WO2002048842A2

WO2002048842A2 - Media files with additional content

Info

Publication number: WO2002048842A2
Application number: PCT/CA2001/001766
Authority: WO
Inventors: Richard A. Klosa; Trevor Trinkaus
Original assignee: J!Ve Media Technologies Inc.
Priority date: 2000-12-15
Filing date: 2001-12-14
Publication date: 2002-06-20
Also published as: AU2002215750A1; WO2002048842A3; WO2002048842A8

Abstract

A data layer is added to a media file to allow for communication with a central server whenever the file is accessed. This permits the provision of additional dynamic content when the media file is played back. This also provides the ability to track use of the file. Standard media content file formats and standard media file player application programs may be used.

Description

MEDIA FILES WITH ADDITIONAL CONTENT

BACKGROUND OF THE INVENTION

This invention relates to providing additional content during playback of a media file.

Multi-user computer usage began with centralized mainframe computers connected via dedicated communications links to several user access devices of limited processing capability, referred to as "dumb terminals". In this architecture, computer software was designed to execute on the mainframe computer, with limited communication of commands and results to the end user device. With the advent of personal computers, more processing capability became available in user access devices. So computer software was designed to execute some functions on the end user devices, under the direction of software executing on the central mainframe computer. This architecture is referred to as "client server", where the client computers are the end users' personal computers acting as clients to a central computer, and the server computer is the centralized mainframe computer that serves information back to the client computers upon request from them. The World Wide Web is an example of computer software implemented under this architecture, where "web servers" are the centralized mainframe computers, and "web browsers" are the several distributed client computers.

With the advent of local area networks and the Internet, it subsequently became possible for end user personal computers to communicate directly with each other, without the need for a centralized mainframe server computer. Under this architecture, there is no specific designation of some computers as "server" and some as "client". All computers interconnected under this architecture are of equal standing, and may at times act as "client" to another computer by requesting information, and may at times act as "server" to another computer by providing information. Such networks of computers are referred to as "peer-to- peer" networks, or simply "P2P".

The increasing performance and economic benefit of using computers has significantly impacted many industries, including the creation and distribution of media content such as recorded music, filmed entertainment, and broadcast television programming. Such media content can be converted to digital format and manipulated by computers. Media content producers have used computers to manipulate, edit and create media content. Media distribution companies have used computers to copy, store and transmit media content over various digital communication networks.

The manipulation of media content by computers has been aided by the emergence and widespread acceptance of standards for the representation and encoding of various media content in digital form. Some of these standards were developed by individuals or corporations and have been accepted as de facto standards within specific industry sectors. Examples of these include GIF (developed by CompuServe Inc.) and QuickTime (developed by Apple Inc.). Some standards have been developed or adopted by national and international standards setting bodies, such as the International Standards Organization. Examples of these include JPEG and MPEG. One version of the MPEG standard, particularly suited for representing high-quality audio content, is MPEG-2 Layer 3, which is commonly referred to as "MP3".

Some media content producers have encoded audio content, typically being recorded music encoded as MP3 format digital files, that are offered freely or for sale on the Internet. The availability of these files has in turn stimulated the development and widespread availability of consumer software capable of reading these files and playing back the encoded audio through the consumer's personal computer. Such software is commonly referred to as a "player application". An example of a widely available player application would be the Winamp^tm software developed and freely distributed by NullSoft Inc. Additional consumer software was developed to allow consumers with personal computers having the ability to play audio compact discs ("CDs") to copy the contents of those CDs onto their personal computer hard disk, encode the contents as one or more MP3 files, and save those new MP3 files for later playback. Such software is commonly referred to as a "CD ripper".

Subsequently, businesses were founded to facilitate the distribution and sharing of digitally encoded media content files, including, but not limited to, MP3 music files. Under the client server architecture, the World Wide Web provided a useful technology for the distribution of MP3 files to consumers. Businesses such as MP3.com, Liquid Audio and Scour were based on this distribution technology.

Businesses were also founded to facilitate media content sharing under a peer-to-peer distribution technology architecture. Some, like Napster Inc., used a centralized server to maintain a catalog of which specific media content (typically individual song recordings) was available on which end-user computer attached to the P2P network. A consumer desiring to obtain a copy of a specific MP3 song file would use software freely provided by Napster Inc. to consult the catalog, and then to subsequently make a direct peer-to-peer connection to the personal computer of another end user possessing the desired song file. The subject file could then be directly copied from that computer to the initiating end consumer's computer.

This copying was observable only by the owners of the initiating and receiving personal computers, and was therefore untracked by any central authority, specifically including the copyright holders. Many media content producers and distributors allege this has led to widespread illegal copying of media content by consumers, referred to as "piracy" or "music piracy". Copyright holders responded by forcing Napster Inc. to restrict such usage of the Napster software, typically by refusing catalog access to consumers who had performed illegal copying of media content files.

In response to this restriction, software was developed by individuals and corporations that removes the catalog function from a centralized mainframe computer and distributes it across the several end-user computers connected in a peer-to-peer network. One example of such software is the Gnutella program (developed by NullSoft Inc.). Having no central catalog or file storage computer, fully distributed P2P systems such as this have no central point of control or accountability. This enables the added threat to copyright holders of uncontrollable piracy of digital media files.

One response by copyright holders has been the development of Digital Rights Management ("DRM") systems. One example of a DRM system is the Secure Digital Media Initiative ("SDMI") being developed by a consortium of media content producer corporations, particularly music recording companies and technology development companies. With DRM systems, the ability to access and playback individual media content files requires a unique password or other access privilege token. This access token is controlled by the copyright holder and is typically given to the consumer only on payment of a royalty to the copyright holder. To date, DRM systems have met with very limited consumer acceptance and have been subject to several "hacker" attacks, wherein skilled technicians have succeeded in accessing and playing back MP3 music files without possessing or paying for the associated access privilege.

Another response by copyright holders has been the creation of secure centralized servers that provide access to media content files. Consumers pay a one-time or periodic payment to the copyright holders to be allowed free access to the files stored on the secure server. Such systems are commonly referred to as "subscription models". To date, such systems have also met with very limited consumer acceptance.

SUMMARY OF THE INVENTION

A data layer is added to a media file to allow for communication with a central server whenever the file is accessed. This permits the provision of additional dynamic content when the media file is played back. This also provides the ability to track use of the file.

According to the present invention, there is provided a method of delivering dynamic content, comprising: receiving over a network from a source, an identification of a media file; responsive to said receiving, selecting content for display during playback of said media file; and sending said selected content toward said source over said network.

According to another aspect of the present invention, there is provided a method of creating a portable media file comprising: embedding tags in a media file, said tags provisioning said media file for the inclusion of additional content; and storing a software agent in association with said media file provisioned for launching and conducting a communication session with a server over a network. According to a further aspect of the present invention, there is provided a method of playing a portable media file, comprising: on accessing said portable media file, launching a communication session with a server over a network; requesting content from said server for use during playback of said media file; receiving said additional content; and providing said additional content at pre-selected points during playback of said media file.

According to another aspect of the present invention, there is provided a portable media file comprising media content for playback by a media player; tags for allowing the provision of additional content during playback of said media content; a unique identifier; a software agent for enabling communication with a server so as to allow communication of said unique identifier and tags to said server.

According to a further aspect of the invention, there is provided a server for delivering dynamic content, comprising: means for receiving over a network from a source, an identification of a media file; means, responsive to said receiving, for selecting content for display during playback of said media file; and means for sending said selected content toward said source over said network.

According to a yet further aspect of the invention, there is provided a computer readable medium which when operating on a processor, causes said processor to: launch a communication session with a server over a network; request content for use during playback of a media file; receive said additional content; and provide said additional content at pre-selected points during playback of said media file.

According to a yet further aspect of the invention, there is provided a wrapped file originator, comprising: means for embedding tags in a media file, said tags provisioning said media file for the inclusion of additional content; and means for storing a software agent in association with said media file provisioned for launching and conducting a communication session with a server over a network..

Other features and advantages will be apparent from a review of the below description of example embodiments in conjunction with the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

In the figures which illustrate example embodiments of the invention,

Figure 1 illustrates a system for use of the subject invention, Figure la is a detail view of a portion of figure 1, Figures 2 and 3 illustrate creation of a wrapped file,

Figure 4 is a flow diagram for playback of media files at an end-user computer, Figure 5 is a flow diagram for a part of the operation of a central server, Figure 6 is a flow diagram for another part of the operation of the central server, and

Figure 7 is a flow diagram of an alternative arrangement for part of the playback of media files at an end-user computer,

Figures 8a and 8b illustrate playback windows on a display of an end-user computer.

DETAILED DESCRIPTION

A file including electronic data, such as media content, is wrapped with a data layer including embedded commands, and may be distributed to end users via a computer network. When the file is accessed on the end user's computer, the commands embedded in the data layer cause the accessing application to communicate with a central server and exchange data with it. Data provided to the central server may include information about the end user's computer and the media content of the file. Data provided back to the end user's computer may include advertising or other additional content determined by the wrapped file originator. Commands embedded in the file data layer may cause this additional content to be displayed on the end user's computer during the time the file is being accessed by the end user.

Figure 1 illustrates an exemplary system for use of the subject invention. A wrapped file originator 10 receives media content from a source 12. The wrapped file originator 10 creates wrapped files 14 and may distribute these (via a computer network, or otherwise) to content providers 16, and/or end user computers 18. Additionally, the wrapped file originator 10 sends information about each wrapped file 14 to a central server 20. The central server 20, content providers 16, and end-user computers 18 are connected to a network, such as the public Internet 22.

With reference to figure 2 along with figure 1, in one embodiment of the invention, at the wrapped file originator 10 media content from source 12 is digitized and encoded as a computer file S202. For example, this encoding may be MP3 for pure audio data, and may be QuickTime, Windows Media, Real Media, or MPEG-4 for mixed audio/video data. With mixed audio/video data, the audio and video data are separated before encoding. The wrapped file originator then decides what forms and amounts of additional content are to be added during playback of the file by the end user S204. This additional content may be advertising or such other forms of encoded audio, video, or graphics data as the wrapped file originator desires. The additional content also includes an indication of the particular media content included in the file, such as an artist name, song title, catalog number, and other descriptive metadata.

Tags are then generated and inserted into the file S206 indicating the points during playback at which the additional content should be displayed. With a QuickTime embodiment, these embedded tags are implemented with atoms and sprites defined in the QuickTime standard. With an MP3 embodiment, these embedded tags are implemented with the MD5 data field defined in the MPEG-2 Layer 3 standard. An initial tag is also inserted into the file in order to launch a communications software agent when the file is accessed, as will be described.

The (hex) data of the (tagged) computer file may be scrambled by re-arranging blocks of data S210. Pointers to the blocks, which may be used to unscramble the computer file data, may be stored in a header S212. Next the tagged and scrambled computer file may be run through a one-way hash algorithm to create a digest. The digest may then be encrypted with an encryption key associated with the wrapped file originator 10, which key is shared with the central server 20. Similarly, each tag may be run through the hash algorithm and each resulting digest encrypted with the encryption key S214, S216. These encrypted digests are also stored in the header S220. File information, such as the media file type, which will allow a media player to use the media content of the wrapped file, is also stored in the header S220. A software agent to allow a platform on which the computer file is run to communicate with the central server may also be stored in the header. This software agent will include a universal resource locator (URL) for the central server. Lastly, a unique identifier may be generated and stored in the header S218, S220.

An exemplary wrapped file 14 is illustrated in figure la with the file information 48, unique identifier 50, pointers 56, encrypted digests 58, and communication software agent 60 in header 62. The header 62 and the tags 52 embedded in the tagged scrambled media file 54 comprise the data layer of the wrapped file. It will be apparent that the actual order of components in a wrapped file may be chosen differently. Due to the described scrambling, it will be apparent that the data layer cannot be removed from the file nor can the encoded audio data be copied into a separate computer file. Thus, from the foregoing, it will be apparent that the separate encoded audio, encoded video, and data layer information is combined as a single "wrapped" file. The resulting wrapped file is a portable media file that can be distributed to end user computers 18 through content providers 16 or other end-user computers 18 using the Internet or other computer networks S222, including peer-to-peer and file sharing networks. The wrapped file may be downloaded onto the computers of end users, using widespread software applications, such as Napster and Gnutella. The wrapped file originator also passes the entire wrapped file, or parts of its data layer, to the central server 20.

The generation and insertion of tags of S206 is detailed in figure 3. The server first selects an advertising model S301, then gets file attributes for advertising S202. A tag is then created for each advertisement S203, S204. The tags are then inserted into the computer file S205.

With reference to figure 4, when the wrapped file is accessed by the end user on an end- user computer 18, the associated player application, such as Winamp^tm. Windows Media Player^tm, or The Jive Player⁴"¹, is launched S401 on the end user's computer. The player application reads the embedded tags in the data layer of the file and acts on the instructions they represent. The first tag encountered launches the communication software agent associated with the file. This results in a communication session with the central server wherein information about the context of playback is sent to the central server S402. This information may include the operating system of the end user computer, the specific player application being used to access the wrapped file, the unique identifier of the file being accessed, the connection speed of the network connecting the end user computer and the server, and other user data. Then a playback execution message with information specific to the current playback event is sent to the central server S403. This information includes time and date, and playback mode.

If the wrapped file originator 10 desires, the embedded tags may include complete copies of the additional content, in which case the resulting wrapped files are completely self- included S404. If the wrapped file originator desires, the embedded tags can be instructions that cause dynamically updated additional content to be downloaded from the central server when the file is accessed by an end user. These dynamic update tags may cause the download 405 of additional content that is subsequently permanently embedded 406 in the file by the player application. In this case, the file is completely self-contained after the first playback. In a subsequent playback, these tags may cause a content indication to be sent to^' the central server so that the embedded content may be selectively updated. As described more fully hereinafter, the dynamic tags may also cause the download of additional content to be included in the file during playback, but not permanently embedded in it. In such case, the additional content must be downloaded during each playback.

Some of the embedded tags may be instructions to cause the player application to seek playback authorization from the central server, thereby enforcing a digital rights management regime S407, S408. The server makes this authorization determination based on whatever digital rights management rules or algorithm the wrapped file originator 10 has chosen, and sends the requested approval or denial back to the player application S409, S411. On receipt of this response, the player application accordingly initiates playback S410 or closes the wrapped file S412.

Where embedded tags are used to seek playback authorization, the tags may cause the communication software agent to send a playback request to the central server along with the encrypted digests and the unique identifier in the header. With this information, the central server can identify the file and check for tampering (by decrypting the digests). With reference to figure 5, when the central server receives a playback authorization request from the end-user computer S501, the corresponding authorization rules and algorithm are fetched from a database S503, S504 where they have been defined and entered S502 by the wrapped file originator. If the data included in the playback authorization request meets the requirements of the corresponding rules S505, the file is approved for playback. The server updates any playback tracking information in the database S506, which in some embodiments allows for authorization rules that specify a maximum number of permitted playbacks of a particular file, and sends the approval message back to the end-user computer S508. If the request does not meet the requirements of the corresponding rules, the server sends a decline message back to the end-user computer S505, S507.

With reference to figure 6, the central server awaits messages from various player applications on various end-user computers. When an end-user initiates playback of a wrapped file, the server receives the playback context message S601 and the playback execution message S603. The contents of these messages are saved in a database S602, S604 to be later available for reporting and analysis purposes. The server then awaits reception of messages from the end-user computer that may be created by embedded dynamic content tags during playback. Where any such messages are received, the server selects relevant dynamic content from a database S605, S606. This dynamic content may comprise an advertisement, the selection of which may be based on information from the playback execution and playback context messages. For example, the selection may be based on the specific file being played and/or the geographic location of the end user (which can be derived from the IP address of the end-user computer). The selection of advertisements can be further narrowed by applying other selection criteria or advertising campaign rules and algorithms S607 that may be defined in the database by the wrapped file originator 10. These rules may, for example, control the frequency of appearance of a specific advertisement in a specific region, or may restrict the appearance of one advertisement in close relation with another advertisement. If, after applying these selection criteria, a plurality of relevant advertisements remains S608, a random selection process may be used S609. Finally, the server chooses the format of the selected advertisement S610 based on the connection speed of the network linking the server and the end-user computer. For connection speeds at or below 56 kbps a low-bandwidth version (such as a Flash Media file) is chosen S611 and sent to the end-user computer for caching or immediate presentment. For connection speeds greater than 56 kbps a high-bandwidth version (such as a full-motion video file) is chosen S612 and sent to the end-user connection.

During the course of playback, the player application encounters additional embedded tags S414 at times specified when the tags were embedded in the file during wrapping. When an embedded tag is encountered, the player application obtains the additional content and displays it S413 according to the instructions included in the tag. This continues until playback of the file is complete S415.

The player application was described in conjunction with figure 4 as operating with files which had the advertising content embedded or downloaded. ■ More generally, the operation of the player application in this regard is as described in conjunction with figure 7. Thus, the player application may operate to present the additional content according to the instructions included in the embedded tags S701. If the requested content is already embedded in the wrapped file S702, it is read and displayed on the end-user computer. If the requested content is to be provided from the central sever, the content is obtained by the communication software agent and the content is displayed on the end-user computer. Where the connection is of sufficient speed, the content may be streamed from the server S703, S704. For slower connections, the download of the content may be initiated as soon as the wrapped file is accessed and the downloaded content cached S706, S707. If the requested content is obtained from the central server, but has already been fetched and cached onto the end-user computer S705, then it is read from cache and displayed. The instructions in the embedded tag may specify that the additional content should be displayed in the same window as any video content in the wrapped file. If so, the playback of the video and audio content is paused or otherwise suspended S709, the additional content is presented in that window S711, and the video and audio content playback is resumed in that same window S712. If the embedded tag instructions specify the additional content should be displayed in a separate window S708, then the content is displayed in a separate window of the player application S710.

The separate window for presenting additional content may be created for the player application by using the "skin" features of common player applications, by painting a customised GUI, or by using COM components to create a GUI, wherein customized user interfaces for the player application software may be easily specified and obtained. In one embodiment for an audio-only player application shown in figure 8a, the user interface skin may specify playback control buttons 30, a window for playback monitoring information 32 such as the name of the file being played, plus an additional window 34 in which the additional content is presented. In one embodiment for a mixed video and audio player application shown in figure 8b, the user interface skin may specify playback control buttons 40, a window for display of the video element 42, plus one or more additional windows 44, 46 in which the additional content is presented. Additionally, the skin may present a button 48 allowing a user to e-mail the wrapped file to another.

A unique identifier that is part of a wrapped file may be associated with a content provider 16. After a wrapped file associated with a given content provider is received by an end-user computer through a distribution chain, the end-user computer may access the file. The resulting playback context message to the central server will include the unique identifier. In consequence, the central server may log the playback event against the given content provider's account. This could result in a credit where an advertiser pays for each exposure of its advertisement. Furthermore, a copy of the file may be sent from one end-user computer to another by way of, for example, an e-mail attachment. In such instance, the copied file may be accessed at the new end-user computer. Where this occurs, the same unique identifier is again sent in the playback context message, which results in another playback event being logged against the content provider's account. Of course, each playback event may be subject to any digital rights management scheme.

The communication software agent has been described as communicating with one central server for playback logging, additional content retrieval, and enforcement of digital rights management. It will, however, be appreciated that the communication software agent may instead be configured to communicate with several different servers for the noted purposes. The wrapping of a media file has been described as occurring at a wrapped file originator 10. Equally, the media file may be wrapped at the central server 20 or at another location and distributed from that location. In such instance, the other location would send information to the central server regarding each wrapped file so that the central server could operate as aforedescribed. Although embodiments of the present invention have been described in detail herein, the present invention is not limited to such embodiments. The claims which follow are directed to the present invention, and are intended to further describe the present invention, but are not intended to limit the scope of the present invention.

WHAT IS CLAIMED IS:

1. A method of delivering dynamic content, comprising: receiving over a network from a source, an identification of a media file; responsive to said receiving, selecting content for display during playback of said media file; and sending said selected content toward said source over said network.

2. The method of claim 1 wherein said receiving further comprises receiving over said network from said source an indicator of a location of said source.

3. The method of claim 2 further comprising determining a location of said source based on said indicator.

4. The method of claim 3 wherein said indicator of a location is an internet protocol address.

5. The method of claim 3 wherein said content comprises a graphic file or a video computer file.

6. The method of claim 1 further comprising logging a playing event of said media file in response to said receiving.

7. The method of claim 6 further comprising determining whether or not to authorise a playback of said media file based at least in part on said received media file identification.

8. The method of claim 7 wherein said determining is also based on a number of logged playing events of said media file.

9. The method of claim 8 further comprising selectively an authorisation indication toward said source dependent on said determining. 10. The method of claim 6 wherein said identification is unique to said media file and is associated with a content provider and comprising logging said playing event of said media file in association with said content provider.

11. The method of claim 1 wherein said media file is for the generation of audio or for the generation of audio and video.

12. A method of creating a portable media file comprising: embedding tags in a media file, said tags provisioning said media file for the inclusion of additional content; and storing a software agent in association with said media file provisioned for launching and conducting a communication session with a server over a network.

13. The method of claim 12 wherein at least one of said tags comprises a request to said central server for additional content.

14. The method of claim 13 further comprising storing a unique identifier in association with said tagged media file.

15. The method of claim 14 further comprising scrambling blocks of said tagged media file and storing pointers for de-scrambling said blocks in association with said scrambled tagged media file.

16. A method of playing a portable media file, comprising: on accessing said portable media file, launching a communication session with a server over a network; requesting content from said server for use during playback of said media file; receiving said additional content; and providing said additional content at pre-selected points during playback of said media file. 17. The method of claim 16 further comprising sending a unique identifier of said media file to said server.

18. The method of claim 17 further comprising receiving a playback authorisation from said server and wherein said playing back is dependent upon receiving said authorisation.

19. The method of claim 16 further comprising permanently saving said additional content in association with said media file.

20. The method of claim 18 wherein said media file is an audio file or an audio-visual file.

21. The method of claim 16 wherein said additional content is display data and wherein said providing said additional content at pre-selected points during playback of said media file comprises displaying said additional content at said pre-selected points during playback.

22. A portable media file comprising media content for playback by a media player; tags for allowing the provision of additional content during playback of said media content; a unique identifier; a software agent for enabling communication with a server so as to allow communication of said unique identifier and tags to said server.

23. The media file of claim 22 wherein said tags are embedded in said media content.

24. The media file of claim 23 wherein said media file, with embedded tags is scrambled and further comprising pointers for use in de-scrambling said media file with embedded tags.

25. A server for delivering dynamic content, comprising: means for receiving over a network from a source, an identification of a media file; means, responsive to said receiving, for selecting content for display during playback of said media file; and means for sending said selected content toward said source over said network.

26. A computer readable medium which when operating on a processor, causes said processor to: launch a communication session with a server over a network; request content for use during playback of a media file; receive said additional content; and provide said additional content at pre-selected points during playback of said media file.

27. A wrapped file originator, comprising: means for embedding tags in a media file, said tags provisioning said media file for the inclusion of additional content; and means for storing a software agent in association with said media file provisioned for launching and conducting a communication session with a server over a network..

Claims

WHAT IS CLAIMED IS:

5. The method of claim 3 wherein .said content comprises a graphic file or a video computer file.

6. The.._nethod of claim 1 .further comprising logging a playing event of said media file in response to said receiving.

7. The .method of claim 6 further comprising determining whether or not to authorise a playback of saidimedia file based at least in parto said received:media.file identification.

8. The method of claim 7 wherein said .determining is .also based .on amumber of logged playing events of saidimedia file.

9. The method of claim 8 further comprising selectively an authorisation indication toward said source dependent on said determining.

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10. The method of claim 6 wherein said identification is unique to said media file and is associated with a content provider and comprising logging said playing event of said media file in association with said content provider.

14. The method of claim 13 further comprising storing a unique identifier in .association with said tagged media file.

15. The.method of claim 14 further comprising scrambling blocks of said tagged media-file .and storing pointers for de-scrambling said blocks in.association withisaid scrambled tagged media file.

16. A method of playing a portable mediaiile, comprising: on accessing isaid portable imedia file, launching a communication session with a server over a network; requesting icontent fromisaid serverfor useiduring playback of said media file; receiving isaid additional content; and providing said additional content at pre-selected points during playback of said media file.

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17. The method of claim 16 further comprising sending a unique identifier of said media file to said server.

19. The method of claim 16 fiirther comprising permanently saving said additional content in association with said media file.

22. A portable media file comprising media content for playback by a media player; tags for .allowing the provision of additional content during playback of saidimedia content; a unique identifier; a software agent for lenabling communication with a server so as to .allow communication of said unique identifi.er.and tags to said server.

-23. The media file of claim.22 wherein said tags are-embedded in said media content.

24. The_media file of .claim.23 wherein said-media .file, with embedded ags is scrambled and further comprising pointers for .use in. de-scrambling said media -file with embedded -tags.

25. A server for delivering dynamic content, comprising: means for receiving over a network from a source, an identification of a media file; means, responsive to said receiving, for selecting content for display during playback of said media file; and

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BNSDOCID <WO 0248842A2 I > means for sending said selected content toward said source over said network.

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