Development and Evaluation of Robust HDTV Transmission System using - - PowerPoint PPT Presentation

Development and Evaluation of Robust HDTV Transmission System using FEC

Tohru Kondo (tkondo@hiroshima-u.ac.jp)

Graduate School of Engineering, Hiroshima University

18th APAN Meetings / HD session 2 2004/10/14

Introduction

Demand expansion of high-quality/definition

picture transmission.

Growth the use of high definition TV technology It is expected to be used in various fields.

Broadcast, Medial, Distance learning…

Applications that needed high-resolution.

The rapid spread of high bandwidth Internet

connections.

The broadband Internet can provide a versatile

application to users.

18th APAN Meetings / HD session 3 2004/10/14

Outline

Introduction HDTV MPEG2 over IP Transmission System

Transmission System outline FEC Gateway for FEC-incapable receivers

Performance Evaluation

The Effectiveness of FEC Delay measurement

3 point Multicast HD Transmission for distance

seminar

Conclusions

18th APAN Meetings / HD session 4 2004/10/14

HDTV over IP Transmission System

ROBST system

System configuration

Support IPv4/v6,

IP Point-to-Multipoint / Multicast.

Use RS (Reed-Solomon) code

as FEC

Support media format

MPEG2-TS (Transport Stream)

SD MPEG2-TS (4-8Mbps)

PCI Encoder/Decoder Card

HD MPEG2-TS (20-30Mbps)

IEEE1394 input MPEG2 decoder output DVB-ASI output IP output (for Video LAN receiving)

DV (30Mbps)

IEEE1394 input/output

IP Network IP Network

Input Output De/capsulate FEC processing Linux-PC

Media packet

RTP

media media FEC FEC

18th APAN Meetings / HD session 5 2004/10/14

HDTV over IP Transmission System

System configuration

Internet Internet

VideoLAN (Windows or Linux)

NIC NIC NIC

Sender

HDTV/MPEG2/RTP

20Mbps (without FEC). 22-30Mbps (with FEC).

JVC HDcam

Software Decoding Without FEC MPEG2 Encoding

MPEG2-TS MP@HL (19.7Mbps, 720/30p)

Receivers

IEEE1394

1920x1080i 1440x1080i 1280x720i 1280x720p 704x480i 704x480p

DVHS

Mediaglue MGHDB3 PCI decoder (Linux) MPEG2 Decoder PCI Card

18th APAN Meetings / HD session 6 2004/10/14

HDTV over IP Transmission System (contd.)

Packet loss recovery function using FEC.

RS (Reed-Solomon) coding based on RFC2733.

RFC2733 defines RTP payload format using parity code Recovery function can apply to all RTP media streams.

Packet format

IPv4 /v6 UDP RTP Payload Media Packet IPv4 /v6 UDP RTP FEC Payload FEC Packet

Media packet FEC packet FEC Recovery Unit

N packet K packet (N,K) coding

FEC packet is sent as a separate stream. Backwards compatible with FEC-incapable receivers. Recoverable up to N-K packets

18th APAN Meetings / HD session 7 2004/10/14

Recovery performance of FEC

FEC recovery performance ( X-axis: Before FEC, Y-axis : After FEC)

(15,8) (15,9) (15,10) (15,11) (15,12) (15,13)

Redundancy (N,K)

1.36 1.67 1.25 1.15 1.86 1.5

Increase in bandwidth

0.5 % → 3e-07 % 1.0 % → 1.8e-07 %

18th APAN Meetings / HD session 8 2004/10/14

Packet Interleaving

Methodology

shuffle the transmitting packet order. disperse bursty packet losses on several FEC units. have buffering delay on both end hosts.

media packet (K) N-K Unit (N) Interleave depth : d = 1

Recover burst packet losses in the unit.

) 1 )( ( + − d K N

18th APAN Meetings / HD session 9 2004/10/14

FEC gateway for FEC-incapable receivers

The problems of the FEC.

FEC processing with low-spec PC or MPEG2

software decoding has higher risk.

It may be affect MPEG2 decoding process.

The advantage of FEC gateway

Applicable FEC function on Video LAN receiving. Converting IP Unicast to IP Muiticast

We can construct flexible distribution network.

Design and implement FEC gateway for FEC-incapable receivers

18th APAN Meetings / HD session 10 2004/10/14

FEC gateway for FEC-incapable receivers

System configuration

Lossy network Lossy network

FEC Gateway FEC-incapable receivers FEC-capable receiver

Multicast FEC Decoding HD stream with FEC Unicast

HD Sender

18th APAN Meetings / HD session 11 2004/10/14

Performance Evaluation of developed system

Performance evaluation was taken for

Tolerance against packet loss.

Impact on received picture.

Processing load.

Impact of FEC process to high-bandwidth stream

Transmission delay.

MPEG2 comp/decompression, FEC processing delay.

18th APAN Meetings / HD session 12 2004/10/14

Tolerance against packet loss

Demonstration environment

Sender sends MPEG2 HD (22.5Mbps) streams

unidirectionally.

Intermediate host (loss generator) randomly drops

the packet

In this experiment, set packet loss rate on 0.1%.

We recorded receiving picture with FEC / without FEC.

Sender Receiver Loss generator

Packet loss!!

100base-TX

DVHS

Sender: DVHS (TT-D3000 ) Receiver: MGHDB3 HD decoder

18th APAN Meetings / HD session 13 2004/10/14

Evaluation of tolerance against packet loss

Comparison of receiving picture.

MPEG2 MP@HL (22Mbps, 1080/60i)

packet loss rate : 0.1 %

Without FEC With FEC: (15,13)coding

18th APAN Meetings / HD session 14 2004/10/14

Measurement of processing load by FEC

Methodology

Sender generates streaming data (4-40Mbps),

applies FEC, and sends to loss generator.

Intermediate host (loss generator) randomly drops

the packet

In this experiment, set packet loss rate on 0-10%.

Receiver recovers lost packets by FEC decoding. We investigate CPU processing load at receiver.

Sender Receiver Loss generator

Packet loss!!

100base-TX

18th APAN Meetings / HD session 15 2004/10/14

Measurement of processing load by FEC

Relation between bandwidth and processing load

Decoding processing with packet loss: (15,13)condig

18th APAN Meetings / HD session 16 2004/10/14

Delay measurement of HD transmission

JVC JY-HD10

VideoLAN

Source image Receive image

Sender Receiver FEC gateway

Measuring method

Compare two images

(source and receive images) side-by-side.

Record by using Digital

Video Camera.

Calculate frame difference

(1frame : 1/30 second) between source and receive images (by comparing SMPTE time-code)

It is not strict measurement

System configuration

18th APAN Meetings / HD session 17 2004/10/14

Delay measurement of HD transmission

JVC JY-HD10

VideoLAN

Source image Receive image

Sender Receiver FEC gateway

Measuring method

Compare two images

(source and receive images) side-by-side.

Record by using Digital

Video Camera.

Calculate frame difference

(1frame : 1/30 second) between source and receive images (by comparing SMPTE time-code)

PCI HD Decoder (MGHDB3)

• approx. 18 frames: 600msec

It is not strict measurement

System configuration

18th APAN Meetings / HD session 18 2004/10/14

Delay measurement of HD transmission

JVC JY-HD10

VideoLAN

Source image Receive image

Sender Receiver FEC gateway

Measuring method

Compare two images

(source and receive images) side-by-side.

Record by using Digital

Video Camera.

Calculate frame difference

(1frame : 1/30 second) between source and receive images (by comparing SMPTE time-code)

It is not strict measurement Video LAN

• approx. 22 frames: 740msec

System configuration

18th APAN Meetings / HD session 19 2004/10/14

Delay measurement of HD transmission

JVC JY-HD10

VideoLAN

Source image Receive image

Sender Receiver FEC gateway

System configuration Measuring method

Compare two images

(source and receive images) side-by-side.

Record by using Digital

Video Camera.

Calculate frame difference

(1frame : 1/30 second) between source and receive images (by comparing SMPTE time-code)

It is not strict measurement Video LAN (loss 1.0%、 through FEC gateway)

• approx. 22 frames: 740msec

Video LAN

• approx. 22 frames: 740msec

18th APAN Meetings / HD session 20 2004/10/14

Summary

Influence of delay

The system constantly produces hundreds more

delay.

MPEG2 (de)compression delay It is fatal impact for applications that needs interaction

communication.

It is important that using various tools as

situation demands.

For distance learning...

Discussion, Interaction ： low-delay application (H.264 etc)

Uncompressed HDTV

Transmission of document and black board：

MPEG2 HDTV

18th APAN Meetings / HD session 21 2004/10/14

3-point HD Multicasting Seminar

We have been performing the student seminar

using HD transmission system.

3-point native IPv6 Multicasting Hiroshima Univ., Hiroshima City Univ., Saga Univ.,

every week.

Saga Univ. Hiroshima City Univ. Hiroshima Univ.

22 2004/10/14

3-point HD Multicasting Seminar

System configuration

We transmit HD video and audio separately.

Audio: MRAT (Multipurpose RAT)

http://lab.ipc.hiroshima-cu.ac.jp/mrat/

Hiroshima Univ.

(Higashi Hiroshima)

Saga Univ.

(Saga)

Hiroshima City Univ.

(Hiroshima City) 45Km 400Km

VideoLAN Okayama Kyushu Saga Hiroshima

JGNv6

18th APAN Meetings / HD session 23 2004/10/14

3-point HD Multicasting Seminar

• Transmission Delay (one-way)

MPEG2-HD : 600msec MRAT

: 130msec

• Voice can be transmitted with the low delay

by separating video and audio.

Although the system can not synchronize video

and audio, it is not affected from a practical standpoint

18th APAN Meetings / HD session 24 2004/10/14

Conclusions

High Definition TV can be used in various fields.

Medial care, Distance learning…

HDTV MPEG2 over IP transmission system FEC gateway for FEC-incapable receivers Performance Evaluation

The Effectiveness of FEC Delay measurement

It is important that using various tools as the situation demands

18th APAN Meetings / HD session 25 2004/10/14

18th APAN Meetings / HD session 26 2004/10/14

Theoretical equation

Packet loss rate : P[X]

In the case of N-K＜ i ≦ K In the case of 0 ≦ i ≦ N-K

i K i i K K i

p p C i K X P

− =

− =

∑

) 1 ( 1 ] [

∑ ∑

− + − − = − − − − =

− − =

K N i K N j j K N j j K N i K i i K K i

p p C p p C i K X P

1

) 1 ( ) 1 ( 1 ] [