MediaFramesnamespace

The MediaFrames namespace of detritus-client-socket.

On this page

Classes3
Interfaces5
Enums1
Functions12
Variables1

import { MediaFrames } from 'detritus-client-socket';

1 enums · 3 classes · 5 interfaces · 1 variables · 12 functions

Classes

Classes you create or receive from the library.

classMediaFrameAssembler Puts one video stream's (ssrc's) rtp packets back together into frames Packets of a frame share a timestamp and the last one has the marker bit set, a frame is complete once every sequence number from its first packet to its marker packet is here. Frames come out in order, a complete frame waits for older incomplete ones (packets get reordered) until they finish or are given up on. After a loss, frames that depend on the lost one would only decode as garbage, so they're held back until a keyframe 5 properties · 10 methods classMediaNackTracker Notices holes in one stream's sequence numbers and says which ones to nack (RFC 4585 Section 6.2.1) 2 properties · 2 methods classMediaPacketHistory The video packets we sent recently, keyed by sequence number 1 property · 3 methods

Interfaces

Object shapes for options, payloads and events.

interfaceAssembledFrame 3 properties interfaceAssemblerResult 2 properties interfaceDepacketizedPayload 3 properties interfaceHistoryPacket 6 properties interfacePacketizeOptions 2 properties

Enums

Named constants.

H264NalTypes

enum src/mediaframes.ts:16

FU_A

IDR

PPS

SEI

SLICE

SPS

STAP_A

Functions

Standalone helpers.

depacketize()

function src/mediaframes.ts:263

function depacketize(codec: string, payload: Buffer): DepacketizedPayload | null

depacketizeH264()

function src/mediaframes.ts:204

function depacketizeH264(payload: Buffer): DepacketizedPayload | null

RFC 6184 Section 5.6 - 5.8, single nal units, STAP-A and FU-A (the only modes discord uses) Returns the packet's nal units as annex b

depacketizeVP8()

function src/mediaframes.ts:88

function depacketizeVP8(payload: Buffer): DepacketizedPayload | null

RFC 7741 Section 4.2

depacketizeVP9()

function src/mediaframes.ts:134

function depacketizeVP9(payload: Buffer): DepacketizedPayload | null

RFC 9628 Section 4.2

isKeyframe()

function src/mediaframes.ts:285

function isKeyframe(codec: string, frame: Buffer): boolean

If an encoded frame is a keyframe, works on e2e encrypted frames too (DAVE leaves these bytes unencrypted)

isSequenceNewer()

function src/mediaframes.ts:79

function isSequenceNewer(a: number, b: number): boolean

If b comes after a, anything more than half the sequence space ahead is treated as behind

packetize()

function src/mediaframes.ts:387

function packetize(
  codec: string,
  frame: Buffer,
  options: PacketizeOptions,
): Buffer<ArrayBufferLike>[]

Splits an encoded frame into rtp payloads, the inverse of depacketize

packetizeH264()

function src/mediaframes.ts:364

function packetizeH264(frame: Buffer): Buffer<ArrayBufferLike>[]

RFC 6184 Section 5.6/5.8, a single nal unit per packet when it fits, FU-A fragments when it doesn't. Takes annex b

packetizeVP8()

function src/mediaframes.ts:304

function packetizeVP8(frame: Buffer, options: PacketizeOptions): Buffer<ArrayBufferLike>[]

RFC 7741 Section 4.2, X=1 | S on a frame's first packet, I=1, then M=1 and a 15 bit picture id

packetizeVP9()

function src/mediaframes.ts:322

function packetizeVP9(frame: Buffer, options: PacketizeOptions): Buffer<ArrayBufferLike>[]

RFC 9628 Section 4.2, non-flexible mode without layers, I=1 | P on inter frames | B on the first packet | E on the last

sequenceDistance()

function src/mediaframes.ts:72

function sequenceDistance(a: number, b: number): number

How far b is ahead of a, 16-bit rtp sequence numbers wrap around

splitAnnexB()

function src/mediaframes.ts:339

function splitAnnexB(frame: Buffer): Buffer<ArrayBufferLike>[]

An annex b frame's nal units, without their start codes (3 or 4 bytes)

Variables

Exported values.

MAX_PAYLOAD_LENGTH

variable const src/mediaframes.ts:274

const MAX_PAYLOAD_LENGTH: 1100 = 1100