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US 2001/0017892 A1Published application
Analog video tagging and encoding system
AssigneeTiVo Inc.
InventorsJames M. Barton, Howard Look
Life of this patent
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AssigneeTiVo Inc.
InventorsJames M. Barton, Howard Look
Estimating the term…
An analog video tagging and encoding system. The invention inserts an analog tag frame into the analog video stream such that the luminance (Y) values are made to approach zero, i.e., black, allowing a potential tag frame to be quickly identified. Tag information is then encoded as a structured color pattern into the chrominance (Cb and Cr) portions of the frame, making the tag itself invisible to the casual viewer and contains program start/stop information, program segment identification, or data downloads. The color pattern is chosen such that when it is converted into digital form, the digital signal so produced may be easily and minimally parsed to recognize the presence or absence of a tag within a normal frame time period. In a simple embodiment of the invention, the structured analog color pattern may appear as a pattern of colored blocks aligned with the macroblock segmentation performed on the analog signal by the MPEG encoding process, causing the DC component of the encoded Cr and C b macroblocks to precisely reflect the color pattern. The simplest color pattern uses two colors with extremely different Cr or Cb values, and derives a binary encoding sequence where a binary zero (0) might be represented by values near one color, and a binary one (1) represented by values near the other color and is easily extended to create a number of different chrominance levels within each encoded macroblock, allowing multiple bits of tag information to be encoded by each macroblock. Another embodiment of the invention provides a method whereby “trimming” of the analog signal (i.e., truncation of the signal in the vertical or horizontal direction during transmission) has no effect on the ability to derive the tag from the encoded frame. A window is selected within the tag frame such that the size of the window is known to most likely fit within a trimmed frame and transmitted in its entirety with the tag information redundantly encoded within or outside the window to guarantee that no portion of the tag information is omitted whenever the frame is transmitted. Square colored blocks of a multiple of the macroblock size are used such that a phase encoding is achieved which is easily detected during a single pass over the MPEG bitstream. To insure that all tag data is present, the tag frame is preceded and possibly followed by “reset” frames which are exactly opposite from the tag frame, forcing the MPEG encoder to generate all macroblocks for the tag frame, regardless of whether the current frame is an I-frame or not.
A process for encoding in-band data into analog video signals that is preserved through the transmission and digital conversion process in a computer environment, comprising the steps of:
A process for encoding in-band data into analog video signals that is preserved through the transmission and digital conversion process in a computer environment, comprising the steps of:
An apparatus for encoding in-band data into analog video signals that is preserved through the transmission and digital conversion process in a computer environment, comprising:
An apparatus for encoding in-band data into analog video signals that is preserved through the transmission and digital conversion process in a computer environment, comprising:
Dependencies are inferred from the claim text.