android_cast/docs/OPUS_SPEEX_VALIDATION.md

Opus / Speex / stream protection — validation checklist (task 3)

E2E validation guide for audio codecs and UDP stream protection (FEC, NACK, negotiation). Code is on next; this doc is the operator checklist.

See also: ndk/README.md, ROADMAP.md, AV_QUALITY_QA_SESSION.md.

Table of contents

• Prerequisites
• Automated baseline (CI / dev machine)
• User settings (both peers)
• Developer settings
• E2E matrix — run on two devices
• What to capture per run
• Pass criteria
• Known limits (next)

---

Prerequisites

• Two Android devices (or sender + receiver) on same LAN for first pass; repeat subset on lossy/WAN if possible.
• Debug builds with NDK codecs built if testing native Opus/Speex probes:

./scripts/build-native-codecs.sh arm64-v8a   # optional; see ndk/README.md
./gradlew :app:assembleDebug

---

Automated baseline (CI / dev machine)

Run before field soak:

./gradlew :app:testDebugUnitTest --tests 'com.foxx.androidcast.network.transport.StreamProtectionNegotiatorTest'
./gradlew :app:testDebugUnitTest --tests 'com.foxx.androidcast.media.AudioNegotiatorTest'
./gradlew :app:testDebugUnitTest --tests 'com.foxx.androidcast.media.codec.*'

Or:

bash scripts/validate_opus_speex.sh

Expect BUILD SUCCESSFUL and all tests green.

---

User settings (both peers)

Global settings (main UI):

Control	Location	Notes
Transport	Sender / receiver	Use UDP for FEC/NACK tests
Stream protection (UDP)	Global settings	Default None; try FEC 3/4, NACK, FEC+NACK
Audio codec	Global settings	AUTO, Opus, Speex, AAC baseline

After changing protection, start a new session — negotiation runs at handshake (CastSession / StreamProtectionNegotiator).

---

Developer settings

Enable Developer options on both devices if testing passthrough / debug audio:

Control	Purpose
Passthrough / debug audio	PASSTHROUGH_DEBUG path
Codec overrides	Align with CodecCatalog / PassthroughCodecPolicy
Diagnostics export	Session stats + negotiated mime + protection string

Check session diagnostics after connect: protection line should match PassthroughCodecPolicy.protectionDescription().

---

E2E matrix — run on two devices

Mark each cell PASS / FAIL / SKIP in a ticket tagged 20260604.

A. Handshake and negotiation

#	Sender protection	Receiver capability	Audio	Expected
A1	None	Any	AUTO	No FEC/NACK; stable video+audio
A2	FEC 3/4	FEC 3/4	AUTO	Agreed FEC 3/4; loss recovery under artificial drop
A3	NACK	NACK	AUTO	Retransmit under single-packet loss
A4	FEC+NACK	FEC+NACK	AUTO	Combined behavior; no deadlock
A5	FEC 3/4	NONE only	AUTO	Prompt or downgrade per StreamProtectionNegotiator

B. Audio codec

#	Sender audio	Receiver audio	Expected
B1	AUTO	AUTO	AAC or negotiated fallback
B2	Opus	Opus	Opus native if .so present; else stub/fallback per AudioNegotiator
B3	Speex	Speex	Speex native if built; else fallback
B4	Opus	AUTO (no Opus)	Fallback — no silent failure

C. Controls (user vs developer)

#	Check
C1	User can change transport UDP ↔ TCP without crash
C2	User protection change applies on next session
C3	Developer diagnostics show negotiated video mime + audio + protection
C4	Receiver UI shows aligned protection label after handshake

D. Stress (optional)

#	Check
D1	Background/rotate sender — session recovers or fails cleanly
D2	~5 min soak with FEC on — no memory runaway (logcat)
D3	Switch Wi‑Fi ↔ mobile data mid-cast — defined behavior (fail or reconnect)

---

What to capture per run

1. Diagnostics export from both devices (or logcat filter androidcast|CastSession|StreamProtection|AudioNegotiator).
2. Negotiated lines: negotiatedVideoMime, audioCodec, streamProtection, wantsNack.
3. Subjective: audio dropouts, video freezes, recovery after packet loss (FEC/NACK test: weak Wi‑Fi or tc netem on Linux AP if available).

---

Pass criteria

• All automated tests green (validate_opus_speex.sh).
• Matrix A1–A4 and B1–B2 pass on reference hardware.
• No unexplained silent fallback (user sees toast/prompt when negotiation downgrades).
• Diagnostics string matches actual wire behavior for UDP protection.

---

Known limits (next)

Item	Status
Opus / Speex native encode	Probe + bridge; full native path per ndk/README.md
FEC 3/4 + RS	Per-shard wire (FecShardWire); v1 monolithic still accepted
TCP transport	Protection spinners disabled / N/A for TCP

File issues under Tickets → tag 20260604, component Opus/Speex.