DTV Infrastructure
from 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
828 Symbols
Field Sync #1
313
Segments
S
e
g
m
e
n
t
S
y
n
c
313
Segments
Data + FEC
24.2
ms
Field Sync #2
Data + FEC
Test Segment
1 Segment
= 77.3 us
24.2
ms
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
720/60P
HD Camera
$300k
18W
D5 Tape Deck
288 Mbps
$150k
KMRL 28
DTV File
Server
Teirnan
THE-1HDTV
Encoder
$200k
HD Storage
$150k
Dolby PD567 AC-3
Encoder
$3k
Audio
SD
camcorder
A/D
PSI/PSIP
Tables
IA File
Server
Internet
Data
Input
8-VSB
Modulator
$50k
DVB-ASI
Audio PES
DVB-ASI
DVB-SPI
T1
$4 k
UP
Converter
$1k
Fiber link
Philips
Token DVB-ASI
Philips VE98 Video PES
SDTV
Encoder
$40k
a site
MUX
$25k
SkyStream
DBN-26
$50k
ASI
Tiernan
Universal
Interface
$5k
IP Data
IA
servers
SMPTE-310
Microwave link $70 k
250KW
KICU 52
DTV
Station
b site
KICU
Signal
Contour
Your DTV Receiver
Intel Video API
Intel ATVEF API
Intel Transport API
IP Multicast API
Intel DTV Driver (K2)
Hauppauge/Philips receiver board (Coney/Maui)
Linux and Windows
Windows
DTV Receiver Board Diagram
Audio
in
Analog
RF in
DTV
RF in
Comp
video in
Audio
MUX &
decoder
Mux
audio
video
Tuner
To sound
card
Analog
Video
Decoder
MUX
I/f
logic
S-video in
8-VSB IF
demodulator
A/D
convert
DTV demod
FEC Decoder
DTV receiver board block diagram
Scaler
PCI bridge
SAA7146
PCI
Bus
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