Review follow-ups on the external-camera capture coalescing.
The coalescing was transplanted from camera.py, which is keyed by printer IP
and so has nothing to hide in a log line. These keys carry the camera URL, and
an RTSP camera URL routinely embeds user:pass@ - so the five new log lines
printed the password, one of them at warning level, where it reaches support
bundles. All five now go through _log_key(), which redacts before truncating:
slicing first can cut the URL short of the @ the pattern anchors on and leave
the password intact, which is why every other URL log in the module already
does it in that order.
_capture_frame_uncoalesced gained the blanket catch its camera.py counterpart
has. That is load-bearing once captures are shared: the wrapper hands one
task's outcome to every caller waiting on it and can only give a follower its
own turn for an outcome it recognises, so an escaping exception reached all of
them at once and none retried - one caller's failure becoming N. The per-type
helpers catch narrowly (aiohttp.ClientError / OSError / timeouts), so the
guarantee belongs here rather than resting on their coverage. CancelledError
is re-raised ahead of it, since the wrapper distinguishes a cancelled leader
from a failed one.
test_connection reports whether it shared a capture. It reaches capture_frame
like any other consumer, so a test landing while Obico is polling got that
frame back and answered "connected" for a connection it never made - the one
answer a connection test must not give silently. It still shares rather than
forcing its own capture, because forcing one would open the second handle to a
single-reader device that this whole mechanism exists to prevent. The response
carries `coalesced`, which also gives capture_in_flight() the consumer its
camera.py counterpart has in the Diagnose tool, and the Test button says
"shared with a capture already running" instead of a bare success.
Tests 12 -> 20: an unexpected error reported as a failed capture, a raising
leader whose follower still gets a frame, the three coalesced states, and
redaction on each log line that can carry a URL. The raising-leader test
patches _capture_rtsp_frame rather than _capture_frame_uncoalesced, since a
stand-in installed in the latter's place sits above the catch and would test
the wrapper against a shape it can no longer be handed.
#2705 fixed simultaneous captures colliding on the built-in camera path,
keyed by printer IP through capture_camera_frame_bytes(). External
cameras reach the same collision through a different function -
external_camera.capture_frame() - that #2705 didn't touch, and a V4L2
USB device allows exactly one open handle just like Bambu's own RTSP
limit.
Nothing coalesced two one-shot capturers here either: Obico polling,
the in-print frame bank, the finish-photo moment, plate detection and
the notification snapshot could each open their own connection to the
same USB camera and collide - is_stream_active() only stops a
capturer from competing with an attached viewer, not with another
capturer (that's what #2707 fixed).
capture_frame() is now a single-flight coalescing wrapper (actual
dispatch moved to _capture_frame_uncoalesced), keyed by (url,
camera_type, snapshot_url) - snapshot_url is part of the key since
#1177's override routes to a completely different endpoint. Mirrors
#2705's shape: coalesces, doesn't cache (a call after the previous one
finishes always captures fresh); each caller keeps its own timeout via
wait_for(shield(...)) rather than inheriting the leader's; a follower
whose leader fails takes its own turn instead of inheriting a failure
it never had a chance to avoid, bounded at two rounds; cancellation is
disambiguated via leader.cancelled() so a follower's own cancellation
still propagates while a cancelled leader is treated as a failed one.
12 tests mirroring test_camera_capture_coalescing.py's structure.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
On a printer with an external camera, watching the live view while a print
ran meant the layer timelapse recorded almost nothing and the finish photo
went out with no image. The reporter measured 0 of 87 layer captures on one
print and 0 of 105 on another, both watched throughout. A USB camera allows
one V4L2 handle, so a capture during a live view fails outright.
The built-in camera has had this rule since #1348 and #1271: reuse the
viewer's buffered frame rather than opening a second connection. It was
never extended to the external paths, and it could not have been -- the
buffer it depends on was only ever populated by the built-in paths.
generate_mjpeg_stream yields multipart-wrapped chunks, so the route layer
could not recover the JPEG, and a guarded caller would have found an empty
buffer and skipped every time.
So the stream now publishes each raw frame through a new on_frame callback
(parallel to on_process from #2675), and the six one-shot consumers reuse
it: layer timelapse, the finish-photo moment and its background fallback,
the notification snapshot, Obico polling, and the plate check. A viewer
attached with nothing buffered yet skips that one attempt rather than
competing -- kicking the viewer off is worse than missing a frame.
on_frame exceptions are logged and swallowed, like iter_subscriber's
on_unsubscribe: buffering is a side effect and must never be able to take
the live stream down with it. The external stream's teardown now releases
the buffered frame too, ownership-checked so a concurrent viewer of the
same printer keeps its own.
Two side effects on paths not touched here, both improvements: the snapshot
endpoint and the finish-photo fallback chain consult get_buffered_frame and
can now serve an external camera's live frame. plate_detection's docstring
already claimed this behaviour while implementing it only for the built-in
fallback; that drift is resolved.
Subprocess output and user-supplied URLs are scrubbed of credentials
before they reach the application log. Adds a shared redaction helper in
core/logging_filters and routes the existing support-bundle sanitizer
through the same pattern.
Closing an external USB (V4L2) camera view abruptly could leave its ffmpeg
running and holding /dev/videoN open -- LED stuck on, and reopening the view
failed or took 10-30s fighting for exclusive device access. Same class of leak
as #776 (built-in RTSP path), but the external path was never wired into that
fix: external streams registered into none of the _active_streams /
_disconnect_events / spawned-PID registries, so /camera/stop returned
{"stopped": 0} for a live USB stream and the orphan janitor's /proc net matched
only rtsp(s)://bblp: cmdlines. Cleanup ran only via the stream generator's own
finally, which an abrupt disconnect can skip.
- Thread an on_process callback + stop_event through generate_mjpeg_stream into
_stream_usb / _stream_rtsp; register the process before the startup probe so a
process that hangs on a locked device (not just one that exits) is reapable.
- Register external streams into the shared registries under a unique
{printer_id}-ext-{token} id so /camera/stop and cleanup_orphaned_streams find
and kill them; stop_event prevents the reconnect loops from respawning.
- Extend the /proc safety-net scan to also match USB (-f v4l2) ffmpeg, excluding
still-active streams and unrelated ffmpeg.
External cameras in HTTP-snapshot mode failed to load with a repeating
"connection lost" when the endpoint served PNG/WebP/BMP stills instead of
JPEG (common on IP cameras and reverse-proxied snapshot URLs). The URL
rendered fine directly in a browser, but Bambuddy's MJPEG stream wraps
every part in a hard-coded Content-Type: image/jpeg boundary, so a
non-JPEG payload labelled as JPEG made the browser reject the frame and
tear down the whole multipart/x-mixed-replace stream.
_capture_snapshot now transcodes non-JPEG stills to JPEG via OpenCV
(already a dependency). Genuine JPEG snapshots keep a byte-for-byte fast
path; truly undecodable responses (HTML error pages, auth redirects) fall
back to the previous raw-return behaviour with a single clear warning
instead of a per-frame log flood.
A previous attempt swapped `-timeout` → `-stimeout` unconditionally to
fix EADDRINUSE on the reporter's transitional ffmpeg. That broke every
install on a modern ffmpeg (5+/6+/7+) — current Debian/Ubuntu/Homebrew
— where `-stimeout` was removed and `-timeout` is back to meaning
socket I/O. Verified locally: `ffmpeg -stimeout ...` errors
"Unrecognized option 'stimeout'" on ffmpeg 7.1.
install on a modern ffmpeg (5+/6+/7+) — current Debian/Ubuntu/Homebrew
— where `-stimeout` was removed and `-timeout` is back to meaning
socket I/O. Verified locally: `ffmpeg -stimeout ...` errors
"Unrecognized option 'stimeout'" on ffmpeg 7.1.
ffmpeg has shipped THREE arrangements of this option over time and
Bambuddy supports the full range:
- Pre-deprecation (early 4.x and earlier): `-timeout` is socket I/O.
- Transitional (~late-4.x, Jammy-era): `-timeout` is deprecated and
repurposed to RTSP listen-mode timeout; any non-zero value implies
`-listen`, which makes ffmpeg bind the TLS-proxy port and fail with
EADDRINUSE. `-stimeout` is the replacement socket I/O option.
- Modern (5.x / 6.x / 7.x): `-stimeout` REMOVED. `-timeout` is back to
socket I/O — the original meaning.
So no single literal is correct on all installs.
Fix: `rtsp_socket_timeout_flag()` in services/camera.py probes
`ffmpeg -h demuxer=rtsp` once and picks `-stimeout` when ffmpeg
advertises it (covers transitional + older builds that kept it as an
alias), else `-timeout` (modern + pre-deprecation). Cached at module
level for the process lifetime — ffmpeg doesn't swap mid-run.
The function returns the option name without a leading dash; callers
prepend it themselves so a formatting bug can't pass an empty flag.
Wired into both RTSP ffmpeg call sites in lockstep: routes/camera.py
(printer camera) and services/external_camera.py (external RTSP),
which use the same TLS-proxy + ffmpeg pattern and would hit the same
regression on either ffmpeg cohort.
Tests: 8 in test_ffmpeg_rtsp_timeout_flag.py — 6 probe unit tests
(prefers stimeout when advertised, falls back to timeout on modern,
defaults to timeout when ffmpeg missing or probe raises, caches across
calls, trailing-space substring guard against `-listen_timeout`
false-positives), 2 parametrised guards against either RTSP ffmpeg
argv re-hard-coding a literal instead of consuming the probe. 37
probe + existing external-camera tests green.
go2rtc and several IP cameras still emit a warm-up / black frame on every
fresh MJPEG connection — even with the v0.2.4b2 warm-up-skip fix it
slipped through intermittently for @nkm8's setup. His own bisect named
the clean solution: go2rtc exposes /api/frame.jpeg as a dedicated
single-frame endpoint that never returns the encoder's stale keyframe.
Adds an optional external_camera_snapshot_url column on printers. When
set, every single-frame capture path (snapshot endpoint, [SNAPSHOT]
notification thumbnails, [PHOTO-BG] finish photo, layer timelapse,
Obico ML, plate-detect / calibrate-plate) routes through _capture_snapshot
on the override URL via plain HTTP GET, bypassing the warm-up dance.
Live view stays on the configured stream URL — only single-frame
captures use the override. Override is camera-type-agnostic. SSRF guard
applies (existing _sanitize_camera_url allowlist). Empty string treated
as unset.
Settings UI: new "Snapshot URL (optional)" input + Test button under
External Cameras, hidden for camera_type=snapshot since the live URL is
already a single-frame source. en + de fully translated; 6 other locales
seeded with English copy.
5 backend tests pin the routing contract; 3 frontend tests pin the
input + debounced PATCH. Documented in
bambuddy-wiki/docs/features/camera.md with the go2rtc example.
_capture_mjpeg_frame returned the very first JPEG it found in the
bytes stream, but many MJPEG sources — go2rtc most notably, and
several IP cameras — emit a warm-up frame on the byte that follows
connection accept: usually the last keyframe held in the encoder,
typically black or stale until the encoder catches up to live
content. Subsequent frames on the same connection are fine.
Result: every code path that opened a fresh capture (snapshot UX,
finish photos in notifications, timelapse, plate-detection CV,
Obico ML inference, Settings → Test button) returned a black image
on go2rtc-fronted cameras.
Reporter's support log showed every black frame was 11095 bytes
(pure-black 1280x720 JPEG ≈ 10-15 KB) while real-content frames
from the same source were 30-45 KB.
Fix:
- Read past the first complete JPEG, return the second.
- Fall back to the first frame if the connection closes / times out /
hits the 5 MB buffer cap before a second arrives. Without that
fallback, slow / single-frame streams that pre-fix returned the
warm-up would post-fix return None — a regression. The fallback
guarantees we never do worse than current behaviour.
- Inner while-loop now drains every complete frame already in the
buffer before pulling the next chunk so high-FPS sources that
pack multiple frames per chunk are handled correctly.
Untouched: snapshot / rtsp / usb capture paths, generate_mjpeg_stream
(live-view fan-out).
7 new regression tests in TestCaptureMjpegFrameWarmupSkip cover
two-frames-in-two-chunks, two-frames-in-one-chunk, partial-frame-
split-across-chunks, single-frame fallback, timeout fallback, zero-
frame stream returns None, non-200 returns None.
Latency penalty: at most one frame interval (typically 50 ms - 1 s
on a steady stream), well within every caller's tolerance window.
The Debian ffmpeg package uses GnuTLS, whose hardened defaults reject
TLS renegotiation and legacy ciphers that some Bambu printer firmwares
(notably P2S) rely on — causing RTSP sessions to drop after a few
seconds.
Add a local TLS termination proxy (Python ssl/OpenSSL) that handles
the TLS connection to the printer and exposes a plain RTSP port to
ffmpeg. The proxy rewrites RTSP request-line URLs (rtsp://proxy →
rtsps://printer) while preserving Authorization headers so Digest
auth hashes remain valid.
Also:
- Reduce RTSP reconnect delay from 1.0s to 0.2s
- Add ffmpeg fast-start flags (-probesize 32, -analyzeduration 0,
-fflags nobuffer, -flags low_delay)
- Fix external camera double rate-limiting causing choppy streams
- Apply TLS proxy to external camera rtsps:// URLs and snapshot capture
- Update orphan ffmpeg cleanup to match rtsp:// (proxied) URLs
- Add unit tests for RTSP URL rewriting and proxy lifecycle
The snapshot endpoint always used the internal printer camera even when
an external camera was configured. Now checks for external camera first,
matching the stream endpoint pattern. Also added retry logic (3 attempts,
2s delay) to MJPEG and RTSP stream generators so they reconnect on
timeout instead of silently ending the stream.
There were several instances where print() debugging was used instead of
or in addition to formal logging. These messages were tagged `[EXT-CAM]`.
Where there was already a logging call, the print statement was removed.
Where there was not, logger.debug() was used as a replacement.
Signed-off-by: Jeff Kletsky <git-commits@allycomm.com>
- Add _sanitize_camera_url() that returns reconstructed URL from
validated and parsed components, breaking CodeQL's taint tracking
- Update _capture_mjpeg_frame, _capture_snapshot, _stream_mjpeg to
use sanitized URLs instead of original user input
- Keep _validate_camera_url as legacy wrapper for backwards compat
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Block access to cloud metadata services and dangerous destinations:
- AWS/GCP/Azure metadata endpoint (169.254.169.254)
- GCP internal metadata hostnames
- localhost and loopback addresses
- All link-local addresses (169.254.x.x)
Local network IPs (192.168.x.x, 10.x.x.x) are still allowed since
cameras are typically on the same LAN as the server.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Path traversal: Convert device number to integer to break taint chain,
use strict /dev/videoN validation with range limit
- SSRF: Add documentation explaining intentional SSRF for user-configured
external camera URLs, add lgtm suppression comments
- Info exposure: Don't expose exception messages in plate calibration
errors, only expose error type name
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Add USB camera type to external camera service
- Auto-detect available V4L2 devices on Linux
- New API endpoint: GET /api/v1/printers/usb-cameras
- Use ffmpeg for USB camera capture and streaming
- Add "USB Camera (V4L2)" option in Settings UI
- Debounce camera URL input to avoid saving on every keystroke
Closes#143
Add support for external network cameras (MJPEG, RTSP, HTTP snapshot)
that replace a printer's built-in camera when configured.
Features:
- Live streaming on printers page (replaces built-in camera)
- Finish photo capture from external camera on print complete
- Layer-based timelapse: captures frame on each layer change,
stitches to MP4 video on print completion
Backend changes:
- Add external_camera_url, external_camera_type, external_camera_enabled
fields to Printer model with database migration
- New external_camera.py service: MJPEG/RTSP/snapshot frame capture,
connection testing, MJPEG stream generation
- New layer_timelapse.py service: TimelapseSession management,
layer-by-layer frame capture, ffmpeg video stitching
- Add on_layer_change callback to MQTT client and printer manager
- Update camera routes with external camera streaming and tracking
- Update print lifecycle hooks for timelapse start/stitch/cancel
- Add external camera fields to backup/restore
- Rate limiting for external camera streams (prevents browser freeze)
Frontend changes:
- Add external camera configuration UI in Settings > Camera
- Per-printer enable toggle, URL input, type selector, test button
- Toast notification on save
Closes#143
maziggy