DTV Infrastructurefrom Standards to Startups

Milton Chen

Overview

• Ground rules

• Your DTV station

• Your DTV receiver

MPEG-2 Transport Stream

• 188 byte packets• 4+ bytes header

– sync_byte (0x47)

– packet ID (13 bits) • 0x11, 21, or 31 are video by convention

• 0x14, 24, or 34 are the corresponding audio

– transport_error_indicator (1 bit)

– transport_scrambling_control (2 bits)

– priority (1 bit)

4

Field Sync #1

Field Sync #2

Test Segment

Segment

Sync

828 Symbols

313Segments

Data + FEC

1 Segment= 77.3 us

Data + FEC313Segments

24.2ms

24.2ms

ATSC 8-VSB Data Rate

• data rate = 2 * W log ( L ) = 32.286 Mbps

– W = 5.381MHz (not 6 because of bandpass filter)

– L = 8 levels

• 32.286 Mbps * 2/3 * 188/(188+20) * 312/313 = 19.4 Mbps (often quoted rate), 2/3 from Trellis Encoding, 20 from parity bytes

• 19.4 Mbps * 184 / 188 = 19.0 Mbps (maximum data rate)

• 19.0 Mbps * (65536 – 20 – 8)/65536 = 19.0 Mbps (maximum UDP/IP data rate), 20 byte IP header, 8 byte UDP header

Your DTV Station

TiernanUniversal Interface

$5k

SkyStreamDBN-26

$50k

Teirnan THE-1HDTV

Encoder$200k

Philips VE98 SDTV

Encoder$40k

Philips TokenMUX$25k

Dolby PD-567 AC-3Encoder

$3k

PSI/PSIPTables

DataInput

A/D

Audio

IP Data

DVB-ASI

Audio PES

Video PES

DVB-ASI

DVB-SPI

DVB-ASI

SMPTE-310

ASI

HD Storage$150k

720/60PHD Camera

$300k

D5 Tape Deck288 Mbps

$150k

IA servers

IA File Server

SD camcorder

UPConverter

$1k

8-VSBModulator

$50k

DTV File Server

KMRL 28

18W

KICU 52DTV

Station

250KW

Fiber link

Microwave link

site

site

$4 k

$70 k

Internet T1

KICUSignal Contour

Your DTV Receiver

Hauppauge/Philips receiver board (Coney/Maui)

Intel DTV Driver (K2)

Intel Transport API

Intel Video API

IP Multicast API

Intel ATVEF API

Linux and Windows Windows

DTV Receiver Board Diagram

audiovideo

MUX

DTV receiver board block diagram

ScalerPCI bridge SAA7146

PCIBus

Tuner

AnalogRF in

Compvideo in

S-video in

AudioMUX &decoder

Audio in

DTVRF in

8-VSB IFdemodulator

DTV demodFEC Decoder

I/flogic

A/Dconvert

AnalogVideoDecoder

To soundcard

Mux

Intel Transport API• Channel Tuning

– DTVInitFromATSC (channel)– DTVInitFromFile (file,bitrate,loop )

• class DTVConn {

DTVConn ( pid, raw );int RetrieveBuffer ( buf, wait );int ReturnBuffer (buf )int Flush();

}• Utility Tools

– VSBM, DTVStat, iDTVtest, DTVRec, Dmon, DTVSim

Intel Video API

• MPEG Processing Library (MPL)– Access to decoded video frames and much

more– Highly optimized codec– path to OpenGL video texture– DirectShow wrappers

IP Multicast API

• Standard Winsock programming– Run DTVSock.exe to enable data flow

• Likely to be supported by all PC DTV cards– Hauppauge/Philips– Creative Labs/Teralogic– Broadlogic

• Realtime back channel to complete the loop

Advanced Televison Enhancement Forum (ATVEF)

• Framework for interactive TV over ATSC, NTSC, and Internet

• Based on WEB standards– HTML, JavaScript

• Use IP to transport all data• Uni-direction HTTP

– All-or-none– Error correction– Object segmentation

• Naming scheme for cached data• At least 1MB of data cache in receiver

ATVEF (2)

• Announcements– address 224.0.1.113 and port 2670

– describe the enhancement and what IP addresses to listen for triggers and resources

• Triggers– 1 UDP packet

• Resources– web pages, images, scripts, gzipped data

Producing Your Content• Capturing Video

– camera, camcorder

• Editing Video– Adobe Premiere, Avid Express

• ATVEF– WEB tools– Intel Broadcast Plus Tools

• scripts

• MPEG2 Transport Stream– Intel’s Dynamux.exe (software mux)

• Other ...

What Next

• Programming session– Next Monday night– Tools and sample codes

• Most systems at three months before tradeshow stage– Tell me what you need