id: The printer ID
layer_num: Current layer number
"""
session = get_session(printer_id)
if session:
await session.capture_layer(layer_num)
async def on_print_complete(printer_id: int) -> Path | None:
"""Stitch timelapse and return path. Cleans up session.
Args:
printer_id: The printer ID
Returns:
Path to stitched video, or None if no session or stitching failed
"""
session = _active_sessions.pop(printer_id, None)
if not session:
return None
if session.frame_count == 0:
logger.info("No timelapse frames captured for printer %s", printer_id)
session.cleanup()
return None
# Create output path in parent of frames dir
output_path = session.frames_dir.parent / f"timelapse_{session.session_id}.mp4"
try:
success = await session.stitch(output_path)
if success:
# Cleanup frames after successful stitch
session.cleanup()
return output_path
else:
session.cleanup()
return None
except Exception as e:
logger.error("Timelapse completion failed: %s", e)
session.cleanup()
return None
def cancel_session(printer_id: int):
"""Cancel and cleanup timelapse session (on print fail/cancel).
Args:
printer_id: The printer ID
"""
session = _active_sessions.pop(printer_id, None)
if session:
session.cleanup()
logger.info("Cancelled timelapse session for printer %s", printer_id)
def get_active_sessions() -> dict[int, TimelapseSession]:
"""Get all active timelapse sessions."""
return _active_sessions.copy()
def cleanup_orphaned_timelapse_sessions(min_age_seconds: float = 300) -> int:
"""Remove timelapse_frames/<printer_id>/* left behind by a crash or
restart that happened while a session was active.
_active_sessions is in-memory only, so a process restart loses track of
any in-flight session without ever calling cancel_session()/cleanup() -
the frames directory (and, if stitching had already produced output
before the restart, a stray `timelapse_<session_id>.mp4`) are then
orphaned on disk with nothing else to reap them (unlike the ffmpeg
orphan janitor in routes/camera.py, there was no equivalent here).
Safe to call once at startup: normal operation always cleans up via
on_print_complete/cancel_session, so anything found here predates this
process - and a restart-recovered print doesn't get a new timelapse
session either (`_maybe_start_layer_timelapse` is only wired into fresh
PRINT_START events, see #1353), so an orphaned directory can never be
resumed. `min_age_seconds` is just a defensive margin against reordering
if this is ever also called mid-run.
Returns the number of orphaned directories/files removed.
"""
base_dir = settings.base_dir / "timelapse_frames"
if not base_dir.exists():
return 0
now = time.time()
removed = 0
for printer_dir in base_dir.iterdir():
if not printer_dir.is_dir():
continue
try:
printer_id = int(printer_dir.name)
except ValueError:
continue
active_session = _active_sessions.get(printer_id)
active_session_id = active_session.session_id if active_session else None
for entry in printer_dir.iterdir():
# Frame dirs are named "<session_id>/"; stitched-but-not-yet-
# attached output files are "timelapse_<session_id>.mp4" (see
# on_print_complete's output_path).
entry_session_id = entry.name.removeprefix("timelapse_").removesuffix(".mp4") if entry.is_file() else entry.name
if entry_session_id == active_session_id:
continue
try:
if now - entry.stat().st_mtime < min_age_seconds:
continue
except OSError:
continue
try:
if entry.is_dir():
shutil.rmtree(entry, ignore_errors=True)
else:
entry.unlink(missing_ok=True)
removed += 1
logger.info("Removed orphaned timelapse artifact: %s", entry)
except OSError as e:
logger.warning("Failed to remove orphaned timelapse artifact %s: %s", entry, e)
return removed