RTP Interleaving Colin P erkins < c.p erkins@cs.ucl.ac.uk > - - PowerPoint PPT Presentation

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Dec 18, 2022 546 likes •613 views

RTP Interleaving Colin P erkins < c.p erkins@cs.ucl.ac.uk > Depa rtment of Computer Science Universit y College London Go w er Street London W C1E 6BT The interleavin g p ro cess Original Stream 1 2 3 4 5 6 7

SLIDE 1 RTP Interleaving Colin P erkins <c.p erkins@cs.ucl.ac.uk> Depa rtment

Computer Science Universit y College London Go w er Street London W C1E 6BT

SLIDE 2 The interleavin g p ro cess

1 5 9 13 2 6 10 14 3 7 11 15 4 8 12 16 3 7 11 15 2 4 1 5 6 8 9 10 12 13 14 16 1 2 4 5 6 8 9 10 12 13 14 16 1 5 9 13 2 6 10 14 3 7 11 15 4 8 12 16

Reconstructed Stream Packet Loss Interleaved Stream Original Stream

Distributes

loss, making

la rge loss app ea r as several smaller losses

Useful

if latency is not an issue, bandwidth ecient Colin P erkins/RTP Interleaving/1

SLIDE 3 P ack etisation

ptions

reconstruct

the stream, the receiver must kno w the interleaving function. Tw

a ys

conveying this info rmation: Implicit where the session description conveys the interleaving function, and the pack et sequence numb er determines the p

sition

in the sequence. Explicit where each pack et contains the relative p

sition
f

each frame in the sequence. Colin P erkins/RTP Interleaving/2

SLIDE 4 Implicit pack etisation Advantages

Minimal

bandwidth

verhead

Disadvantages

Interleaving

function is xed fo r the duration

a session

Need

to kno w talkspurt sta rt to determine p

sition

in the sequence, can cause p roblems if rst pack et is lost Colin P erkins/RTP Interleaving/3

SLIDE 5 Explicit pack etisation Advantages

Interleaving

function can change during a session

build a common deco der fo r interleaved and redundant streams (RF C2198)

Each

pack et is indep endently deco dable Disadvantages

Overhead

due to the timestamp info rmation (4 b ytes p er frame) Colin P erkins/RTP Interleaving/4

SLIDE 6 Prop

sal
Reuse

the pa yload fo rmat fo r redundant audio, to enco de interleaved streams (draft-ietf-avt-interl eavi ng-00.txt).

Deco

ders fo r this fo rmat should b e able to deco de such streams without mo dication.

e this an explicit requirement in the next revision

RF C2198. Colin P erkins/RTP Interleaving/5