Disparity data transport and signaling
View Patent ↗A method of decoding closed caption disparity data, involves a TV receiver receiving closed caption disparity data for a 3D display encoded as a sequence of frame interval/slope change pairs, with the frame interval representing a designated number of frames over which each linear function representing disparity is to be applied paired with a value indicating a change in slope from the slope of a preceding segment. A first segment in the sequence presumes a predetermined slope as a reference. A sequence of caption data packets specifies a closed caption display window containing closed caption text. The disparity value is used in each frame to determine a horizontal offset of left and right eye views of the CC display that establishes the closed caption display window's perceived z-axis position. This abstract is not to be considered limiting, since other embodiments may deviate from the features described in this abstract.
1. A method of decoding closed caption disparity data, comprising:
at a television receiver device, receiving the closed caption disparity data encoded as a sequence of one or more frame interval and slope change pairs, each frame interval and slope change pair including a frame interval, which represents a designated number of frames that occur prior to application of the slope change paired with the respective frame interval, and a slope change value, which indicates a change in slope from the slope set by a preceding frame interval and slope change pair;
where the sequence of one or more frame interval and slope change pairs further includes an initial frame interval and slope change pair that precedes the one or more frame interval and slope change pairs, the initial frame interval and slope change pair including a slope change value which indicates a change in slope to be applied to a slope of zero;
receiving a sequence of closed caption data packets, where the sequence of closed caption data packets specify closed caption text, where the closed caption data packets are packaged in a digital television caption channel stream of packets;
where the closed caption disparity data is used in a 3D rendering of left and right eye views of the closed caption text to establish a horizontal offset that establishes a perceived z-axis position of the closed caption text corresponding to each frame;
receiving an alternate fixed disparity value that establishes a fixed disparity for the closed caption text packaged along with the closed caption disparity data for use as an alternative perceived z-axis position; and
processing the closed caption text and the closed caption disparity data to produce an output suitable for defining the rendering of a three dimensional image with a display of the closed caption text at the perceived z-axis position defined by the closed caption disparity data.
2. A method of decoding closed caption disparity data, comprising:
at a television receiver device, receiving the closed caption disparity data encoded as a sequence of one or more frame interval and slope change pairs, each frame interval and slope change pair including a frame interval value, which represents a designated number of frames that occur prior to application of the slope change paired with the respective frame interval, and a slope change value, which indicates a change in slope from the slope set by a preceding frame interval and slope change pair;
where the sequence of one or more frame interval and slope change pairs further includes an initial frame interval and slope change pair that precedes the one or more frame interval and slope change pairs, the initial frame interval and slope change pair including a slope change value which indicates a change in slope to be applied to a predetermined slope;
receiving a sequence of caption data packets, where the sequence of caption data packets specify closed caption text; and
where the closed caption disparity data is used to determine a horizontal offset of left and right eye views of the closed caption text that establishes a perceived z-axis position of the closed caption text corresponding to each frame.
3. The method according to claim 2 , where the predetermined slope is zero.
4. The method according to claim 2 , where the slope change is signaled as a value in the range −16 to +15 that indicates the amount of change in slope to apply after the designated frame interval.
5. The method according to claim 2 , further comprising receiving an alternate fixed disparity value that establishes a fixed perceived z-axis position for the closed caption text packaged along with the encoded closed caption disparity data for use as an alternative z-axis position.
6. The method according to claim 2 , further comprising low pass filtering the encoded closed caption disparity data to smooth transitions in the disparity values.
7. The method according to claim 2 , further comprising processing the closed caption text and the closed caption disparity data to produce an output suitable for defining a rendering of a three-dimensional image with a display of the closed caption text at the perceived z-axis position defined by the closed caption disparity data.
8. The method according to claim 2 , where the slope change is given as a value representing a change in disparity over 2 N frames where N is an integer.
9. The method according to claim 8 , where N=5.
10. A non-transitory computer readable storage medium storing instructions that when executed on one or more programmed processors carry out a process of decoding closed caption disparity data, comprising:
receiving the closed caption disparity data encoded as a sequence of one or more frame interval and slope change pairs, each frame interval and slope change pair including a frame interval value, which represents a designated number of frames that occur prior to application of the slope change paired with the respective frame interval, and a slope change value, which indicates a change in slope from the slope set by a preceding frame interval and slope change pair;
where the sequence of one or more frame interval and slope change pairs further includes an initial frame interval and slope change pair that precedes the one or more frame interval and slope change pairs, the initial frame interval and slope change pair including a slope change value which indicates a change in slope to be applied to a predetermined slope;
receiving a sequence of caption data packets, where the sequence of caption data packets specify closed caption text; and
where the closed caption disparity data is used to determine a horizontal offset of left and right eye views of the closed caption text that establishes the perceived z-axis position of the closed caption text, to be displayed in the closed caption display region, corresponding to each frame.
11. A television receiver device that processes disparity data for closed captions, comprising:
circuitry configured to:
receive the closed caption disparity data encoded as a sequence of one or more frame interval and slope change pairs, each frame interval and slope change pair including a frame interval value, which represents a designated number of frames that occur prior to application of the slope change paired with the respective frame interval, and a slope change value, which indicates a change in slope from the slope set by a preceding frame interval and slope change pair;
where the sequence of one or more frame interval and slope change pairs further includes an initial frame interval and slope change pair that precedes the one or more frame interval and slope change pairs, the initial frame interval and slope change pair including a slope change value which indicates a change in slope to be applied to a predetermined slope;
parse the encoded closed caption disparity data and closed caption text from one or more signals; and
generate, based on the encoded closed caption disparity data and the closed caption text, a sequence of video frame signals including the closed caption text displayed at a perceived z-axis position in each frame.
12. The device according to claim 11 , where the predetermined slope is zero.
13. The device according to claim 11 , where the frame interval is given as a predetermined value of 2 N frames, where N is an integer.
14. The device according to claim 11 , where the slope change is signaled as a value in the range −16 to +15 that indicates the amount of change in slope to apply after the designated frame interval.
15. The device according to claim 11 , where the circuitry is further configured to receive an alternate fixed disparity value that establishes a fixed z-axis position for a portion of the closed caption text packaged along with the encoded closed caption disparity data for use as an alternative perceived z-axis position.
16. The device according to claim 11 , further comprising a low-pass filter that processes the encoded closed caption disparity data to smooth transitions in the disparity values.
17. The device according to claim 11 , where the circuitry is further configured to process the closed caption text and the encoded closed caption disparity data to produce an output suitable for defining a rendering of a three-dimensional image with a display of the closed caption text at the perceived z-axis position defined by the encoded closed caption disparity data.
18. The device according to claim 11 , where the slope change is given as a value representing a change in disparity over 32 frames.
19. The device according to claim 18 , where the slope change is signaled as a value in the range −16 to +15 that indicates the amount of change in slope to apply after the designated frame interval.
20. A method of decoding closed caption disparity data, comprising:
at a television receiver device, receiving encoded dynamic closed caption disparity data that determines a perceived z-axis position for a closed caption display region that changes frame by frame for a sequence of video frames;
at the television receiver device, receiving an encoded alternate closed caption disparity value that sets the perceived z-axis position for the closed caption display region that is static for the sequence of video frames;
receiving a sequence of caption data packets, where the sequence of caption data packets specify closed caption text to be displayed in the closed caption display region;
where one of the encoded dynamic closed caption disparity data and the alternate disparity value is used for the sequence of video frames to determine a horizontal offset of left and right eye views of the closed caption display region that establishes the perceived z-axis position of the closed caption display region corresponding to each frame; where the encoded dynamic closed caption disparity data is encoded as a sequence of one or more frame interval and slope change pairs, each frame interval and slope change pair including a frame interval value, which represents a designated number of frames that occur prior to application of the slope change paired with the respective frame interval, and a slope change value, which indicates a change in slope from the slope set by a preceding frame interval and slope change pair; and
where the sequence of one or more frame interval and slope change pairs further includes an initial frame interval and slope change pair that precedes the one or more frame interval and slope change pairs, the initial frame interval and slope change pair including a slope change value which indicates a change in slope to be applied to a predetermined slope.
21. The method according to claim 20 , where the predetermined slope is zero.
22. The method according to claim 20 , further comprising low pass filtering the encoded dynamic closed caption disparity data to smooth transitions in disparity values.
23. The method according to claim 20 , further comprising processing the closed caption text and the encoded dynamic closed caption disparity data to produce an output suitable for defining a rendering of a three-dimensional image with a display of the closed caption text at the perceived z-axis position defined by the encoded dynamic closed caption disparity data.
24. A non-transitory computer readable storage device medium storing instructions that when executed on one or more programmed processors carry out a process of decoding closed caption disparity data, comprising
receiving encoded dynamic closed caption disparity data that determines a perceived z-axis position for a closed caption display region that changes frame by frame for a sequence of video frames;
at the television receiver device, receiving an encoded alternate closed caption disparity value that sets the perceived z-axis position for the closed caption display region that is static for the sequence of video frames;
receiving a sequence of caption data packets, where the sequence of caption data packets specify closed caption text to be displayed in the closed caption display region;
where one of the encoded dynamic closed caption disparity data and the alternate disparity value is used for the sequence of video frames to determine a horizontal offset of left and right eye views of the closed caption display region that establishes the perceived z-axis position of the closed caption display region corresponding to each frame; where the encoded dynamic closed caption disparity data is encoded as a sequence of one or more frame interval and slope change pairs, each frame interval and slope change pair including a frame interval value, which represents a designated number of frames that occur prior to application of the slope change paired with the respective frame interval, and a slope change value, which indicates a change in slope from the slope set by a preceding frame interval and slope change pair; and
where the sequence of one or more frame interval and slope change pairs further includes an initial frame interval and slope change pair that precedes the one or more frame interval and slope change pairs, the initial frame interval and slope change pair including a slope change value which indicates a change in slope to be applied to a predetermined slope.