Dual compression format digital video production system

Abstract

An audio/video production system is implemented on a PC-based platform, preferably utilizing various forms of removable magnetic, optical, or magneto-optical storage media. Specially modified cameras or other sources provide digitally data-compressed audio and video program materials in two formats, a first format having a higher data-compression ratio and intended for use in off-line systems to develop edit decision lists, and a second format having a lower data-compression ratio and intended for use in on-line editing and to produce the final representations of the programs. Off-line editing decisions may thus be developed on a PC using removable storage media, and final representations of the programs may be produced on-line in accordance with stationary-head or rotary-head digital-tape-based formats, such as DAT, 6-mm or 8-mm tapes. In an alternative embodiment, automatic and unattended editing, or extended program playback of more than 40 hours duration of digital video, is available.

Description

REFERENCE TO RELATED APPLICATIONS

(Audio/Video Interleave) file format. As an alternative, an independent system for recording audio signals may be implemented, either by employing separate digital recording provisions controlled by the same system and electronics, or by implementing completely separate equipment external to the camera system described above.

FIG. 3 shows an off-line digital video editing system, implemented with a PC-based edit controller having provisions for accepting materials in the form of removable storage media. The controller 102 is preferably of conventional design, but operates at least at the level of current Intel Pentium or high-level “486” processors. The unit is equipped with a color display, and preferably includes a PCI internal bus structure, and provisions for interfacing with a removable PCMCIA storage card 104. In one embodiment this card 104 is implemented with magnetic or magneto-optical disks, or with an optical disc unit. Alternatively, a stand-alone external data storage unit (not shown) could be interfaced through the PCMCIA facilities, or by way of an SCSI-type interface.

As an optional feature, a PCMCIA expansion adapter 106 may be provided, so that a plurality of PCMCIA cards or PCMCIA devices 108 may be accessed conveniently through a single PCMCIA slot on the PC, as shown. This expansion adapter is provided with internal selection and multiplexing circuitry, so that each plug-in card or device may be accessed independently and without interference with any other card or device in [he the expansion adapter. The selection may be performed by employing techniques well-known in the art, such as the addressing schemes utilized for SCSI or GPIB data busses. Since a single 420 MByte PCMCIA card module is capable of holding 75 minutes of programming material with image dimensions in pixels of 320×240, 4:2:2 sampling and a 50:1 data compression ratio, an expansion adapter equipped with ten PCMCIA slots and plug-in cards is capable of providing ten hours of original program material, and this programming capacity is capable of being further expanded with other types of PCMCIA-compatible devices. As a further option, a custom-designed PC could be provided with multiple PCMCIA slots to accept a plurality of storage devices without the need for an external expansion adapter.

In operation, the off-line digital video editing system PC is used to edit and combine the materials stored on various data-storage devices, producing an edit decision list which then may be utilized by an on-line editing system. The availability of multiple storage devices enables the operator to rehearse and then confirm “A/B-roll” edits with only two storage devices, and “A/B/C-roll” edits with three storage devices. When equipped with expansion provisions or additional SCSI-bus devices, the system is capable of controlling the various storage devices so as to produce highly complicated sequences in a convenient and timely manner. While the lower-quality (higher data-compression ratio) program materials are utilized only for determining the edit points (edit decision list) for the program, the off-line editing system described herein below is capable of producing the final edited version of the program with high-quality results in accordance with the preferred embodiment.

The versatility of the system may be further enhanced if planning for the program is begun by providing script and staging information to the computer in advance of editing, or even in advance of filming or taping the original production. The script may be provided as a simple text file, or as a formatted word processor file, such as used in “WordPerfect” or “Word for Windows”. As an alternative, the file may be of a custom format, as is commonly used by professional scriptwriters. This script and staging information is then reformatted to include specific commands, such as when to switch camera coverage to a particular actor, or the choice of a particular camera angle. Further details may now be included, such as the ability to identify close-up camera coverage, or points at which specific visual special effects (such as split-screen views or chroma-keyed backgrounds) or sound effects are to be incorporated. The modified script file is then used to guide the operator of the off-line editing system in making edit decisions to match the program materials to the script, to make any modifications to the script that are necessitated by the circumstances of the taping, or to take advantage of any unforeseen artistic opportunities presented by the actual taped materials.

In addition, it is common practice in broadcast-television news studios to use remotely controlled cameras to telecast the live programs. These cameras are mounted on motorized bases which are capable of moving the cameras to any desired position on the stage, within the physical limits imposed by the stage itself (such as the length of the camera cables or the clearance available for cameras to move relative to each other on the stage). The zoom-lenses, pan-tilt mounts, and camera electronic control settings are manipulated through the camera remote-control facilities, which may include either separate electronic control panels or alternatively computer interfaces with appropriate control software, such as the unit described by washino Washino, U.S. Pat No. 5,325,202. By coupling the software script materials to instructions for control of the camera movements, the capabilities of all of these systems may be optimized. The modified script file must be prepared before the actual taping occurs, however, and should include the physical layout of the sets and props for each scene.

The staging information described herein above, is identified by special camera-remote-control software, and the camera control operator is provided with a graphical interface which depicts the layout of the set and the “blocked” positions of the actors and props for a given scene. This system preferably also includes a user interface (such as a touch-screen or a mouse) to enable the camera control operator to program the cameras to be in the correct location, and to have the correct zoom-lens and pan-tilt positions, to capture the scene as desired, as described in co-pending application U.S. Ser. No. 08/050,861. At this time, the operator optionally may add information to control automated lighting systems, which are well-known in the are art of the film, video, and stage production. This enhanced version of the modified script file is then used to direct camera actions during the actual taping of the scenes, and is further modified as part of the off-line editing process as the EDL is developed, as described above, in accordance with the invention.

An on-line digital video editing system is depicted in block-diagram form in FIG. 4. The functional operation of the editing system follows that of the digital video editing system disclosed in FIG. 2, or in an alternative embodiment, may be implemented in a more sophisticated form, as described in our co-pending application “Multi-Format Audio/Video Production System,” U.S. application Ser. No. 08/298,104 filed Aug. 30, 1994. This system is implemented with a PC-based edit controller 206 having separate provisions for accepting removable storage media. In the preferred embodiment, the digital video tapes recorded by the system of FIG. 2 are installed in a tape-storage “jukebox” 208 for easy access during editing. Such tape cassette handling devices are well-known in the art of computer data storage, and are generally utilized for data back-up applications or for archival storage.

The edits incorporated into the edit decision list are utilized to sequence the various digital tapes so as to assemble a recording of the desired program materials into a final finished product, which is then recorded on the videotape recorder 202. This video recorder may be implemented as any of the commonly used choices for analog recorders, including, among others, 1″ C-format, Betacam, Betacam-SP, U-matic-SP, and Hi-8. If implemented as a digital recorder, the available choices include, among others, D-1, D-2, D-3, D-5, DCT, and Digital Betacam. Furthermore, the final format could be another digital data tape such as the type used for program source material or any other removable storage media. Since the time-code identification numbers on the removable media of the off-line system correlate with those utilized in the on-line system, no conversion or adaptation of the edit decision list is needed. The video monitor 204 is used to manipulate the windows-based edit system control software, and to view the program materials as the edit process proceeds. This process will be essentially automatic, as all of the necessary decisions already have been made in the off-line editing process as described above. In addition, this is an appropriate time for adding digital video effects to the program or to implement any special effects included in the program script.

The invention may be used for other applications limited to record/playback, without implementing the full range of editing features. For example, in applications such as master playback for video duplication, the program master nape tape must be played, rewound to the beginning, and then restarted, on a repeating cycle. In facilities employing a conventional video tape recorder, this represents a great deal of physical stress on the program master tape, thereby requiring a large number of copies of this master tape when many production runs are required to complete an order. In addition, some production time is lost due to the rewinding process itself. In a disk-based application of the system disclosed herein, there is no significant deterioration of the master program even in repeated usage, and it is possible to begin playing a program at any point desired, with essentially no delay due no cueing the program media to the physical location containing that part of the recorded program. In order to provide the necessary recording time duration, additional hard-disk drives would be added to achieve the required playback duration. Based on an MPEG-2 data-compression ratio of 20:1 (with a 4:2:2 recording system for NTSC signals), two hours of digital video would require approximately 8 GB of disk storage capacity. Disk-drives offering capacity of 9 GB are currently available, and until removable media achieve comparable levels, a program would accordingly be loaded into internal or external disk-storage units from the required number of removable media units.

The invention may also be employed as a playback unit for cable television usage or other extended-playing time applications. By adding as many “juke-box” units as desired, it is a simple matter to extend the playback time capability of the system, with each “juke-box” providing approximately 40 hours of digital video playback. By fully utilizing the RAM-based audio/video buffering capabilities discussed with reference to FIG. 2, it is possible to supply digital video playback on a continuous basis by changing the tape storage cassettes or cartridges “on-the-fly” while video playback proceeds. If provided with computer-readable identification codes on each cassette or cartridge, the computer is able to locate the “juke-box” and the particular physical storage slot containing program materials that previously have be scheduled for playback. Identification and library management systems of this type are well-known in the art, and are in common usage implemented as “cart-machines” employed for playback of commercial advertisements or other program materials at broadcast stations. In addition, playback at any frame rate or television system standard would be available, in accordance with our co-pending U.S. application Ser. No. 08/298,104 filed Aug. 30, 1994.

The versatility of the Digital Video Production System may be enhanced further, if planning for the program is begun by providing script and staging information to the computer in advance of editing, or even in advance of filming or taping the original production. Computer software having access to the script materials will enable the operator to match the scenes to the recorded video materials quickly, thereby speeding the editing process. In addition, it is common practice in broadcast-television news studios to use remotely-controlled cameras to telecast the live programs. By coupling the software script materials to instructions for control of the camera movements, the capabilities of all of these systems will be optimized.

Claims

1. A digital audio/video production system adapted for use with an on-line video editing facility, the production system comprising:

a digital video recorder capable of simultaneously recording information representative of the same program source material, including correlated edit-time-code information, onto first and second removable storage, media in first and second formats, respectively, the information in the first format being data-compressed relative to the information in the second format;

a programmed personal computer configured to receive the first removable storage medium, enabling an operator to edit the information representative of the program source material in the first format in off-line fashion so as to develop an edit decision list; and

means to transfer the edit decision list to an on-line video editing facility, the on-line editing facility being further configured to receive the second removable storage medium, whereby an operator of the on-line facility may edit the program source material in the second format using the edit decision list to create a final video production.

2. The digital video production system of claim 1, wherein the information in the second format is non-compressed.

3. The digital video production system of claim 1, wherein the digital video recorder forms part of a camcorder.

4. The digital video production system of claim 1, wherein the first removable medium is a magnetic hard disk.

5. The digital video production system of claim 1, wherein the first removable medium is an optical disk.

6. The digital video production system of claim 1, wherein the first removable medium is a magneto-optical disk.

7. The digital video-production system of claim 1, wherein the second removable medium is a tape drive.

8. The digital video production system of claim 1, including digital audio and video program data which are interleaved.

9. The digital video production system of claim 1, the means to transfer the edit decision list to the on-line video editing facility including means to record the edit decision list onto a third removable storage medium.

10. The method of producing a final video program, comprising the steps of:

providing video program source material in first and second digital formats, the material in the first format being compressed relative to the material in the second format;

recording the material in the first and second formats, respectively, onto first and second removable storage media along with correlated edit-time-code information;

interfacing the first storage medium to an off-line video editing system to develop edit decision information;

transferring the edit decision list to an on-line video editing system;

accessing the program material in the second storage medium using the on-line video editing system; and

editing the material in the second format on the second storage medium in accordance with the edit decision list to produce a final video program.

11. The method of claim 10, the second format being a non-compressed format.

12. A digital video production system adapted to deliver program material and an accompanying edit decision list to an on-line video editing facility for the purpose of creating a final program, the system comprising:

digital video recording apparatus, including:

an input to receive a video program,

means to digitally compress the program in accordance with more than one compression ratio,

an interface to a first removable storage medium,

an interface to a second removable storage medium, and

means no simultaneously record the video program onto the first removable storage medium at a first compression ratio and onto the second removable storage medium at a second compression ratio, the first compression ratio being greater than the second; and

an off-line digital video editing system, including:

an interface co receive the first removable storage medium.

a display to review portions of the video program, enabling a user to make edit decisions concerning the program, and

an interface to a third removable storage medium to store a list of the edit decisions,

whereby an on-line video editing facility, upon receiving the second and third storage medium, may be used to produce a final, edited version of the program in accordance with the decision list.

13. The digital video production system of claim 12, wherein the second compression ratio is zero.

14. The digital video production system of claim 12, wherein the off-line digital video editing system forms part of a programmed personal computer.

15. The digital video production system of claim 12, wherein the digital video recorder forms part of a camcorder.

16. The digital video production system of claim 12, wherein the first removable medium is a magnetic disk drive.

17. The digital video production system of claim 12, wherein the first removable medium is an optical disk.

18. The digital video production system of claim 12, wherein the first removable medium is a magneto-optical disk.

19. The digital video production system of claim 12, wherein the second removable medium is a tape drive.

20. The digital video production system of claim 12, including interleaved digital audio and video program data are interleaved.

21. The digital video production system of claim 12, wherein the program includes separately recorded audio and video portions.

22. A digital video recording apparatus adapted or use with an on-line video editing facility and a personal computer configured to perform off-line editing, including edit-list development, the apparatus comprising:

a camera outputting information representative of a video program;

means to digitally compress the program information at a plurality of compression ratios;

a removable disk drive to store a highly compressed version of the program information suitable for off-line editing using the personal computer; and

a removable tape drive to store a less compressed version of the program information suitable for on-line editing;

both versions of the program being stored with correlated edit-time-code information, thereby enabling the on-line editing to use the edit list developed during off-line editing.

23. The digital video recording apparatus of claim 22, wherein the camera, means to digitally compress the program at a plurality of compression ratios, removable disk drive, and removable tape drive are all integral to a camcorder.

24. A digital audio/video production system, comprising:

(a) digital video recording apparatus, including:

an input to receive a video program,

first and second removable digital storage media, and

means to simultaneously record the program, including correlated edit-time-code information, onto the first and second removable storage media in first and second formats, respectively, the first format being data-compressed relative to the information in the second format;

(b) a first video editing system, including:

means to receive the first removable storage medium, and

controls enabling an operator to edit the program in the first format and develop a set of edit decision directives; and

(c) a second video editing system, including:

means to receive the second removable storage medium,

means to receive the edit decision directives, and

means to edit the program information in the second format in accordance with the edit decision directives to create a final video production.

25. The digital audio/video production system of claim 24, wherein the digital video recording apparatus includes means to receive a plurality of the first removable storage media.

26. The digital audio/video production system of claim 24, wherein the second video editing system includes means to receive a plurality of the second removable storage media, wherein the edit decision directive being applicable to all of the second removable storage media received.

27. The digital audio/video production system of claim 26, wherein the digital video recording apparatus forms part of a camcorder.

28. The digital audio/video production system of claim 26, wherein the first video editing system forms part of a programmed personal computer.

29. The digital audio/video production system of claim 26, wherein the first removable digital storage medium is a magnetic disk.

30. The digital audio/video production system of claim 26, wherein the first removable digital storage medium is an optical disk.

31. The digital audio/video production system of claim 26, wherein the first removable digital storage medium is a magneto-optical disk.

32. The digital audio/video production system of claim 26, wherein the first removable digital storage medium is a semiconductor memory.

33. The digital audio/video production system of claim 24, wherein the second removable digital storage medium is a magnetic tape.

34. A video production method, comprising the steps of:

simultaneously recording information representative of a video program, plus correlated edit-time-code information, onto first and second removable digital storage media in first and second formats, respectively, the pro,ram information in the first format being data-compressed relative to the program information in the second format;

receiving the first removable storage medium at a first video editing facility and editing the program information at the first facility in the first format to develop a see of edit decision directives based upon the edit-mime-code information; and

receiving the second removable storage medium and edit decision directives at a second video editing facility and editing the program information at the second facility in the second format in accordance with the edit decision directives so as to create a final video production.

35. The video production method of claim 34, further including the step of recording the final video production onto a third removable storage medium at the second video editing facility.

36. The video production method of claim 34, further including the step of outputting the final video production as the program information is edited in the second format in accordance with the edit decision directives.

37. The video production method of claim 34, wherein the step of editing the program information at the second facility further includes the step of adding audio special effects in the final video production.

38. The video production method of claim 34, wherein the step of editing the program information at the second facility further includes the step of adding video special effects in the final video production.

39. The video production method of claim 38, wherein the step of adding video special effects includes the step of adding titling.

40. A dual format digital video recording system for recording a program having audiovisual content, comprising:

a first digital storage medium;

a second digital storage medium;

a first digital interface associated with the first digital storage medium for receiving a first signal representing the audiovisual content in a first digital format having a frame rate of substantially 24 frames per second and edit-time-code information, wherein the audiovisual content in the first digital format and the edit-time-code information are recorded onto the first digital storage medium;

a second interface associated with the second digital storage medium for receiving a second signal representing the audiovisual content in a second digital format having a frame rate of substantially 24 frames per second and edit-time-code information wherein the audiovisual content in the second digital format and the edit-time-code information are recorded onto the second digital storage medium;

wherein the edit-time-code information for the audiovisual content in the first compressed, digital format and the edit-time code for the audiovisual content in the second compressed, digital format are correlated; and

wherein the audiovisual content in the first digital format is compressed relative to the audiovisual content in the second digital format.

41. The dual format digital video recording system of claim 40, wherein the first digital storage medium is a removable storage medium.

42. The dual format digital video recording system of claim 40, wherein the second digital storage medium is a removable storage medium.

43. The dual format digital video recording system of claim 40, wherein the first signal representing the audiovisual content in a first digital format and the second signal representing the audiovisual content in a second digital format comprises a video program, and wherein a complete copy of the video program is stored on the first digital storage medium and a complete copy of the program is stored on the second digital storage medium.

44. The dual format digital video recording system of claim 40, wherein the digital video recording system forms part of a camcorder.

45. The dual format digital video recording system of claim 40, further including random access memory (RAM) for temporarily storing a portion of the audiovisual content in the first digital format.

46. The dual format digital video recording system of claim 45, wherein the first digital storage medium is removable and wherein the first digital storage medium is hot-swappable from the system.

47. The dual format digital video recording system of claim 40, wherein the audiovisual content in the second digital format is not compressed.

48. The dual format digital video recording system of claim 40, wherein the audiovisual content in the first digital format is recorded simultaneously with the audiovisual content in the second digital format.

49. A dual format digital video recording method for recording a program having audiovisual content, comprising:

providing a first signal representing the audiovisual content in a first digital format having a frame rate of substantially 24 frames per second and edit-time-code information;

providing a second signal representing the audiovisual content in a second compressed, digital format having a frame rate of substantially 24 frames per second and edit-time-code information, wherein the audiovisual content in the first digital format is more compressed than the audiovisual content in the second digital format and wherein the edit-time-code information for the audiovisual content in the first compressed, digital format and the edit-time code for the audiovisual content in the second compressed, digital format are correlated;

recording the audiovisual content in the first digital format with its edit-time-code information; and

recording the audiovisual content in the second digital format with its edit-time-code information correlating the audiovisual content in the first digital format with the audiovisual content in the second digital format.

50. The dual format digital video recording method of claim 49, wherein the audiovisual content in the first digital format with its edit-time-code information is recorded onto a first digital storage medium and wherein the audiovisual content in the second compressed, digital format with its edit-time-code information is recorded onto a second digital storage medium.

51. The dual format digital video recording method of claim 50, wherein the second digital storage medium is a removable storage medium.

52. The dual format digital video recording method of claim 50, wherein the first signal representing the audiovisual content in a first digital format and the second signal representing the audiovisual content in a second digital format comprises a video program, and wherein a complete copy of the video program is stored on the first digital storage medium and a complete copy of the program is stored on the second digital storage medium.

53. The dual format digital video recording method of claim 50, wherein the first and second digital storage media are part of a camcorder.

54. The dual format digital video recording method of claim 49, further including temporarily storing a portion of the audiovisual content in the first compressed, digital format on random access memory (RAM).

55. The dual format digital video recording method of claim 54, wherein the first digital storage medium is removable and further including hot-swapping the first digital storage medium.

56. The dual format digital video recording method of claim 49, wherein the audiovisual content in the second digital format is not compressed.

57. The dual format digital video recording method of claim 49, wherein the audiovisual content in the first digital format is recorded simultaneously with the audiovisual content in the second digital format.