IP Video Communication Issues & SolutionsIP Video Communication Issues & SolutionsAmir Zmora, RADVISIONAmir Zmora, RADVISION

State of IP Video CommunicationState of IP Video Communication

From Picturephone to TelepresenceFrom Picturephone to Telepresence

This is TelepresenceThis is Telepresence

Matt Harding dancing over Telepresence @ Yahoo headquarters

Evolution of Video StandardsEvolution of Video Standards

H.26x Lifecycle StatusH.26x Lifecycle Status

H.264H.264

H.263H.263

H.261H.261

Who is to Blame?Who is to Blame?

• The network

• Bandwidth

• Packet Loss

• Burstiness

Packet LossPacket Loss

Packet LossPacket Loss

Random Noise Artifacts

Insufficient BandwidthInsufficient Bandwidth

Trails

High Compression RateHigh Compression Rate

Blockiness Effect

Advanced Video Coding Technologies

Advanced Video Coding Technologies

Focus on Quality of Experience

P-Frame DependencyP-Frame Dependency

1 2 3 4 5

Result – Packet loss has dramatic effect on quality of experience

Multi Description CodingMulti Description Coding

• Splitting one source of information to multiple entities

• Each decodable

• The more the merrier – Quality

• Example – splitting of PCM stream

Scaled Video Coding (SVC)Scaled Video Coding (SVC)

• Uses MDC concept

• H.264 Annex G

• Spatial - Change of frame size (resolution)

• Temporal - Change of frame rate

• Fidelity / SNR - Change of quality

• Object - Selection of “Region of interest”

Spatial ScalabilitySpatial Scalability

Temporal ScalabilityTemporal Scalability

• Hierarchal P Structure

Signaling layered decoding dependency Signaling layered decoding dependency

96 97

98 99

100 101

OR

OR AND

L1

L2

L3

Error Resilience – Protecting only what Matters

Error Resilience – Protecting only what Matters

• Forward Error Correction

• Retransmission

• Video Fast Update

Error ResilienceError ResiliencePSNR Vs. Packet loss rate

20

25

30

35

40

45

0 1 2 3 4 5 6 7 8 9

Packet loss rate (%)

PS

NR SVC

H.264

MDC: Hierarchical P-Structure

Putting it All TogetherPutting it All Together