Calls

client.call.* wraps the LINE call control plane (Thrift /V4) and provides a CallSession that drives an AndromedaTransport for the media plane.

Control plane

// Allocate a 1:1 call route (returns cscf/mix/fromToken/stnpk).
const route = await client.call.acquireRoute({
	to: "u<peer-mid>",
	callType: "AUDIO", // or "VIDEO" | "FACEPLAY"
});

// Group-call URLs
const url = await client.call.createGroupCallUrl({ /* ... */ });
const urls = await client.call.listGroupCallUrls();
await client.call.deleteGroupCallUrl({ /* ... */ });

// Incoming-call event
client.on("call:incoming", ({ callMid, from, kind }) => {
	console.log("incoming call from", from, "type", kind);
});

Media plane

import {
	AndromedaTransport,
	bufferSource,
	bufferSink,
	decodeWavSync,
} from "@evex/linejs";

// Plug in an Opus codec (caller supplies a WASM impl)
client.call.setCodecFactory(myOpusCodecs);

const session = client.call.startSession({
	to: "u<peer-mid>",
	kind: "AUDIO",
	transport: new AndromedaTransport({ localMid: client.profile.mid }),
});

await session.start(); // acquires route + REGISTER + INVITE + ACK

// Play a WAV file into the call
const wav = await Deno.readFile("./greeting.wav");
const pcm = decodeWavSync(wav);
await session.sendBuffer(pcm);

// Receive peer audio
const sink = bufferSink();
await session.receiveInto(sink);
// sink.frames contains PCM frames

await session.end();

Audio pipeline

• PcmFrame { samples: Int16Array, sampleRate, channels } — base unit.
• bufferSource({samples, sampleRate, frameDurationMs?}) — split a PCM buffer into 20-ms frames.
• bufferSink() / streamSink(stream) — receive frames.
• decodeWavSync(bytes) — bundled 16-bit PCM WAV decoder. For mp3, pass any WASM mp3 decoder via session.sendFile({bytes, decode}).
• resampleLinear(samples, fromRate, toRate, channels) — quick resample.

Codec

CodecFactory is caller-supplied so linejs doesn't pin a specific Opus WASM. Pattern:

import type { CodecFactory } from "@evex/linejs";

const myOpusCodecs: CodecFactory = {
	newEncoder({ sampleRate, channels }) {
		// Return an AudioEncoder backed by your Opus binding
		// (encode(pcm) → Uint8Array | null)
	},
	newDecoder({ sampleRate, channels }) {
		// Return an AudioDecoder
	},
};

client.call.setCodecFactory(myOpusCodecs);

Wire format

LINE Android calls run standard protocols:

Layer	Spec
Signaling	SIP/2.0 over UDP, pjsip-shaped
Auth	HTTP Digest, CallRoute.fromToken as password
SDP	RFC 4566, m=audio P RTP/SAVP 96, Opus 48 kHz/2 ch
Key mgmt	MIKEY-PKE (RFC 3830 §6.1), peer key = CallRoute.stnpk
Media	SRTP AES_CM_128_HMAC_SHA1_80 (RFC 3711)
Codec	Opus only on the wire

AndromedaTransport implements all of this. Use SDES (a=crypto:) by default; when CallRoute.stnpk is set the offer switches to MIKEY-PKE.