Method and apparatus for providing computer-compatible fully synchronized audio/video information

• US 20030038807A1
• Filed: 08/22/2002
• Published: 02/27/2003
• Est. Priority Date: 08/22/2001
• Status: Abandoned Application

• Current Assignee: Dolby Laboratories Incorporated, Dolby Licensing Corporation
• Original Assignee: Dolby Laboratories Incorporated, Dolby Licensing Corporation
• Inventors: Spoer, Peter, Demos, Gary Alfred
• Application Number:
  US10/226,696
• Publication Number:
  US 20030038807A1
• Time in Patent Office: Days
• US Class Current: 345/473
• CPC Class Codes: G09G 5/006 Details of the interface to the display terminal specific for a display terminal using a CRT G09G1/167; using a flat panel G09G3/2096; circuits for interfacing with colour displays G09G5/04
• CPC Class Codes: G09G 5/008 Clock recovery
• CPC Class Codes: G09G 5/12 Synchronisation between the display unit and other units, e.g. other display units, video-disc players
• CPC Class Codes: G09G 5/399 using two or more bit-mapped memories, the operations of which are switched in time, e.g. ping-pong buffers
• CPC Class Codes: G11B 20/1403 characterised by the use of two levels
• CPC Class Codes: G11B 27/3036 Time code signal
• CPC Class Codes: G11B 27/3054 Vertical Interval Time code [VITC]

Abstract

An inventive display and input method and apparatus providing fully synchronized audio/video information for use with computers and for display on computer-compatible monitors is described. The inventive display and input system includes a computer interface, and provides synchronized digital video and audio input, as well as synchronized digital and analog audio/video output. The display and input system provides synchronization of moving images for display on 72 Hz and 75 Hz computer-compatible monitors. The inventive display and input system facilitates 72 Hz and 75 Hz display of synchronized moving images, such as 24 fps tripled on 72 Hz computer-monitor displays, without using frame dropping or tearing techniques. In accordance with one aspect of the present invention, a “triple-repeat” method (of 24 fps and 25 fps video) is used to provide synchronized display onto 72 Hz and 75 Hz displays, respectively. A “double-repeat” method is used to provide synchronized display of 36 fps and 37.5 fps images on 72 Hz and 75 Hz displays, respectively.

Claims

1. A fully synchronized audio/video display and input system capable of displaying fully synchronized video on computer-compatible display monitors, comprising:

a) an optional video input/output (I/O) having a first plurality of associated video clock signals for communicating video information;

b) an optional audio I/O having a first plurality of associated audio clock signals for communicating audio information;

c) a frame buffer memory, coupled to the optional audio I/O, wherein video frames are stored within and retrieved from the frame buffer memory on a first in, first out (FIFO) basis;

d) a computer interface, adapted to interface to a computer and coupled to the frame buffer memory; and

e) a clock synchronization system adapted to receive the first plurality of video and audio clock signals, wherein the clock synchronization system generates a second plurality of video and audio clock signals used internally by the display and input system to store and retrieve audio and video information within and from the frame buffer memory;

wherein the display and input system generates fully synchronized audio and video at selected frame rates, and wherein the selected frame rates exceed 60 Hz.

2. The display and input system of claim 1, wherein video frames are accessed from the frame buffer memory on a frame by frame basis, and wherein a selected video frame is automatically displayed a pre-determined repeat number of times at a selected output video frame rate.

3. The display and input system of claim 2, wherein selected video frames are repeated three times to synchronize 24 fps video for display on a 72 Hz monitor.

4. The display and input system of claim 2, wherein selected video frames are twice repeated to synchronize 36 fps video for display on a 72 Hz monitor.

5. The display and input system of claim 2, wherein selected video frames are repeated three times to synchronize 25 fps video for display on a 75 Hz monitor.

6. The display and input system of claim 2, wherein selected video frames are twice repeated to synchronize 37.5 fps video for display on a 75 Hz monitor.

7. The system of claim 2, wherein the selected output video frame rate is reduced by a refresh rate reduction factor of 1000/1001 thereby providing compatibility with legacy NTSC monitors and other 59.94 Hz video systems.

8. The system of claim 2, wherein the selected video frames are repeated six times providing synchronization of 12 fps video with a 72 Hz monitor.

9. The system of claim 2, wherein the selected video frames are repeated six times providing synchronization of 12.5 fps video with a 75 Hz monitor.

10. The system of claim 2, wherein the selected video frames are repeated five times providing synchronization of 12 fps video with a 60 Hz monitor.

11. The system of claim 1, wherein the display and input system synchronizes the first plurality of video and audio clock signals to the second plurality of video and audio clock signals.

12. The system of claim 11, wherein the system locks the first and second plurality of video and audio clock signals to one another using phase-locked loop clock synchronization.

13. The system of claim 11, wherein the optional video I/O inputs a video data rate for use by the system, and wherein the second plurality of internally generated clock signals are derived from and synchronized with the input video data rate.

14. The system of claim 13, wherein the optional video I/O inputs a digital video signal having an associated data rate clock, and wherein the second plurality of internally generated clock signals are derived from and synchronized with the data rate clock.

15. The system of claim 13, wherein the optional video I/O inputs an analog video signal having associated horizontal and vertical synchronization signals, and wherein the second plurality of internally generated clock signals are derived from and synchronized with the horizontal and vertical synchronization signals.

16. The system of claim 15, wherein the second plurality of internally generated clock signals are derived from and synchronized with the horizontal and vertical synchronization signals using a phase-locked loop (PLL) clock generation circuit.

17. The system of claim 11, wherein audio I/O is synchronized to video I/O using a word clock.

18. The system of claim 17, wherein the display and input system generates an audio sample clock for use by an audio I/O device, wherein the audio sample clock is derived from the second plurality of video clock signals.

19. The system of claim 18, wherein the audio sample clock comprises a 48 kHz audio sample clock.

20. The system of claim 18, wherein the audio sample clock comprises a 96 kHz audio sample clock.

21. The system of claim 11, wherein audio information is stored within the frame buffer memory at a location that is logically related to its associated and respective video information.

22. The system of claim 17, wherein the audio I/O is synchronized to the video I/O using Longitudinal Time Codes (LTC) associated with a frame sub-rate derived from the video I/O, and wherein the LTC is used for synchronization of the audio with digital audio devices.

23. The system of claim 17, wherein the audio I/O is synchronized to the video I/O using Vertical Interval Time Codes (VITC).

24. The system of claim 11, wherein the audio I/O is synchronized to the video I/O using metadata.

25. The system of claim 22, wherein the video data rate comprises 72 fps, and wherein the 72 fps video data rate is divided by a factor of 3 thereby producing a 24 fps sub-rate, and wherein the LTC is synchronized to every third frame of the 72 fps video.

26. The system of claim 25, wherein video frames associated with each time code are distinguished from each other using userbits carrying phase information associated with each video frame.

27. The system of claim 25, wherein video frames associated with each time code are distinguished from each other using metadata carrying phase information associated with each video frame.

28. The system of claim 1, wherein the video information output by the display and input system through the optional video I/O comprises analog video.

29. The system of claim 28, wherein the analog video comprises RGB video.

30. The system of claim 1, wherein the video information output by the display and input system through the optional video I/O comprises digital video.

31. The system of claim 30, wherein the digital video conforms to an SMPTE 292M standard for HDTV bit-serial digital interfaces.

32. The system of claim 30, wherein the digital video comprises Digital Video Interactive (DVI) digital video.

33. The system of claim 2, wherein the frame buffer memory holds at least two video frames.

34. The system of claim 33, wherein the frame buffer memory compensates for timing variations between the computer and the display and input system.

35. The system of claim 33, wherein the frame buffer memory compensates for timing variations in preparation of video displays.

36. The system of claim 2, further comprising an optional color space transformation (CST) block operatively coupled to the optional video I/O.

37. The system of claim 1, wherein the display and input system selectively outputs the fully synchronized audio and video for display on 72 Hz and 75 Hz computer-compatible monitors.

38. The system of claim 1, wherein the display and input system selectively outputs the fully synchronized audio and video to a digital video interface.

39. The system of claim 1, wherein the display and input system selectively outputs the fully synchronized audio for input to an external analog audio device.

40. The system of claim 1, wherein the display and input system selectively outputs the fully synchronized audio for input to an external digital audio device.

41. The system of claim 31, wherein relatively high-precision pixel values are used to represent the digital video information.

42. The system of claim 41, wherein at least 8-bits are used to represent each color component of the digital video.

43. The system of claim 41, wherein 10-bits are used to represent each color component of the digital video.

44. The system of claim 41, wherein at least 12-bits are used to represent each color component of the digital video.

66. The system of claim 31, wherein the SMPTE 292M standard for HDTV bit-serial interfaces includes a blanking interval, and wherein unused data bandwidth available within the blanking interval is used to transmit the digital video with increased resolution.

67. The system of claim 66, wherein the increased resolution digital video comprises 2560 (horizontal) by 1080 (vertical) digital video.

68. The system of claim 66, wherein the increased resolution digital video comprises 2048 (horizontal) by 1280 (vertical) digital video.

45. A fully synchronized audio/video display and input system capable of displaying fully synchronized video on computer-compatible display monitors, comprising:

a) means for optionally inputting and outputting (I/O) video information having a first plurality of associated video clock signals;

b) means for optionally inputting and outputting (I/O) audio having a first plurality of associated audio clock signals;

c) means, responsive to the optional audio and video I/O means, for storing video frames, wherein video frames are stored within and retrieved from the storage means on a first in, first out (FIFO) basis;

d) means, coupled to the storage means, for interfacing with a computer; and

e) means, responsive to the first plurality of video and audio clock signals, for performing clock synchronization, wherein the clock synchronization means generates a second plurality of video and audio clock signals used internally by the display and input system to store and retrieve audio and video information within and from the storage means;

wherein the display and input system generates fully synchronized audio and video at selected frame rates, and wherein the selected frame rates exceed 60 Hz.

46. The fully synchronized audio/video display and input system of claim 45, further comprising:

a) means, responsive to the optional video I/O means and coupled to the storage means, for performing color space transformations (CST) from a first color space to a second color space.

47. The system of claim 45, wherein the display and input system selectively outputs the fully synchronized audio and video for display on 72 Hz and 75 Hz computer-compatible monitors.

48. The system of claim 45, wherein the display and input system selectively outputs the fully synchronized audio and video to a digital video interface.

49. The system of claim 45, wherein the display and input system selectively outputs the fully synchronized audio for input to an external analog audio device.

50. The system of claim 45, wherein the display and input system selectively outputs the fully synchronized audio for input to an external digital audio device.

51. A method of fully synchronizing input and display of audio and video information for use with computer-compatible display monitors, comprising:

a) optionally inputting and outputting (I/O) video information having a first plurality of associated video clock signals;

b) optionally inputting and outputting (I/O) audio having a first plurality of associated audio clock signals;

c) generating a second plurality of video and audio clock signals, wherein the first and second plurality of video and audio clock signals are locked to one another;

d) accessing video frames in a storage means on a first in, first out (FIFO) basis; and

e) generating fully synchronized audio and video at selected frame rates, wherein the selected frame rates exceed 60 Hz.

52. The method of fully synchronizing input and display of audio and video information for use with computer-compatible display monitors of claim 51, further comprising:

a) optionally performing color space transformations (CST) on video information from a first color space to a second color space.

53. The method of fully synchronizing input and display of audio and video information for use with computer-compatible display monitors of claim 51, further comprising:

a) selectively displaying the fully synchronized audio and video generated in step e) on 72 Hz and 75 Hz computer-compatible monitors.

54. The method of claim 51, further comprising:

a) selectively outputting the fully synchronized audio and video to a digital video interface.

55. The method of claim 51, further comprising:

a) selectively outputting the fully synchronized audio for input to an external analog audio device.

56. The method of claim 51, further comprising:

a) selectively outputting the fully synchronized audio for input to an external digital audio device.

57. A fully synchronized audio/video input system for use with computers, comprising:

a) an optional video input having a first plurality of associated video input clock signals for communicating video information;

b) an optional audio input having a first plurality of associated audio input clock signals for communicating audio information;

c) a frame buffer memory, coupled to the optional audio input and capable of storing video frames received from the optional video input, wherein video frames are stored within and retrieved from the frame buffer memory on a first in, first out (FIFO) basis;

d) a computer interface, adapted to interface to a computer and coupled to the frame buffer memory; and

e) a clock synchronization system adapted to receive the first plurality of video and audio input clock signals, wherein the clock synchronization system generates a second plurality of video and audio clock signals used internally by the input system to store audio and video information within the frame buffer memory;

wherein the input system generates fully synchronized audio and video at selected video frame rates, and wherein the selected video frame rates exceed 60 Hz.

58. The fully synchronized audio/video input system of claim 57, wherein the selected video frame rates comprise 72 fps and 75 fps video frame rates.

59. The fully synchronized audio/video input system of claim 57, further comprising:

a) a color space transformation (CST) block operatively coupled to the optional video input, wherein the CST block optionally converts video from a first color space representation to a second color space representation.

60. A fully synchronized audio/video display system capable of displaying fully synchronized video on computer-compatible display monitors, comprising:

a) an optional video input/output (I/O) having a first plurality of associated video clock signals for communicating video information;

b) an optional audio I/O having a first plurality of associated audio clock signals for communicating audio information;

c) a frame buffer memory, coupled to the optional audio I/O and responsive to the video I/O, wherein video frames are stored within and retrieved from the frame buffer memory on a first in, first out (FIFO) basis;

d) a computer interface, adapted to interface to a computer and coupled to the frame buffer memory; and

e) a clock synchronization system adapted to receive the first plurality of video and audio clock signals, wherein the clock synchronization system generates a second plurality of video and audio clock signals used internally by the display system to retrieve audio and video information stored within the frame buffer memory;

wherein the display system generates fully synchronized audio and video at selected frame rates, and wherein the selected frame rates exceed 60 Hz.

61. The system of claim 60, wherein the display system selectively outputs the fully synchronized audio and video for display on 72 Hz and 75 Hz computer-compatible monitors.

62. The system of claim 60, wherein the display system selectively outputs the fully synchronized audio and video to a digital video interface.

63. The system of claim 60, wherein the display system selectively outputs the fully synchronized audio for input to an external analog audio device.

64. The system of claim 60, wherein the display system selectively outputs the fully synchronized audio for input to an external digital audio device.

65. The fully synchronized audio/video display system of claim 60, further comprising:

a) a color space transformation (CST) block operatively coupled to the optional video I/O, wherein the CST block optionally converts video from a first color space representation to a second color space representation.