US20010018693A1 - Video cataloger system with synchronized encoders - Google Patents

Abstract

One aspect of the invention is directed to a system and method for video cataloging. The video is cataloged according to predefined or user definable metadata. The metadata is used to index and then retrieve encoded video.

Description

PRIORITY
• The benefit under 35 U.S.C. § 119(e) of U.S. provisional application Ser. No. 60/055,751, filed Aug. 14, 1997, is hereby claimed.[0001]
Related Applications
• The subject matter of U.S. patent applications: Ser. No. ______, filed Aug. 14, 1998 and entitled “VIDEO CATALOGER SYSTEM WITH EXTENSIBILITY”; Ser. No. ______, filed Aug. 14, 1998 and entitled “VIDEO CATALOGER SYSTEM WITH HYPERLINKED OUTPUT”; and Ser. No. ______, filed Aug. 14, 1998 and entitled “VIDEO CATALOGER SYSTEM WITH AUDIO TRACK EXTRACTION” are related to this application.[0002]
BACKGROUND OF THE INVENTION
• 1. Field of the Invention[0003]
• The present invention generally relates to asset management of digital media, and more specifically, to a system and method for capturing and managing video and associated data.[0004]
• 2. Description of the Related Technology[0005]
• Today's broadcast corporations, advertising agencies, consumer products and services companies, and other businesses have demanding media asset management needs. These organizations have been simultaneously empowered by the growth in tools and infrastructure for creating, storing and transporting media-rich files and challenged by the problem of managing the media assets that they've amassed and come to rely upon for their core businesses. The sheer volume of information available over the World Wide Web and corporate networks continues to accelerate. Because media assets are so crucial to these companies, they have an extreme need for an intelligent and efficient way to catalog, browse, search and manage their media assets. Prior attempts at a content management solution have yielded point solutions or proprietary applications. These applications have not leveraged the technologies already deployed by many organizations, such as industry-standard browsers and Web servers.[0006]
• A system is needed that would automatically watch, listen to and read a video stream so as to intelligently extract information, termed metadata, about the content of the video stream in real-time. This information would become the foundation of a rich, frame-accurate index that would provide immediate, non-linear access to any segment of the video. Such a logging process would result in the transformation of an opaque video tape or file, with little more than a label or file name to describe it, into a highly leveragable asset available to an entire organization via the Internet. What was once a time consuming process to find the right piece of footage would be performed instantly and effortlessly by groups of users wishing to quickly and efficiently deploy video across a range of business processes. Television and film production, Web publishing, distance learning, media asset management and corporate communications would all benefit by such technology.[0007]
SUMMARY OF THE INVENTION
• In one aspect of the invention, there is a media cataloging and media analysis application which performs real-time, or non-real-time, indexing and distribution of video across an enterprise. A multimedia cataloger is the first application to make video-based solutions pervasive in enterprise markets by creating and publishing intelligent video via the World Wide Web. The multimedia cataloger is the logical starting point for creating or distributing significant amounts of video. The cataloger transforms video into a powerful data type that is both compelling and profitable in both Web and client-server environments. Using advanced media analysis algorithms that automatically watch, listen to and read a video stream, the multimedia cataloger intelligently extracts metadata-keyframes, time codes, textual information and an audio profile from the video in real-time. This information becomes the foundation of a rich, frame-accurate index that provides immediate, non-linear access to any segment of the video.[0008]
• In parallel to the indexing process, the multimedia cataloger may also optionally control the encoding of a streamable version of the original content. Synchronized encoding and indexing allows users to intelligently navigate through the video by using the index to go directly to the exact point of interest, rather than streaming it from start to finish. This approach provides video previewing that is faster than real-time, conserves valuable network bandwidth and dramatically reduces costs associated with editing and repurposing video.[0009]
• The multimedia cataloger permits accessing and distributing media for digital television, Web publishing, distance learning or media asset management initiatives using advanced methods for accessing and leveraging media assets.[0010]
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a block diagram of one embodiment of a multimedia cataloger system of the present invention.[0011]
• FIG. 2 is an exemplary screen display of a user interface for the multimedia cataloger system shown in FIG. 1.[0012]
• FIG. 3 is a block diagram of exemplary input and peripheral components for the multimedia cataloger system shown in FIG. 1.[0013]
• FIG. 4 is a block diagram of exemplary components and processes used in the cataloger and encoder portion of the multimedia cataloger system shown in FIG. 1.[0014]
• FIG. 5 is an exemplary timeline of encoder start-up and synchronization for the components and processes shown in FIG. 4.[0015]
• FIG. 6 is a diagram of an exemplary set of metadata types in a time-based track representation as derived by the cataloger of the multimedia cataloger system shown in FIG. 1.[0016]
• FIG. 7 is a block diagram of an object model for the metadata shown in FIG. 6 along with a software process that manages the metadata.[0017]
• FIG. 8 is a block diagram of the software architecture for the cataloger of the multimedia cataloger system shown in FIG. 1.[0018]
• FIG. 9 is a block diagram of the elements of the extensible video engine shown in FIG. 8.[0019]
• FIG. 10 is a block diagram of the audio analysis extractor shown in FIG. 9.[0020]
• FIG. 11 is a flowchart of the extensible video engine initialization (start-up extensibility initialization) process shown in FIG. 8.[0021]
• FIG. 12 is a flowchart of the video encoding (and metadata capture) synchronization process shown in FIG. 8.[0022]
• FIG. 13 is a flowchart of the capture metadata process shown in FIG. 12.[0023]
• FIG. 14 is a flowchart of the feature extraction process shown in FIG. 13.[0024]
• FIG. 15 is a block diagram of the architecture of the HTML output filter shown in FIG. 9 as used in the multimedia cataloger system shown in FIG. 1.[0025]
• FIG. 16 is a flowchart of a HTML output filter process corresponding to the HTML output filter architecture shown in FIG. 15.[0026]
• FIG. 17 is an exemplary screen display seen as an output of the HTML output filter process of FIG. 16 while using a client browser for the multimedia cataloger system shown in FIG. 1.[0027]
• FIG. 18 is a block diagram of another embodiment of a multimedia cataloger system of the present invention.[0028]
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
• The following detailed description of the preferred embodiments presents a description of certain specific embodiments to assist in understanding the claims. However, the present invention can be embodied in a multitude of different ways as defined and covered by the claims. Reference is now made to the drawings wherein like numerals refer to like parts throughout.[0029]
• The detailed description is organized into the following sections: 1. Top Level System Overview, 2. Example User Interface, 3. Cataloger Configuration Detail, 4. Logging and Encoding, 5. Example Timeline, 6. Metadata Track Representation, 7. Metadata Index Object Model, 8. Cataloger Architecture, 9. Extensible Video Engine Architecture, 10. Audio Feature Extractors, 11. Extensible Video Engine Start-up Initialization, 12. Video Encoding and Metadata Synchronization, 13. Capture Metadata, 14. Feature Extraction, 15. HTML Output Filter Architecture, 16. HTML Output Filter Process, 17. Example HTML Output, 18. Alternative System. Before describing the detailed internal engineering of the inventive system, a top level system overview will be helpful.[0030]
• 1. Top Level System Overview[0031]
• FIG. 1 depicts a[0032]typical system100 that incorporates aVideo Cataloger110. TheVideo Cataloger110 typically operates in a networked environment which includesdata communication lines112,122,132, and142. Some variants of such a system include:
• Analog Sources[0033]102: may be any of a number of possible sources, such as an analog or digital tape deck, a laser disc player, a live satellite feed, a live video camera, etc. A video signal, such as NTSC or PAL, is all that is needed for input into theVideo Cataloger110.
• Metadata Server[0034]130: may be as simple as a file system containing hypertext markup language (HTML) files, or as complex as a relational database supporting a client-server application environment for media management.
• Client interfaces may be HTML web browsers, Java, or native client applications, for example.[0035]
• Digital Video Encoding[0036]120: the existence of digital video is an optional component. It may be the case that the metadata merely indexes video that resides on analog video tapes stored on shelves.
• Content Server[0037]140: may be as simple as a file system containing digital video files, or as complex as a digital video stream server such as those offered by Real Networks, Silicon Graphics Mediabase, Oracle OVS, and the like.
• Digital Video Formats: digital video data is encoded by an[0038]encoder process120 and communicated to theContent Server140 over anetwork channel122. The format of the digital video may be any of a wide variety of formats, such as Real Video (at various bit rates from 20 kbps up to 500 kbps), MPEG-1 (at various bit rates up to 3.5 mbps), MPEG-2 (at various bit rates up to 40 or 50 mbps), MPEG-4, MPEG-7, Motion JPEG, Apple QuickTime, Microsoft AVI, and so forth.
• 2. Example User Interface—screen shot[0039]
• FIG. 2 depicts an example user interface that is representative of the type of graphical user interface (GUI) than could be built around the Video Engine shown in FIG. 9. In FIG. 2, the Video Cataloger user interface is contained in a[0040]window170. The main controls are exposed as menus and atool bar182. A panel172 displays the live video being digitized, with play, stop, etc. controls that interact remotely with the analog source via a deck controller240 (FIG. 3). Keyframes extracted during the capture process are displayed in a panel176, while the corresponding close-caption text and timecodes are displayed in apanel178. Apanel184 displays the user-defined clip annotations, created by marking in- and out-points. Thecolumns186 and188 display the in- and out-time codes for the marked clip, respectively, while the remainingcolumns190,192,194 are an example of a user defined schema of labels to describe the clip. Finally, at the bottom of thewindow170 is atimeline180 that depicts the total time of the capture session, with a highlighted section corresponding to the currently selected range of keyframes.
• 3. Cataloger Configuration Detail[0041]
• FIG. 3 depicts a typical configuration of the[0042]Video Cataloger110 connected to various peripheral devices that interface the Cataloger to an analog source such as thevideotape deck102, aDeck Controller240, and a closecaption decoding device230. Thedeck controller240 is typically an external device that provides protocol translation between an industry standard protocol such as V-LAN, and the native protocol of broadcast devices (such as tape decks) from Sony, Panasonic, etc. An example device is the Video Media Express from Video Media Corp. Some hardware configuration may incorporate the V-LAN controller into a card in the Cataloger workstation, for instance.
• The close[0043]caption text decoder230 can be an external box as shown, (such as EEG Enterprises Digital Recovery Decoder), or the CC-text decode functionality can be incorporated on the frame capture board inside of the Cataloger workstation. Furthermore, the video signal may be routed through the close caption text decoder230 (as shown), or it may be split and fed directly to both thevideo Cataloger110 and the decoder in parallel.
• The[0044]Video Deck102 is one example of an analog source. Several others are possible: laser disk, satellite feed, live camera feed, digital disk recorder such as a Tektronix Profile, etc. Some of these configurations would not incorporate the V-LAN control (such as a live or satellite feed).
• Analog signals[0045]232 may be fed from theVideo Deck102, through theclose caption decoder230, into theVideo Cataloger110. The analog signals correspond to video information which generally includes audio information. Decoded close caption text is passed to theVideo Cataloger110 by adata connection234 which is typically an RS-232 cable. Deck commands pass from theVideo Cataloger110 to theDeck Controller240, and then to theVideo Deck102 byphysical data connections236 and242 which are typically RS-232 serial connections, but may be other signaling protocols. The time codes proceed from thevideo deck102 to thevideo cataloger110 via thedeck controller240. Of course, in alternate implementations, theVideo Cataloger110 may receive video information from a digital source such as a digital camcorder.
• 4. Logging & Encoding—detail[0046]
Overview
• FIG. 4 depicts one of a great variety of possible encoding scenarios, driven by the Video Cataloger. The[0047]Video Cataloger software110 runs on acomputer workstation111. The “Vidsync”process260 running on each of theencoder workstations123,125,127 is responsible for responding to Start and Stop commands from theVideo Cataloger110, and affecting the start and stop of the corresponding encoding process on each workstation. Theanalog source102 will typically need to be split by an audio-video switcher252 so that the signal can be fed to each receiving workstation without degradation. FIG. 4 shows examples of Real Video encoding124, MPEG-1encoding126, and MPEG-2encoding128. Further information on the Moving Pictures Experts Group (MPEG) encoding standards may be found at the following URL: http://drogo.cselt.stet.it/mpeg. Naturally, other encoding formats are possible. All machines are connected by adata network250, which is typically a TCP/IP network, although other network protocols may be employed.
• Some of the many variations for encoding scenarios include:[0048]
• a. Incorporation of an encoder hardware board[0049]126 (such as an MPEG-1 encoder from Optibase, Minerva, etc.) directly inside theVideo Cataloger workstation111. Because most of the computation occurs on the dedicated board, this is feasible in practice)
• b. Use of a stand-alone “black-box” encoder such as those from Lucent and Innovacom for[0050]MPEG 1, which do not require a workstation. The black-box simply accepts an analog input, and a network connection to deliver the MPEG data packets to a video server. These boxes are typically rack mounted, and can be configured with up to eight encoders per enclosure. This is ideal for large scale encoding scenarios where several feeds or tape decks must be encoded.
• c. Using one, two, or N encoders simultaneously. For simple browse applications, a single encoded proxy is all that is needed. For web publishing applications, publishers typically want to encode a low-resolution stream (such as Real Video at 20 kbps) and a high resolution stream (such as Real Video at 100 kbps) to service different users having different Internet connection bandwidths.[0051]
Command Structure
• The[0052]Cataloger110 issues commands to each of theVidsync daemons260 running on the encoder workstations. These daemons, or processes that are periodically spawned to carry out a specific task and then terminate, are responsible for initiating the encoding process for whatever type of encoding is going to occur. That is, intimate knowledge of the encoding is maintained in Vidsync, and the Cataloger is generic in this respect. The Vidsync daemons also are responsible for returning certain pieces of information to the Cataloger, such as the actual start time, and a digital video asset ID or name for later use.
• START Command: The[0053]Cataloger110 issues a “start encoding” command via TCP/IP to each of the encoders (Vidsyncs) in parallel. Each of theVidsyncs260 then communicates with whatever software and hardware encoding processes/boards are required to initiate encoding. This may also involve communicating with a video server to set up an encoding session, and may take from 1 to several seconds. Thus, each encoder process may have a different actual start time. The Vidsync daemons then return the actual start time and a digital video asset ID to theCataloger110. When allVidsyncs260 have returned, the metadata capture begins at a nominal T=0 time. Each of the actual start times is stored as a delta-time from this T=0 time. When a piece of metadata (such as a keyframe) is used to index the digital video, an absolute time from the beginning of the digital video is computed by adding the delta-time to the time-code of the metadata.
• STOP Command: The[0054]Video Cataloger110 issues a “stop encoding” command via TCP/IP to each of the encoders in parallel.
• 5. Example Timeline[0055]
• FIG. 5 illustrates the timing associated with video encoder start-up and synchronization. Each[0056]timeline123,125,127 represents a separate video encoder. TheVideo Cataloger110 issues aStart Command290. Some time after that, each encoder actually begins encoding, resulting in an “actual start time”292. After all the encoders have started, theVideo Cataloger110 itself begins cataloging metadata, at a time nominally labeled “T=0”294. Thus, each encoder has a start offset ‘delta’time296. This delta time is then stored with the video metadata to be used later when a video stream is requested, to insure the offset is accounted for in time code calculations.
• 6. Metadata Track Representation[0057]
• FIG. 6 is a logical illustration of a number of metadata types in the form of the preferred time-based track representation. The[0058]keyframe track320 consists of a set ofindividual keyframes340,342,344,346,348,350,352 which have been intelligently extracted from the video based on visual information and scene changes by the Keyframe Extractor512 (FIG. 9). Each keyframe is time stamped for later correlation with the digital video or a time-code on a videotape.
• The close caption text (cc-text)[0059]track322 consists of sentences of text parsed from the cc-text input by the cc-text extractor514 (FIG. 9). Each text element spans a period of time in the video, denoted by an in-time and an out-time.
• Likewise, the remaining metadata tracks ([0060]Audio Classes324, Speech326,Speaker ID328, Keywords330) are each a parcel of metadata spanning a time period, and are extracted by their corresponding feature extractor shown in FIG. 9.
• The[0061]Clip Track332 is somewhat unique in that the definition/creation of this metadata is performed by a user using the GUI to mark in- and out-times, and type in associated alphanumeric data. Each bar in the Clip Track consists of a user-defined group of metadata fields that are application specific. The bar length is timespan from intime to outtime. Clips may be overlapping. Typically, the clips all have the same schema. For instance, metadata may include: Story Title, Report, Location, Shot Date, Air Date, Keywords, Summary, and so on. Each bar shows a clip label. So for instance, the clip labelled “Logo” may make use of the Story Title data item. Lastly, a Custom Trk is shown to indicate that metadata is extensible. That is, unique metadata can be defined and added to theVideo Cataloger110 by a user. Custom metadata tracks could include information provided in collateral data to the video information. For instance, global positioning satellite (GPS) data specifying latitude and longitude of a video camera and telemetry data of a vehicle carrying a video camera are examples of such collateral data.
• 7. Metadata Index Object Model[0062]
• FIG. 7 is an Object Model of the same logical metadata illustrated in FIG. 6. The elements of this diagram depict the software objects and processes that manage this metadata. The main object, the Metadata[0063]Track Index Manager402, is the manager of the entire index of metadata. It is extensible in that it allows registration of individual metadata track data types, and then manages the commitment of instances of that data into the index by feature extractors. There is one global metadata structure (the Session Level metadata404) that is not time based, and contains metadata that pertains to the entire video. Here, for example, is where the information for managing and time-synching the encoded video resides (digital video ID's and actual start time offsets). User defined annotations may also exist here. Each of the metadata tracks is a collection of data objects406,408,410,412, etc. that hold the metadata for a specific feature extractor, and are sequenced in time according to their in- and out-times.
• The metadata index also provides access for outputting metadata (data read-out) used by the Output Filters.[0064]
• In an object oriented programming implementation, every Track data type is derived from a “virtual base class” that provides the basic functions for insertion, deletion, read-out, etc., and defines storage for the in-time and out-time of each metadata element. Such an implementation may be coded in the C++ programming language. One exemplary reference guide is C++ Primer by Stanley Lippman, Second Edition, Addison Wesley, which is hereby incorporated by reference.[0065]

  TABLE 1
  Track Data Types

  	Metadata Data
  Track	Type	Notes
  Virtual	untyped (void *)	Defines In-time and Out-time for all
  Base Class		tracks
  Keyframe	image (bitmap)	In-time equals Out-time, i.e., keyframe is
  Track		a point in time
  CC-text	Text fragment	Each text fragment is typically a sentence
  Track		(but not required to be so) and spans a
  		time interval
  Audio	Enumerated	Speech, Silence, Music, Applause, Siren,
  Class	Classes	etc . . . , each spanning a time interval
  Track		when that classification was valid
  Speech	Text fragment	Each text fragment spans a time interval
  Track
  Keyword	Word (text)	keyword utterance spans a short (½ sec)
  Track		time interval
  Speaker	Enumerated	Identifiers of individuals whose speech is
  ID Track	Classes	recognized . . . each Speaker ID spans a
  		time interval when that speaker was
  		speaking
  Clip	Label Set (user	Different Label Set schemas can be used
  Track	defined set of	in different applications. Each Label Set
  	labels): Text,	is applied to all clips within a Cataloging
  	Enums, Dates,	session. The Clip definition spans a time
  	Numbers, etc.	interval marked by the user. Each Label
  		field value is entered manually by the
  		user.
  Custom	Data type defined	Typically, a custom metadata generator
  	by plug-in	uses a custom track data type for storing
  		its metadata. It could also re-use existing
  		track data types such as Text Fragment.

• Table 1 is a summary of the various standard metadata tracks, detailing the data types of each, and providing descriptive notes.[0066]
• 8. Video Cataloger—Architecture[0067]
• FIG. 8 is a global architecture illustration of the entire Video[0068]Cataloger software process420. The main components of this software are theMedia Capture Services430, the Video Encoding andSynchronization facility450, the Start-upExtensibility Initialization manager470, and the core Extensible Video Engine component440. The details of the core Extensible Video Engine440 are provided in FIG. 9. The Video Encoding andSynchronization module450 is responsible for communicating with the “Vidsync” daemon processes running on the video encoders, e.g.,123,125 and127 (FIG. 4). TheMedia Capture Services430 are further described in conjunction with FIG. 9.
• The registration interfaces for the extensible aspects of the Extensible Video Engine[0069]440 are explicitly shown in FIG. 8. Upon start-up of theVideo Cataloger110, registration processes are invoked for the four primary extensibility aspects of the Video Cataloger:Metadata track registration476,Feature Extractor registration472, Output Filter registration478, andEvent registration472. A set ofoutput filters484 are installed during system start-up. These registration processes, as well as user input andoutput functions550,554, are further described in conjunction with FIG. 11 below.
• 9. Extensible Video Engine—Architecture[0070]
• FIG. 9 depicts the main architectural elements of the extensible Video Engine[0071]440. Incoming media is processed by theMedia Capture Services430 consisting ofTimecode Capture502,Video Capture504,Audio Capture506, andText Capture508.Digital media509 is then made available to theFeature Extractor Framework510 for processing. Metadata from theFeature Extractors512,514,516,518,520,522 is then committed to the MetadataTrack Index Manager530 in a time based track representation as shown in FIGS. 6 and 7.
• During metadata capture, the user may mark video clips and annotate them. This[0072]input552 is captured by the GUIInput Capture element550.Event monitoring540 and dispatch544 also occurs during capture, driven by an Event Dictionary542. Finally, when capture is complete, the metadata may be output in a variety of formats such as Virage Data Format (VDF)562,HTML564, XML566,SMIL568 and other570, which are managed by theOutput Filter Manager560. A VDF API and Toolkit may be licensed from Virage of San Mateo, Calif. Furthermore, the use of the format is described in “Virage VDF Toolkit Programmer's Reference”. One reference for the extensible Mark-up Language (XML) is the following URL: http://www.w3.org/TR/REC-xml which is a subpage for the W3C. Also, information on Synchronized Multimedia Integration Language (SMIL) may be accessed at the W3C site.
• The Metadata[0073]track Index Manager530 represents the object that manages the multiplicity of metadata tracks. When data is committed to the track index by either a feature extractor512-522 orGUI input550 and552 (i.e., user marks clips and annotates them), this can trigger display updates as follows: the particular metadata track that receives the data decides if this requires a display update. If so, it sends a message to the GUIDisplay Update Manager554 which marks the relevant GUI object as “dirty” and in need of a redraw. In Windows Microsoft Foundation Classes (MFC), the event model allows Windows to detect these dirty GUI objects and issue redraw messages to them directly (see FIG. 12—Get Event)
• The core aspects of extensibility are:[0074]
• Extensible Track data types are registered with the Metadata[0075]Track Index Manager530. Any desired data representation can be defined and installed, such as region markers, OCR text and confidence values, face identifiers, camera parameters (pan, tilt, zoom), etc. Any property that a feature extractor chooses to extract can be placed in a custom metadata track.
• Extensible Feature Extractors can be registered with the[0076]Feature Extractor Framework510 to operate on digital media, or on any collateral data they may choose to collect when called.
• Extensible Event triggers: event criteria (e.g., cc-text “clinton”, or audio_class=“tone”) can be registered in the Event Dictionary[0077]542, and arbitrary actions can be registered and triggered (e.g., grab a keyfirame right then, or stop capture). TheEvent Monitor540 monitors the incoming metadata to decide if an event is triggered. If so, it sends a message to theEvent Dispatcher544 which invokes thecorresponding action546 for the event.
• Extensible Output Filters may be registered with the[0078]Output Filter Manager560. Further discussion of Output Filters is provided below with respect to FIGS. 15 and 16.
• [0079]Time code capture502 is typically via VLAN (as in FIG. 3), but may come from a variety of sources. Time code capture is another aspect of extensibility (though not core) since we have a plug-in for time-code extraction
• 10. Audio Feature Extractors[0080]
• FIG. 10 depicts the architectural components of the audio[0081]analysis feature extractors516 in one embodiment of the Video Engine440. As can be seen in the diagram, there are various cross-couplings between these feature extractors, which may not be precluded in the extensibility mechanisms managed by the feature extractor framework510 (FIG. 9).
• The analog audio signal[0082]592 is captured and digitized byaudio digitization device506, which may be any standard audio digitization device, such as a Sound Blaster audio card for a PC. The digital signal is then normalized by asoftware component596 to account for variability in signal amplitude (volume). The normalizeddigital audio signal598 is then fed into anAudio Class Profiler600 which classifies the signal into one of several possible categories, such as “speech”, “music”, “silence”, “applause”, etc., where each of the categories may be trainable using well understood techniques, and is stored in aClass Dictionary602. An Audio Classification (AC)Engine604 is a modular component that is available from multiple vendors, or may be proprietary. One skilled in the relevant technology may evaluate and utilize a specific engine depending on the application requirements.
• When the[0083]Audio Class Profiler600 detects that the class is “speech”, it triggersswitch610 which then allows the normalizeddigital audio signal598 to pass into additional feature extractors which are capable of processing speech. Aspeech transcription module620 is designed to interface with any availableSpeech Recognition Engine624 using anindustry standard interface626, such as the “Speech API”, or SAPI defined by Microsoft. Typically, theSpeech Recognition Engine624 utilizes a Vocabulary Dictionary622 to aid in the speech recognition process and improve accuracy by limiting the speech domain, although this is not required. It is a typical feature of existing speech recognition engines available on the market today. Examples include offerings from IBM, BBN, Dragon Systems, SRI, and so on.
• The output of the Speech[0084]Transcription Feature Extractor620 may then be further processed as follows: thefull text628 of the transcription process may be used directly as metadata; additionally, a KeywordSpotting Feature Extractor640 may be employed to selectively identify keywords of interest, and produce atext output648 limited to the keywords specified by aDomain Dictionary642. ADomain Dictionary Engine644 is responsible for making these selections. Again, theDomain Dictionary644 Engine is typically a modular component that may be one of several available, interfacing with the Keyword Feature Extractor normally via astandard interface646 such as the Domain Dictionary API, or DDAPI.
• The normalized digital audio signal containing speech can also be fed into a Speaker[0085]ID Feature Extractor630 to identify individual speakers by name. ASpeaker ID Engine634 may also be a modular component that is offered by several speech recognition vendors, and interfaces with the SpeakerID Feature Extractor630 typically via anindustry standard interface636 such as the SVAPI. Typically, the Speaker ID Engine utilizes aSpeaker Dictionary632 to constrain the space of possible speakers, and store signatures or sample speech of individual speakers which are used during speaker identification.
• 11. Extensible Video Engine Start-up Initialization - flowchart[0086]
• FIG. 11 is the process flowchart for the start-up initialization of the Video Cataloger[0087]110 (FIG. 1). This flowchart depicts the process for registering data types, algorithms, and events which are important to the extensibility features of theVideo Cataloger110.
• Upon start-up of the Video Cataloger, the extensible video[0088]engine initialization process470 is executed by theworkstation111. Starting at abegin step702, theprocess470 moves to step704 to install metadata tracks. This occurs first since later extensions (mainly Feature Extractors) may then utilize the track data types previously installed. Built-in Track Types are installed first atstep704, followed by installation of custom track types defined by plug-in modules atsteps706 to710. For each track plug-in, the data representation defined by that plug-in is installed at step708.
• Next, feature extractors are installed. The built-in feature extractors are first installed at[0089]step714, followed by feature extractors defined by plug-ins at steps716 to722. For each plug-in feature extractor, it is first registered atstep718 with the Feature Extraction Framework510 (FIG. 9). Atstep720, each of these plug-in feature extractors may request a metadata track type to receive its metadata.
• Following the feature extractor initialization, the Output Filters are initialized. As with the other elements, the built-in Output Filters are installed first at[0090]step724, followed by the installation of plug-in Output Features atsteps726 to730.
• Finally, Events are registered. All events are application specific (i.e., there are no built-in events), and are registered by plug-ins starting at[0091]steps734 to740. Each plug-in may define one or more events in the dictionary atstep736, and each event will have an associated event handler registered with it atstep738. Theextensibility initialization process470 completes at anend step742.
• 12. Video Encoding/Synchro—flowchart[0092]
• FIG. 12 details an important aspect of the present invention, which is the control and synchronization of the video encoding process with the metadata capture process. This synchronization is necessary because time-code indices within the metadata elements should correspond to correct and known points within the digital video that results from the encoding process.[0093]
• When video capture is initiated by the user, the[0094]video encoding process450 starts at abegin step762 and moves to step764 wherein the Video Cataloger110 (FIG. 1) first issues a Start Encoding command to each of N video encoders in parallel by spawning process threads766 for each encoder present. A process thread or a lightweight process is well understood by computer technologists. This command/control is effected by the “Vidsync” daemon process260 (FIG. 4) running on each encoder station. These Start commands are issued in parallel so that all the encoders begin encoding as close together in time as possible. However, their exact start times will not in general, be coincident. For this reason, theVidsync process260 returns the actual start times to the encoder flow control, and these times are stored by theVideo Cataloger110 with the video metadata instep774 for later use. Next, the general process of capturing metadata occurs instep776 until the process is stopped by the user. The details of themetadata capture process776 are provided in FIG. 13. When capture is done, Stop Encoding commands are sent in parallel to each encoder (via Vidsync) by spawningprocess threads780. It is of no consequence that the N encoders may stop encoding at slightly different times, as no metadata is associated with these time intervals.
• 13. Capture Metadata—flowchart[0095]
• FIG. 13 details the[0096]metadata capture process776 which is an important activity of the Video Engine440 of FIG. 9. Themetadata capture process776 was first introduced in FIG. 12.
• The[0097]capture process776 begins with the scheduling of a system timer event instep804 set to go off {fraction (1/30)} of a second in the future. The control flow of theprocess776 immediately proceeds to theGet Event step806 where other system events (besides the timer event) may be processed. When an event occurs, control passes to theEvent Dispatcher808 which decides if the event is one of the two types of events: a normal GUI event, or the scheduled timer event.
• For a GUI event, the event is first inspected in[0098]step812 to determine if it is an End Capture event, in which case the capture process loop terminates. If not, processing proceeds to step816 to handle the GUI event (such as keystroke, window resized, etc.). Some GUI events may generate metadata (if the user marked a video clip), which is determined instep818. If metadata (a video clip) was in fact generated, that metadata is committed to the Metadata Track Index Manager530 (FIG. 9) duringstep820. This also necessitates a GUI redraw, so the affected parts of the GUI are marked for Redraw instep822.
• If the event dispatched in[0099]808 is the timer event, this signifies that feature extraction of metadata from the video signals is to take place at afeature extraction process810. The details of thefeature extraction process810 are provided in conjunction with FIG. 14. Once feature extraction is complete, control moves to step804 where the next timer event is scheduled.
• This flow of activity is tied to the event model of the operating system under which the software application is running. The flow that is shown is an event model that is typical of a Windows MFC-based application. Other operating system platforms, such as Unix, have event models that differ somewhat. The event model illustrates how the feature extraction process fits into an application event framework. Note that, in the depicted embodiment, the[0100]Get Event task806 is a call out to Windows MFC, which processes Redraw Events by calling the Redraw method of the appropriate GUI elements directly (this process diagram does not “call” the Redraw methods directly). Note that it is acceptable if feature extraction takes more than {fraction (1/30)} second.
• 14. Feature Extraction—Flowchart[0101]
• FIG. 14 details the[0102]feature extraction process810, which is an important aspect of the present invention, relying on the innovative architecture of FIG. 9.
• The[0103]feature extraction process810 begins at astart step842 and proceeds to step844 where the current time code is obtained bymodule502 of FIG. 9. This time code is used by all feature extractors to time-stamp the metadata they extract. Next, all digital media is captured instep846 bymodules504,506, and508 of FIG. 9. This digital media is then passed on to the Feature Extractor Framework510 (FIG. 9) for processing. TheFeature Extractor Framework510 spawns aprocess thread850 for each feature extractor. Each feature extractor processes the digital media instep852 in whatever way it desires, for example, extract a keyframe, classify the audio signal, etc. In certain cases, but not all, some metadata will be generated from this process. Step854 determines if this is the case, and if so, the metadata is passed to the Metadata Track Index Manager530 (FIG. 9) duringstep856. Since metadata is usually displayed in real-time in the GUI, the GUI is marked for redraw instep858. One particular exemplary feature: extractor for video keyframes is described in the pending U.S. patent application entitled “Key Frame Selection” filed on Jun. 6, 1997.
• When all feature extractor threads complete, as determined at wait (synchronization)[0104]step862, control is returned to the capture metadata process atend step864.
• 15. HTML Output Filter—Architecture[0105]
• The Output Filter Manager[0106]560 (FIG. 8) may utilize aHTML output filter564 in one embodiment. Referring to FIG. 15, elements of FIGS. 1, 2 and9 are shown together as utilized in generating HTML output. The user may invoke a GUI command such as the “Save-As” command on the “File”menu553, which in turn provides a list of output filter choices (HTML, Real Networks SMIL, XML, custom, etc.). When theHTML filter564 is invoked, it accesses the metadata in the MetadataTrack Index Manager530 and processes it into HTML form in a browser window916 (FIG. 17), which also involves keyframe images in a keyframe frame176 (FIG. 2) or904 (FIG. 17), and the digital video142 (FIG. 1) or as seen in a video frame896 (FIG. 17). For instance, hyperlinks may be formed from displayed keyframes to video sequences. Thedigital video142 may or may not be served by acontent server140. For instance, it could be a simple file on the file system of the client computer or, say, a networked mass storage device visible to the computer.
• Some key features of the Video Cataloger HTML output are:[0107]
• a. The HTML files used to generate the display in the browser window[0108]916 (FIG. 17) are completely stand-alone, internally linked HTML, such that no Web server is required. Exemplary HTML files are provided in the Appendix and are described in conjunction with FIG. 17 below.
• b. It incorporates play-back of[0109]digital video142 from a file or from avideo server140. That is, the digital video may be streamed directly to the browser, or it may simply be played from a local file on disk. The stand-alone aspect is strengthened when the digital video is a local file. This way, all of the content (HTML, keyframes, digital video) could be packaged up, compressed, and e-mailed to someone.
• c. All metadata is cross-referenced/cross-linked based on time-codes.[0110]
• d. Digital video is independent of the HTML representation—any digital video source can be linked into the playback frame.[0111]
• 16. HTML Output Filter—flowchart[0112]
• FIG. 16 details a[0113]HTML export process890 from the Video Cataloger. Thisprocess890 is performed bymodule564 identified in FIGS. 9 and 15.
• The[0114]output process890 starts at abegin step892 and proceeds to step894 to process the session level metadata. This metadata is not time-based, but rather is descriptive of the entire logging session. The session level metadata corresponds to theinformation404 generated by the MetadataTrack Index Manager402 shown in FIG. 7. The nature of the session level metadata is a schema which may be defined by the user, in addition to standard items such as the location where the video is taken. This information is encapsulated in anHTML frame896 used to view this data on request, and is linked to themain HTML frame916.
• The next step is to process the keyframe track in[0115]step898. Keyframe images, which are captured raster images, may be converted to JPEG images suitable for display in a web browser. JPEG is but one possible viewable format. For convenience, the JPEG image files900 may be stored in a separate subdirectory of the Cataloger file system. Atstep902, the keyframe track is then further processed by constructing an HTML keyframe frame containing the keyframe time code information used to invoke video playback in896, and establishes hyperlinks directly to thecorresponding JPEG images900.
• Next, the close caption text track is processed in[0116]step906. The cc-text is output into an HTML frame, with hyperlinks created from time-codes into the keyframes of theHTML keyframe frame904. This allows the user to click on cc-text elements, and invoke the corresponding set of related keyframes.
• Video Clips are processed in[0117]step910. The clips (defined by in- and out-times, and a user defined set of text labels) are output into anHTML Clip frame912. The time codes are used to establish hyperlinks into the correspondingclose caption text908, and the corresponding keyframes inkeyframe frame904.
• Finally, a main HTML page that incorporates the above frames is constructed in[0118]step914. This HTML page embeds all the other frames for display and navigation. A video play-out helper application to decode and display video can be embedded in the web page frame. Examples of helper applications include RealPlayer (for RealVideo), Compcore SoftPEG (for MPEG) and Apple Quicktime.
• Exemplary reference guides which could be useful to write the code to automatically generate HTML are HTML: The Definitive Guide, The second Edition (1997) Chuck Musciano and Bill Kennedy , O'Reilly & Associates, Inc. and “Treat Yourself Web Publishing with HTML”, Laura LeMay, Sams Publishing, 1995, which are hereby incorporated by reference.[0119]
• Note that this process flow is one example which incorporates a subset of all available metadata tracks. The[0120]output process890 described above generated the exemplary screen shot in FIG. 17.
• 17. Example HTML Output—screen shot[0121]
• Referring to FIGS. 16 and 17, a screen shot of the HTML output as seen at a client browser and as generated by the HTML output process[0122]890 (FIG. 16) will be described.Element896 corresponds to the video frame in the upper left portion of the screen display.Element904 corresponds to the keyframe frame in the lower left portion of the screen display.Element908 corresponds to the cc-text frame in the lower right portion of the screen display.Element912 corresponds to the clip frame in the upper right portion of the screen display.Element916 corresponds to the whole browser window. As with most browsers, including Microsoft Explorer and Netscape Navigator, if the displayable page is larger than the physical display, the browser will cause the page to be scrolled. Video data is retrieved by sending a time code to the embedded player application. The player application then retrieves the video, seeks to the requested time code (in-time), and begins playback. The user can interrupt the playback using standard VCR type controls on the player.
• The HTML code for an exemplary screen display is provided in the Appendix. Sheet A of the Appendix lists the directory names (clip and icons) and file names at a top level. Sheet B lists the files in the clip directory, while sheets C, D and E list the files in the icons directory. Sheet F lists the HTML code for the top level index.html file which provides the framework for the display shown in the browser window[0123]916 (FIG. 17). Sheet G lists the contents of the topr.html file (as would be seen in the clip frame912 (FIG. 17)). Sheet H lists the contents of the video_label.html file. Sheet I lists the contents of the video_mbase.html file. Sheet J lists the contents of the video_netshow.html file. Sheet K lists the contents of the video_noproxy.html file. Sheet L lists the contents of the video_ovs.html file. Sheet M lists the contents of the video_real.html file. Sheets J, K, L, and M may be used to provide the proxy video to allow different video formats to be displayed in the video frame896 (FIG. 17). Sheet N lists the contents, including a set of keyframes and corresponding timecodes (as would be seen in the keyframe frame904 (FIG. 17)), of the0001.html file in the clips directory. Sheet P lists the contents, including a set of icons in a closed-caption text frame (as would be seen in the cc-text frame908 (FIG. 17)), of the000r.html file in the clips directory. The remaining sheets in the Appendix are alternate instances of the contents shown in exemplary sheets N and P. Of course, other programming languages besides HTML code could be used to implement hyperlinked output conversion.
• 18. Alternative System[0124]
• An[0125]alternate embodiment940 of the video encoding process, which involves avideo server942, is shown in FIG. 18. In this scenario, digital video is encoded in a MPEG stream on theCataloger workstation111. The data stream is broadcast as a set of UDPs (Universal Datagram Packets)946 on a specific port number (configurable). UDPs is a standard which is a member of the IP family of protocols. When cataloging begins, theVideo Cataloger110 sends aSTART command944 to aVidsync process260 which is running on thecontent server140 where the videoserver software process942 is running.Vidsync260 in turn tells thevideo server942 to “start listening” forUDP packets946 on the specific port number. Thevideo server942 then begins “catching” theUDP packets946, and converting the MPEG data into a digital video asset on thatserver942. As always,metadata112 is sent from theVideo Cataloger110 to themetadata server130 in parallel to this encoding process. When aSTOP command944′ is issued,Vidsync260 signals thevideo server942 to stop listening for theUDP packets946.
• In point of fact, the allocations of support hardware, computer workstations and software processes are only described here as but one example. Many other functional partitions can be defined to implement the present invention.[0126]
• While the above detailed description has shown, described, and pointed out the fundamental novel features of the invention as applied to various embodiments, it will be understood that various omissions and substitutions and changes in the form and details of the system illustrated may be made by those skilled in the art, without departing from the concepts of the invention.[0127]

Claims (17)

What is claimed is:

1. A video cataloger system, comprising:

a video cataloger receiving video information and a plurality of time codes associated with the video information, and generating a plurality of digital data tracks indicative of the video information and the time codes; and

a plurality of video encoders, each encoder receiving the video information and generating a type of encoded digital video data indicative of the video information;

wherein the video cataloger controls the video encoders to start and stop encoding and stores the start time of each encoder so that the time codes associated with the digital data tracks and the stored start times permit selective access to the encoded digital video data.

2. The system of

claim 1

, wherein the video information is provided by a videotape deck.

3. The system of

claim 1

, wherein the video information is provided by a live satellite feed.

4. The system of

claim 1

, wherein the video encoders include at least one encoder to generate digital data encoded to an MPEG standard.

5. The system of

claim 1

, wherein the video encoders include at least one streaming video encoder.

6. The system of

claim 1

, wherein the video cataloger and the encoders each reside on individual computers, the computers being connected in a computer network.

7. The system of

claim 1

, wherein the digital data tracks include one or more of the following: keyframe, close caption text, audio class, speech, speaker identification, keyword and clip.

8. The system of

claim 1

, wherein the video information time codes are SMPTE time codes.

9. The system of

claim 1

, additionally comprising:

a digital data track server receiving the digital data tracks from the video cataloger and providing network access for client computers; and

a content server receiving the encoded digital video data from at least one of the video encoders and providing network access for client computers, wherein the content server receives requests from the digital data track server to send encoded digital video data to a selected one of client computers.

10. The system of

claim 1

, wherein the video information is received form a digital source.

11. A method of synchronizing a plurality of digital video encoders with a video cataloger, comprising:

receiving video information at a video cataloger and a plurality of digital video encoders;

commanding each of the digital video encoders to start encoding;

storing actual start times associated with the start command for each digital video encoder at the video cataloger;

encoding the video information at each digital video encoder into a type of encoded digital video data; and

capturing digital data tracks indicative of the video information at the video cataloger.

12. The method of

claim 1

1, additionally comprising the step of accessing the encoded digital video data from one of the digital video encoders based on data located in at least one of the data tracks and the stored start time.

13. The method of

claim 1

1, additionally comprising repeating the aforementioned acts a plurality of times thereby generating a digital video library.

14. The method of

claim 13

, additionally comprising browsing the digital video library using the digital data tracks as indices into the encoded digital video data.

15. The method of

claim 1

1, wherein the video information is received from a videotape deck.

16. The method of

claim 1

1, wherein the video information is received from a real-time source.

17. The method of

claim 1

1, wherein the video information is received from a digital videocamera.

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