Communication of HBI data in digital television data streams

• US 6,400,767 B1
• Filed: 09/18/1998
• Issued: 06/04/2002
• Est. Priority Date: 01/16/1997
• Status: Expired due to Term

• Current Assignee: ARRIS Enterprises LLC (CommScope Holding Company, Inc.)
• Original Assignee: General Instrument Corporation (CommScope Holding Company, Inc.)
• Inventors: Nuber, Ray, Walker, G. Kent
• Primary Examiner(s): Britton, Howard
• Application Number:
  US09/156,484
• Time in Patent Office: 1,355 Days
• Field of Search: H04/N.7025, H04/N.7088, 375/240.26, 375/240.01, 375/240.25, 348/467, 348/473, 348/476, 348/479, 348/716
• US Class Current: 375/240.26
• CPC Class Codes: H04N 19/107 between spatial and temporal predictive coding, e.g. picture refresh
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 19/89 involving methods or arrangements for detection of transmission errors at the decoder

Abstract

A method and apparatus are provided for communicating HBI user information in digital television data streams via a generic syntax. The syntax allows the digital transport of virtually any type of user data that may be carried in the HBI or overscan portion of an analog television signal. A pixel generator is used to insert HBI data into a digital video signal using information provided in the user portion of the digital data stream. The syntax provides the pixel generator with the start time of the first symbol, the number of pixels per symbol, the high and low levels to insert, the fraction of the symbol time that is transition time, the number of symbols to insert and the first frame line number on which to insert the data.

Claims

1. A method for communicating, in a digital television data stream, information of a type conventionally carried as PAM data in a horizontal blanking interval (HBI) waveform or in video overscan regions of an analog television signal, said digital television data stream transporting data according to a convention that includes a user data syntax, said method comprising the steps of:

supplementing said user data syntax with a line indicator value specifying a first horizontal television field line in which user information is carried as PAM data in a counterpart television signal;

supplementing said user data syntax with at least one timing reference value that defines a relationship between a symbol rate of said PAM data and a reference clock of said digital television data stream; and

supplementing said user data syntax with a user information field sufficient to carry the user information.

2. A method in accordance with claim 1 comprising the further step of:

supplementing said user data syntax with a start sample value indicative of a sample point at which a transition into a first luma PAM symbol is to commence in a counterpart television signal reconstructed from said digital television data stream.

3. A method in accordance with claim 2 comprising the further step of:

supplementing said user data syntax with a first amplitude value indicative of an amplitude at which luma PAM symbols are to appear in said counterpart television signal reconstructed from said digital television data stream.

4. A method in accordance with claim 3 comprising the further step of:

supplementing said user data syntax with a pulse shape value indicative of a pulse shape that is to be provided for said luma PAM symbols in said counterpart television signal reconstructed from said digital television data stream.

5. A method in accordance with claim 4 comprising the further step of:

supplementing said user data syntax with a field number indicative of a television field in which corresponding HBI data is to be inserted in said counterpart television signal reconstructed from said digital television data stream.

6. A method in accordance with claim 5 comprising the further step of:

supplementing said user data syntax with a second amplitude value indicative of a second amplitude level of said luma PAM symbols.

7. A method in accordance with claim 6 wherein said timing reference value comprises a luma PAM symbol clock increment value and a luma PAM modulus value, said symbol clock increment and modulus values being related to said PAM symbol rate and said reference clock as follows:

$\frac{\mathrm{increment}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{value}}{\mathrm{modulus}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{value}}=\frac{\mathrm{symbol}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{rate}}{\mathrm{reference}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{clock}}.$

8. A method in accordance with claim 6 wherein said count value comprises a word count indicating an integer number of luma PAM words that follow and a remainder count indicating a number of luma PAM bits totaling less than a full luma PAM word that follow;

said syntax thereby providing an efficient use of bandwidth by enabling remainders of less than a full PAM word to be communicated.

9. A method in accordance with claim 8 wherein said luma PAM words are each 22 bits in length, said method comprising the further step of:

inserting a marker bit after each luma PAM word to guard against a false MPEG start code.

10. A method in accordance with claim 6 wherein:

said user information is carried according to said user data syntax as luma PAM words and luma PAM bits;

each luma PAM word comprises a string of luma PAM symbols with the first bit corresponding to a first luma PAM symbol to be reconstructed on video lines as displayed from left to right and then top to bottom; and

each luma PAM bit represents a luma PAM symbol to be reconstructed on said video lines;

said luma PAM bits being provided in the order in which their symbols are to be reconstructed on said video lines subsequent to symbols reconstructed from any luma PAM words, as displayed from left to right and then top to bottom.

11. A method in accordance with claim 1 wherein:

said PAM data is carried in a luminance (luma) portion of said television signal; and

said timing reference value comprises a luma PAM symbol clock increment value and a luma PAM symbol clock modulus value, said symbol clock increment and modulus values being related to said PAM symbol rate and said reference clock as follows;

$\frac{\mathrm{increment}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{value}}{\mathrm{modulus}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{value}}=\frac{\mathrm{symbol}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{rate}}{\mathrm{reference}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{clock}}.$

12. A method in accordance with claim 1 wherein:

said PAM data is carried in a luminance (luma) portion of said television signal; and

said count value comprises a word count indicating an integer number of luma PAM words that follow and a remainder count indicating a number of luma PAM bits totaling less than a full luma PAM word that follow;

said syntax thereby providing an efficient use of bandwidth by enabling remainders of less than a full PAM word to be communicated.

13. A method in accordance with claim 1 wherein:

said PAM data is carried in a luminance (luma) portion of said television signal;

said user information is carried according to said user data syntax as luma PAM words and luma PAM bits;

each luma PAM word comprises a string of luma PAM symbols with the first bit corresponding to a first luma PAM symbol to be reconstructed on a video line as displayed from left to right and then top to bottom; and

each luma PAM bit represents a luma PAM symbol to be reconstructed on said video line;

said luma PAM bits being provided in the order in which their symbols are to be reconstructed on said video lines of said field, starting on said first horizontal television field line subsequent to symbols reconstructed from any luma PAM words, as displayed from left to right and then top to bottom.

14. Receiver apparatus for decoding, from a digital television data stream, user information of a type conventionally carried as PAM data in a horizontal blanking interval (HBI) waveform or video overscan region of an analog television signal, said digital television data stream transporting data according to a convention that includes a user data syntax, comprising:

a syntax processor for detecting information carried in accordance with said user data syntax, said information including;

a first value identifying first horizontal television line(s) in which particular user information is carried in a counterpart television signal,

a second value identifying a relationship between a PAM symbol rate of said counterpart television signal and a digital television data reference clock,

a third value indicating an amount of user information carried in the digital television data stream, and

said user information;

a reconstruction processor responsive to said first, second and third values for formatting said user information into HBI PAM data; and

a HBI inserter for inserting said HBI PAM data into a television signal reconstructed from said digital television data stream.

15. Apparatus in accordance with claim 14 wherein:

said syntax processor detects a start sample value indicative of a sample point at which a transition into a first PAM symbol is to commence on each line in said reconstructed television signal; and

said HBI inserter is responsive to said start sample value for inserting said PAM data into said reconstructed television signal.

16. Apparatus in accordance with claim 15 wherein:

said syntax processor detects a first amplitude value indicative of an amplitude at which PAM symbols are to appear in said reconstructed television signal; and

said reconstruction processor is responsive to said first amplitude value to provide said HBI PAM data at said amplitude.

17. Apparatus in accordance with claim 16 wherein:

said syntax processor detects a pulse shape value indicative of a pulse shape that is to be provided for said PAM symbols in said reconstructed television signal; and

said reconstruction processor is responsive to said pulse shape value to provide said HBI PAM data with said pulse shape.

18. Apparatus in accordance with claim 17 wherein:

said syntax processor detects a field number indicative of a television field in which corresponding HBI data is to be inserted in said reconstructed television signal; and

said HBI inserter is responsive to said field number for inserting said corresponding HBI data into a proper field.

19. Apparatus in accordance with claim 18 wherein:

said syntax processor detects a second amplitude value indicative of a second amplitude at which PAM symbols are to appear in said reconstructed television signal; and

said reconstruction processor is responsive to said first and second amplitude values to provide said HBI PAM data at said first and second amplitudes.