WO2006067761A1

WO2006067761A1 - Dispersive chapter-allocation to dvd recordings

Info

Publication number: WO2006067761A1
Application number: PCT/IB2005/054366
Authority: WO
Inventors: Leonardus Matheus Marie Veugen
Original assignee: Koninklijke Philips Electronics, N.V.; U.S. Philips Corporation
Priority date: 2004-12-22
Filing date: 2005-12-21
Publication date: 2006-06-29

Abstract

A chapter budget in archiving from a hard disk (308) to a recordable or rewritable DVD (302) is gracefully complied with for a title (104) that would otherwise exceed the budget. If the budget provides too few normal chapters (128), the needed number of normal chapters to be archived is eliminated based on the importance as judged by the user's behavior (S540). If the budget provides too few chapters to accommodate the indicated automatic chapters, the budgeted automatic chapters are equitably distributed among all normal chapters based on the chapter duration (S608).

Description

DISPERSIVE CHAPTER-ALLOCATION TO DVD RECORDINGS

The present invention relates to copying to a digital video disc (DVD) a title that would exceed the DVD chapter budget and, in particular, to methods for intelligently allocating chapters to that title.

Referring to FIG. 1, audio and video information recorded on an optical disc such as a digital video disc (DVD) is logically organized into a hierarchy 100 of titles 104, chapters 108, cells 112 and video object units (VOBUs) 116. Each VOBU 116 containing a NavPack 120 and groups of pictures (GOPs) 124 comprises video packets, audio packets and other private packets. The hierarchy 100 supports user navigation throughout the recorded content information during playback, such as when jumping from one scene to another, searching for a specific scene, performing trick-play mode operations such as fast-forward and fast-reverse, and configuring a presentation based upon multi- angle viewing, parental control, etc. A chapter 108 is also known, according to conventional DVD terminology, as a "part-of-title (PTT) unit." Any given chapter 108 may correspond, for example, to a particular scene of a movie. The designation "normal chapter" and the component "automatic chapter" will be described further below.

Several consumer electronics (CE) manufacturers are marketing video recorders that combine a hard disk drive (HDD) with an optical disk drive (ODD), i.e., for a rewriteable DVD. The latter type is typically referred to as an HDD-DVD combination box, or "combi" for short. Such a combi then includes an HDD-based video recorder, also known as personal video recorder (PVR), enhanced with archival capabilities provided by the ODD. This ability to archive to the ODD content of the HDD is likewise typically found in an up-to-date PC, which has an HDD, a CD drive and a DVD drive, preferably with CD- and DVD-burning equipment.

The emerging DVD Video Recording (DVD VR) standard, which is largely identical to DVD+RW and DVD+R for rewritable and recordable DVDs, respectively, introduces the term "virtual chapter" which represents a different concept for navigating through a title than does a "nonvirtual chapter." A major difference between the two terms is that a non- virtual chapter encompasses an integral number of cells 112, whereas a virtual chapter can start and/or end within cell 112 or VOBU 116 boundaries. Hereinafter, we will simply use, for simplicity, the term "chapter" to mean a non-virtual chapter, although the principles of the instant invention apply as well as to virtual chapters.

In archiving from a hard disk to a DVD, chapters are preserved by laying down markers in the DVD recording, but some chapters may be of long duration. Accordingly, additional, "automatic chapters" are inserted periodically, i.e., at a fixed interval of 5 minutes, to facilitate navigation. In one implementation, each time a chapter, "automatic" or otherwise, is inserted in recording to a DVD, a chapter timer is started or restarted; when the timer expires, an automatic chapter marker is laid down in the recording medium, thereby restarting the timer. For convenience, we hereinafter refer to any chapter that is not an automatic chapter as "normal." Accordingly, and referring back to FIG. 1, a normal chapter 108 may contain one or more automatic chapters 128.

Referring to FIG. 2, a normal chapter 108 to be archived to a DVD may, while still on the hard drive, has been prioritized by the user into one of two classes: a visible chapter 210, of higher priority, or a hidden chapter 220, of lower priority. A normal chapter 108 of the respective class can be referred to as a "visible scene" and a "hidden scene" respectively. During playback of the recorded title on the HDD or DVD and according to the default, the visible chapters 210 are played back and hidden chapters 220 are skipped. By a particular input selection, however, the user can play back the full title of visible and hidden chapters 210, 220. The designations "visible" and "hidden" are attributes of the chapter 210, 220 that are part of the metadata accompanying the media content on the HDD. All normal chapters 108 not designated as hidden 210 are visible 220. Optionally, the user may elect to skip over hidden chapters 220 during archiving. Also, copyright-protected parts are not archived.

According to the DVD VR standard, the total number of chapters 108, 128 per disc TotalNrChsPerDisc is limited to a maximum of 254, and the total number of chapters 108, 128 per title TotalNrChsPerTitle is limited to no more than 99. The budget of available chapters 108, 128, based on the DVD VR standard and/or user defined options takes into account the following.

In the case of a rewritable disc, when parts of already recorded titles are overwritten, resources of that title, such as chapters 108, 128, are released.

If the new recording covers all sectors until the end of the disc, the recording may also be allocated the remaining chapters 108, 128 in the budget.

Each recording requires a non-automatic chapter 108 at the beginning of that recording. If, after a new recording, there will be room for other recordings, then the system can reserve chapters 108, 128 for those other recordings.

If the recording will cover only a part of the disc, then the system can grant only a limited number of chapters 108, 128 based on the disc contents, and the size and location for that recording.

If, while archiving, it is discovered that allocation of another chapter 108, 128 to the title would exceed the granted budget, some combis continue to record to DVD without inserting any further chapters 108, 128, or any further automatic chapters 128. The existing algorithms dealing with automatic chapters 128 do not look ahead to determine if the chapter budget is in danger of being exceeded. The lack of chapters 108, 128, from this point forward in the DVD, impacts with unnecessary harshness the ability of the user to navigate in that portion.

An alternative solution in the prior art is to stop recording as soon as the chapter shortage is encountered. This alternative does not take into account how the user would have preferred to allocate the logical DVD space to the title 104 whose end has now been truncated. There exists a need to better handle the chapter shortage problem in archiving from HDD to DVD, by taking into account user preferences and by maximizing the user's ability to navigate throughout the title 104.

The present invention addresses the above-noted shortcomings in the prior art.

In one aspect, a digital video disc (DVD) recorder assigns automatic chapters in a title to avoid exceeding a chapter budget in copying the title to a DVD. In particular, the title is divided into non-automatic chapters whose durations are determined, and the available automatic chapters are distributed among the non-automatic chapters according to the respective durations.

In another aspect, a DVD recorder eliminates non-automatic chapters in a title to avoid exceeding a chapter budget in copying the title to a DVD. In particular, the title is divided into the non-automatic chapters, which are assigned respective priority classes. At least one of the chapters is removed based upon at least one of the following: a plurality of durations of chapters of said title, a location where media content has been excluded that would otherwise have been contiguous with a chapter, and the priority class of a chapter.

Details of the invention disclosed herein shall be described with the aid of the figures listed below, wherein:

FIG. 1 is a chart showing a hierarchy of a logical arrangement of elements of a DVD recording;

FIG. 2 is a conceptual diagram classifying types of normal chapters by priority;

FIG. 3 is a block diagram of a chapter-budget-responsive-archiving HDD-DVD combination box according to the present invention;

FIG. 4 is a format diagram comparison between a hard disk recording and its DVD-archived counterpart recording, according to the present invention;

FIG. 5 is a flow chart of a process applied when there are too few normal chapters available for archiving a title;

FIG. 6 is a flow chart of a process applied when there are too few automatic chapters available for archiving a title; and

FIG. 7 is a flow chart refinement to FIG. 6 which includes or excludes hidden, normal chapters in the automatic chapter allocation.

FIG. 3 shows an example of a chapter-budget-responsive-archiving combination box 300 according to the present invention. The combi box 300 has an optical disc drive (ODD) or a DVD drive 302, into which a disc can be inserted. The combi box 300 further includes a DVD recorder 304 having a recording module 306, an HDD 308 and an HDD recorder 310. Processes of the present invention may be implemented in the recording module 306, which includes a processor (not shown) and a computer-readable medium (not shown) such as random-access memory (RAM), read-only memory (ROM) and/or any of their respective variations. These elements of the recording module may be realized in any known and suitable combination of hardware, software and firmware. Operationally, the HDD recorder 310 records to the HDD 308. The recording module 306 archives recorded content from the HDD 308 to the ODD 302, and does so in a manner responsive to the chapter budget, as will be described in more detail further below.

FIG. 4 provides, by way of illustrative and non-limitative example, a recording format 400 on HDD 308, and a format 402 of the recording as archived on DVD 302 in accordance with the present invention. The format 400 spans four normal chapters 404, 408, 410, 412, which may correspond, for example, to four respective scenes in a movie. The HDD recorder 310 can be operable to automatically detect scene changes and to lay down normal chapter markers 426, 438, 439, 440 in the recording to separate the chapters 404, 408, 410, 412. Illustratively, three of the chapters 404, 408, 412 are visible and one of the chapters 410 is hidden. In archiving, the user may elect not to record hidden chapters, and therefore, in the present example, the hidden chapter 410 does not appear in the archived format 402. As mentioned above, copyrighted material is automatically prevented from being archived. The durations of the chapters 404, 408, 412 are 416, 420, 424, respectively.

Conventional archiving proceeds as follows. The recording module 306 encounters a marker for a first normal chapter 404 in the recording read from the HDD 308, and likewise inserts a marker 426 for the normal chapter 404 in the DVD recording. After a default duration 428 of 5 minutes into the first normal chapter 404, an automatic chapter 432 is inserted and the duration timer is reset. After another 5 minutes, a second automatic chapter 436 is placed and the duration timer is reset. Before the duration timer reaches 5 minutes, a marker 438 for a normal chapter 408 is encountered, thereby resetting the duration timer. Since the second chapter 408 has a duration 420 less than 5 minutes, no automatic chapter is inserted for the second chapter. A marker 440 for the third normal chapter 412 is encountered, and the duration timer is reset. After 5 minutes, an automatic chapter 444 is inserted. During the above processing, if the chapter (or "PTT unit") budget is exceeded, further processing for this title is impacted adversely.

By contrast, it is preferable to maintain chapter characteristics in a title administration section of the recording on HDD 308, and to use the characteristics to better allocate chapters in the archiving process. These characteristics include the duration 416 of each normal chapter 108, the priority 210, 220 of the chapter, and whether the chapter is seamless or non-seamless. A seamless chapter is a normal chapter 108 for which the immediately preceding media content was recorded. An example of a seamless chapter is chapter 408. An example of a non-seamless chapter is chapter 412.

Upon archiving a title 104, its chapter characteristics can be pre-analyzed by the recording module 306 to prepare for chapter allocation. The variables determined include:

NrAvChs: the number of chapters 108, 128 still remaining in the budget, i.e., still available to be allocated, subject to the TotalNrChsPerDisc and TotalNrChsPerTitle thresholds of 254 and 99, respectively;

NrReqNorChs: the number of normal chapters 108 in the title 104 to be archived; NrAvAutoChs: the number of available automatic chapters 128 for the title 104 to be archived, which is equal to NrAvChs - NrReqNorChs, or to zero if this is a negative number;

NrReqAutoChs: the number of required automatic chapters 128 in the title 104 to be archived, which depends upon the durations 416 and the default duration 428;

NrReqAutoChsVis: that portion of NrReqAutoChs calculated for visible chapters 210; and

NrReqAutoChsHid: that portion of NrReqAutoChs calculated for the hidden chapters 220, if any, that exist in this title 104;

HidFlag: set to 1 if any hidden scenes 220 exist in this title 104, and to 0 otherwise.

If NrAvChs > NrReqNorChs + NrReqAutoChs, the recording module 306 straightforwardly allocates normal chapters 108 and automatic chapters 128 to the title 104 being archived, and then allocation is performed for the next title 104 to be archived, if any.

Otherwise, if NrAvChs < NrReqNorChs + NrReqAutoChs, a determination is made as to whether NrAvChs > NrReqNorChs. If NrAvChs < NrReqNorChs, the present title 104 has run up against a resource threshold, and will therefore be archived with fewer normal chapters 108 than the amount indicated by the chapter characteristics.

FIG. 5 is an exemplary iterative procedure to reduce the number of normal chapters 108 to be allocated to the present title 104, in accordance with the present invention. A remainder N = NrReqNorChs - NrAvChs represents the number of normal chapters 108 to be eliminated (step S504). Assuming that N is initially 1 or greater (step S508), inquiry is made as to whether a seamless chapter in the title is located between two consecutive hidden chapters 220 (step S516). If more than one such pair of consecutive hidden chapters 220 exists, the pair that spans the shortest duration is chosen, with ties being arbitrarily decided (step S520). If no such pair exists, processing queries whether a non- seamless chapter in the title is located between two consecutive hidden chapters 220 (step S 524). If there are more than one such pair of consecutive hidden chapters 220, the pair that spans the shortest duration is chosen, with ties being arbitrarily decided (step S 520). If no such pair exists, a query is made as to whether a seamless chapter is located between two consecutive visible chapters 210 (step S528). If more than one such pair of consecutive visible chapters 210 exists, the pair that spans the shortest duration is chosen, with ties being arbitrarily decided (step S 520). If no such pair exists, a query is made as to whether a non-seamless chapter is located between two consecutive visible chapters (step S 532). If more than one such pair of consecutive visible chapters 210 exists, the pair that spans the shortest duration is chosen, with ties being arbitrarily decided (step S520). If no such pair exists, a hidden chapter 220 of the shortest duration in the title, with ties being arbitrarily decided, is converted into a visible chapter 210 (step S536), and processing returns to step S528. The above sequence of steps assures that step S520 will be executed. The seamless or non-seamless chapter, as appropriate, between the pair chosen in step S520 is then removed (step S540), and the chapter removal count is updated (step S550). If the chapter removal count has now been reduced to zero (step S508), processing ends; otherwise, processing returns to step S516 to remove another normal chapter 108.

By the above iterative procedure, the normal chapters 108 for this title, although reduced in number, are intelligently distributed.

This reduction procedure is skipped altogether if NrAvChs > NrReqNorChs; yet, another resource threshold must be dealt with if NrAvChs < NrReqNorChs + NrReqAutoChs. In the latter situation, the need for normal chapters 108 is fulfilled, but fewer than the desired number of automatic chapters 128 will be allocated. If any hidden scenes 220 exist, i.e., HidFlag is one, the equitable allocation takes this into consideration, as described further below in connection with FIG. 7. Otherwise, if HidFlag = 0, processing proceeds directly to FIG. 6.

FIG. 6 provides one example of an iterative procedure executed to disperse the distribution of automatic chapters 128 equitably among all the normal chapters 108 in accordance with the present invention. The variable A; represents the number of automatic chapters 128 in NC;, i.e., normal chapter i 108, and is initialized to zero for all NC; (step S602). D; is the duration of the normal chapter i. For each normal chapter i for which the allocation has not been completed, d; is set equal to Dj/(1+Ai) (step S604). Next, an automatic chapter 128 is allocated to the normal chapter 108 for which d; is maximal (step S608). A query is then made as to whether another automatic chapter 128 is available to be allocated (step S612). If another automatic chapter 128 is available, processing returns to step S604. Step S612 may be implemented to carry out the division for only the d; that would change, i.e., the d; for that NC; just having been allocated an automatic chapter 128 in step S608. Otherwise, if in step S612 no other automatic chapter 128 is available, the index i is set equal to one (step S616). If d_; is less than the default (step S620), it is set equal to the default (step S624). The index i is bumped up by one (step S628) and then tested to see if the last d_; has been processed (step S630). If last d_; has been processed, control returns to step S620; otherwise, the allocation of automatic chapters 128 is complete. The effect is to spread out the automatic chapters 128 evenly among all normal chapters 108. In addition, the automatic chapters 128 allocated to normal chapter 108 are generally spread out evenly within the normal chapter, although, for example, automatic chapters smaller than the default size are shifted out to the default size thereby cutting short a last automatic chapter. For automatic chapters 128 greater than the default size, the spread can be implemented to be done evenly.

On the other hand if HidFlag = 1, an initial procedure is preferably executed to take into account a priority that is accorded to visible chapters 210 in equitably distributing the available automatic chapters 128. As shown by example in FIG. 7, the relevant variables are calculated if this has not already been done (step S710). If NrAvAutoChs < NrReqAutoChsVis (step S720), the algorithm of FIG. 6 is then executed, but only for those NC; that are visible 210 (step S730). On the other hand, if NrAvAutoChs > NrReqAutoChsVis (step S720), the visible chapters 210 are allocated the automatic chapters 128 they require in a straightforward manner, and the remaining NrAvAutoChs - NrReqAutoChsVis automatic chapters are allocated by executing the procedure in FIG. 6 only for the NC; that are hidden in? 220 (step S740).

Preferably, automatic chapters 128 equitably distributed according to FIG. 6 are aligned to cell and VOBU borders. Referring back to FIG. 4, a marker 445 to be placed in the DVD for the automatic chapter 444 is shifted in the direction indicated by the arrow 446 to the end of the cell 448. The default chapter duration 428 is preferably set to an integral number of default cell durations to avoid the need for this shifting.

While there have been shown and described what are considered to be preferred embodiments of the invention, it will, of course, be understood that various modifications and changes in form or detail could readily be made without departing from the spirit of the invention. It is therefore intended that the invention not be limited to the exact forms described and illustrated, but should be constructed to cover all modifications that may fall within the scope of the appended claims.

Claims

WHAT IS CLAIMED IS:

1. A digital video disc (DVD) recorder (304) configured for assigning automatic chapters (128) in a title (104) to avoid exceeding a chapter budget in copying the title to a DVD, said title being divided into units (108), said recorder comprising a recording module (306) configured to determine respective durations (428) of said units and to distribute available automatic chapters among said units according to said respective durations (S608), said assigning being based on insertion of said automatic chapters onto the DVD periodically during said copying.

2. The recorder of claim 1, wherein the recording module is configured so that the distributing aligns the available automatic chapter with a boundary between cells (446, 448), each of the cells containing one or more video object units (VOBUs) (116).

3. The recorder of claim 1, wherein said units are divided into priority classes (210, 220), the distribution being performed for the class of highest priority (S 730), and not for any other class as long as any unit in said class of highest priority can accommodate an additional automatic chapter (S740).

4. The recorder of claim 1, wherein the recording module is configured so that the distributing distributes in proportion to the respective durations (S608).

5. The recorder of claim 4, wherein the recording module is configured so that the distribution comprises the following steps: a) for at least some of said units, dividing the determined duration by the sum of one and a count of automatic chapters allocated to the unit, thereby producing respective quotients (S604); b) allocating an available automatic chapter to a unit for which no other of said automatic chapters has a larger quotient (S608); and c) returning to a) if an automatic chapter remains available within said budget for said allocating (S612).

6. The recorder of claim 5, wherein the recording module is configured so that the allocating sets the respective quotient as a duration of the allocated chapter, subject to a predetermined minimum duration (S620).

7. The recorder of claim 6, wherein said minimum duration is equal to an integer number of default cell durations (446), each of the cells containing one or more video object units (VOBUs) (116).

8. A digital video disc (DVD) recorder (304) configured to avoid exceeding a unit budget in copying a title (104) to a DVD, said title being divided into units (108) assigned to respective priority classes (210, 220), said recorder comprising a recording module (306) configured for removing at least one of said units based upon at least one of the following: a plurality of durations of said units (S520), a location where media content has been excluded that would otherwise have been contiguous with a unit of said units (410), and a priority class of a unit of said units (S524, S528).

9. The recorder of claim 8, wherein said module is configured so that said removing to avoid said exceeding, in selecting said at least one unit for removal, takes account of at least two of the following: a plurality of durations of said units (S520), a location where media content has been excluded that would otherwise have been contiguous with a unit of said units (410), and a priority class of a unit of said units (S524, S528).

10. The recorder of claim 8, wherein a non-seamless chapter (412) constitutes a unit of said units that immediately follows the user-excluded content, a seamless chapter (408) is a unit of said units that is not a non-seamless chapter, a visible chapter is a unit of said units assigned to a class of highest priority (210), and a non-visible chapter (220) is a unit of said units that is not a visible chapter, said module being configured so that said removing comprises a process that: a) removes a seamless chapter between two consecutive hidden chapters (S516), if such a seamless chapter exists and, if not, b) removes a non-seamless chapter between two consecutive hidden chapters (S 524), if such a non-seamless chapter exists, and, if not, c) removes a seamless chapter between two consecutive visible chapters (S528), if such a seamless chapter exists, and, if not, d) removes a non-seamless chapter between two consecutive visible chapters (S532), if such a non-seamless chapter exists, and, if not, e) changes a hidden chapter into a visible chapter (S536) and returns, starting from c), until a unit of said units is removed (S540).

11. The recorder of claim 10, wherein said module is configured such that said process has a number of iterations equal to a count of available units subtracted from a count of units (S504).

12. The recorder of claim 8, wherein said module is configured such that said removing comprises a process having a number of iterations equal to a count of available units subtracted from a count of units (S504).

13. A hard disk drive/digital video disc (HDD-DVD) combination box (300) comprising the recorder of claim 1.

14. A method for assigning automatic chapters (128) in a title (104) to avoid exceeding a chapter budget in copying the title to a digital video disc (DVD), said title being divided into units (108), said method comprising the acts of: determining respective durations (S604) of said units; and distributing available automatic chapters among said units according to said respective durations (S608), said assigning being based on insertion of said automatic chapters onto the DVD periodically during said copying.

15. The method of claim 14, wherein said distributing distributes in proportion to the respective durations (S608).

16. The method of claim 14, wherein said units are divided into priority classes (210, 220), said distribution being performed for the class of highest priority (S730), and not for any other class as long as any unit in said class of highest priority can accommodate an additional automatic chapter (S740).

17. The method of claim 16, wherein the act of distributing comprises the acts of: a) for at least some of said units, dividing the determined duration by the sum of one and a count of automatic chapters allocated to the unit, thereby producing respective quotients (S604); b) allocating an available automatic chapter to a unit for which no other of said automatic chapters has a larger quotient (S608); and c) returning to act a) if an automatic chapter remains available within said budget for said allocating (S612).

18. A method for avoiding exceeding a unit budget in copying a title (104) to a digital video disc (DVD) by eliminating at least one unit (108) in a title that is divided into units, said units being assigned respective priority classes (210, 220), said method comprising: determining, to reach a determination, at least one of the following: a plurality of durations of said units (S520), a location where media content has been excluded that would otherwise have been contiguous with a unit of said units (410), and a priority class of a unit of said units (S524, S528); and removing said at least one unit based upon the determination (S 540).

19. The method of claim 18, wherein said removing to avoid said exceeding, in selecting said at least one unit for removal, takes account of at least two of the following: a plurality of durations of said units (S520), a location where media content has been excluded that would otherwise have been contiguous with a unit of said units (410), and a priority class of a unit of said units (S524, S528).

20. The method of claim 18, wherein said method comprises a process having a number of iterations equal to a count of available units subtracted from a count of units (S 504).

21. A computer software product for assigning automatic chapters (128) in a title (104) to avoid exceeding a chapter budget in copying the title to a digital video disc (DVD), said title being divided into units (108), said product being embedded within a medium readable by a processor, said product including instructions executable to perform acts comprising the following steps: determining respective durations of said units (S604); and distributing available automatic chapters among said units according to said respective durations (S608), said assigning being based on insertion of said automatic chapters onto the DVD periodically during said copying.

22. A computer software product to avoid exceeding a unit budget in copying a title to a digital video disc (DVD) by eliminating at least one unit in a title that is divided into units (S540), said units being assigned respective priority classes (210, 220), said product being embedded within a medium readable by a processor, said product comprising instructions executable to perform acts comprising the following steps: determining, to reach a determination, at least one of the following: durations of said units (S520), a location where media content has been excluded that would otherwise have been contiguous with the unit of said units (410), and a priority class of a unit of said units (S524, S528); and removing said at least one unit based upon the determination (S 540).