1. Understanding & Troubleshooting Closed Captions
Closed Caption EIA708/608
Doug Keltz
Sr Video Account Manager

2. Closed Caption by Closed viewer Captions within can the be program
Closed Caption can be enabled by the viewer within the program material.
As you can see Closed Captioning provides a means for hard of hearing viewers to be able to read a text description of the program. Allowing them to follow along with what is being said during the program, but it also can be used for a variety of other applications. You may have used Closed Captioning at home or seen it being used in a sports bar or other location to aid in the viewers following along with the program material.
It certainly has a wide variety of applications, but how does the program provider and broadcaster ensure that the closed caption data is carried within the video signal. by
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Understanding & Troubleshooting Closed Captions

3. Agenda FCC Requirements ANC Data Closed Captioning
Closed Caption Troubleshooting
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Advanced Ancillary Data Analysis and Closed Captions

4. FCC Requirements Agenda ANC Data Closed Captioning
Closed Caption Troubleshooting
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Advanced Ancillary Data Analysis and Closed Captions

5. Overview of new rules
July 1993, the FCC required all analog television receivers with screens 13 inches or larger sold or manufactured in the United States to contain built-in decoder circuitry to display closed captioning.
1996, Congress required video programming distributors (VPDs) to close caption their television programs.
1997, the FCC set a transition schedule requiring distributors to provide an increasing amount of captioned programming.
July 1, 2002, the FCC also required that digital television (DTV) receivers include closed captioning display capability.
Understanding & Troubleshooting Closed Captions

6. FCC Requirments
(12) Video programming provider. Any video programming distributor and any other entity that provides video programming that is intended for distribution to residential households including, but not limited to broadcast or nonbroadcast television network and the owners of such programming.
(b) Requirements for closed captioning of video programming—(1) Requirements for new English language programming. Video programming distributors must provide closed captioning for nonexempt video programming that is being distributed and exhibited on each channel during each calendar quarter in accordance with the following requirements:
(iv) As of January 1, 2006, and thereafter, 100% of the programming distributor's new nonexempt video programming must be provided with captions.
Seems pretty clear to me. 100% compliance.
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7. FCC Requirements
(c) Obligation to pass through captions of already captioned programs; obligation to maintain equipment and monitor for captions. (1) All video programming distributors shall deliver all programming received from the video programming owner or other origination source containing closed captioning to receiving television households with the original closed captioning data intact in a format that can be recovered and displayed by decoders meeting the standards of this part unless such programming is recaptioned or the captions are reformatted by the programming distributor.
(2) Video programming distributors shall take any steps needed to monitor and maintain their equipment and signal transmissions associated with the transmission and distribution of closed captioning to ensure that the captioning included with video programming reaches the consumer intact. In any enforcement proceeding involving equipment failure, the Commission will require video programming distributors to demonstrate that they have monitored their equipment and signal transmissions, have performed technical equipment checks, and have promptly undertaken repairs as needed to ensure that equipment is operational and in good working order.
(3) Each video programming distributor shall maintain records of the video programming distributor's monitoring and maintenance activities, which shall include, without limitation, information about the video programming distributor's monitoring and maintenance of equipment and signal transmissions to ensure the pass through and delivery of closed captioning to viewers, and technical equipment checks and other activities to ensure that captioning equipment and other related equipment are maintained in good working order. Each video programming distributor shall maintain such records for a minimum of two years and shall submit such records to the Commission upon request.
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8. FCC Requirements
(2) The video programmer will make reasonable efforts to employ live display captioning instead of real-time captioning for prerecorded programs if the complete program can be delivered to the caption service provider in sufficient time prior to airing.
(iii) Monitoring and Remedial Best Practices. Video programmers adopting Best Practices will take the following actions aimed at improving prompt identification and remediation of captioning errors when they occur.
(A) Pre-air monitoring of offline captions. As part of the overall pre-air quality control process for television programs, conduct periodic checks of offline captions on prerecorded programs to determine the presence of captions.
(B) Real-time monitoring of captions. Monitor television program streams at point of origination (e.g., monitors located at the network master control point or electronic monitoring) to determine presence of captions.
(D) Recording of captioning issues. Maintain a log of reported captioning issues, including date, time of day, program title, and description of the issue. Beginning one year after the effective date of the captioning quality standards, such log should reflect reported captioning issues from the prior year.
(B) The intended message of the spoken dialogue is conveyed in the associated captions in a clear and comprehensive manner.
Electronic Code of Federal Regulations
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9. The New Rules
On February 20, 2014, the FCC set new, improved rules for TV closed captioning to ensure that viewers who are deaf and hard of hearing have full access to programming, resolving concerns on captioning quality and providing much-needed guidance to video programming distributors and programmers.
The new rules apply to all television programming with captions, addressing quality standards for accuracy, synchronicity (timing), program completeness, and placement of closed captions, including the requirement that captions be:
Accurate: Captions must match the spoken words in the dialogue and convey background noises and other sounds to the fullest extent possible.
Synchronous: Captions must coincide with their corresponding spoken words and sounds to the greatest extent possible and must be displayed on the screen at a speed that can be read by viewers.
Complete: Captions must run from the beginning to the end of the program to the fullest extent possible.
Properly placed: Captions should not block other important visual content on the screen, overlap one another, run off the edge of the video screen, or be blocked by other information.
Understanding & Troubleshooting Closed Captions

10. Original content production – SDI
Places to monitor
Original content production – SDI
Completed files transferred in – MPEG & SDI
Files ready for transmission – MPEG & SDI
Programing leaving the broadcaster or MSO
8VSB, QAM-B, IPTV
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11. ANC Data Agenda FCC Requirements Closed Captioning
Closed Caption Troubleshooting
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Advanced Ancillary Data Analysis and Closed Captions

12. Analog NTSC Closed Caption
CEA 608 defines analog Closed Captioning
Data added to Line 21 of Field 1 and Field 2
Signal contains clock and two data bytes
Data rate of 120 Bytes per second or 960 bits per second
CEA 608 can carry services CC1-4 and TXT 1-4
In SD-SDI analog signal can be digitized as part of the active video or carried as ANC Data Packet.
Here we can see line 21 of a NTSC signal on a waveform monitor. The signal contains a clock run-in and two data bytes. There are two data bytes per field that are transmitted on each of the fields 1 and 2 of the composite video signal. This produces a total of a 120 bytes per second or a total of 960 bit per second. So the overall data rate is quite a small part of the video signal.
In this case the two data words are null since the data bits are at a low level. So there would be no active data at this time. The data bits will change dynamically when there is active data present within the signal. When this happens you should start to see decoded caption present within the picture display, if it is enabled within the device.
Within the closed caption data stream there are a variety of services defined as Closed Caption 1-4 and Text Services 1-4. The user can enable any one of the services to be displayed within the picture display via a menu of the television set or the picture display menu of the waveform monitor. To verify the presence of these service the Auxiliary Data Status of the waveform monitor can be used. This can help the engineer and operator determine which services are actually present within the signal.
Note the amplitude of the signal is typically 50 IRE, although if the signal is being received off- air it may have more noise present or have a lower amplitude. The position of the caption signal is important and the clock run in should nominally start 10.5us from the H-sync. To aid in decoding of the early or late closed caption signal there is a configuration menu within the waveform monitor that can be used to adjust the time of the decoded signal within the configuration menu of Aux Data Settings and the CEA 608 settings submenu. In this menu you can set the VBI Timing between Normal, early or late to aid in the decoding of the closed caption data on line 21.
The closed caption line 21 signal maybe digitized and be present in an SD-SDI signal as an active video line or the closed caption data can be carried as a ANC data packet within the vertical ancillary data space..
Advanced Ancillary Data Analysis

13. VANC HANC Ancillary Data Space
There are two blanking areas where data can be placed. The horizontal ancillary data space is between the EAV and SAV region of the signal. Typically such data as embedded audio is placed in this region of the signal.
The vertical blanking interval or VANC is typically where metadata such as timecode or VPID is placed each standard typically defines the location of the packets in conformance with SMPTE 291M.
Note the switching region in the vertical interval should not have ANC data present as this data could be lost or become corrupt when signals are switched.
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14. Digital 708 Closed Caption
CEA 708 defines Digital Closed Captioning
Data added VANC
One signal looks like any other
You need other tools to tell what the data is
Here we can see line 21 of a NTSC signal on a waveform monitor. The signal contains a clock run-in and two data bytes. There are two data bytes per field that are transmitted on each of the fields 1 and 2 of the composite video signal. This produces a total of a 120 bytes per second or a total of 960 bit per second. So the overall data rate is quite a small part of the video signal.
In this case the two data words are null since the data bits are at a low level. So there would be no active data at this time. The data bits will change dynamically when there is active data present within the signal. When this happens you should start to see decoded caption present within the picture display, if it is enabled within the device.
Within the closed caption data stream there are a variety of services defined as Closed Caption 1-4 and Text Services 1-4. The user can enable any one of the services to be displayed within the picture display via a menu of the television set or the picture display menu of the waveform monitor. To verify the presence of these service the Auxiliary Data Status of the waveform monitor can be used. This can help the engineer and operator determine which services are actually present within the signal.
Note the amplitude of the signal is typically 50 IRE, although if the signal is being received off- air it may have more noise present or have a lower amplitude. The position of the caption signal is important and the clock run in should nominally start 10.5us from the H-sync. To aid in decoding of the early or late closed caption signal there is a configuration menu within the waveform monitor that can be used to adjust the time of the decoded signal within the configuration menu of Aux Data Settings and the CEA 608 settings submenu. In this menu you can set the VBI Timing between Normal, early or late to aid in the decoding of the closed caption data on line 21.
The closed caption line 21 signal maybe digitized and be present in an SD-SDI signal as an active video line or the closed caption data can be carried as a ANC data packet within the vertical ancillary data space..

15. Digital Television Closed Caption
CEA 708 defines Digital Television Closed Captions
Supports backward compatibility with CEA 608
DTV
Bitstream
Audio
Video
MPEG
Control
User
Data
Bits
DTVCC
Transport
Channel
PMT
EIT
NTSC Caption CEA 608
DTVCC Caption Channel
Caption Service 1
Caption Service n
DTVCC Service Directory
608 Data rate of 960bps
708 Data rate of 9600bps
(708)
1080i places data in Field one only at p places data in at Frame rate at So the amount of data sent in 720p has to be ½ of what is sent in 1080i.
With the transition from analog to digital it is important to understand the CEA 708 closed captioning standard for Digital Television system.
The DTV bit stream contains a variety of elements which make up the transmission of the signal.
We will focus on the DTV closed caption data stream for the video signal which is encapsulated in the User data bits of the video stream in VANC, rather than carrying the data on line 21 within the video signal of the composite signal. DTV closed captions allows for a large capacity of data to be transported within the channel and the constant data rate is 9600bps . This increased capacity allows for the possibilities to simultaneous transmit captions in multiple languages and at multiple reading levels. The text is placed within the caption window on top of the picture and the text can have a variety of colors, size and other attributes.
Within the DTV closed caption channel backward compatibility to NTSC CEA 608 Closed caption is supported by allowing carriage of the two data bytes per field within the data stream.
As I have mentioned the data rate for the closed caption stream is a constant 9600pbs which means for a 60Hz frame rate signal that 20 bytes are transmitted per frame. CEA 608 occupies 960pbs and therefore within the data stream 8640bps can be used for DTV closed caption channel.
There are 6 standard services available within DTV closed caption with the ability to carry up to 57 additional extended services for a total of 63 services.
Service #1 is designated as the Primary Caption Service.
Service #2 is designated as the Secondary Language Service. This service contains captions in a secondary language which are translations of the captions in the Primary Caption Service.
The other service sub-channels are not pre-assigned.
We will take a look later at how this data stream is embedded within the video signal, as you can see it is a little more complex than NTSC closed captions with a variety of different services and support of CEA 608 captions within the data stream.

16. Ancillary Data Format ADF ADF – Ancillary Data Flag 000h,3FFh,3FFh
Type 2
SDID
(000h)
(3FFh)
(3FFh)
DID DC
User Data
Words
(max 255) CS
DBN
ADF
Type 1
ADF – Ancillary Data Flag 000h,3FFh,3FFh
DID – Data Identification Word
DBN – Data Block Number - for Type I
SDID – Secondary Data Identification - for Type 2
DC – Data Count
User Data Words up to a maximum of 255 words
CS – Checksum
The Ancillary data format is structure as shown in this diagram.
The Ancillary Data Flag is used to identify the start of the ANC data packet and uses the codeword 000,3FF,3FF. This is the reverse of the code words used for EAV and SAV data.
A DID Data Identification word is used to signify the type of data being carried.
For Type 1 ANC data the Data Block Number signifies the count of this particular data series. For instance this packet has a DBN of 12 then the next packet should have a DBN of 13 otherwise a data packets has been lost. This type 1 structure is used for embedded audio.
For the Type 2 Anc data the SDID is used which is a secondary Data ID allowing for a series of data to be grouped for instance the Dolby VANC data has a series of SDID to identify the audio channels the data is associated with.
The DC Data Count provide information on the number of data words within this ANC data packet. The amount of User data is variable up to a maximum of 255 words.
Finally a checksum is added to ensure the integrity of the data packet.
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17. Closed Captioning Agenda FCC Requirements ANC Data
Closed Caption Troubleshooting
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Advanced Ancillary Data Analysis and Closed Captions

18. Closed Caption Standards
Closed Caption is defined by the following standards
CEA 608 for standard definition analog NTSC
CEA 708 for Digital Television (DTV)
SMPTE 334-1
Vertical Ancillary Data Mapping of Caption Data and Other Related Data
SMPTE 334-2
Caption Distribution Packet (CDP) Definition
SMPTE EG 43
System Implementation of CEA 708 and CEA 608 Closed Captioning
Standard available from and
Closed caption was developed for analog composite NTSC and is standardized by CEA608 which carries that information on line 21 of the active video signal.
Within this data stream various closed caption services are available, these services can allow the support of multiple languages for instance English and Spanish captions. We will discuss this signal in more detail in a moment.
For digital television systems CEA 708 defines the process of embedding captions within the digital signal. In this system there is backwards compatibility support for CEA 608 allowing NTSC captions to be embedded along with the DTV Closed captions services.
For transport of the closed caption services within a broadcast facility SMPTE 334 defines the process of mapping the closed caption and other data services within the vertical ancillary data in the first part of the standard. While the second part of the standard defines the syntax and structure of the Caption Distribution Packet which carries a variety of closed caption and other data. We will take a look at this syntax structure later in the presentation.
SMPTE’s Engineering Guideline provides information on the system implementation of CEA 708 and CEA 608 closed caption data.
These standard are available from the Consumer Electronics Association at CEA.ORG and from the Society of Motion Picture and Television engineers at smpte.org.
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19. How to Configure Closed Caption Decoding
Select one of the tiles and press PICT button
Push and Hold PICT button to access menu
Navigate to CC/ Teletext format
Select CEA 708
Repeat process for another tile and select CEA 608
For this demonstration we are using a WFM7200, but the same process can also be performed on a WVR series rasterizer.
The aim is to configure the instrument to simultaneously decode both CEA708 and 608 closed captions using two separate picture displays.
Firstly select one of the tiles using one the Display select buttons and then press the PICT button to select the picture display for that tile.
If you wish press the full button to display the picture tile full screen as in this case.
Then Push and Hold the Picture button to bring up the picture menu as shown in this image.
Use the arrow to navigate up and down the menu or use the general knob to scroll to the CC /Teletext Format menu item.
Press SEL to enter the submenu and select CEA 708 in order to decode the captioning within the picture display if present .
Now repeat this process for a different tile. Press Full to return to 4 tile mode and select a different tile and press the picture button to display another picture display. Push and Hold picture button to display the menu. Now in this case within the CC Teletext format submenu select CEA 608.
Now one picture tile will be decoding CEA708 and the other picture tile will be decoding CEA608 closed caption if present.
If you do not see closed caption being decode you should check that you are decoding the appropriate closed caption services. For CEA 708 you can select service 1 to 6 and for CEA 608 you can select CC1-4 or TXT 1-4 services.
You can verify that certain services are present within the Aux illary Data Display which we will discuss in the next slde.
Understanding & Troubleshooting Closed Captions

20. Simultaneous Closed Caption Display
Configure one Tile to decode CEA 708
Configure another tile for to decode CEA 608
Multiple Language Captions
Select one Tile for CC1 for 608 or Service 1 for 708
You can also look for 2nd service, CC3 for 608 or Service 2 for 708
Within the configuration menu of the waveform monitor there are a variety of configuration for the CEA 708 and 608 settings.
Press the CONFIG button and navigate to AUX Data Settings using the Up and down arrow keys or the general knob
Press SEL to enter the sub menu and select CEA 608 Settings. Press SEL again to enter this menu and select CEA 608 Transport as shown in the display. There are a set of modes to set for CEA 608 decoding types.
In Auto mode: The instrument automatically searches for CEA 608 streams and sets the transport based on the first stream detected.
For Composite: Searches only for CEA 608 (VBI)
For SD: Searches for CEA 608 (VBI), then 608-ANC
For HD: Searches for 608-ANC, then CEA 608
The user can also force the mode to one of the types such as
Line 21 that selects the data present on line 21 in a 525 format of a composite or SD SDI signal.
S334 (RAW) select ANC Data conforming to CEA 608 and
S334 (CDP) select 608 data that is present within the DTV closed caption transport commonly referred to as CEA 608 in 708.
CEA 708
CEA 608
Understanding & Troubleshooting Closed Captions

21. Tools to use for Troubleshooting Closed Caption
In-Picture closed caption decode
Check V-Chip rating
CEA708 CC1 CA:(US TV) TV-G
CEA608 CC1 CA:(US TV) TV-G
The closed caption data embedded within the video signal should conform to SMPTE 334 which defines the process of encapsulating the closed caption data within the vertical Ancillary data space of the signal.
To view this data the DAT option should be installed within the WFM7200. To enable the ANC Data Inspector select one of the tiles and press the measure button.
Push and hold the measure button to access the measure menu. Navigate to the Display Type menu and press SEL: to enter the sub menu, using the arrow keys or general knob select the ANC Data Display within the menu.
Press the Full menu to display the ANC Data Inspector in full screen mode and the screen will look something similar to the display shown.
Next look for the Closed caption data which should be identified by the S334 name. Use the arrow keys to navigate to the specific data type. The lower window will contain detailed information on the ANC data packet.
ANC data inspector provides a simply way to verify the presence of all ANC data present within the video signal.
Understanding & Troubleshooting Closed Captions

22. Tools to use for Troubleshooting Closed Caption
In-Picture closed caption decode
Check V-Chip rating
Aux Data Status
Shows presence
Shows Number of services
ANC Data Inspector
Shows presence of ANC data packets
The closed caption data embedded within the video signal should conform to SMPTE 334 which defines the process of encapsulating the closed caption data within the vertical Ancillary data space of the signal.
To view this data the DAT option should be installed within the WFM7120. To enable the ANC Data Inspector select one of the tiles and press the measure button.
Push and hold the measure button to access the measure menu. Navigate to the Display Type menu and press SEL: to enter the sub menu, using the arrow keys or general knob select the ANC Data Display within the menu.
Press the Full menu to display the ANC Data Inspector in full screen mode and the screen will look something similar to the display shown.
Next look for the Closed caption data which should be identified by the S334 name. Use the arrow keys to navigate to the specific data type. The lower window will contain detailed information on the ANC data packet.
ANC data inspector provides a simply way to verify the presence of all ANC data present within the video signal.
Understanding & Troubleshooting Closed Captions

23. ANC Data Inspector and Closed Caption Data
Select one of the tiles and press MEASURE button
Push and Hold MEASURE button to access menu
Navigate to Display Type and select ANC Data Display
Press Full to display ANC Data Display
Navigate to Closed Caption data and press MAG
The closed caption data embedded within the video signal should conform to SMPTE 334 which defines the process of encapsulating the closed caption data within the vertical Ancillary data space of the signal.
To view this data the DAT option should be installed within the WFM7120. To enable the ANC Data Inspector select one of the tiles and press the measure button.
Push and hold the measure button to access the measure menu. Navigate to the Display Type menu and press SEL: to enter the sub menu, using the arrow keys or general knob select the ANC Data Display within the menu.
Press the Full menu to display the ANC Data Inspector in full screen mode and the screen will look something similar to the display shown.
Next look for the Closed caption data which should be identified by the S334 name. Use the arrow keys to navigate to the specific data type. The lower window will contain detailed information on the ANC data packet.
ANC data inspector provides a simply way to verify the presence of all ANC data present within the video signal.
Understanding & Troubleshooting Closed Captions

24. Closed Caption Troubleshooting
Agenda
FCC Requirements
ANC Data
Closed Captioning
Closed Caption Troubleshooting
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Advanced Ancillary Data Analysis and Closed Captions

25. Closed Caption Problems
Picture Display not decoding Closed Captions
Verify that CC is enabled and the correct service is selected
Check Aux Data Status for presence of Closed Captions
Verify that there is not more than one caption being inserted
Verify the order of the Caption inserter in the food chain
Does the frame rate of closed caption match video frame rate
Mismatches in frame rate can cause encoder problems
May need to delve into the ANC data packet or MPEG
You first indication of a closed caption problem will likely be that the caption are not being decoded within the picture display.
In this case you need to verify if the closed caption data stream is actually present within the signal and the appropriate services are present.
This information can be found within the Aux Data Status that provides indication of the presence of the closed caption data types present and which services have been detected.
You should then verify if the appropriate service is being decoded within the picture display
For CEA 608 caption you may wish to check the presence of the V-Chip rating and that the value is set correctly for the program. This could affect the ability of the television receiver to display a signal depending on the configuration of the consumers set. That could lead to the program being blocked an not being displayed on the TV. by by
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Understanding & Troubleshooting Closed Captions

26. Closed Caption Problems
Picture Display not decoding Closed Captions
Check Aux Data Status for presence of Closed Captions
You first indication of a closed caption problem will likely be that the caption are not being decoded within the picture display.
In this case you need to verify if the closed caption data stream is actually present within the signal and the appropriate services are present.
This information can be found within the Aux Data Status that provides indication of the presence of the closed caption data types present and which services have been detected.
You should then verify if the appropriate service is being decoded within the picture display
For CEA 608 caption you may wish to check the presence of the V-Chip rating and that the value is set correctly for the program. This could affect the ability of the television receiver to display a signal depending on the configuration of the consumers set. That could lead to the program being blocked an not being displayed on the TV.
Advanced Ancillary Data Analysis and Closed Captions

27. Cross converted 720p materialX
A lot of material for 720p airing starts it’s life as 1080i content.
1080i to 720p Video Cross convert
Copy 708 Anc data
1080i to 720p Video Cross convert
1080i to 720p Anc Data Cross convert

28. Understanding 720p Auxiliary Data Status Display
Select one of the tiles and press Status button
Push and Hold Status button to access menu
Navigate to Display Type and select Aux Data Status
You should now have two picture tiles one decoding CEA 708 and the other decoding CEA 608. If not you may need to verify the presence of the closed caption data within the signal. This can be done using the Auxiliary Data Status
To enable this display select one of the tiles and press the Status button.
Push and Hold the Status button to access the menu and navigate to Display Type and select the Aux Data Status to view the display as shown.
This display will show the presence of the types of closed caption data streams within the signal.
In this case CEA608 is present as a CDP ANC packet with closed caption service 1 & 3 present.
Additionally CEA 708 is present as a CDP ANC packet with Closed caption service 1 present.
Besides informing you about the types of closed caption data stream present and the services contained within the streams.
You can also determine if a variety of other data services are present such as V Chip Rating, Extended Data Services XDS, Transport ID RP 207, CGMS-A, Broadcast Flag and Caption Distribution Packets are present.
Once you have verified the services present you may have to configure the CEA 608 settings within the configuration menu to select the appropriate data stream.
For 720p
Frame rate must be 59.94
608 data count must be 2
Understanding & Troubleshooting Closed Captions

29. Bad 720p Frame rate Frame rate set at a 1080i rate
Understanding & Troubleshooting Closed Captions

30. Understanding 1080i Auxiliary Data Status Display
Select one of the tiles and press Status button
Push and Hold Status button to access menu
Navigate to Display Type and select Aux Data Status
You should now have two picture tiles one decoding CEA 708 and the other decoding CEA 608. If not you may need to verify the presence of the closed caption data within the signal. This can be done using the Auxiliary Data Status
To enable this display select one of the tiles and press the Status button.
Push and Hold the Status button to access the menu and navigate to Display Type and select the Aux Data Status to view the display as shown.
This display will show the presence of the types of closed caption data streams within the signal.
In this case CEA608 is present as a CDP ANC packet with closed caption service 1 & 3 present.
Additionally CEA 708 is present as a CDP ANC packet with Closed caption service 1 present.
Besides informing you about the types of closed caption data stream present and the services contained within the streams.
You can also determine if a variety of other data services are present such as V Chip Rating, Extended Data Services XDS, Transport ID RP 207, CGMS-A, Broadcast Flag and Caption Distribution Packets are present.
Once you have verified the services present you may have to configure the CEA 608 settings within the configuration menu to select the appropriate data stream.
For 1080i
Frame rate must be 29.97
608 data count must be 4
Understanding & Troubleshooting Closed Captions

31. Caption Data Packet (CDP) lengths
CDP with one service with and with out Service Information.
CDP with Service Information
Video Format
Contains Service Information
CDP Length
720p
Yes 52 No 43
1080i 82 73
Video Format
Number of Services
CDP Length
720p 1 52 2 59 3 66 4 73
1080i 82 89 96
103
Caption Service Descriptor that is carried in the PMT and EIT tables in the MPEG-2 emission transport stream. During the distribution chain, the EIA 708-B captioning data may be rendered and displayed for quality control purposes.
Understanding & Troubleshooting Closed Captions

32. ANC Data Inspector and Closed Caption Data
Check the DC (Data Count) and Check Sum
The closed caption data embedded within the video signal should conform to SMPTE 334 which defines the process of encapsulating the closed caption data within the vertical Ancillary data space of the signal.
To view this data the DAT option should be installed within the WFM7120. To enable the ANC Data Inspector select one of the tiles and press the measure button.
Push and hold the measure button to access the measure menu. Navigate to the Display Type menu and press SEL: to enter the sub menu, using the arrow keys or general knob select the ANC Data Display within the menu.
Press the Full menu to display the ANC Data Inspector in full screen mode and the screen will look something similar to the display shown.
Next look for the Closed caption data which should be identified by the S334 name. Use the arrow keys to navigate to the specific data type. The lower window will contain detailed information on the ANC data packet.
ANC data inspector provides a simply way to verify the presence of all ANC data present within the video signal.
Understanding & Troubleshooting Closed Captions

33. Caption Data Packet (CDP) lengths
CDP with one service with and with out Service Information.
For a 720P service with one 708 service we should have a CDP length of 43
Video Format
Contains Service Information
CDP Length
720p
Yes 52 No 43
1080i 82 73
Understanding & Troubleshooting Closed Captions

34. Caption Data Packet (CDP) lengths
CDP with one service with and with out Service Information.
One thing to look for CDP Length
Correct
No Service Information
The data for showing service Information may be formatted correctly and Legal, some processing equipment may not be able to handle it correctly
Service Information for two services
Service Information for three services
Understanding & Troubleshooting Closed Captions

35. Interpreting Closed Caption Data Stream
To help in interpreting the closed caption data stream I have extracted the ANC Data Inspector lower window and then added the syntax for each part of the data stream. Lets go through these values step by step.
First there is a closed caption distribution packet header denoted by this should always be at the start of the data stream. Following this value is a Data Count value which should match the DC value contain in the summary information of ANC Data Inspector. These value has a certain allowed range which depends on the format of the video signal. For instance in 1080i with service information the CDP length will be 82 bytes decimal or 52 hex.
The CDP also contains the Frame Rate value this bytes is shown in cyan in the image and can be decode using the Aux Data Status display. The frame rate is denoted by the first 4 Most Significant Bits of the byte in this case 4 which indicates a frame rate of
The next data byte provides information on the services present within the data stream and the following two bytes are a CDP header count sequence..
The closed caption data section is denoted by the hex value of 272 followed by the closed caption data count. The lowest 5 bits of this value indicate the number of data words which in this case is 20.
A value of 2FC hex indicates CEA608 line 21 field 1 closed caption data and the following two bytes are the actual closed caption data a value of would indicate no actual active data is present. Similarly a value of 1FD hex indicates CEA 608 line 21 field 2 closed caption data. So we have identify the presence of CEA 608 closed caption data within the stream.
Understanding & Troubleshooting Closed Captions

36. Missing Window Clear or Toggle Command
Understanding & Troubleshooting Closed Captions

37. Caption Issues
Blank line
Strange Text

38. What caused the Issue Telestream’s MacCaption / CaptionMaker
Understanding & Troubleshooting Closed Captions

39. Strange Caption issues
608 Captions show up in the wrong line order

40. Strange Caption issues
608 Captions show up in the wrong line order

41. MPEG Stream with Missing Captions
No Caption in the #1 service
Only 608 in the #2 service
No captions in the #3 service

42. MPEG Stream with Good Captions
Has 608 & 708 on all services

43. MPEG Caption Decode and Analysis
Service to Show on Screen
Window Parameters
On picture Text overlay
What is in the Stream
Text Buffer Window
Understanding & Troubleshooting Closed Captions

44. MPEG Header view
Formatted correctly but most STB’s will not decode the captions. The Caption are not the First User data Packet
Captions are in User data fields in the header of the Video before the Picture
Good CC File
Data before Caption Data in the file
Caption Data in the file
Only Caption Data in the file

45. Closed Caption Data in MPEG (MTS4EA Dump)
Unknown User
data as 1st packet
Closed caption
data as 1st packet
Closed caption
data as 2nd item
Some Decoders will not be able to decode because captions are not the first User data packet
AFD Code
data as 2nd item
Good Closed Caption
Bad Closed Caption

46. Interpreting Closed Caption Data Stream
Ancillary Data is becoming more prevalent within SDI for a variety of functions.
Embedded Audio, Video Payload ID
Ancillary Data Inspector simplifies ANC Data monitoring
Easily shows what ANC data is present within the SDI signal
The high speed data for 3Gb/s can be monitored in a familiar way using the traditional waveform display. The WFM7120 with option 3G allows the 3G data to be combined to produce traces displays which are in common use with operators and engineers today.
The 3Gb/s standard supports a variety of data mapping structures although today most equipment is primarily support mapping structure 1 for Level A and B.
Within the SDI transport a wide variety of ANC data can be placed such as Embedded audio or video payload identification. It can be difficult to determine all of the various data types present within the signal. With the Ancillary data inspector ANC Data monitoring can be simplified by using the Watch List. This shows all of the present ANC data within the signal and clearly shows if ANC Data has been present or is missing.
Advanced Ancillary Data Analysis

47. MOC.KET.WWW More Information 9/17/2018 48
Advanced Ancillary Data Analysis and Closed Captions
Advanced Ancillary Data Analysis