function rtpPacket
rtpPacket(): Coder<RtpPacket>

Creates a coder for an RTP packet's fixed header, CSRC list, and payload (RFC 3550).

The CSRC list's length is derived from versionFlags.csrcCount, so a packet with no contributing sources needs csrcCount: 0 and csrc: []. Nothing is validated on encode beyond what bitStruct enforces (field values must fit their bit widths) — csrcCount and csrc.length are not cross-checked, matching this repo's no-defensive-programming stance.

Header extensions are not parsed; the rest of the buffer after the CSRC list — extension block included, if extension is set — is surfaced verbatim as payload.

Examples

Round-trip a packet with two CSRC identifiers

import { assertEquals } from "@std/assert";
import { rtpPacket, RTP_HEADER_MIN_SIZE, RTP_VERSION } from "@binstruct/rtp";

const coder = rtpPacket();
const payload = new Uint8Array([0x01, 0x02, 0x03]);
const packet = {
  versionFlags: { version: RTP_VERSION, padding: 0, extension: 0, csrcCount: 2 },
  markerPayloadType: { marker: 1, payloadType: 8 },
  sequenceNumber: 4321,
  timestamp: 160000,
  ssrc: 0xcafebabe,
  csrc: [0x11111111, 0x22222222],
  payload,
};

const buffer = new Uint8Array(RTP_HEADER_MIN_SIZE + 8 + payload.length);
const written = coder.encode(packet, buffer);
const [decoded, read] = coder.decode(buffer.subarray(0, written));

assertEquals(written, RTP_HEADER_MIN_SIZE + 8 + payload.length);
assertEquals(read, written);
assertEquals(decoded.csrc, packet.csrc);
assertEquals(decoded.markerPayloadType.marker, 1);
assertEquals(decoded.payload, payload);

Decode a known-wire minimal packet (no CSRC, no payload)

import { assertEquals } from "@std/assert";
import { rtpPacket, RTP_HEADER_MIN_SIZE, RTP_VERSION } from "@binstruct/rtp";

// deno-fmt-ignore
const wire = new Uint8Array([
  0x80, 0x00, 0x00, 0x01,
  0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x2a,
]);

const [decoded, read] = rtpPacket().decode(wire);

assertEquals(read, RTP_HEADER_MIN_SIZE);
assertEquals(decoded.versionFlags.version, RTP_VERSION);
assertEquals(decoded.versionFlags.csrcCount, 0);
assertEquals(decoded.sequenceNumber, 1);
assertEquals(decoded.ssrc, 0x2a);
assertEquals(decoded.csrc, []);
assertEquals(decoded.payload.length, 0);

Return Type

Coder<RtpPacket>

A coder for RtpPacket values.

Usage

import { rtpPacket } from ".";