android_cast/docs/ALPHA.md

# Android Cast — alpha release & QA

Last updated: 2026-05-23. Use this document for **feature freeze**, **alpha builds**, and **sign-off** before widening testing.

**Related:** [ROADMAP.md](ROADMAP.md) · [README.md](../README.md)

---

## Alpha scope (what we ship)

| In scope | Out of scope (frozen) |
|----------|------------------------|
| LAN discover → PIN → cast → stop | Internet relay, TLS on stream |
| **UDP** or **TCP** transport (must match on both devices) | QUIC, WebRTC, USB-tether transport in UI |
| H.264 + AAC (Android 10+ audio) | Passthrough video, Opus/Speex as default |
| **Single receiver** per cast session | 1:N multi-receiver (disabled in `CastConfig`) |
| Stream protection **None** (default) | FEC/NACK soak required for alpha sign-off |
| Screen capture (full / user-choice on API 34+) | Secondary-display capture, Miracast in-app |
| Camera cast (API 29+, best-effort) | Live sender mirror while casting |
| Receiver playback + notification stop | Play Store / AdMob production |

Code gate: `CastConfig.ALPHA_FEATURE_FREEZE = true` hides experimental transports and turns off multi-receiver selection.

---

## Recommended defaults (both devices)

Set in **Settings** (or use fresh install defaults):

| Setting | Sender | Receiver |
|---------|--------|----------|
| Transport | **UDP** | **UDP** |
| Stream protection | **None** | **None** |
| Quality | Medium | Medium |
| Resolution | Adaptive (or HD 720p if rotation is shaky) | — |
| Video codec | Auto | Auto |
| Audio | On (if API 29+) | Play incoming audio: On |
| Capture mode | Full screen (or User choice on Android 14+) | — |
| PIN | Same on both (default `1234`) | Same |

**Rotation soak:** On Mediatek / Freeme senders (e.g. BL6000), prefer **system rotation lock ON** during first alpha pass; then repeat with lock **OFF** to validate debounced reconfigure.

---

## Feature freeze checklist (engineering)

| Item | Status |
|------|--------|
| `ALPHA_FEATURE_FREEZE` — UDP/TCP only in settings | Done |
| Multi-receiver disabled for alpha | Done |
| Stored QUIC/WebRTC transport clamped to UDP on load | Done |
| Camera strings (permission vs unavailable) | Done |
| README matches `CastConfig` / `CastSettings` defaults | Done |
| Receiver: keyframe idle grace + debounced sender resize | Done (verify on soak) |
| Preview paused during cast (single MediaProjection) | Done |
| Developer-only: FEC, QUIC, USB-tether, immersive presets | Gated (dev settings) |

---

## Alpha app sign-off (manual QA)

Run on **two physical devices**, same Wi‑Fi subnet. Record build: About / `versionName` from APK, git commit, date.

### A. Smoke (required — all must pass)

| # | Step | Pass |
|---|------|------|
| A1 | Install same debug/release APK on sender + receiver | ☐ |
| A2 | Receiver: **Receive** → Start listening → notification *Listening* / *Ready* | ☐ |
| A3 | Sender: **Send** → discover receiver → correct PIN → approve capture | ☐ |
| A4 | Video appears on receiver within **15 s** of auth | ☐ |
| A5 | Audio audible (if enabled and API 29+) within **20 s** | ☐ |
| A6 | Sender notification shows *Casting* with resolution | ☐ |
| A7 | **Stop** from sender notification → stream ends, receiver returns to idle | ☐ |
| A8 | **Stop** from receiver notification → sender stops cleanly | ☐ |
| A9 | Second cast without reinstall (A2→A7 again) | ☐ |

### B. Resilience (required)

| # | Step | Pass |
|---|------|------|
| B1 | Sender home → cast 5 min, no reboot / ANR | ☐ |
| B2 | Receiver app to background 2 min → return → video recovers or clean idle | ☐ |
| B3 | Receiver rotate once → video continues or recovers within 10 s | ☐ |
| B4 | Sender rotate **with rotation lock ON** → 5 min stable | ☐ |
| B5 | Sender rotate **with lock OFF** (optional / device-specific) → no permanent freeze; note if reboot | ☐ |

### C. Settings matrix (pick one row for official alpha demo)

| Profile | Transport | Protection | Use |
|---------|-----------|------------|-----|
| **Alpha default** | UDP | None | Primary sign-off |
| Fallback | TCP | None | If UDP glitches on your AP |

| # | Step | Pass |
|---|------|------|
| C1 | UDP + None: 10 min soak | ☐ |
| C2 | (Optional) TCP + None: 10 min soak | ☐ |

### D. Regression guards (quick)

| # | Step | Pass |
|---|------|------|
| D1 | Wrong PIN → clear error, no crash | ☐ |
| D2 | Mismatched transport (sender TCP / receiver UDP) → fails fast with message | ☐ |
| D3 | Camera mode (if used): permission grant → cast 2 min | ☐ |
| D4 | Calibration test mode → pattern on receiver | ☐ |

### E. Known limitations (not alpha blockers)

- No TLS; LAN cleartext.
- UDP may drop frames under congestion.
- No live preview on sender while casting.
- Some apps silent under playback capture policy.
- Heavy rotation on some OEMs may still stress system WFD/WM (watchdog) — document device + lock state.

**Alpha approved when:** all **A**, **B1–B4**, and **C1** pass on your reference sender + receiver pair.

---

## Log capture (when something fails)

From repo root:

```bash
./scripts/alpha-qa-logcat.sh SENDER_SERIAL RECEIVER_SERIAL
```

Or manually:

```bash
adb -s SENDER logcat -s ScreenCastService:* ReceiverCastService:* AndroidCast:* SenderScreenPreview:*
adb -s RECEIVER logcat -s ReceiverCastService:* AndroidCast:*
```

---

## Alpha backend (optional for LAN-only alpha)

LAN demo does **not** require OTA/crash backend. For **full alpha** with updates and crash upload:

| Item | Notes |
|------|--------|
| Host `examples/ota/v0/` | See [OTA.md](OTA.md) |
| Deploy crash reporter | See [CRASH_REPORTER.md](CRASH_REPORTER.md) |
| Configure URLs | Developer settings or `local.properties` |

---

## Ending feature freeze

1. Complete sign-off table above; note devices + APK build id in git tag message.
2. Tag release on `master` per [GIT_FLOW.md](GIT_FLOW.md).
3. To re-enable experiments on a dev branch: set `CastConfig.ALPHA_FEATURE_FREEZE = false` and restore `MULTI_RECEIVER_ENABLED` as needed.

Post-alpha priorities: rotation-stable encode path, encoder thumbnail on sender, secondary-display capture (roadmap D).