atsc program and system information protocol (psip)
TRANSCRIPT
1 © 1997-2000Sarnoff Corporation
ATSC Program andSystem Information Protocol
(PSIP)
Reproduction in any form requires written permission from the Sarnoff Corporation.
Michael IsnardiSarnoff Corporation
e-mail: [email protected]
April 8, 2000
BroadcastTechnology
Society
2 © 1997-2000Sarnoff Corporation
Why PSIP exists
• Avoids rebranding expense by broadcasters• Provides a basic channel selection method
using an electronic program guide– Simple enough to go in every receiver– Extensible for higher end products– Small change in tuning paradigm for consumer– Compatible with printed media
• Supports V-Chip and Conditional Access
3 © 1997-2000Sarnoff Corporation
ATSC Standards
replacedby
• Standards documents:– A/52: AC-3 Audio Compression– A/53: ATSC DTV Standard (contains video formats)– A/54: Guide to use of the ATSC DTV Standard– A/55: Program Guide (Optional)– A/56: System Information (Optional)– A/57: Program/Episode/Version Identification– A/58: Harmonization with DVB SI (Rec. Practice)– A/63: Standard for Coding 25/50 Hz Video– A/64: Transmission Measurement & Compliance...– A/65: Program and System Information Protocol…– A/66: PSIP Technical Corrigendum No. 1– A/67: PSIP Technical Amendment No. 1– A/70: Conditional Access System for Terrestrial Broadcast– A/80: Modulation and Coding Reqt’s for DTV Apps. Over Satellite
• For more info, see www.atsc.org
4 © 1997-2000Sarnoff Corporation
PSIP = Your DTV Identity
• PSIP = Program and System InformationProtocol
• Covered by ATSC Standard A/65, A/66, A/67• Combines and Compacts A/55 and A/56• Must be transmitted by ATSC terrestrial
broadcasters in their DTV Transport Stream• Is an ATSC (not FCC) requirement
5 © 1997-2000Sarnoff Corporation
Program and System Info Protocol
• PSIP features:– allows navigation and access to each of the channels
within the Transport Stream– preserves channel branding– program guide (from 12 hours to 16 days)– gives the user information for browsing and selection– key system info (e.g., carrier freqs and source ID’s)– rating and content advisory info
• ATSC Receiver can scan active channels forPSIP and can build an integrated guide.
6 © 1997-2000Sarnoff Corporation
Electronic Program GuidesName 6:00 pm 6:30 pm 7:00 pm 7:30 pm 8:00 pm 8:30 pmChan
CBZ City Life Travel Movie:Texas Wild II6-0
CBZ City Life Travel6-1
CBZ6-2
LCL
Movie: Secret Agent
6-3 Local News Airport Info
Movie:Texas Wild II
(HDTV)
• Interactive and Useful- Event and Channel Information- Automatic Recording- With Future Extensions, can enable Thematic
Browsing and Sorting
7 © 1997-2000Sarnoff Corporation
Scope of PSIP
Ch. 2 Ch. 31 Ch. 46WXYZ WXYZ-DT WPQR-DT
Analog Digital Digital
PSIP DataMust describe its ownDTV programming.May describe associated
analog channel’sprogramming.
May describeanother DTVchannel’sprogramming.
(6 MHz) (6 MHz) (6 MHz)
8 © 1997-2000Sarnoff Corporation
ATSC Transmission System
MPEG-2Encoder
Video(one of
18 formats)
AC-3Encoder
Audio(up to
5.1 channels)
MPEG-2Bitstream
AC-3Bitstream Trans-
portMux
SPTransport
Stream
(3 - 18 Mb/s)
Data
SPTransport
Stream
••• MPTrans-portMux
PAT: ProgramAssociation Table
PMT: Program Map TablePSI: Program Specific
InformationSP: Single ProgramMP: Multi Program
MPTransport
Stream
(19.4 Mb/s)
ChannelCoder
&8-VSB
Modulator
DTVTransmitter
Single-Program Encoder
PATPSI and
PSIP Generator PSIP
PMT
6 MHzRF Channel
Program and System InfoSystem Time
9 © 1997-2000Sarnoff Corporation
TransportStream
(19.4 Mb/s)
ATSC Decoder
MPEG-2Decoder
Video
AC-3Decoder
Audio
MPEG-2Bitstream
AC-3Bitstream
Program GuideDatabase
Single-Program Decoder
8-VSBDemod-ulator
DTVTuner
PhysicalChannelSelect
Clock Recoveryand A/V
SynchronizationPCR’s
ProgramSelect
TimeStamps
DisplayProcessing
Program Select(from User)
Trans-port
Demux
PSIP DataOn-ScreenDisplay
10 © 1997-2000Sarnoff Corporation
Tuning Example - PSIP
To A/V/DDecodersPID
0x1FFB
Look UpPID’s
Virtual ChannelTable
Multi-Program
TransportStream
Filter PID’s forElementary Streams
PID # Type
PID-V Video
PID-P PCR
PID-A Audio
PID-D Data
“Tune to Program 12-3”
DumpOther
PacketsCreateProgram
Guide
11 © 1997-2000Sarnoff Corporation
PSIP TablesTable Description
STT System Time Table - provides date and time
MGT Master Guide Table - provides version, size and PID’s of allother tables (except STT)
VCT Virtual Channel Table - provides attributes for all virtualchannels in this Transport Stream
RRT Rating Region Table - provides rating information for multiplegeographic regions
EIT Event Information Table - provides information for events onthe virtual channels
ETT Extended Text Table - provides detailed descriptions of virtualchannels and events
12 © 1997-2000Sarnoff Corporation
PSIP and MPEG Acronyms
bslbf bit serial, leftmost bit first
CRC Cyclic Redundancy Check
ETM Extended Text Message
PAT Program Association Table
PMT Program Map Table
PTC Physical Transmission Channelsb smoothing buffer
rpchof remainder polynomial coefficients, highest order first
uimsbf unsigned integer, most significant bit first
UTC Coordinated Universal Time
13 © 1997-2000Sarnoff Corporation
What’s Required for Transmission?… an ATSC, not FCC, requirement...
Table Required forBroadcast?
Required forCable?
STT
MGT
VCT
RRT
EIT
ETT
4
4
4 (TVCT)
4
4
4
4 (EIT-0, -1, -2, -3)(all others optional)
optional
4 (CVCT)
4
optional
optional
Note: CEA and NCTA have agreed on PSIP over cable.Out-of-band profiles are defined in SCTE DVS-234r2.
Update
14 © 1997-2000Sarnoff Corporation
Table HierarchyBase PID0x1FFB
STT
MGT
RRT
VCT
Chan AChan B
Chan Z
•••
ETT-V
EIT-0Event(s)
•••
ETT-0
Event(s)
Event(s)
EIT-1Event(s)
•••
ETT-1
Event(s)
Event(s)
EIT-2Event(s)
•••
ETT-2
Event(s)
Event(s)
EIT-3Event(s)
•••
ETT-3
Event(s)
Event(s)
PID-EIT0
PID-ETT0
PID-EIT1
PID-ETT1
PID-EIT2
PID-ETT2
PID-EIT3
PID-ETT3PID-ETTV
• STT, RRT, MGT and VCT are carried in TransportPackets with Base PID
• MGT contains PID values for EIT and ETT TransportPackets
• EIT’s carry event information for 3-hour time slots
•••ProgramGrid
15 © 1997-2000Sarnoff Corporation
Generic PSIP Table Format• PSIP tables follow format of MPEG-2 Systems “Private Sections”• 9-byte header; N bytes of table data; 4-byte CRC (check sum) trailer• 10+N bytes following section_length field• 13+N bytes total size
Syntax of MPEG-2 Private Section Bits Formattable_id 8 uimsbfsection_syntax_indicator 1 ‘1’private_indicator 1 ‘0’reserved 2 ‘11’section_length 12 uimsbftable_id_extension 16 uimsbfreserved 2 ‘11’version_number 5 uimsbfcurrent_next_indicator 1 bslbfsection_number 8 uimsbflast_section_number 8 uimsbfprotocol_version 8 uimsbfactual_table_data 8*N –CRC_32 32 rpchof
1
2
2
1
111
4N
Bytes
3
6
4
Hea
der
16 © 1997-2000Sarnoff Corporation
Table Header and Trailer Summary
• Fields that are variable or peculiar to aspecific table are highlighted
Syntax STTtable_id 0xCDsection_syntax_indicator ‘1’private_indicator ‘1’reserved ‘11’section_length (allowed values) 17-1021table_id_extension 0x0000reserved ‘11’version_number 0current_next_indicator ‘1’section_number 0last_section_number 0protocol_version 0actual_table_data –CRC_32 rpchof
1
2
2
1
111
4N
Bytes
3
6
4
MGT0xC7
‘1’‘1’‘11’
14-40930x0000
‘11’0-31‘1’000–
rpchof
TVCT0xC8
‘1’‘1’‘11’
13-1021TSID‘11’0-310-1
0-2550-255
0–
rpchof
RRT0xCA
‘1’‘1’‘11’
18-1021rating_region
‘11’0-31‘1’000–
rpchof
EIT-j0xCB
‘1’‘1’‘11’
11-4093source_id
‘11’0-31‘1’
0-2550-255
0–
rpchof
ETT-k0xCC
‘1’‘1’‘11’
14-4093
‘11’0-31‘1’000–
rpchof
0x0000
17 © 1997-2000Sarnoff Corporation
Other Table Parameters
Parameter STT
Maximum Table Size (bytes) 1024
MGT
4096
TVCT
256*1024
RRT
1024
EIT-j
256*4096
ETT-k
4096
Maximum Cycle Time (msec) 1000 150 400 60000 500(rec EIT-0)
–
Maximum Bit Rate (kbps) 250 250250
sb_leak_rate 625 625625
sb_size (bytes) 1024 10241024
Typical Table Size (bytes) 20 520 perchan or event
356per chan
138 443 901
Maximum Section Size (bytes) 1024 4096 1024 1024 4096 4096
Maximum Sections per Table 1 1 256 1 256 1
18 © 1997-2000Sarnoff Corporation
Maximum Cycle Times
MGT
TVCT
EIT-0
STT
RRT
0 1 2 3 4 5 6 7t (sec)
150 ms
400 ms
500 ms(recommended)
1 s
60 s
19 © 1997-2000Sarnoff Corporation
STT FormatSyntax of STT Table Bits Format or Note
system_time 32
GPS_UTC_offset 8 UTC = GPS - GPS_UTC_offset
Number of GPS seconds since 12 am, 1/6/80Must be accurate to ± 4 sec
DS_status 1 0 = Not in DST; 1 = In DST
5 Day of month in which transition occurs (1-31)reserved 2 ‘11’
descriptors 8*D Descriptor data
7
D
BytesSTT Header 9*8 STT Header9
CRC_32 32 32-bit Cyclic Redundancy Check4
DS_day_of_monthDS_hour 8 Local hour at which transition occurs (0-18)
dayl
ight
savi
ngs
• In order to calculate correct local time, receiver must:– calculate UTC (local time in Greenwich, England)– adjust for local time zone difference– adjust for daylight savings time (if applicable)– convert to date and time format for display
20 © 1997-2000Sarnoff Corporation
What is GPS?
• Global Positioning System (GPS) units are used for“System Time” (current date and time of day) in STT andevent start times in EIT’s.
• GPS time begins at midnight, January 6th, 1980.• GPS time is related to Coordinated Universal Time (UTC),
which is the current local time at Greenwich, England.• UTC = GPS - GPS_UTC_offset (offset = 13 “leap
seconds” as of Jan. 1, 1999)• Example: UTC = 599,320,813 - 13 = 599,320,800 =
2:00:00 PM, Jan 2nd, 1999• For more info, see http://tycho.usno.navy.mil/gps.html
21 © 1997-2000Sarnoff Corporation
Master Guide Table (MGT)
• Lists key information about all other PSIPtables (except STT):– version numbers– table sizes– PID’s
• Allows simpler decoder designs since anychange in PSIP status is flagged in thistable.
• Only the base PID (0x1FFB) needs to bemonitored to detect change in PSIP status.
22 © 1997-2000Sarnoff Corporation
MGT FormatSyntax of MGT Table Bits Format or Note
16 Number of tables in loop (6 - 370)
table_type 16
0x0000: TVCT with current_next_indicator=10x0001: TVCT with current_next_indicator=00x0002: CVCT with current_next_indicator=10x0003: CVCT with current_next_indicator=00x0004: Channel ETT0x0100 - 0x017F: EIT-0 to EIT-1270x0200 - 0x027F: Event ETT-0 to Event ETT-1270x0301 - 0x03FF: RRT with rating_region 1-255
3 ‘111’
reserved 3 ‘111’
13
BytesMGT Header 9*8 MGT Header9
CRC_32 32 32-bit Cyclic Redundancy Check4
reservedtable_type_PID 13 PID for table_type in field above
tables_definedfor each table
table_type_version_numbernumber_bytes
5 Must be the same as version number in actual table32 Total number of bytes used for this table4 ‘1111’reserved
descriptors_length 12 Total length (in bytes) of event descriptorsdescriptors 8*D2 Descriptor data
table_type_descriptors_length 12 Total length (in bytes) of event descriptorsdescriptors 8*D1 Descriptor data
4 ‘1111’reserved 2
D2
D1
23 © 1997-2000Sarnoff Corporation
MGT Example: Time T0
MGTtables_defined = 6; version = 8
0x0000
0x0100
0x0101
0x0102
0x0103
0x0301
Type
TVCT(current_next = 1)
EIT-0
EIT-1
EIT-2
EIT-3
RRT(rating_region = 1)
Name
0x1FFB
0x1AA0
0x1AA1
0x1AA2
0x1AA3
0x1FFB
PID
Note: Underlined values are variable from station to station.
2
2
2
1
1
0
Version
450
98
68
77
80
990
Bytes
24 © 1997-2000Sarnoff Corporation
MGT Example: EIT-1 Content ChangesMGT
tables_defined = 6; version = 9*
0x0000
0x0100
0x0101
0x0102
0x0103
0x0301
Type
TVCT(current_next = 1)
EIT-0
EIT-1
EIT-2
EIT-3
RRT(rating_region = 1)
Name
0x1FFB
0x1AA0
0x1AA1
0x1AA2
0x1AA3
0x1FFB
PID
Note: Asterisks indicate changed values
2
2
3*
1
1
0
Version
450
98
73*
77
80
990
Bytes
25 © 1997-2000Sarnoff Corporation
MGT Example: Just prior to EIT Cross-over
MGTtables_defined = 6; version = 9
0x0000
0x0100
0x0101
0x0102
0x0103
0x0301
Type
TVCT(current_next = 1)
EIT-0
EIT-1
EIT-2
EIT-3
RRT(rating_region = 1)
Name
0x1FFB
0x1AA0
0x1AA1
0x1AA2
0x1AA3
0x1FFB
PID
Note: EIT content shifts every three hours. EIT PID shifting is an easy way to implement this(but not required).
2
2
3
1
1
0
Version
450
98
73
77
80
990
Bytes
26 © 1997-2000Sarnoff Corporation
MGT Example: Just after EIT Cross-over
MGTtables_defined = 6; version = 10*
0x0000
0x0100
0x0101
0x0102
0x0103
0x0301
Type
TVCT(current_next = 1)
EIT-0
EIT-1
EIT-2
EIT-3
RRT(rating_region = 1)
Name
0x1FFB
0x1AA0*
0x1AA1
0x1AA2
0x1AA3
0x1FFB
PID
Note: EIT-0 content is shifted out. EIT-1 becomes EIT-0, etc. PID’s may cycle through afixed pool as shown, but this is not required.
2
1
3
1
1
0
Version
450
88
73
77
80
990
Bytes
27 © 1997-2000Sarnoff Corporation
Virtual Channel Table (VCT)• Contains list of channels in the Transport Stream.• May also include broadcaster’s analog channel
and digital channels in other Transport Streams.• TVCT = Terrestrial VCT; CVCT = Cable VCT• Key info in VCT:
– short name– major and minor channel numbers– modulation mode and carrier frequency– Transport Stream ID (TSID) and program number– source ID, service type, access controlled and hidden flags– Service Location Descriptor: contains list of PID’s for
elementary streams
28 © 1997-2000Sarnoff Corporation
Major and Minor Channel Numbers• major_channel_number is used to group all services
associated with a broadcaster’s NTSC brand• minor_channel_number specifies a particular channel
within that group. “0” is reserved for analogservice. All other values (1-999) are allowed fordigital services. One suggestion is to start with 1and to continue numerically.
• A/65, Annex B assigns major_channel_numbers asfollows:– for existing NTSC broadcasters, major_channel_number is
the same as the current NTSC RF channel number (2-69)– for new DTV broadcasters, major_channel_number is the
same as the new DTV RF channel number (2-69)– major_channel_numbers in range 70 - 99 may be used to
identify groups of digital services carried separately
29 © 1997-2000Sarnoff Corporation
Major-Minor Channel Number Example
RF Ch. 2
RF Ch. 31“2-0”“2-1”
RF Ch. 46“46-1”
WXYZ WXYZ-DT WPQR-DT
analog digital digital
An existing analog broadcaster witha second digital channel. Brandingis preserved. The DTV RF channelnumber is hidden from the viewer!
A digital-onlybroadcaster
(no analog channel)
30 © 1997-2000Sarnoff Corporation
Which Delimiter?
• None specified. All shown are legal.• Dots and commas may not reproduce well in printed
program guides.• Dashes are popular. May become de facto standard.
31 © 1997-2000Sarnoff Corporation
Channel TSID - What and Why?• Channel TSID is a 16-bit number that stands for
– Transport Stream ID (digital)– Transmission Signal ID (analog )
• The receiver may use the Channel TSID to verifythat the Transport Stream acquired at thereferenced carrier frequency is actually the desiredmultiplex.
• Can help resolve co-channel issues and instanceswhere a DTV signal frequency is translatedwithout modification of listed carrier frequency.
32 © 1997-2000Sarnoff Corporation
Channel TSID
• For digital programs contained in this Transport Stream,the Channel TSID must match this Transport Stream ID.
• For digital programs contained in other Transport Streams,the Channel TSID must match the Transport ID of theother streams.
• For analog programs, the Channel TSID must match the“Transmission Signal ID”, or must contain 0xFFFF ifunknown.
• TSID Assignments proposed by MSTV (www.mstv.org):– NTSC = even TSID, DTV = odd TSID– Example
• WNBC (Ch. 4) = 0x086E• WNBC-DT (Ch. 28) = 0x086F
33 © 1997-2000Sarnoff Corporation
Proposed TSID’s for New York City
2156215821602162216421662168
0x086C0x086E0x08700x08720x08740x08760x0878
2157215921612163216521672169
0x086D0x086F0x08710x08730x08750x08770x0879
2457112531
56284445332430
Chan Dec HexNTSC
Chan Dec HexDTV
Transmission Signal ID(TSID)
Transport Stream ID(TSID)
34 © 1997-2000Sarnoff Corporation
TSID Issues
• If a broadcaster is transmitting the same signal in differentchannels, each TSID should be unique.
• If a signal is frequency translated without othermodification, then the TSID will remain the same, but thecarrier frequency listed in the VCT will be wrong. In thiscase, receiver should match channel_TSID’s with actualTSID’s to ensure correct presentation.
• A receiver should minimize reliance on carrier frequencieslisted in the VCT. Instead, a receiver should associate theTSID with the carrier frequency at which it is found.
35 © 1997-2000Sarnoff Corporation
Program Number
0x00B3
Program Number
0x00B3
PAT and PMT• The Program Association Table (PAT) associates MPEG-2
Program Numbers with Program Map Table (PMT) PID’s• The PMT associates program elements with PID’s• These tables are required for MPEG-2 compliance
Program Association Table (PAT)
table_id = 0x00
•••
transport_stream_id = 0x0AA1
•••
Program Association Table (PAT)
table_id = 0x00
•••
transport_stream_id = 0x0AA1
•••
Program Number PMT PID
0x00F1 0x0100
0x00C2 0x0440
0x00B3 0x0301
Program Number PMT PID
0x00F1 0x0100
0x00C2 0x0440
0x00B3 0x0301
Example PAT
Stream Type PID
PCR 0x0303
Video 0x0303
Audio 0x0206
Stream Type PID
PCR 0x0303
Video 0x0303
Audio 0x0206
Example PMT atPID 0x0301
36 © 1997-2000Sarnoff Corporation
Program Association Table (PAT)
table_id = 0x00
•••
transport_stream_id = 0x0AA1
•••
Program Association Table (PAT)
table_id = 0x00
•••
transport_stream_id = 0x0AA1
•••
TSID and Program Number
• Transport Stream ID and Program Numbers in theVCT and PAT must match
Program Number PMT PID
0x00F1 0x0100
0x00C2 0x0440
0x00B3 0x0301
Program Number PMT PID
0x00F1 0x0100
0x00C2 0x0440
0x00B3 0x0301
Example PAT
Terrestrial Virtual Channel Table (TVCT)
table_id = 0xC8
•••
transport_stream_id = 0x0AA1
•••
Terrestrial Virtual Channel Table (TVCT)
table_id = 0xC8
•••
transport_stream_id = 0x0AA1
•••
Program Number Channel TSID Descriptor
0x00F1 0x0AA1 Service Location
0x00C2 0x0AA1 Service Location
0x00B3 0x0AA1 Service Location
Program Number Channel TSID Descriptor
0x00F1 0x0AA1 Service Location
0x00C2 0x0AA1 Service Location
0x00B3 0x0AA1 Service Location
Corresponding TVCT
0x0AA0 0x0AA0 Analog program0x0AA0 0x0AA0 Analog program
0x00F4 0x0AA3 Service Location
0x00E5 0x0AA3 Service Location
0x00F4 0x0AA3 Service Location
0x00E5 0x0AA3 Service Location
37 © 1997-2000Sarnoff Corporation
Service Location Descriptor• The PID’s in the Service Location Descriptor and
in the PMT must matchProgram Association Table (PAT)
table_id = 0x00
•••
transport_stream_id = 0x0AA1
•••
Program Association Table (PAT)
table_id = 0x00
•••
transport_stream_id = 0x0AA1
•••
Program Number PMT PID
0x00F1 0x0100
0x00C2 0x0440
0x00B3 0x0301
Program Number PMT PID
0x00F1 0x0100
0x00C2 0x0440
0x00B3 0x0301
ExamplePAT
Terrestrial Virtual Channel Table (TVCT)
table_id = 0xC8
•••
transport_stream_id = 0x0AA1
•••
Terrestrial Virtual Channel Table (TVCT)
table_id = 0xC8
•••
transport_stream_id = 0x0AA1
•••
Program Number Channel TSID Descriptor
0x00F1 0x0AA1 Service Location
0x00C2 0x0AA1 Service Location
0x00B3 0x0AA1 Service Location
Program Number Channel TSID Descriptor
0x00F1 0x0AA1 Service Location
0x00C2 0x0AA1 Service Location
0x00B3 0x0AA1 Service Location
CorrespondingTVCTStream Type PID
PCR 0x0303
Video 0x0303
Audio 0x0206
Stream Type PID
PCR 0x0303
Video 0x0303
Audio 0x0206Example
PMT
Stream Type PID
PCR 0x0303
Video 0x0303
Audio 0x0206
Stream Type PID
PCR 0x0303
Video 0x0303
Audio 0x0206
CorrespondingService Location Descriptor
38 © 1997-2000Sarnoff Corporation
TVCT Format (1)Syntax of TVCT Table Bits Format or Note
8 Number of channels in loop (0 - 31)
modulation_mode 8
0x01: analog0x02: SCTE_mode_10x03: SCTE_mode_20x04: ATSC (8 VSB)0x05: ATSC (16 VSB)0x80: Defined by private descriptor
10 First part of virtual channel number (1 - 99)
carrier_frequency 32 In Hz. Pilot tone for VSB; Pix carrier for analog
27
BytesTVCT Header 9*8 transport_stream_id is in table_id_extension9
major_channel_number
short_name 112 7 BMP Unicode characters
num_channels_in_sectionfor each channel
channel_TSIDprogram_number
16 MPEG-2 TSID or Analog Transmission Signal ID16 MPEG-2 PAT/PMT number or 0xFFFF for analog
4 ‘1111’reserved
10 Last part of virtual channel number (0 - 999)minor_channel_number
continued on next slide
39 © 1997-2000Sarnoff Corporation
TVCT Format (cont’d)
service_type 6
0x01: analog television0x02: ATSC_digital_television0x03: ATSC_audio_only (audio and data, no video)0x04: ATSC_data_broadcast_service (T3/S13)
CRC_32 32 32-bit Cyclic Redundancy Check4
for each channel (cont’d)
source_id 16
Uniquely identifies programming source.0x0000: reserved0x0001 - 0x0FFF: must be unique within this TS0x1000 - 0xFFFF: must be unique at regional level
reserved 6 ‘111111’descriptors_length 10 Length (in bytes) of descriptors that followdescriptors 8*D1 Descriptor data
additional_descriptors_length 10 Length (in bytes) of additional descriptorsadditional_descriptors 8*D2 Additional descriptor data
reserved 6 ‘111111’
reserved 6 ‘111111’
ETM_location 2
access_controlled 1 1 = events for this virtual channel may be access controlled
1 1 = virtual channel cannot be accessed by direct user entryhidden
6
D1
0x00: No ETM0x01: ETM located in the PTC carrying this PSIP0x02: ETM located in the PTC specified by the channel_TSID
D2
2
This is where the Service Location Descriptor appears.
40 © 1997-2000Sarnoff Corporation
The Program Number Myth• MPEG-2 Program Numbers are not related to Major-Minor
Channel Numbers!• MPEG-2 Program Numbers are hidden from the viewer and
serve to link MPEG-2 data structures (PAT and PMT).• Major-Minor channels numbers are what viewers “tune to”!
Terrestrial Virtual Channel Table (TVCT)Terrestrial Virtual Channel Table (TVCT)
Major-Minor Number Program Number Channel TSID Descriptor
12-1 0x00F1 0x0AA1 Service Location
12-2 0x00C2 0x0AA1 Service Location
12-3 0x00B3 0x0AA1 Service Location
Major-Minor Number Program Number Channel TSID Descriptor
12-1 0x00F1 0x0AA1 Service Location
12-2 0x00C2 0x0AA1 Service Location
12-3 0x00B3 0x0AA1 Service Location
What the viewer“tunes to”
Hidden from theviewer
Tells the receiverwhere to find PID’s
41 © 1997-2000Sarnoff Corporation
TVCT ExampleTVCT
number_channels_in_section = 5; TSID = 0x0AA1
12
12
12
12
12
MajorNum.
0
1
5
12
31
MinorNum.
NBZ
NBZ-D
NBZ-S
NBZ-M
NBZ-H
ShortName
205.25
620.31
CarrierFreq (MHz)
0x0AA0
0x0AA1
0x0AA1
0x0AA1
0x0AA1
ChannelTSID
Adapted from A/65
620.31
620.31
620.31
0xFFFF
0x0F21
0x00B2
0x0CC7
0x0CD0
ProgramNumber
analog
digital
digital
digital
digital
ServiceType
20
21
38
54
14
SourceID
ch name
ch name;serv loc
ch name;serv loc
ch name;serv loc
ch name;serv loc
Descrip-tors
42 © 1997-2000Sarnoff Corporation
Event Information Tables
• Each EIT spans 3 hours• Start time for each EIT is constrained to be one of
the following UTC times:– 0:00 (midnight), 3:00, 6:00, 9:00– 12:00 (noon), 15:00, 18:00, 21:00
• EIT-0 represents the current 3 hours ofprogramming
• For terrestrial PSIP, first 4 EIT’s (EIT-0, -1, -2,-3), representing 12 hours, are required
• Maximum number of EIT’s = 128 (16 days)
43 © 1997-2000Sarnoff Corporation
EIT FormatSyntax of EIT Table Bits Format or Note
num_events_in_section 8 Number of events in this EIT sectionfor each event:
reserved 2 ‘11’event_id 14 Event ID. Also part of ETM_idstart_time 32 In units of GPS seconds since 12 am, 1/6/80reserved 2 ‘11’
ETM_location 2
00 = No ETM01 = ETM in PTC carrying this PSIP10 = ETM in PTC carrying this event11 = [reserved for future ATSC use]
length_in_seconds 20 Duration of event in secondstitle_length 8 Length (in bytes) of title_texttitle_text 8*T Event title (multiple string structure format)reserved 4 ‘1111’descriptors_length 12 Total length (in bytes) of event descriptorsdescriptors 8*D Descriptor data
1
10
T
2
D
BytesEIT Header 9*8 EIT Header9
CRC_32 32 32-bit Cyclic Redundancy Check4
44 © 1997-2000Sarnoff Corporation
EIT Example
EIT-0source_id = 22
num_events_in _section = 3
51
52
53
EventID
12:30
14:30
LocalStartTime
7200
3600
9000
Length(seconds)
Adapted from A/65
15:30
01(this PTC)
00(no ETM)
01(this PTC)
ETMLocation
Soccer Live
Golf Report
Car Racing
Title
content_advisoryclosed_caption
content_advisory
Descrip-tors
45 © 1997-2000Sarnoff Corporation
Source ID’s and Event ID’s
VCT
Channel Asource_id_A
Channel Bsource_id_B
Channel Csource_id_C
EIT-0
Event B1source_id_Bevent_id_B1
Event C1source_id_Cevent_id_C1
Event A3source_id_Aevent_id_A3
Event B2source_id_Bevent_id_B2
Event A2source_id_Aevent_id_A2
Event A1source_id_Aevent_id_A1
18:00 - 19:00 19:00 - 20:00 20:00 - 21:00
• Source ID’s link events to virtual channels. 0x0001 - 0x0FFF areunique within this Transport Stream; 0x1000 - 0xFFFF areunique at the regional level.
• Event ID’s are unique within this Transport Stream.
46 © 1997-2000Sarnoff Corporation
Events that Span EIT Boundaries
VCT
Channel Asource_id_A
Channel Bsource_id_B
Channel Csource_id_C
EIT-0
Event B1event_id_B1
Event C1event_id_C1
Event A3event_id_A3
Event B2event_id_B2
Event A2event_id_A2
Event A1event_id_A1
18:00 -19:00
19:00 -20:00
20:00 - 21:00
EIT-1
Event B3event_id_B3
Event C3event_id_C3
Event A6event_id_A6
Event B4event_id_B4
Event A5event_id_A5
Event A4event_id_A4
21:00 -22:00
22:00 -23:00
23:00 - 0:00
Event C2event_id_C2
Event C2 spans an EIT time interval. It must appearin both EIT’s, with the same event ID.
47 © 1997-2000Sarnoff Corporation
ETT FormatSyntax of ETT Table Bits Format or Note
ETM_id 32
channel ETM_id =source_id + ’00000000000000’ + ‘00’event ETM_id =source_id + event_id + ‘10’
extended_text_message 8*M Multiple string structure message
4
M
BytesETT Header 9*8 ETT Header9
CRC_32 32 32-bit Cyclic Redundancy Check4
• The Extended Text Table (optional) is used to provide detaileddescriptions of virtual channels or events.
• These descriptions are called Extended Text Messages (ETM’s).• The format of the 32-bit ETM_id tells the receiver whether the ETM
describes a channel or and event• This format allows the receiver to search for a single description quickly
without having to parse the payload of a large table
48 © 1997-2000Sarnoff Corporation
Rating Region Table
• The RRT defines the rating standard for a particulargeographic region and/or country
• Each RRT instance is identified by the rating_region field in thetable_id_extension
• Only one rating region is currently defined: “US (50 states +possessions)”
• The Content Advisory Descriptor, which may appear in theEIT and PMT, indicates, for a given event, the ratings for anyor all of the rating dimensions defined in the RRT.
• Full implementation in the U.S. requires document EIA-766:“U.S. Region Rating Table (RRT) and Content Advisory Descriptor for Transportof Content Advisory Information Using ATSC A/65 Program and SystemInformation Protocol (PSIP)”, September 1998.
49 © 1997-2000Sarnoff Corporation
RRT FormatSyntax of RRT Table Bits Format or Note
8
dimensions_defined 8 Number of rating dimensions (1-255)
Length (in bytes) of next field
dimension_name_length 8 Length (in bytes) of next field
3 ‘111’dimension_name_text var Multiple string structure
values_defined 4 Number of values for this dimension (1-15)var
Bytes
RRT Header 9*8rating_region is LS byte of table_id_extension0x00: Forbidden0x01: US (50 states + possessions)0x02 - 0xFF: Reserved
9
CRC_32 32 32-bit Cyclic Redundancy Check4
reservedgraduated scale 1 1 if higher values means higher rated content
rating_region_name_lengthrating_region_name_text var Multiple string structure
for each dimension
for each valueabbrev_rating_value_lengthabbrev_rating_value_text
rating_value_lengthrating_value_text
8 Length (in bytes) of next fieldvar Multiple string structure8 Length (in bytes) of next field
var Multiple string structure
6 ‘111111’reserveddescriptors_length 10 Total length (in bytes) of event descriptorsdescriptors 8*D Descriptor data
50 © 1997-2000Sarnoff Corporation
RRT Information for U.S.• To date, the U.S. is the only rating region that has been defined• This is documented in EIA-766, Sept. 1998 and summarized below
and in the following slides:
Syntax Element Valuerating_region 0x01version_number 00000rating_region_name_text() US (50 states + possessions)dimensions_defined 0x08
Text Formatting ValueISO_639_language_code 0x656E67compression_type 0x00mode 0x00number_strings 0x01number_segments 0x01
51 © 1997-2000Sarnoff Corporation
RRT Information for U.S.RRT
rating_region = 1 (first instance)
rating_region_name_text = “US (50 states + possessions)”
dimension_name = “Entire Audience”; dimension index = 0; grad = “1”index abbrev value
0 “ ” “ ”1 “None” “None”2 “TV-G” “TV-G”3 “TV-PG” “TV-PG”4 “TV-14” “TV-14”5 “TV-MA” “TV-MA”
From EIA-766, Sept. 1998
52 © 1997-2000Sarnoff Corporation
RRT Information for U.S.RRT
rating_region = 1 (first instance)
rating_region_name_text = “US (50 states + possessions)”
dimension_name = “Dialogue”; dimension index = 1; grad = “0”index abbrev value
0 “ ” “ ”1 “D” “D”
From EIA-766, Sept. 1998
index abbrev value0 “ ” “ ”1 “L” “L”
index abbrev value0 “ ” “ ”1 “S” “S”
dimension_name = “Language”; dimension index = 2; grad = “0”
dimension_name = “Sex”; dimension index = 3; grad = “0”
53 © 1997-2000Sarnoff Corporation
RRT Information for U.S.RRT
rating_region = 1 (first instance)
rating_region_name_text = “US (50 states + possessions)”
dimension_name = “Violence”; dimension index = 4; grad = “0”index abbrev value
0 “ ” “ ”1 “V” “V”
From EIA-766, Sept. 1998
index abbrev value0 “ ” “ ”1 “TV-Y” “TV-Y”2 “TV-Y7” “TV-Y7’
index abbrev value0 “ ” “ ”1 “FV” “FV”
dimension_name = “Children”; dimension index = 5; grad = “1”
dimension_name = “Fantasy Violence”; dimension index = 6; grad = “0”
54 © 1997-2000Sarnoff Corporation
RRT Information for U.S.RRT
rating_region = 1 (first instance)
rating_region_name_text = “US (50 states + possessions)”
dimension_name = “MPAA”; dimension index = 7; grad = “0”
index abbrev value0 “ ” “ ”1 “N/A” “MPAA Rating Not Applicable”2 “G” “Suitable for All Ages”3 “PG” “Parental Guidance Suggested”4 “PG-13” “Parents Strongly Cautioned”5 “R” “Restricted, under 17 must be accompanied by adult”6 “NC-17” “No One 17 and Under Admitted”7 “X” “No One 17 and Under Admitted”8 “NR” “Not Rated by MPAA”
From EIA-766, Sept. 1998
55 © 1997-2000Sarnoff Corporation
PSIP DescriptorsDescriptor Name TerrestrialTag
stuffing *0x80CAT MGT VCT EIT
CablePMT MGT VCT EIT
* * * * * * *AC-3 audio 0x81 M M Ocaption service 0x86 M M Ocontent advisory 0x87 M M O
extended channel name 0xA0 M Mservice location 0xA1 S Mtime-shifted service 0xA2 M Mcomponent name 0xA3 M
user private *0xC0-0xFE * * * * * * *
Legend*MOS
descriptor may appear without restrictionswhen present, descriptor must appear in location shownwhen present, descriptor may optionally appear in second location shownthe service location descriptor must be present in the location shown
ATSC_CA (cond. access) 0x88 O O
*PMT
MOO
M
*
56 © 1997-2000Sarnoff Corporation
AC-3 Audio DescriptorSyntax Bits Format or Note
8
bsid 5 Same as bsid field in AC-3 stream
Number of bytes following this field
langcod2 8 Same as langcod2 field in AC-3 stream
4
Bytesdescriptor_tag 8 0x812descriptor_length
if num_channels = 0
if bsmod<2mainidreserved
textlentext_code
3‘11111’5Identifies main audio service
7 Length of text field that follows1 1 = ISO Latin-1; 0 = 16-bit Unicode
8*T Brief description of audio servicetext
3 Sample rate of encoded audiosample_rate_code
elseasvcflags 8 Links main and associated services
bit_rate_code 6 Indicates bit rate (exact or upper limit)surround_mode 2 Same as dsurmod field in AC-3 streambsmod 3 Same as bsmod field in AC-3 streamnum_channels 4 Indicates audio coding or number of channelsfull_svc 1 Indicates full or partial audio servicelangcod 8 Same as langcod field in AC-3 stream
8*A Additional description (not currently defined)additional_info
1
2
TA
57 © 1997-2000Sarnoff Corporation
Caption Service DescriptorSyntax Bits Format or Note
8
number_of_services 5 Number of closed caption services (1-16)
Number of bytes following this field
language 24 3-byte language code (ISO 639.2/B)
1 ‘1’cc_type 1 1 = DTV caption; 0 = line21 caption
7
Bytesdescriptor_tag 8 0x862
reserved
descriptor_length
for each service
if cc_type==line21reservedline21_field
easy_readerwide_aspect_ratio
5 ‘11111’1 1 = field 2; 0 = field 1
1 1 = text tailored to needs of beginning readers1 1 = text formatted for 16:9 displays14 ‘11111111111111’reserved
3 ‘111’reserved
elsecaption_service_number 6 Service number for this closed caption stream
For implementation details, see:• EIA-708-B, “Digital Television (DTV) Closed Captioning”.
58 © 1997-2000Sarnoff Corporation
Content Advisory DescriptorSyntax Bits Format or Note
8
rating_region_count 6 Number of rating regions (1-8)
Number of bytes following this field
rating_region 8 Rating region numberrated_dimensions 8 Number of rated dimensions2
Bytesdescriptor_tag 8 0x872descriptor_length
for each rating region
for each rated dimensionrating_dimension_jreserved
rating_description_lengthrating_description_text
8 Index into the RRT instance for this region4 ‘1111’
8 Length of text that follows (1 - 80)8*T Text in multiple string structure format
2 ‘11’reserved
rating_value 4 Rating value of this dimension and region
1
2
1T
Used to describe the content advisory rating value for an event.
59 © 1997-2000Sarnoff Corporation
Content Advisory Information for U.S.• To date, the U.S. is the only rating region that has been defined• This is documented in EIA-766, Sept. 1998 and summarized below
and in the following slides:
Syntax Element Valuerating_region 0x01rated_dimensions [0x01, 0x08] (program specific)rating_dimension [0x00, 0x07] (signifies dimension)rating_value Index into Rating Message Tablerating_description_length 0x00rating_description_text None
From EIA-766, Sept. 1998
60 © 1997-2000Sarnoff Corporation
Content Advisory Descriptor Examples
rating_region 0x01 Rating region = USrated_dimensions 0x01 Number of rated dimensions
rating_dimension_0 0x05 Signifies dimension “Children”rating_value 1 Signifies “TV-Y”
Example 1: “TV - Y”
rating_region 0x01 Rating region = USrated_dimensions 0x01 Number of rated dimensions
rating_dimension_0 0x00 Signifies dimension “Entire Audience”rating_value 3 Signifies “TV-PG”
Example 2: “TV - PG”
rating_region 0x01 Rating region = USrated_dimensions 0x01 Number of rated dimensions
rating_dimension_0 0x07 Signifies dimension “MPAA”rating_value 4 Signifies “MPAA-PG13”
Example 3: “MPAA - PG13”
From EIA-766, Sept. 1998
61 © 1997-2000Sarnoff Corporation
Content Advisory Descriptor Examples
rating_region 0x01 Rating region = USrated_dimensions 0x02 Number of rated dimensions
rating_dimension_0 0x00 Signifies dimension “Entire Audience”rating_value 4 Signifies “TV-14”
Example 4: “TV - 14 - V”
rating_dimension_1 0x04 Signifies dimension “Violence”rating_value 1 With Above, Signifies “TV-14-V”
rating_region 0x01 Rating region = USrated_dimensions 0x03 Number of rated dimensions
rating_dimension_0 0x00 Signifies dimension “Entire Audience”rating_value 5 Signifies “TV-MA”
Example 5: “TV - MA - L - S”
rating_dimension_1 0x02 Signifies dimension “Language”rating_value 1 With Above, Signifies “TV-MA-L”
rating_dimension_2 0x03 Signifies dimension “Sex”rating_value 1 With Above, Signifies “TV-MA-L-S”
From EIA-766, Sept. 1998
62 © 1997-2000Sarnoff Corporation
ATSC Conditional Access DescriptorSyntax Bits Format or Note
8 Number of bytes following this field
Bytesdescriptor_tag 8 0x882descriptor_length
16 Conditional Access System ID(privately defined)CA_system_ID 2
• The ATSC Conditional Access System (A/70) requires PSIPin order to be implemented. However, PSIP does notrequire CA descriptors.
• If present in the VCT, the CA descriptor is applicable to allevents on that virtual channel.
• The CA descriptor can be made event-specific by placing itin the EIT.
private_data_byte 8*T Private CA infoT
63 © 1997-2000Sarnoff Corporation
Extended Channel Name DescriptorSyntax Bits Format or Note
8 Number of bytes following this field
Bytesdescriptor_tag 8 0xA02descriptor_length
8*T Text in multiple string structure formatlong_channel_name_text T
The short name for a virtual channel is limited to 7 Unicode characters.This descriptor is used to provide a longer name for a virtual channel.
64 © 1997-2000Sarnoff Corporation
Service Location DescriptorSyntax Bits Format or Note
8
number_elements 8 Number of PID’s used for this program
Number of bytes following this field
stream_type 8
0x00: ITU-T/ISO/IEC reserved0x01-0x7F: As specified in Table 2.29 (stream type
assignments) of MPEG-2 Systems,ISO/IEC 13818-1
0x80: Used in other systems0x81: ATSC A/53 audio0x82-0x84: Used in other systems0x85: UPID (ATSC A/57)0x86-0xBF: Reserved0xC0-0xFF: User private
elementary_PID 13 PID for this elementary stream
6
Bytesdescriptor_tag 8 0xA12descriptor_length
for each element
ISO_639_language_code
reserved
24 Language used for this elementary stream
3 ‘111’
3 ‘111’reserved3 13 PID of TS packets containing PCR for this programPCR_PID
Note: this descriptor must be present in the TVCT!
65 © 1997-2000Sarnoff Corporation
Time Shifted Service DescriptorSyntax Bits Format or Note
8
number_of_servcies 5 Number of time-shifted services (1-20)
Number of bytes following this field
time_shift 10 Number of minutes this service is shifted (1-720)5
Bytesdescriptor_tag 8 0xA22descriptor_length
for each service
major_channel_number
reserved
10 Major channel number (1-99) of time shifted service
6 ‘111111’
3 ‘111’reserved 1
reserved 4 ‘1111’
minor_channel_number 10 Minor channel number (0-999) of time shifted service
This descriptor can be used for Near Video On Demand (NVOD) services,in which the same event is repeated, usually at regular intervals, on differentvirtual channels.
66 © 1997-2000Sarnoff Corporation
Component Name Descriptor (in PMT)Syntax Bits Format or Note
8 Number of bytes following this field
Bytesdescriptor_tag 8 0xA32descriptor_length
8*T Name in multiple string structure formatcomponent_name_string T
This descriptor can be used to provide a name for a component listed in theProgram Map Table (PMT). If used, it must appear in the PMT.
67 © 1997-2000Sarnoff Corporation
Multiple String Structure FormatSyntax Bits Format or Notenumber_strings 8 Number of strings in the following data
ISO_639_language_code 24 Language used for this stringnumber_segments 8 Number of segments in the following data4
Bytes
for each string
for each segment
compression_type
number_bytes
8
8 Number of bytes in field that followscompressed_string_byte 8*S A byte of this segment
1
3
0x00: No compression0x01: Huffman coding using standard encode/
decode defined in Table C.4 and C.5in A/65 Annex C.
0x02: Huffman coding using standard encode/decode defined in Table C.6 and C.7in A/65 Annex C.
0x03-0xAF: Reserved0xB0-0xFF: User private
mode 8
0x00-0x3E: 8-bit Unicode™0x3F: 16-bit Unicode™0x40-0xDF: Reserved for future ATSC use0xE0-0xFE: User private0xFF: Text mode is not applicable
S
68 © 1997-2000Sarnoff Corporation
Huffman-Based Text Compression• First-order (two-character) Huffman coding may be used
for text compression• Receivers must support Huffman decoding (requires less
than 2KB of storage)• Optimized Huffman tables for Titles and Program
Descriptions are provided
T h e n e x t010
00
0110010100 01101110
01000010011
01010
<term><term>assumed
Uncompressed:9 bytes = 72 bits
Compressed:39 bits
“T” followed by an “h”is much more likely than“e” followed by “x”
“ ” followed by an “n”uses an 8-bit escape sequencefollowed by the ASCII code for “n”
Example:
69 © 1997-2000Sarnoff Corporation
“Dino World”
Program Guide Formation
NBZ Local News “Dino World”12-0
NBZ
Local News12-1
NBZ-S Soccer - World Cup Golf12-2
(1997) Harrison Pontiac, Peg O’RyanDinosaurs eat Newark, NJ in this
Francis Ford Spielberg oscar-winning film.
April 8, 2000 6:11 pmChan Name 6:00 pm 6:30 pm 7:00 pm 7:30 pm 8:00 pm 8:30 pm
Table Tennis
PG-13
STT
VCT EIT-0 ETT-0
News&
Movies
ETT-V
CC (Eng, Fr)
RRT&
ContentAdvisory
CaptionService
Subscription Only
ConditionalAccess
70 © 1997-2000Sarnoff Corporation
Interra MProbe Demo
www.interra-video.com
71 © 1997-2000Sarnoff Corporation
Example: Sarnoff’s “Lipsync4” BitstreamTVCT
PID = 0x1FFB
“source1”6-1
source_id = 4092
“source2”6-2
source_id = 4091
“source3”6-3
source_id = 4090
EIT-0PID = 0x1FFA
“704x480 source2”source_id = 4091; event_id = 256
start_time = 573827062; length_in_seconds = 300
“704x480 source3”source_id = 4090; event_id = 320
start_time = 573827062; length_in_seconds = 300
“704x480 source1”source_id = 4092; event_id = 192
start_time = 573827062; length_in_seconds = 300
“source4”6-4
source_id = 4089
“704x480 source4”source_id = 4089; event_id = 384
start_time = 573827062; length_in_seconds = 300
Service Location Descriptor:PCR PID 0x61MPEG-2 Video PID 0x61AC-3 Audio PID 0x64
Note: TSID = all channel_TSID’s = 4
72 © 1997-2000Sarnoff Corporation
Forming PSIP Packets
• PSIP tables can start at any byte in a Transport Packetexcept for MGT, whose first byte must be the first payloadbyte. For MGT packets carrying the table_id field:– payload_unit_start_indicator = 1– pointer_field = 0x00.
• Table sections may span packet boundaries.• More than one PSIP table may be present within a single
Transport Packet.– pointer_field used to indicate offset of first table header– subsequent table locations found by section_length fields
• If packet payload does not include start of any PSIP table:– payload_unit_start_indicator = 0– pointer_field not present
73 © 1997-2000Sarnoff Corporation
Forming PSIP Packets
sync_byte(8 bits)
Generic PSIP Transport Packet Formattransport
errorindicator
(1 bit)
payloadunit startindicator
(1 bit)
transportpriority(1 bit)
PID(13 bits)
transportscrambling
control(2 bits)
adaptationfield
control(2 bits)
continuitycounter(4 bits)
0x47 0 0 or 1 0 PID 00 01 CC Pay-load
PSIP requires “01” for this field,meaning “no adaptation field,payload only”
PSIP requires “00” for this field,meaning “payload not scrambled”
PSIP requires “0x1FFB” for STT, MGT, VCT and RRT.EIT and ETT PID’s are defined in the MGT.
• For MGT packet carryingtable_id: PSIP requires “1” forthis field and 0x00 for pointerfield.
• If other tables start in this packet,PSIP requires “1” for this field,and a valid number for the pointerfield.
• If no tables start in this packet,PSIP requires “0” for this field andno pointer field
PF
pointerfield
(8 bits)
74 © 1997-2000Sarnoff Corporation
Example PSIP Packets
0x47 0 1 0 0x1FFB 00 01 CC MGT0x00MGT& STT
STT
sync tei pusi tpi PID tsc afc cont pointer
stuffing
0x47 0 1 0 0x1FFB 00 01 CC End of VCT0x80VCT& RRT
RRT
188 bytes
0x47 0 0 0 0x1FD0 00 01 CC Middle of EIT-0 SectionEIT-0(no pointer field)(PID pointed
to by MGT)
75 © 1997-2000Sarnoff Corporation
PSIP Generation/InsertionNTSC PLANT
[24] Etc.NTSC
INPUT
DATAEXTRACTOR
[31]
DATAINSERTER
[33]
DATABRIDGE
[32]
PSIP, UPIDand PSI
GENERATOR
M
ATSC
MUX
[90]
DIGITAL
OUTPUT
DATASERVER
[88]
M
MUX[81]
VIDEOENCODER
[79]
AUDIOENCODER
[80]
DATAEXTRACTOR
[77]
DIGITALPLANT[70] Etc.
WAN
[89]
DECODERS[52-53] Etc.
DEMUX[50][57]
M
DIGITAL
INPUT
NTSC
OUTPUT
Copyright © 1998 by the Advanced Television Systems Committee.
TOP-DOWN DATA PLANE
(taken from ATSC ImplementationSubcommittee’s “Top Down”
Report)
Management and ControlPlane Interface
Ensures consistencybetween PAT/PMT &
PSIP data.
76 © 1997-2000Sarnoff Corporation
Relevant PSIP Documents• PSIP Standard (A/65)
– “Program and System Information Protocol for TerrestrialBroadcast and Cable”, ATSC Document A/65, 23 Dec 1997.
– Available at www.atsc.org
• PSIP Corrigendum 1 (A/66)– “Technical Corrigendum No. 1 to ATSC Standard: Program
and System Information Protocol for Terrestrial Broadcastand Cable Doc. A/65 (23 Dec 97)”, ATSC Document A/66,17 Dec 1999.
– Flips polarity of 2 reserved bits in the tables– Revises core descriptor table– Adds Informative Annex G (PSIP for Cable)– Available at www.atsc.org
77 © 1997-2000Sarnoff Corporation
Relevant PSIP Documents (cont’d)• PSIP Amendment 1 (A/67)
– “Amendment No. 1 to ATSC Standard: Program and SystemInformation Protocol for Terrestrial Broadcast and CableDoc. A/65 (23 Dec 97)”, ATSC Document A/67, 17 Dec 99.
– Provides a means to deal with currently inactive channels– Available at www.atsc.org
• Conditional Access System for Terrestrial B’cast (A/70)– Defines ATSC_CA_descriptor for VCT and EIT
• “U.S. Region Rating Table (RRT) and Content AdvisoryDescriptor for Transport of Content Advisory InformationUsing ATSC A/65 Program and System InformationProtocol (PSIP)”, September 1998 (EIA-766)– Used for rating and content advisory in the U.S.
78 © 1997-2000Sarnoff Corporation
PSIP and Data Services (T3/S13)
• The Draft ATSC Data Broadcast Standardlists several requirements for PSIP:– Each virtual channel in the VCT shall include no
more than one data service– The data elementary stream is listed in the Service
Location Descriptor– The Data Event Table (DET) announces data
services.– DET’s are similar to EIT’s in structure, time span
and other constraints.– Long Term Service Table (LTST) can announce
data events far into the future.
79 © 1997-2000Sarnoff Corporation
Data Event Table Format (draft)Syntax of DET Table Bits Format or Note
num_data_in_section 8 Number of events in this DET sectionfor each data:
reserved 2 ‘11’data_id 14 Data ID. Also part of ETM_idstart_time 32 In units of GPS seconds since 12 am, 1/6/80reserved 2 ‘11’
ETM_location 2
00 = No ETM01 = ETM in PTC carrying this PSIP10 = ETM in PTC carrying this event11 = [reserved for future ATSC use]
length_in_seconds 20 Duration of data in sec (unbounded = 0xFFFFF)title_length 8 Length (in bytes) of title_text (0 = no title)title_text 8*T Data title (multiple string structure format)reserved 4 ‘1111’descriptors_length 12 Total length (in bytes) of data descriptorsdescriptors 8*D Descriptor data
1
10
T
2
D
BytesDET Header 9*8 DET Header (table_id = 0xCE)9
CRC_32 32 32-bit Cyclic Redundancy Check4
80 © 1997-2000Sarnoff Corporation
DET Example
DET-0source_id = 22
num_data_in _section = 3
71
72
73
DataID
12:30
14:30
LocalStartTime
7200
3600
9000
Length(seconds)
Adapted from draft ATSCData Broadcasting Standard
15:30
01(this PTC)
00(no ETM)
01(this PTC)
ETMLocation
Oodles ‘o bits
Solitaire
Game Pak
Title
data_servicedata_
servicedata_service,
PID_count
Descrip-tors
81 © 1997-2000Sarnoff Corporation
Data Service DescriptorSyntax Bits Format or Note
8 Number of bytes following this field
Bytesdescriptor_tag 8 0xA42descriptor_length
8data_service_profile 1
Note: a Data Service Descriptor is required for every data event
0x00: reserved0x01: ATSC Data Bcast Service Profile G10x02: ATSC Data Bcast Service Profile G20x03: ATSC Data Bcast Service Profile G20x04: ATSC Data Bcast Service Profile A10x05-0xFF: ATSC reserved
8data_service_level 1
0x00: no synchronized stream in service0x01: Data Service Level 1 (DBESn = 120120 B)0x02-0x03: ATSC reserved0x04: Data Service Level 4 (DBESn = 480480 B)0x05-0x0F: ATSC reserved0x10: Data Service Level 16 (DBESn = 1921920 B)0x11-0x3F: ATSC reserved0x40: Data Service Level 64 (DBESn = 7687680 B)0x41-0xFF: ATSC reserved
private_data_length 8 Length in bytes of field that followsfor each byte
private_data_byte 8 Private data
1
1
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Data Profile Attributes (draft)
383,896b/s
5
960
4500
System Latency(seconds)
sb_leak(x 400 b/s)
sb_size(bytes)
Max TerrestrialData Rate
ProfileG1Attributes
3,838,960b/s
10
9600
4500
ProfileG2
19.2Mb/s
10
48,000
10,000
ProfileG3
19.2Mb/s
N/A
48,000
10,000
ProfileA1
Guranteed BW Opportun-istic BW
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PID Count Descriptor (draft)Syntax Bits Format or Note
8 Number of bytes following this field
Bytesdescriptor_tag 8 0xA52descriptor_length
3 ‘111’reserved
2
This optional descriptor can help the receiver determine resources requiredfor PID handling.
13Max number of concurrent PID’s for thedata services. Shall include PID’s for DataService Table and Network Resources Table
total_number_of_PIDs
3 ‘111’reserved
2 13
Minimum number of PID’s that a receiver mustacquire simultaneously to provide a meaning-ful rendition of the service. 0 means theminimum number is unspecified.
min_number_of_PIDs
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Long Term Service Table (draft)
This is a special Data Event Table that can announce data services beyond thecurrently defined time period (far into the future).
Syntax of LTST Table Bits Format or Note
num_data_in_section 8 Number of events in this DET sectionfor each data:
reserved 1 ‘1’AV_association_flag 1 1 means the data is associated with AV event
start_time 32 In units of GPS seconds since 12 am, 1/6/80length_in_seconds 16 Duration of data in sec (unbounded = 0xFFFFF)
title_length 8 Length (in bytes) of title_text (0 = no title)title_text 8*T Data title (multiple string structure format)reserved 4 ‘1111’descriptors_length 12 Total length (in bytes) of data descriptorsdescriptors 8*D Descriptor data
1
10
T
2
D
BytesLTST Header 9*8 LTST Header (table_id = 0xD2)9
CRC_32 32 32-bit Cyclic Redundancy Check4
data_id 14 Data ID.
reserved 7 ‘1111111’ETM_flag 1 Indicates whether ETM is available
85 © 1997-2000Sarnoff Corporation
Relevant Committee Work• T3/S8 PSIP Ad Hoc Groups
– PSIP Ad Hoc Group (Art Allison, chair)– Directed Channel Change: Provides a means to enable
directed channel change, either by direct viewer selection orautomatically (Merrill Weiss, chair)
– Extensions to Accommodate Non-Alphabetic Characters:needed to support PSIP in other ATSC countries, such asKorea and Taiwan. Draft Recommended Practice has beenprepared. (Chao Yang, chair)
– Advanced EPG Functionality: Looking at content-baseddescription of events to allow improved browsing (RegisCrinon and Paul Martinez, chairs)
86 © 1997-2000Sarnoff Corporation
Relevant Committee Work (cont’d)• Other Topics (closed):
– GPS Time Annex– NVOD clarification– ETT table_id_extension– Unicode issues– Clarify events that cannot overlap– Correct private indicator bit in Table 4.1
• Other Topics (still open)– VCT scaling– Transmission of VCT’s with different branding (cable/air)– Private descriptors– Single-part channel numbers (cable)– Version management of shifting EIT’s– Clarify situations where analog pointer is to be believed
Update
87 © 1997-2000Sarnoff Corporation
Thank you!
• And thanks to the following for reviewingand improving this presentation:– Art Allison (NAB)– Jean-Louis Diascorn (Thomson Consumer
Electronics)– Art Greenberg (formerly of Sarnoff)– Tom Gurley (MSTV)– Bernie Lechner (Consultant, T3/S8 chair)– Gomer Thomas (LGERCA)