Video player

The template uses react-native-video on Expo platforms and @amazon-devices/kepler-media on Vega. Both are wrapped by the shared <Player> component. Most player work is about getting stream URLs and metadata right, not about touching the player guts.

Supported stream types in the template

If the manifest mixes types: that's fine. The player reads stream_type and configures itself.

Apple TV note: HLS-only in practice

Apple TV's media pipeline expects HLS for live and most VOD. DASH works in some cases but has higher failure rates. For any Apple TV target, prefer HLS streams. If the source is DASH-only, the harness should flag it; it's still buildable but expect playback issues.

Vega note: use the override, not direct deps

The shared <Player> has a .kepler.ts override that swaps react-native-video for @amazon-devices/kepler-media. Don't import react-native-video directly in a Vega screen — it will silently fail at runtime. Always use <Player> from packages/shared-ui.

DRM — current state and upgrade path

v1 of the harness does not support DRM. The template's player is configured for clear streams only. If the manifest indicates DRM is needed:

• For HLS: FairPlay (Apple TV), Widevine (Android TV, Fire TV FOS, Web), PlayReady (some Vega cases).
• For DASH: Widevine.

Adding DRM requires:

1. License server URL per scheme.
2. Certificate file (FairPlay).
3. Per-platform config in react-native-video and kepler-media.
4. Token-based or anonymous license acquisition.

This is multi-day work. If the user needs DRM, escalate — don't fake it.

Player overlay controls

The template ships overlay controls with:

• Play / pause
• Seek bar with scrubbing
• Time remaining
• Title and metadata
• Back / close button

D-pad bindings (already wired):

• Select while playing → toggle play/pause
• Left / Right → seek -10s / +10s
• Up → show controls if hidden
• Down / Menu / Back → return to detail

Don't rebind these. Users expect them.

Customizing the overlay

The overlay is in packages/shared-ui/components/Player/Controls/. Reasonable customizations:

• Brand color on the scrub bar (already pulled from theme tokens).
• Logo on the controls bar.
• Title typography.

Avoid:

• Replacing the scrub bar with a custom slider. Focus and scrubbing are coupled in non-obvious ways.
• Auto-hiding controls aggressively (< 3 seconds idle). Users miss them.

Buffering, errors, and resilience

The player must handle these gracefully. The template does:

• Buffering → semi-transparent spinner overlay. Don't block input; allow back to detail.
• Error (onError) → toast with error code, auto-return to detail after 5s, log to RunLog.
• End (onEnd) → either auto-play next (if useRelated() returns items) or return to detail.

When a stream URL is dead, the user lands back on detail with a non-mysterious error. Black screen forever is the worst outcome.

Audio and subtitles

• HLS streams often carry multiple audio tracks and CC. react-native-video exposes them via selectedAudioTrack and selectedTextTrack.
• The template's <Player> has hooks but doesn't ship a UI for switching. If the user's content needs CC (most accessibility-conscious apps do), add a controls-overlay menu.
• Defaults: pick the audio track matching device language; pick CC if device has "always on subtitles" accessibility setting; otherwise off.

Playback metrics (out of v1 scope, but design for it)

Most production apps want:

• Time-to-first-frame
• Rebuffer ratio
• Bitrate over time
• Error events

The player exposes onProgress, onBuffer, onBandwidthUpdate, onError. The harness doesn't need to wire telemetry in v1, but it should leave the hooks in place so adding analytics later is trivial.

Common playback failures

Decision tree: "the player isn't working"

1. Does the stream URL play in VLC on your machine? If no → it's the source, not the app.
2. Is the URL HTTPS? Mixed-content blocks are a top cause on Apple TV / iOS-derived platforms.
3. Is stream_type correct? hls for .m3u8, dash for .mpd, mp4 for direct files.
4. Are you running on Vega and seeing black? Confirm <Player> is the shared-ui import, not react-native-video directly.
5. Does it play on one platform but not another? Likely a codec issue; check HLS variants.
6. Errors logged to console? onError has a code; look it up against react-native-video docs or Kepler media docs.

Anti-patterns

• Building a custom player from <Video> on a new screen. Use shared <Player> even if it means lifting controls behavior.
• Importing react-native-video in a .tsx file (no platform extension). That file resolves on Vega and breaks. Use <Player> or split with .kepler.ts.
• Hardcoding bitrate or codec selection. Let the adaptive stream pick.
• Showing a generic "Error" message to users. At least show "Couldn't play. Try again or pick another." with a back button.