toposync-ext-streaming 0.1.1

Toposync first-party extension: streaming settings, API surface, and pipeline sink bootstrap.

Toposync Streaming Extension

Extension ID: com.toposync.streaming

This extension provides "pipeline-rendered streaming" in Toposync:

• Users define Transmissions (domain objects) with one or more Outputs.
• Pipelines publish frames to a Transmission via the sink operator stream.publish_video.
• A local MediaMTX engine serves RTSP/HLS/WebRTC (WHEP) URLs.
• FFmpeg publishers (one per output) push encoded video into MediaMTX paths.

The core design goal is reliability in local-first setups with highly dynamic pipelines:

• Pipelines can be intermittent (open/update/close based on detection/tracking).
• Multiple pipelines can write to the same Transmission (multi-writer arbitration).
• Encoding should happen only when there is an actual viewer (on-demand).

Implemented features (high level)

• MediaMTX engine lifecycle management (start/stop/restart/status) with on-demand binary install (download + SHA256 verification) and dynamic port resolution.
• Transmission and output CRUD stored in extension settings.
• Per-output URLs for RTSP, HLS, and WebRTC/WHEP.
• Pipeline sink operator stream.publish_video that publishes frames into a transmission (multi-writer capable).
• Multi-writer arbitration using lifecycle (open/update/close), priority, and a sticky window.
• Output-level placeholder frames when no writer is active.
• Output-level resolution and FPS enforcement, including contain resizing with black padding.
• FFmpeg publishers (one per output) that publish RTSP into MediaMTX.
• On-demand encoding based on MediaMTX viewer count, with debounce stop.
• Demand priming to reduce "first connect" 404/no-stream failures.
• Distributed hosting via Transmission.host_server_id, plus URL proxying and processing-side settings sync.
• Dashboard playback (Rendering -> Streams) using WebRTC/WHEP with HLS fallback.

Supported protocols (as implemented)

RTSP

• URL format: rtsp://<host>:<rtsp_port>/<path>
• Best for VLC, ffplay, NVRs, or re-streaming with FFmpeg.
• MediaMTX is configured to accept both UDP and TCP transports. For reliability, prefer TCP on the client.

HLS

• URL format: http://<host>:<hls_port>/<path>/index.m3u8
• Intended as the stable baseline for broad playback compatibility (including future mobile/PiP usage).
• Browser:
  • Safari can play HLS natively.
  • Chrome/Firefox need MSE playback; the Toposync dashboard uses hls.js.
• MediaMTX is configured with hlsVariant: mpegts (non-LL-HLS) by default.

WebRTC (WHEP)

• URL format: http://<host>:<webrtc_port>/<path>/whep
• Used by the Toposync dashboard for lower latency than HLS.
• Current implementation is LAN-first (HTTP, no TLS termination built in). If you expose streaming beyond LAN, plan to terminate TLS.

Architecture overview

Data flow

pipeline frames -> stream.publish_video -> TransmissionRuntimeState -> StreamWriterBridge -> FFmpeg publisher -> MediaMTX path -> viewers (RTSP/HLS/WHEP)

Components

• MediaMtxEngineManager
  • Ensures the correct MediaMTX binary is available for the current OS/arch (downloads on demand when missing).
  • Renders a YAML config and starts/stops/restarts the MediaMTX process.
  • Resolves ports (preferred vs actual) and exposes engine status and test URLs.
• TransmissionRuntimeState
  • Stores latest frame per writer and per transmission.
  • Applies lifecycle and multi-writer arbitration to select the active writer.
  • Stores viewer_count per output (fed by the writer bridge).
• StreamWriterBridge
  • Periodic "tick loop" that loads streaming settings, ensures engine is running, refreshes viewer counts, starts/stops publishers on-demand, and pushes frames (or placeholders) into publishers.
  • Implements best-effort demand priming and a fallback "synthetic demand" hint.
  • Implements a bypass mode for simple pipelines (publisher pulls camera RTSP directly).
• PublisherManager
  • Spawns and supervises FFmpeg processes.
  • Supports rawvideo frames over stdin (rawvideo_pipe) or RTSP pull (rtsp_pull).
  • Maintains per-output logs and runtime status.

Domain model and settings

Transmission

A Transmission is the durable configuration entity. Fields (as implemented by the API model):

• id: UUID (generated server-side if omitted).
• name: display name.
• enabled: if false, the runtime ignores it.
• host_server_id: "local" or a processing server id (distributed hosting).
• path: slug used in the MediaMTX URL path.
• placeholder: "gray" or "black".
• arbitration: "latest" or "priority_latest".
• outputs: list of TransmissionOutput.
• created_at, updated_at: managed by the server on update.

Uniqueness rules:

• Transmission.id must be unique.
• (host_server_id, path) must be unique.
• Output id must be unique inside a transmission.

TransmissionOutput

Each output is independently configurable:

• id: stable output id (important for stable URLs when multiple outputs exist).
• protocol: "hls" | "rtsp" | "webrtc".
• enabled: output-level enable.
• resolution: optional { width, height } (defaults are applied in runtime when missing).
• fps_limit: optional integer FPS cap.
• bitrate_kbps: optional bitrate target.
• latency_profile: "normal" | "low" | "ultra_low" (maps to FFmpeg preset/tune behavior).
• authentication: optional { enabled, username, password } for read/playback.

Notes:

• Authentication is applied only when enabled == true and both username and password are present (non-empty).
• The API model allows extra fields (extra="allow"). Some runtime behavior also reads optional extra fields:
  • output.path (override the resolved engine path)
  • output.resize_mode (contain or none; best-effort)

Engine settings

Stored under the extension settings as engine:

• enabled: start/stop the engine.
• expose_to_lan: bind the engine to 0.0.0.0 (otherwise 127.0.0.1).
• preferred_ports: { rtsp, hls, webrtc, api } (preferred; runtime may change if occupied).
• mediamtx_version: selects which MediaMTX version to download/install.
• webrtc_ice_servers: optional list of stun: / turn: / turns: URLs for NAT traversal.

Engine distribution (on-demand download)

This repo does not ship MediaMTX binaries. The backend downloads the correct release asset at runtime when the engine is started.

Defaults:

• Install location: ~/.toposync/runtime/streaming/mediamtx/<version>/<platform>/mediamtx(.exe)
• Source: GitHub Releases (bluenviron/mediamtx) using the published checksums.sha256 for verification.

Environment variables:

• TOPOSYNC_STREAMING_ENGINE_PATH: use a pre-installed binary (file or directory containing mediamtx).
• TOPOSYNC_STREAMING_ENGINE_CACHE_DIR: override the cache root (defaults to ~/.toposync/runtime).
• TOPOSYNC_STREAMING_ENGINE_DOWNLOAD_BASE_URL: mirror the download base URL (must keep the same {version}/{asset} layout).

Manual download:

• POST /api/streams/engine/download downloads and installs the engine without starting it (useful to avoid surprise downloads).

URL paths and stability

Each output resolves to a MediaMTX engine path:

1. If output.path is set (extra field), it is used.
2. If there is only one enabled output, the path is transmission.path.
3. If there are multiple enabled outputs, the default path becomes:

{transmission.path}-{output.id}

Integration guidance:

• Keep transmission.path and output.id stable if you plan to integrate external tools (NVRs, mobile apps, dashboards).

Engine behavior (MediaMTX)

Default security posture

• Default bind host is localhost only: 127.0.0.1.
• Publishing is restricted to localhost IPs.
• MediaMTX API access is restricted to localhost IPs.

Read/playback can be open or authenticated per output, depending on TransmissionOutput.authentication.

Ports (preferred vs actual)

Defaults (preferences):

• RTSP: 8554
• HLS: 8888
• WebRTC/WHEP: 8889
• API: 9997

Also:

• RTP/RTCP UDP pair is auto-managed by the engine manager (defaults to 50000/50001 and auto-picks a free consecutive pair).

Source of truth:

• GET /api/streams/engine/status includes the ports the engine is actually using and warnings when remapped.

Config highlights (as generated)

• authMethod: internal
• api: true (guarded by localhost IP permissions in authInternalUsers)
• rtsp: true with rtspTransports: [udp, tcp]
• hls: true with hlsVariant: mpegts
• webrtc: true with WHEP enabled at /<path>/whep

Security considerations

• Default bind host is 127.0.0.1 (safe-by-default). Enabling expose_to_lan binds MediaMTX to 0.0.0.0.
• The generated config allows HLS and WebRTC origins with * for LAN/dev convenience. If you expose to LAN, consider hardening origins.
• There is no TLS termination built into the streaming engine endpoints in this implementation. If you expose beyond LAN, terminate TLS in front of MediaMTX.
• Output authentication is Basic-style credentials managed by MediaMTX. Some clients require embedding username:password@ in the URL (notably native HLS playback in browsers), which can leak credentials in logs/history.
• GET /api/streams/transmissions and GET /api/streams/settings return the full transmission/output objects, including authentication passwords. Protect these endpoints with Toposync platform auth and avoid exposing them to untrusted clients.

Publisher behavior (FFmpeg)

The streaming runtime starts a publisher per output when demanded.

Input modes

• rawvideo_pipe (default)
  • The writer bridge writes BGR24 frames into FFmpeg stdin.
  • Frame shape must exactly match the output resolution.
• rtsp_pull (bypass mode)
  • FFmpeg pulls the camera RTSP URL directly and applies fps + contain scaling/padding.

Codec and latency

Current default behavior:

• Uses libx264 (CPU) unless future settings expose hardware selection.
• Applies a GOP close to the configured FPS (keyframe interval ~1s).
• Applies preset/tune based on latency_profile.

Debugging knob:

• TOPOSYNC_STREAMING_FFMPEG_LOGLEVEL controls FFmpeg loglevel (default: warning).

On-demand encoding

On-demand is enforced per output:

• If viewer_count > 0, publishers are started (or kept running).
• If viewer_count == 0, publishers stop after a debounce (default: 3s) to avoid flapping.

Viewer count is obtained from MediaMTX API (/v3/paths/list) by counting per-path readers.

Demand priming (important for "first connect" reliability)

Some clients (notably RTSP) can receive "no stream is available" (404) when no publisher exists yet. That can keep viewer_count at 0 and prevent on-demand from starting.

This implementation includes:

1. Explicit priming endpoint:
   • POST /api/streams/transmissions/{transmission_id}/demand/prime
   • The dashboard calls this before attempting WebRTC/HLS.
   • URL resolution also primes demand best-effort.
2. Synthetic demand hint:
   • The writer bridge scans the MediaMTX log for "no stream is available on path ..." and temporarily treats the path as demanded to let client retries succeed.

Practical tip:

• If ffplay/VLC returns 404 right after a restart, call the prime endpoint (or load URLs in Settings) and retry.

Multi-writer arbitration

Multiple pipelines can write into the same Transmission.

Writer identity

Writer id is derived by the operator runtime as:

writer_id = "{pipeline_name}:{node_id}"

Eligibility

Writers are eligible only when:

• Lifecycle is open or update.
• A frame is present.
• The frame is fresh (default freshness window: 2 seconds).

Arbitration modes

Transmission arbitration is per Transmission:

• latest
  • Selects the writer with the most recent frame.
  • writer_priority is used only as a tie-breaker.
• priority_latest
  • Selects highest writer_priority, then most recent frame.

Sticky selection:

• Once selected, the writer is kept for a short sticky window (default 0.5s) if still eligible.

Cardinality limits:

• Max writers per transmission: 32 (oldest writers are evicted with a warning).
• Stale writers are evicted after 30 seconds.

Placeholder and resizing

Placeholder

When no eligible writer exists, the bridge publishes a cached placeholder frame at the output resolution.

Modes:

• gray (default)
• black

Resizing

The bridge always targets the output resolution. Default behavior is "contain" (letterbox/pillarbox, black padding).

Optional extra field on output:

• resize_mode: "contain" | "none"

Current behavior for none is best-effort:

• It avoids resizing only when the incoming frame already matches the target.
• Otherwise it falls back to contain to preserve publisher invariants.

Pipeline operator: stream.publish_video

Operator id: stream.publish_video

Purpose:

• Writes "latest frame" state into TransmissionRuntimeState.
• Does not encode or block the pipeline on I/O.

Config (as implemented):

{
  "transmission_id": "uuid",
  "frame_with_fallback": ["frame", "best_frame", "segmented", "frame_original"],
  "resize_mode": "contain",
  "writer_priority": 0,
  "bypass_mode": "auto"
}

Notes:

• resize_mode exists in the operator config, but resizing is currently applied by the writer bridge based on output settings.
• Artifact selection:
  • Iterates frame_with_fallback and selects the first artifact that contains an image.
  • Supports payload image mapping (packet.payload.images) when present.
  • Normalizes frames to uint8 BGR and contiguous memory.
• Lifecycle handling:
  • On close, the writer is marked closed and becomes ineligible for arbitration.

Wizard: create pipeline from a Transmission

Endpoint:

• POST /api/streams/wizard/create-pipeline

Presets (as implemented):

• simple_stream
• motion_gate_stream
• detection_stream
• tracking_stream
• segmentation_stream

Generated topology (high level):

• Always starts with camera.source (with configurable backend).
• Optionally adds core.fps_reducer.
• Adds one optional "vision" step depending on preset.
• Ends with stream.publish_video configured for the selected transmission.

Critical validation:

• Transmission.host_server_id must match the pipeline processing_server_id (wizard enforces this).

Bypass mode (publisher input optimization)

When a pipeline matches a "simple stream" shape, the writer bridge can switch publishers to rtsp_pull.

Eligible graph shapes:

• camera.source -> stream.publish_video
• camera.source -> core.fps_reducer -> stream.publish_video

Config:

• stream.publish_video.config.bypass_mode:
  • auto (use bypass when eligible)
  • force_on (use bypass when eligible; keep trying)
  • force_off (never bypass for this writer)

Behavior:

• Publisher FFmpeg reads the camera RTSP URL directly and applies fps + contain scaling/padding.

Distributed mode (processing servers)

Transmission.host_server_id

When host_server_id != "local":

• MediaMTX engine runs on the processing server.
• Pipelines that publish to this transmission must run on the same processing server.
• Viewers connect to the processing server host.

URL resolution proxy

GET /api/streams/transmissions/{transmission_id}/urls works for both local and remote transmissions:

• Local: resolves ports locally and returns URLs.
• Remote: calls the processing server internal endpoint and rewrites host based on the processing server URL.

Processing server internal endpoint (used by core proxy):

• GET /api/streams/internal/transmissions/{transmission_id}/urls

Settings sync (processing pulls from core)

Processing servers can periodically pull their filtered streaming settings from core:

• Core endpoint:
  • GET /api/streams/distributed/settings/{server_id}
• Processing loop:
  • polls periodically, writes settings into the processing server config store, and applies engine settings.

Environment variables (processing side):

• TOPOSYNC_ROLE=processing
• TOPOSYNC_PROCESSING_SERVER_ID=<server_id>
• TOPOSYNC_STREAMING_SYNC_CORE_URL=http://<core_host>:8100 (or TOPOSYNC_CORE_URL)
• Optional auth:
  • TOPOSYNC_STREAMING_SYNC_BEARER_TOKEN
  • or TOPOSYNC_STREAMING_SYNC_USERNAME + TOPOSYNC_STREAMING_SYNC_PASSWORD
• Optional tuning:
  • TOPOSYNC_STREAMING_SYNC_INTERVAL_SECONDS (default 5)
  • TOPOSYNC_STREAMING_SYNC_TIMEOUT_SECONDS (default 5)

Core auth (enforced mode):

• The core can accept Basic auth for the distributed settings endpoint by setting:
  • TOPOSYNC_STREAMING_SYNC_USERNAME
  • TOPOSYNC_STREAMING_SYNC_PASSWORD
• This Basic auth is intentionally scoped to /api/streams/distributed/settings/*.

UI behavior (Settings and Dashboard)

Settings panel

The extension adds a Streaming panel in Settings where users can:

• Create/edit transmissions and outputs.
• Start/stop the engine.
• Resolve URLs (and best-effort prime demand).
• Create a pipeline from a transmission using the wizard.

Dashboard (Rendering -> Streams)

The main UI includes a "Streams" rendering mode with:

• Grid modes 1x1 and 2x2 with pagination.
• Auto-hide overlay.
• Playback strategy:
  1. Prime demand for the selected transmission.
  2. Attempt WebRTC/WHEP (low latency).
  3. Fallback to HLS (native HLS when supported, otherwise hls.js).

Authentication in browser playback:

• WHEP uses Authorization: Basic ... when output auth is enabled.
• HLS:
  • hls.js uses Authorization headers for playlist and segments.
  • Native HLS embeds username:password@ in the URL because <video> cannot attach headers.

WHEP integration notes (as used by this project)

If you build external clients, the dashboard implements a WHEP handshake like:

1. Create RTCPeerConnection.
2. Add transceivers:
   • video recvonly
   • audio recvonly (even when no audio is published)
3. Create offer, setLocalDescription.
4. Wait for ICE gathering to complete (timeout).
5. POST the offer SDP to the WHEP endpoint:
   • POST http://<host>:<webrtc_port>/<path>/whep
   • headers:
     • Accept: application/sdp
     • Content-Type: application/sdp
     • Authorization: Basic ... (optional)
   • body:
     • SDP with CRLF line terminators and ending with a trailing CRLF (important for MediaMTX parsing).
6. Read the SDP answer from the response body and setRemoteDescription.
7. If the response includes a Location header, store it and call DELETE on it to teardown the session when done.

API reference (implemented)

All endpoints are under /api/streams.

Health

• GET /api/streams/health

Settings (extension storage)

• GET /api/streams/settings
• PATCH /api/streams/settings

Engine

• GET /api/streams/engine/status
• POST /api/streams/engine/start
• POST /api/streams/engine/stop
• POST /api/streams/engine/restart

Transmissions CRUD

• GET /api/streams/transmissions
• POST /api/streams/transmissions
• PUT /api/streams/transmissions/{transmission_id}
• DELETE /api/streams/transmissions/{transmission_id}

URL resolution

• GET /api/streams/transmissions/{transmission_id}/urls (local or proxy)
• GET /api/streams/internal/transmissions/{transmission_id}/urls (only on host server)

Distributed settings

• GET /api/streams/distributed/settings/{server_id}

Runtime

• GET /api/streams/runtime/outputs
• GET /api/streams/runtime/diagnostics

Demand

• GET /api/streams/transmissions/{transmission_id}/demand
• POST /api/streams/transmissions/{transmission_id}/demand/prime

Wizard

• POST /api/streams/wizard/create-pipeline

Minimal payload examples

Engine status (GET /api/streams/engine/status):

{
  "running": true,
  "pid": 12345,
  "bind_host": "127.0.0.1",
  "ports": { "rtsp": 8554, "hls": 8888, "webrtc": 8889, "api": 9997 },
  "last_error": null,
  "mediamtx_version": "v1.16.2",
  "log_path": "/.../runtime/streaming/logs/mediamtx-YYYYMMDD-HHMMSS.log",
  "test_path": "test",
  "urls": {
    "rtsp_url": "rtsp://127.0.0.1:8554/test",
    "hls_url": "http://127.0.0.1:8888/test/index.m3u8",
    "webrtc_url": "http://127.0.0.1:8889/test/whep"
  },
  "warnings": []
}

Transmission URLs (GET /api/streams/transmissions/{id}/urls):

{
  "transmission_id": "uuid",
  "engine_running": true,
  "outputs": [
    {
      "output_id": "hls_main",
      "protocol": "hls",
      "resolved_engine_path": "front-door",
      "url": "http://127.0.0.1:8888/front-door/index.m3u8",
      "requires_auth": false,
      "auth_username": null
    }
  ],
  "warnings": []
}

Demand (GET /api/streams/transmissions/{id}/demand):

{
  "transmission_id": "uuid",
  "demand_signal": true,
  "viewer_count_total": 1,
  "outputs": [
    { "output_id": "hls_main", "output_key": "uuid:hls_main", "viewer_count": 1 }
  ]
}

Practical quickstart (curl + ffplay)

Start the engine:

curl -X POST http://127.0.0.1:8100/api/streams/engine/start

Create a transmission:

curl -X POST http://127.0.0.1:8100/api/streams/transmissions \
  -H 'content-type: application/json' \
  -d '{
    "name": "Front Door",
    "path": "front-door",
    "host_server_id": "local",
    "enabled": true,
    "outputs": [
      {
        "id": "hls_main",
        "protocol": "hls",
        "enabled": true,
        "resolution": { "width": 1280, "height": 720 },
        "fps_limit": 12,
        "bitrate_kbps": 2500,
        "latency_profile": "normal",
        "authentication": { "enabled": false }
      }
    ]
  }'

Resolve URLs:

curl http://127.0.0.1:8100/api/streams/transmissions/<transmission_id>/urls

Prime demand (recommended before external players, especially right after restart):

curl -X POST http://127.0.0.1:8100/api/streams/transmissions/<transmission_id>/demand/prime

Play RTSP (prefer TCP):

ffplay -rtsp_transport tcp "rtsp://127.0.0.1:8554/front-door"

Play HLS:

ffplay "http://127.0.0.1:8888/front-door/index.m3u8"

LAN access (non-local viewers)

By default the engine binds to 127.0.0.1, so URLs only work on the same machine.

To enable LAN viewers:

1. Enable LAN exposure in engine settings (expose_to_lan: true).
2. Restart the engine.
3. Fetch URLs while calling the API via the LAN hostname/IP you want to advertise.

Notes:

• GET /api/streams/transmissions/{id}/urls chooses the host component based on the current request host when expose_to_lan is enabled.
• MediaMTX still restricts publishing and API access to localhost IPs; LAN exposure is for viewer playback only.

Troubleshooting

RTSP/HLS returns 404 ("no stream is available")

Likely causes:

• Engine is stopped.
• Transmission/output is disabled.
• On-demand is active and no publisher has been started yet.
• Path mismatch (URL not matching the resolved engine path).

Fix:

• Call POST /api/streams/transmissions/{id}/demand/prime and retry.
• Check GET /api/streams/engine/status.
• Use GET /api/streams/runtime/diagnostics and inspect engine, publisher, and runtime_state.

RTSP returns 401 Unauthorized

The output requires authentication.

Use credentials in the URL:

ffplay -rtsp_transport tcp "rtsp://username:password@127.0.0.1:8554/front-door"

WebRTC/WHEP fails in browser (400/404)

Common causes:

• No publisher yet (prime demand and retry).
• Engine ports changed (use engine/status and transmission/urls).
• ICE/NAT issues outside simple LAN (configure STUN/TURN servers).

Debug:

• GET /api/streams/runtime/diagnostics
• Check MediaMTX and FFmpeg logs paths from that payload.

FFmpeg not found

Publishers require ffmpeg.

Current behavior:

• Uses TOPOSYNC_STREAMING_FFMPEG_PATH when set.
• Falls back to ffmpeg from PATH.
• Only tries a packaged FFmpeg binary when a custom distribution explicitly ships one.

Install system FFmpeg if needed:

• macOS: brew install ffmpeg

Runtime files, logs, and paths

Under the Toposync data dir (data_dir), the extension uses:

• MediaMTX binary cache:
  • runtime/streaming/mediamtx/<version>/<platform>/mediamtx(.exe)
• Generated MediaMTX config:
  • runtime/streaming/mediamtx.yml
• MediaMTX logs:
  • runtime/streaming/logs/mediamtx-YYYYMMDD-HHMMSS.log
• Per-output publisher logs:
  • runtime/streaming/logs/ffmpeg-<output_key>-YYYYMMDD-HHMMSS.log
• Publish credential secret (HMAC seed for per-path publish user/pass):
  • runtime/streaming/publish-secret.key

Prefer reading these paths via:

• GET /api/streams/runtime/diagnostics

Local development

uv pip install -e extensions/streaming
npm --workspace @toposync/extension-streaming-ui run build

Then run Toposync as usual (see repo docs/DEVELOPMENT.md).

Licensing and packaging notes

• Public wheels do not ship MediaMTX binaries. The extension downloads the correct release asset on demand and caches it under runtime/streaming/mediamtx/<version>/<platform>/.
  • License notice: LICENSE.mediamtx
• FFmpeg integration expects an external binary by default (PATH or TOPOSYNC_STREAMING_FFMPEG_PATH). Bundling FFmpeg binaries is optional and must be handled carefully for redistribution.
  • License placeholder: LICENSE.ffmpeg

If you plan to ship FFmpeg binaries, pay attention to LGPL/GPL build flags and codec licensing constraints depending on distribution model.

Known limitations (current implementation)

• Video-only: audio is not published (-an in FFmpeg).
• No built-in TLS for MediaMTX endpoints (LAN-first).
• No Low-Latency HLS by default (to avoid TLS requirements and keep the default simpler).
• Hardware encoding selection exists in code paths but is not exposed as a stable user-facing setting yet.
• On-demand stops publishers, but does not stop pipeline execution; pipeline compute is controlled by pipeline configuration and lifecycle semantics.