IP Networks in the TV Studio Recent work by BBC R&D Stuart Grace - - PowerPoint PPT Presentation

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Apr 09, 2024 420 likes •768 views

IP Networks in the TV Studio Recent work by BBC R&D Stuart Grace April 2016 Part One: The IP Studio Project at BBC R&D n T Current TV Studio Technology: Video SDI (serial digital interface) for raw video feeds Coax cables with BNC

SLIDE 1

IP Networks in the TV Studio

Recent work by BBC R&D

Stuart Grace

April 2016

SLIDE 2

The IP Studio Project at BBC R&D

Part One:

SLIDE 3

Current TV Studio Technology: Video

SDI (serial digital interface) for raw

video feeds

Coax cables with BNC connectors
Synchronous, circuit switched

n T

Blanking intervals for

compatibility with CRT displays

SLIDE 4

Current TV Studio Technology: Other Systems

Digital Audio (AES3 and AES10)
Timing and

synchronisation

Talkback between

locations

Tally lights
Teleprompter

…all with separate cables

SLIDE 5

Manual Patching in an OB Van

SLIDE 6

Current Studio

Expensive specialist hardware
Multiple cabling systems
Formats fixed in hardware
Commodity hardware
Single multipurpose network
Software defined formats
New production techniques
New forms of content

IP-based Studio

SLIDE 7

Image Composition at the Studio

Vision Mixer

Studio Home

Combined image

SLIDE 8

Image Composition at the Display

Studio Home

IP streams

www.bbc.co.uk/rd

Search for “forecaster”

SLIDE 9

SMPTE 2022-6: SDI video data over UDP

SLIDE 10

Society of Motion Picture & T elevision Engineers European Broadcasting Union

SLIDE 11

Recommended Protocols

RFC 768 – User Datagram Protocol RFC 3550 – RTP: A Transport Protocol for Real-Time Applications RFC 4175 – RTP Payload Format for Uncompressed Video RFC 3190 – RTP Payload Format for 12-bit DAT Audio and 20- and 24-bit Linear Sampled Audio RFC 4566 – SDP: Session Description Protocol PTP: Precision Time Protocol IEEE 1588-2008 – Standard for a Precision Clock Synchronization Protocol for Networked Measurement and Control Systems

SLIDE 12

Registration & Discovery

Standard

pen APIs

Replication

SLIDE 13

Streaming UHD Video – Uncompressed

Part Two:

SLIDE 14

Uncompressed Studio Video

Data format: 10-bit YCbCr 4:2:2  20 bits per pixel HD (high definition): 2M pixels

1920 1080

41.5 Mbits per frame 25 frames / sec  1.04 Gbit/s

SLIDE 15

Uncompressed Studio Video

Data format: 10-bit YCbCr 4:2:2  20 bits per pixel HD (high definition): 2M pixels

1920 1080

41.5 Mbits per frame 25 frames / sec  1.04 Gbit/s UHD-1 (ultra high definition, 4K): 8M pixels

3840 2160

166 Mbits per frame 100 frames / sec 

16.6 Gbit/s

SLIDE 16

BBC News Gallery

SLIDE 17

33M pixels UHD-2 (Super Hi-Vision, 8K):

7680 4320

664 Mbits per frame 120 frames / sec  80 Gbit/s

SLIDE 18

UHD Trial at the 2014 Commonwealth Games, Glasgow UHD-1 @ 50 frames / sec  8.3 Gbit/s

SLIDE 19

Linux Network Stack

SLIDE 20

Netmap with Standard NIC Driver

SLIDE 21

Netmap with Optimised NIC Driver

SLIDE 22

NIC Hardware Offloads

SLIDE 23

NIC Hardware Offloads

SLIDE 24

NIC Hardware Offloads

SLIDE 25

Bursts of Traffic

SLIDE 26

Bursts of Traffic

Flow 1 Flow 2

SLIDE 27

Bursts of Traffic

Flow 1 Flow 2 Combined Flows

SLIDE 28

Packet Pacing

Tx rate limited to 3.5 Gbit/s in the NIC

SLIDE 29

Packet Pacing

Tx rate limited to 3.5 Gbit/s in the NIC

Flow 1 Combined Flows Flow 2

SLIDE 30

Limitations

UDP  TCP 
Security – app sees all network traffic
Use separate interface for media streaming
Monolithic – app builds all headers from L2

upwards

SLIDE 31

Limitations

UDP  TCP 
Security – app sees all network traffic
Use separate interface for media streaming
Monolithic – app builds all headers from L2

upwards But we get 75x increase in network I/O performance using COTS hardware

SLIDE 32

CPU Load of RTP Sender

Sending UHD-1 @ 50Hz Transmitting 8.6 Gbit/s with no packet loss

Only one CPU core is busy

SLIDE 33

Thank you

www.bbc.co.uk/rd

Stuart.Grace@bbc.co.uk @BBCRD