developervideotutorial

Implementing Second-Screen Playback Controls: A Developer’s Guide

tthemes

2026-01-27

10 min read

Replace brittle casting: build a server‑mediated second‑screen remote playback system that works across TVs, sticks, and consoles in 2026.

Stop chasing casts — build reliable second‑screen control that works everywhere

If you’ve been blindsided by platforms pruning casting support (Netflix’s Jan 2026 decision is the latest example), you’re not alone. Developers and product teams are facing fractured device support, unpredictable SDK changes, and rising privacy constraints. The smart move in 2026 is to stop depending on a single vendor's casting workflow and implement a resilient second‑screen remote playback architecture that spans TVs, streaming sticks, game consoles, and mobile devices.

Quick summary — what you’ll get from this guide

This article delivers a practical, battle‑tested blueprint for replacing traditional casting with a cross‑device remote playback system. You’ll get:

A recommended architecture and device adapter strategy
Concrete integration patterns for WebRTC, DLNA/UPnP, DIAL, Chromecast/receiver fallbacks, and AirPlay
Code examples: Presentation API + postMessage, WebSocket signaling, DLNA SOAP control
Security, DRM, analytics, and testing checklists tuned for 2026

Why second‑screen remote playback matters in 2026

Streaming platforms and device manufacturers are shifting habits. Between tightened platform policies and moves like Netflix removing mobile‑to‑TV casting in early 2026, relying exclusively on proprietary casting workflows is brittle. Second‑screen remote playback — the phone/tablet as a controller while the media plays on a target device — gives you:

Vendor‑agnostic control so a single app can manage playback on many device types
Clear security boundaries (server mediated session tokens and DRM integration)
Robust analytics because your app can receive playback events even when the target is closed‑ecosystem
Lower user‑friction by preserving UX from phone to TV without reinventing playback stacks

High‑level architecture (inverted pyramid)

Start with a single, simple concept: separate control signaling from media delivery. That separation lets you swap device adapters without touching DRM or CDN logic.

Server: Session creation, auth tokens, DRM license broker, playback state relay, analytics collector.
Controller app (phone/tablet/web): Discovers devices, requests a session, sends control commands (play/pause/seek), displays state and errors.
Receiver (TV app, Smart TV webview, streaming stick): Accepts session tokens, requests media with DRM tokens from server, reports playback state back to server/controller.
Transport: Control channel (WebSocket/WebTransport/DataChannel) + optional discovery (mDNS/SSDP) + fallback protocols per platform.

Why this model beats classic casting

Traditional casting often tightly couples controller and receiver through vendor APIs. The new model put the server in the middle for authorization, logging, and DRM. That yields predictable behavior when device vendors deprecate SDKs (as seen in 2026) — you only update the device adapter layer.

Device adapter strategies (practical approach)

Implement a small adapter interface on your server and controller that maps to platform capabilities. Prioritize adapters based on your user base and device telemetry.

WebReceiver (Presentation API / Dedicated Receiver Page): Best for smart TVs with webviews. Fast to deploy and easy to debug.
WebRTC Receiver: Use when you need low latency or can't rely on platform players. Good for live events or interactivity.
DLNA/UPnP (AVTransport): Works with many legacy smart TVs and media players. Use SOAP control for play/pause/seek.
DIAL: Useful to launch installed apps (Netflix-style) on TVs/streaming devices and hand off control tokens.
Chromecast SDK: Still required for devices that depend on Google’s ecosystem. Implement as a separate adapter with graceful fallback.
AirPlay: For Apple device targets; control via private AP protocols or using Apple’s APIs on iOS/tvOS where possible.

Discovery & connection: Patterns you can implement today

Device discovery is the most fragmented piece. Combine local network discovery with cloud device registration to cover the widest surface.

Hybrid discovery

Local discovery — mDNS / SSDP to find devices and their capabilities. Offer a “Connect to local device” flow in your controller.
Cloud pairing — QR + short PIN or OAuth to link remote devices (important for mobile hotspots or cross‑network scenarios).
Fallback manual input — device code or pairing string when discovery is blocked by network policies.

Example: SSDP discovery (Node sketch)

const dgram = require('dgram');
const ssdp = dgram.createSocket('udp4');
ssdp.on('message', (msg, rinfo) => { console.log('SSDP:', msg.toString()); });
ssdp.send(Buffer.from(
  'M-SEARCH * HTTP/1.1\r\n' +
  'HOST: 239.255.255.250:1900\r\n' +
  'MAN: "ssdp:discover"\r\n' +
  'MX: 2\r\n' +
  'ST: urn:schemas-upnp-org:device:MediaRenderer:1\r\n\r\n'
), 1900, '239.255.255.250');

SSDP returns device descriptions that tell you whether a device supports DLNA/AVTransport, DIAL, or a web receiver endpoint.

Control channel implementations (choose one primary)

For real‑time control and reliability you’ll use one of these transports:

WebSocket / WebTransport — simple, low‑latency channel for commands and events. Works across NAT when anchored by a server.
WebRTC DataChannel — peer‑to‑peer option for low latency and reduced server bandwidth. Also supports media when needed.
Polling / HTTP webhooks — simple fallback for constrained devices (rare but supported).

Control message schema (JSON example)

{
  "type": "command",
  "command": "play",
  "sessionId": "abc123",
  "position": 120.5,
  "mediaUrl": "https://cdn.example.com/movie.m3u8",
  "drm": { "token": "JWT…", "scheme": "playready" }
}

Keep messages small and idempotent. Respond with explicit ACKs and status messages from receivers so the controller can display accurate state.

Integrations: Patterns and code

1) Presentation API + postMessage (fast web receiver)

Use this when you can open a receiver page on the target device’s browser. It's an easy way to get a receiver up and running without native SDKs.

// Controller (web)
const url = 'https://tv.example.com/receiver?session=abc123';
const request = new PresentationRequest(url);
request.start().then(conn => {
  conn.onmessage = (e) => console.log('from receiver', e.data);
  conn.send(JSON.stringify({ command: 'load', mediaUrl: 'https://...' }));
});

On the receiver page, listen for messages and use the HTMLMediaElement or MSE to play content. Post back playback events.

2) DLNA / UPnP AVTransport control (SOAP over HTTP)

Many TVs still support the UPnP AVTransport action set. Use SOAP calls to set AVTransportURI and Send Play/Pause commands.

POST /upnp/control/avtransport/1 HTTP/1.1
SOAPACTION: "urn:schemas-upnp-org:service:AVTransport:1#SetAVTransportURI"
Content-Type: text/xml; charset="utf-8"

<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/">
  <s:Body>
    <u:SetAVTransportURI xmlns:u="urn:schemas-upnp-org:service:AVTransport:1">
      <InstanceID>0</InstanceID>
      <CurrentURI>https://cdn.example.com/movie.mp4</CurrentURI>
      <CurrentURIMetaData></CurrentURIMetaData>
    </u:SetAVTransportURI>
  </s:Body>
</s:Envelope>

Note: you must broker DRM tokens server‑side. Many AV devices cannot handle license exchange; the receiver may need to be a web app that pulls DRM licenses.

3) Chromecast / Google Cast fallback

Even as some platforms change casting policies, Chromecast devices remain common. Implement Cast as a dedicated adapter and fall back to your server‑mediated workflow when Cast is unavailable.

Key points:

Use receiver URLs you control so you can attach your server auth tokens and logging.
Handle cast.sessionstate and cast.ended events and mirror them back to your analytics.

4) WebRTC Receiver (low latency / P2P)

When you need sub‑second latency or peer connectivity (e.g., multiplayer interactive video), stream via WebRTC and use DataChannels for control. Signal through your server for NAT traversal — the same considerations you use for low latency trading systems apply here: careful signaling, prioritized retransmit strategies and aggressive monitoring.

Security, DRM, and token flows

Security is non‑negotiable once you control playback remotely. Follow these rules:

Short‑lived session tokens — issue per‑session JWTs that receivers must exchange to fetch media manifests and DRM licenses.
Server‑brokered DRM — do not embed license keys in the client; the receiver should request licenses from your server, which validates the session token.
Origin and CORS — receivers that are webviews must be validated by origin checks at the license/CDN layer.
Logging and alerts — log every token exchange and fail fast on suspicious activity (multiple simultaneous sessions, unusual IPs).

Testing & reliability checklist

Before shipping, validate these items:

Device matrix: test top 10 devices by your analytics (smart TVs, sticks, consoles)
Network scenarios: NAT, double NAT, mobile hotspots, captive portals
Reconnection: controller loses network but receiver keeps playing — restore state on reconnect
DRM edge cases: license expiry mid‑session, offline playback fallbacks
Telemetry: session start, pause, seek, errors, end; export to your analytics pipeline and feed into your cloud warehousing or low-latency alerting

Common pitfalls and how to avoid them

Assuming universal APIs exist — vendors differ; build adapters not assumptions.
Heavy server bandwidth for media — avoid proxying media through your servers unless necessary; use CDN signed URLs and token exchange.
DRM on legacy devices — many old DLNA devices can’t do modern DRM; present a clear migration path and messaging to users.
No graceful fallback — provide local playback if remote control fails; don’t leave users staring at a blank screen.

Video SDKs and vendor solutions in 2026

By late 2025 and into 2026, major video SDKs (Bitmovin, THEOplayer, Mux, JW Player) have added receiver helpers, session token utilities, and sample receiver apps to speed up second‑screen integration. Choose a vendor that supports your DRM scheme (Widevine, PlayReady, FairPlay) and has flexible receiver template code — this shaves months off development.

Performance and analytics

Measure two things: control latency (time from controller command to device response) and playback fidelity (buffering ratio, startup time, bitrate switches). Add event hooks in receivers to send telemetry to your server and tie that into SLO alerts. For scale and static asset delivery, consider an edge distribution strategy and specialized caching rules.

Future predictions (2026–2028)

Standardized remote playback primitives will gain traction. Expect more consistent support for a lightweight W3C control spec or expanded Presentation API semantics.
WebRTC and WebTransport will expand as primary transports for low‑latency remote playback control.
Device manufacturers will publish receiver templates and cloud pairing flows to make secure pairing faster, reducing platform fragmentation.

In short: architect for adapters, broker security server‑side, and treat discovery + control as first‑class components.

Actionable implementation plan — 8‑week roadmap

Week 1–2: Instrument analytics and prioritize device list. Add tokenized manifest support on CDN and DRM server hooks.
Week 3–4: Implement control channel (WebSocket) and basic Presentation API receiver for smart TVs. Add session create/validate endpoints.
Week 5: Add DLNA adapter for legacy targets and implement SOAP control handlers server‑side to translate your JSON commands to AVTransport actions.
Week 6: Add Chromecast adapter and a Chromecast receiver URL you control. Test token exchange and license flow.
Week 7: Harden security — short‑lived tokens, origin checks, logging. Set up SLO/alerts for control latency.
Week 8: Beta rollout to a subset of users, collect telemetry, iterate on UI/UX edge cases (pairing, lost connections).

Real‑world example: flow sequence

User taps "Connect to TV" in your mobile app. App runs SSDP/mDNS or shows QR for cloud pairing.
Controller calls server /session create. Server issues a JWT session token and registers the receiver ID.
Controller sends a WebSocket message: { command: 'load', mediaUrl, drm.token }.
Receiver validates the token with the server, requests DRM license, and starts playback via its local player.
Receiver sends playback updates (position, buffering) via WebSocket. Controller updates UI. Server logs events for analytics.

Final checklist before launch

Session token rotation implemented
DRM license broker tested across devices
Discovery fallbacks in place (local/cloud/manual)
Graceful local playback fallback and clear UX messaging
Monitoring: latency, errors, active sessions, playback KPIs

Conclusion — pragmatic advice for teams

Don’t wait for a magic unified casting API. The safest path in 2026 is to adopt a server‑mediated remote playback architecture with device adapters for specific ecosystems. That gives you security, analytics, and the flexibility to replace or extend adapters when vendors change direction — like the recent streaming platform policy shifts we saw in early 2026.

Next steps (start today)

Audit your telemetry to identify the top devices to support.
Prototype a Presentation API receiver and a WebSocket-based control channel in a single sprint.
Plan DRM token flows and align with your CDN/DRM vendors.

Make your first prototype: open a blank receiver page, attach a WS server, and get play/pause working from your phone — you’ll be surprised how fast you can replace brittle casting workflows with something resilient and maintainable.

Resources & sample repos

W3C Presentation API docs and examples
UPnP/DLNA AVTransport examples and SOAP templates
WebRTC signaling starter kits (server + DataChannel examples)
Vendor SDKs: Bitmovin/THEOplayer/JW/Mux receiver templates (check your vendor for the latest 2026 receiver helpers)
Field reviews: compact live-stream kits, and PocketLan & PocketCam pop-up cinema workflows

Call to action

Ready to stop chasing casting and build a future‑proof second‑screen experience? Start with a one‑day spike: implement a Presentation API receiver and a WebSocket control channel. If you want, share your device telemetry and I’ll outline a prioritized adapter roadmap for your product team.

themes

Contributor

Senior editor and content strategist. Writing about technology, design, and the future of digital media. Follow along for deep dives into the industry's moving parts.