Application Programming Interface for Utilizing Multimedia Data

(19) TZZ_¥_T

(11) EP 1 376 978 B1

(12) EUROPEAN PATENT SPECIFICATION

(45) Date of publication and mention (51) Int Cl.: of the grant of the patent: H04L 29/06 (2006.01) H04L 29/08 (2006.01) 28.11.2012 Bulletin 2012/48

(21) Application number: 03013067.8

(22) Date of filing: 10.06.2003

(54) Application programming interface for utilizing multimedia data Anwendungsprogrammierungsschnittstelle mit Verwendung von Multimediadaten Interface de programmation d’applications utilisant des données multimedia

(84) Designated Contracting States: • Weiss, Rebecca C. AT BE BG CH CY CZ DE DK EE ES FI FR GB GR Kirkland, WA 98033 (US) HU IE IT LI LU MC NL PT RO SE SI SK TR • Wei, Dong Bellevue, WA 98006 (US) (30) Priority: 28.06.2002 US 185161 • Debique, Kirt Seattle, WA 98109 (US) (43) Date of publication of application: • Miller, Danny 02.01.2004 Bulletin 2004/01 Carnation, WA 98014 (US) • Dunbar, Geoffrey T. (73) Proprietor: MICROSOFT CORPORATION Kirkland, WA 98033 (US) Redmond, WA 98052 (US) (74) Representative: Grünecker, Kinkeldey, (72) Inventors: Stockmair & Schwanhäusser • Speed, Robin C. B. Leopoldstrasse 4 Kirkland, WA 98033 (US) 80802 München (DE) • Mohammed, Sohail B. Redmond, WA 98052 (US) (56) References cited: • Grigorovitch, Alexandre US-A- 5 996 025 US-A1- 2002 004 855 Redmond, WA 98052 (US) US-A1- 2002 065 952 • Crites, Brian D. Sammamish, WA 98074 (US)

Note: Within nine months of the publication of the mention of the grant of the European patent in the European Patent Bulletin, any person may give notice to the European Patent Office of opposition to that patent, in accordance with the Implementing Regulations. Notice of opposition shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). EP 1 376 978 B1

Printed by Jouve, 75001 PARIS (FR) EP 1 376 978 B1

Description

[0001] The presentinvention is directed tomethods, systems, andcomputer programproducts for accessing multimedia data of a variety of different formats from a variety of multimedia sources. 5 [0002] The advent of the computer revolution has had a tremendous impact on the ability to record and edit multimedia content (e.g., video and audio data). For instance, multimedia content can now be recorded in a digital format and stored on a condensed storage medium, thereby decreasing the cost and space previously required to archive desired multimedia content. Examples of condensed storage media that are capable of storing digital multimedia content include, for example, Compact Disks (CDs), Digital Video Disks (DVDs), MP3 disks, computer hard disk drives, floppy disks, smart 10 media cards, and compact flash cards. [0003] One advantage of digitizing multimedia content is that multimedia content can be broadcast and rendered with higher quality in a digital format than in an analog format. The devices and storage media used to capture and render digital multimedia are also typically smaller than the devices and storage media that are required to capture and render the same multimedia in analog formats. Yet another advantage of digitizing multimedia content is that digital data can 15 typically be indexed and accessed more quickly than analog data. [0004] The advantages provided by digitizing multimedia content have increased the demand for digital devices and multimedia applications that are capable of capturing, editing, and rendering multimedia content. Accordingly, the computer industry has worked to develop improved devices and applications to meet the increased demand. [0005] One underlying problem with providing improved applications for multimedia content, however, is that there 20 are many different types of formats, standards, and protocols that are used to encode and transmit digital data. Examples of different formatting standards include, for example, MPEG (Moving Picture Experts Group), ASF (Advanced Streaming Format), AVI (Audio Video Interleave), Active Movie, Cinepaq, QuickTime, Indeo, ATVEF (Advanced Television En- hancement Forum) and ATSC (Advanced Television Systems Committee). [0006] Examples of different protocols and languages include RTSP (Real- Time Streaming Protocol), RTP (Real- Time 25 Protocol), RTCP (Real-Time Control Protocol), UDP (User Datagram Protocol, HTTP (Hypertext Transport Protocol), MMS (Microsoft Media Server), TCP (Transmission Control Protocol), XML (extensible Markup Language), and SMIL (Synchronized Multimedia Integration Language). [0007] There are also many different multimedia sources including, but not limited to, broadcast television stations, cable stations, radio stations, CDs, DVDs, computer hard drives, the Internet, MP3 players, and so forth. Each of these 30 various multimedia sources may present multimedia content in a different manner to the multimedia application that is used to access and process the multimedia content, thereby requiring the multimedia applications to be configured to interpret a variety of different formats, standards and protocols. [0008] Accordingly, the large variety of different multimedia formats, standards, and protocols creates a burden on programmers for creating multimedia applications that are capable of accommodating the various standards, protocols, 35 languages and requirements that can be used to present multimedia content. Individually programming the multimedia applications in this manner, however, is inefficient, particularly when a single computing system is configured with multiple applications that must each be programmed to interpret certain basic information of the multimedia content. For instance, it may be necessary for the applications to each determine the duration of the multimedia content, the formatting of the multimedia content, the types of data present in the multimedia content, arid so forth. 40 [0009] Programming each of the different applications to individually determine basic information regarding the multimedia content requires duplicated efforts and undesirably wastes time, costs, and resources that are required to individually program the multimedia applications. Accordingly, there is currently a need in the art for improved methods for enabling multimedia applications to access and process multimedia data without the applications having to individually interpret and determine the characteristics of the multimedia content directly. 45 [0010] US-A-5 996 025 discloses a network transparent access framework for multimedia serving wherein a control serverin a client/ server environmentcomprises an API frameworkthat facilitates scalable, networktransparent, integrated multimedia content loading and data streaming. Assets are digital multimedia content resources stored for subsequent retrieval by an application. Assets include information about the file, such as title and play- rate. Once an asset is defined over the control interface, the asset may be loaded with either a file or a stream protocol. A load balancing technique is 50 intended to assist in optimizing overall system performance by balancing loads across processors, busses, ports and stripe groups. [0011] US 2002/004355 A1 discloses methods for facilitating display of content within application programs executing on electronic devices. An API enables application programs to communicate with other application programs and to send/retrieve content to/from other application programs. A gateway is configured to serve content retrieved from the 55 content server to the electronic device, as well as to other servers and/or devices. Methods, apparatuses and computer program products are provided for dynamically selecting advertisements for use within user requested content, wherein the advertisements are stored locally within a user client device. [0012] US 2002/065952 A1 discloses an extensible multimedia application program interface, selectively invoked in

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a computing system to interface any video decoder application with any video accelerator comprising a command data structure and a residual difference data structure. The control command data structure includes control commands which are dynamically tailored to interface the decoder application with a hardware accelerator in accordance with an acceptable media processing standard negotiated between the decoder and the accelerator. 5 [0013] It is the object of the present invention to provide a method and corresponding computer program product and computing system for facilitating the manner in which multimedia applications access and process multimedia data and, more particularly, for facilitating the manner in which applications obtain basic information regarding the multimedia data. [0014] This object is solved by the subject matter of the independent claims. [0015] Preferred embodiments are defined in the dependent claims. 10 [0016] According to one embodiment of the invention, a computing system accesses at least one multimedia source having multimedia content so that the multimedia content can be processed by one or more applications that are associated with the computing system. The computing system may include, but is not limited to, a computer, a DVD player, and a programmable video recorder (PVR). The multimedia content may include, but is not limited to, audio and video data. In one example, the applications are configured to process the multimedia content in a predetermined manner, 15 including, but not limited to, authoring, editing and playing the multimedia content. [0017] According to one aspect of the invention, the applications obtain basic information regarding the multimedia source and multimediacontent, whichmay be required to processthe multimediacontent, from a mediasource Application Programming Interface (API), rather than obtaining the basic information directly from the multimedia source(s). This generally reduces the programming requirements for creating multimedia applications. In particular, the applications do 20 not have to be programmed with duplicative code for enabling each of the applications to interpret and obtain basic multimedia information, which may be presented in various formats. Instead, in accordance with the invention, the applications can easily obtain basic multimedia information in a standard and predetermined manner from the media source API, thereby simplifying the tasks that need to be performed by the applications to process the multimedia content. [0018] According to one embodiment, basic information may include both format-agnostic data and format-specific 25 data. Nevertheless, even though the media source API makes basic information available to the applications, it will be appreciated that certain applications can still be programmed to obtain the format- specific information by themselves. [0019] Examples of basic multimedia information that may be obtained and made available by the media source API include, but are not limited to, the duration of a multimedia presentation, the duration of any individual stream in the presentation, the number of streams in the presentation, the media types supported by each stream, and the start and 30 stop times associated with each stream in the presentation, as described below in more detail. [0020] According to another aspect of the invention, the media source API is configured to manage one or more event queue tables in which multimedia source events and multimedia content events are queued. This enables the applications of the computing system to issue function calls to the media source API for events that are (or may become) queued in the event queue table. One benefit of the event queue is that a single function call may generate several events, therefore 35 the event queue provides a means for deferring the processing of the events until the current call is complete. Typically the media source generates events, which are added to the event queue until they are processed. The events can be added to the queue at any time, even in the middle of processing an application. [0021] Upon receiving an appropriate event request from an application, the media source API returns an object that is associated with the requested event to the requesting application. If a requested event is not queued, then the request 40 remains pending until the event is queued. The objects that are returned to the applications may include, but are not limited to, basic information regarding the multimedia content, presentation information for presenting the multimedia content, commands for initiating a presentation, and commands for enabling control over how the multimedia content is presented, as described below in more detail. The control that is provided may be used to manage several media streams and several media types at the same time. 45 [0022] Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The features and advantages of the invention may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter. 50 BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to describe the manner in which the above- recited and other advantages and features of the invention can be obtained, a more particular description of the invention briefly described above will be rendered by reference to 55 specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

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[0024] Figure 1 illustrates one embodiment of a computing system in a network that may be used to practice methods of the invention; [0025] Figure 2 illustrates one embodiment of an environment for practicing methods of the invention in which a computing system that includes an application, a storage medium, and a media source Application Programming Interface 5 (API) is in communication with a multimedia source and a rendering device; [0026] Figure 3 illustrates a flow chart of one method for facilitating at least one application to access basic multimedia information and for facilitating how multimedia content is processed; and [0027] Figure 4 illustrates a flow chart of one method in which the media source API of Figure 2 is used to create a multimedia presentation object. 10 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] The present invention extends to methods, systems, and computer program products for facilitating the manner in which applications are able to access and process multimedia content originating from various multimedia sources. 15 According to one aspect of the invention, a computing system includes an Application Programming Interface (API) that is configured to obtain basic information about the multimedia source (s) and the multimedia content contained therein. [0029] Once the basic information is obtained, it is made available to any number of applications associated with the computing system through the inventive media source API. In this manner, the applications that understand the media source API can access and use the basic multimedia information to process the multimedia content, with little or no 20 reprogramming that would otherwise be required to obtain the information directly from the multimedia source. [0030] It will be appreciated by those or ordinary skill in the art (upon reading this description) that this can reduce the time, cost and resources that are otherwise required for creating multimedia applications. In particular, multimedia applications do not have to be programmed to interpret and obtain basic multimedia information directly from a multimedia source in the variety of different media formats in which the multimedia information may be presented. 25 [0031] The embodiments of the present invention may comprise a special purpose or general-purpose computer including various computer hardware, as described in greater detail below. Embodiments within the scope of the present invention also include computer-readable media for carrying or having computer-executable instructions or data structures stored thereon. Such computer-readable media can be any available media that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, such computer- readable mediacan comprise 30 physical storage media such as RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to carry or store desired program code means in the form of computer-executable instructions or data structures and which can be accessed by a general purpose or special purpose computer. [0032] When information is transferred or provided over a network or another communications connection (either 35 hardwired, wireless, or a combination of hardwired or wireless) to a computer, the computer properly views the connection as a computer-readable medium. Thus, any such connection is properly termed a computer- readable medium. Combi- nations of the above should also be included within the scope of computer-readable media. Computer-executable instructions comprise, for example, instructions and data which cause a general purpose computer, special purpose computer, or special purpose processing device to perform a certain function or group of functions. 40 [0033] Figure 1 and the corresponding discussion provide a general description of a network 100 and a computing system 110 in which the present invention may operate. In one embodiment, the present invention is implemented in a network 100 that includes a computing system 110 that is associated with a multimedia rendering device, such as display device 114 and audio system 116. A remote computer 160 including other rendering devices may also be in communication with the computing system 110. 45 [0034] According to one embodiment, computing system 110 may be a computer, a PVR, a DVD player or any other device that has been adapted to perform the operations disclosed herein. The computing system may also be integrally positioned with or separate from display device 114, which may be a high definition television display, a standard television display, a flat panel display, a projection device, a high definition television display, a computer monitor, or any other device capable of displaying or otherwise processing viewable image data. Audio system 116 may be a speaker, a 50 stereo system, or any other device capable of emitting sound data, and similarly may be integrally positioned with or separate from display device 114. [0035] Computing system 110 includes a signal input 118, which receives multimedia data from a signal source 120. The multimedia data is transmitted from signal source 120 to signal input 118 via an input line 122, which can be a cable or optic connection, a terrestrial antenna system, a satellite system, or any device or system capable of transmitting 55 multimedia data to computing system 110. [0036] The signal source 120 may be either a single channel signal source or a multiple channel signal source. A single channel signal source provides programming from a recorded medium, such as a videocassette, compact disc, etc. Examples of a single channel signal source include a VCR, a DVD, and the like. Alternatively, a multiple channel

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signal source includes any system or device that is capable of sending a signal that may be received by a satellite receiver, a cable or optic connection, a terrestrial antenna, or the like. Examples of a multiple channel signal source include DSS/DVB, a cable box, locally broadcast programming (i.e. programming broadcast using UHF, VHF, or ATVEF), and the like. 5 [0037] While Figure 1 illustrates the computing system 110 as having a single programming input line 122 and a single signal source 120, there can instead be a plurality of programming input lines that transmit multimedia data from a plurality of signal sources. In such embodiments, the computing system 110 may receive the multimedia data from one signal source or from a plurality of signal sources at a time. [0038] Computing system 110 also includes a user input interface 124, which receives input from an input device 126, 10 such as a remote control, keyboard, microphone, or any other device capable of generating electronic instructions for computing system 110. Input device 126 is communicatively coupled to computing system 110 over an input link 128 so as to enable such control. Input device 126 generates electronic instructions over input link 128 in response to preprogrammed data or in response to a viewer pressing buttons on input device 126. Input device 126 may also control Web browser software within computing system 110 as when the computing system 110 receives multimedia data 15 through an Internet connection. [0039] The operation of the computing system 110 is controlled by a central processing unit ("CPU"), illustrated as processing unit 136, which is coupled to an application-specific integrated circuit ("ASIC") 138 and uses computer- executable instructions implemented in software and/or hardwired logic circuitry. Processing unit 136 and ASIC 138 are coupled via a system bus 140, which also interconnects various other system components, such as the system memory 20 142, mass storage interface 144, user interface 124 and signal input 118. Processing unit 136 executes software designed to implement features of computing system 110 including features of the present invention. ASIC 138 contains circuitry that is used to implement certain functions of the computing system 110. Instructions, data, and other software necessary for the operation of processing unit 136 and ASIC 138 may be stored in the system memory 142, such as in read-only memory ("ROM") 146 and/or in random-access memory ("RAM") 148, and/or in a mass storage device 150, which is 25 coupled to mass storage interface 144. ROM 146, RAM 148 and mass storage device 150 are communicatively coupled to ASIC 138 so as to be readable by ASIC 138 and so that data may be written from ASIC 138 to RAM 148 and possibly mass storage device 150. [0040] Mass storage device 150 may be a magnetic hard disk 152 or any other magnetic or optical mass memory device that is capable of storing large amounts of data. Any desired computer-readable instructions or data, including 30 multimedia applications 154, other program modules 156, and multimedia data, such as audio and video data. According to the invention, multimedia data should be broadly construed in this application to also include markers, events, metadata and other data that is transmitted with corresponding audio and video data. [0041] In the embodiment where the computing system 110 receives multimedia data from the Internet, computing system 110 communicates with a remote computer 160 via a wide area network ("WAN") 162 by including a serial port 35 interface 164 that is interposed between the system bus 140 and a modem 166, a wireless link, or other means for establishing communications over a WAN that may be internal or external to computing system 110. Computing system 110 is also capable of transmitting information and receiving multimedia data via the Internet by direct- dial communication over standard telephone lines, or by using any other available communication medium. [0042] Referring now to signal input 118, if the signal on programming input line 122 includes multiple channels that 40 are each receiving different streams of data, a tuner 170 included in signal input 118 tunes to a selected channel in the signal. Multiple tuners 170 can be used to provide enhanced features, such as recording multimedia data from one channel while processing multimedia data on another channel. A signal decoder 172 converts video data from an analog format to a digital format, or from a digital format to an analog format, as necessary. Signal decoder 172 can also decode, decompress, and split audio, video, metadata and other data from a compressed stream format (e.g. MPEG, ASF). In 45 embodiments where the computing system 110 includes multiple tuners 170, computing system 110 may also include multiple signal decoders 172 to perform the operations disclosed herein. [0043] Computing system 110 also includes a video output 174 and an audio output 176 which are useful for transmitting data to rendering devices such as display device 114 and audio system 116. It will be appreciated, however, that the computing system 110 is not limited to transmitting data to local rendering devices. In particular, the computing system 50 110 can also transmit data to any number of remote computing devices, such as remote computer 160, which can be independently configured to process multimedia data that is stored in the mass storage device 150 of the computing system 110 and to transmit the multimedia data to other rendering devices. The remote computer 160 can directly receive the data from the computing system 110 via signal output 192 through a cable or optic connection, a terrestrial antenna system, a satellite system, or any other device or system capable of transmitting streamed data to the remote computer 55 160. Alternatively, the remote computer 160 can indirectly receive the data from the computing system 110 through the wide area network 162. [0044] While Figure 1 and the corresponding discussion above provide a general description of a suitable environment in which the invention may be implemented, it will be appreciated that the features of the present invention disclosed

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herein may be practiced in association with a variety of different system configurations. [0045] Figure 2 illustrates one example environment 200 for practicing the methods of the invention that includes a computing system 210 that is in communication with a multimedia source 220 and a rendering device 230. As shown, the computing system 210 includes at least one application 240, a storage medium 250, and a media source API 260, 5 each of which will now be discussed. The computing system 210 may be, for example, the computing system 110 of Figure 1, although the invention is by no means limited to such a specific environment. [0046] The application(s) 240 of the computing system 210 may include any application programs configured to process multimedia content received from the multimedia source 220. For example, the application(s) may be, multimedia applications 154 if the computing system 210 was, in fact, the computing system 110 of Figure 1. The term "process" 10 should be construed as any act or step performed on the multimedia data for enabling the multimedia data to be rendered, played, edited, or otherwise manipulated. [0047] Examples of application(s) 240 include, but are not limited to the following: control applications for playing, pausing, seeking, and so forth; transforming applications for resampling, equalizing, amplifying, mixing, and so forth; and applications specifically associated with individual computer components like video cards, sound cards, CD ROM 15 reading and writing drives, and so forth. [0048] According to one embodiment of the invention, the computing system 210 accesses multimedia content from the multimedia source 220 through a connection 262, which may include, but is not limited to a cable or optic connection, a terrestrial antenna system, the Internet, and a satellite system. [0049] As mentioned above, multimedia content (which is also referred to herein as multimedia data) can include audio 20 and video data, as well as other data, such as meta-data, markers, events, and IP data, that are associated with the audio and video data. Multimedia content may be encoded according to a variety of standards and formats, including, but not limited to, MPEG, MP3, ASF, AVI, WMF, RTP, WAV, MIDI, Active Movie, Cinepaq, QuickTime, and Indeo. [0050] Upon receiving multimedia content from the multimedia source 220, the computing system 210 stores the multimedia content in the storage medium 250. To facilitate methods of the invention, the storage medium 250 is 25 configured with a buffer 264, tables of basic information 266, and an event queue 268, each of which is discussed in more detail below. The storage medium 250 abstractly represents any memory capab ility such as, for example, volatile memory, non-volatile memory, or combinations thereof. [0051] During use, the application(s) 240 process the multimedia content which is stored in the storage medium 250. According to one embodiment, the manner in which the application(s) 240 may access and process the multimedia 30 content is facilitated by the media source API 260. In particular, the media source API 260 includes several interfaces through which the application (s) 240 may obtain basic information regarding the multimedia content and the multimedia source that may be required to process the multimedia content. [0052] According to one embodiment, the interfaces of the media source API 260 include a multimedia source interface 270, a multimedia content interface 272, a multimedia presentation interface 274, a multimedia stream interface 276, 35 and an event manager interface 278, each of which will now be described. [0053] The multimedia source interface 270 is configured to identify basic information or capabilities about the multimedia source, such as, for example, whether the multimedia source is push, pull or live, the bit rate ranges at which the multimedia source is capable of transmitting data, the formats in which the multimedia source is capable of transmitting the data, the capabilities provided or enabled by the multimedia source (e.g., seeking, pausing, and so forth), whether 40 or not the multimedia source includes a clock for assigning and synchronizing the presentation of the multimedia content, and whether or not the multimedia source is capable of transmitting multiple data streams at a single time. This basic information is useful because the manner in which an application processes the multimedia content may depend on any of the foregoing multimedia source attributes or capabilities. These capabilities may be obtained without creating any implication that the multimedia content corresponds to a particular interface. 45 [0054] As a matter of example, it may be useful to know whether the multimedia source is a push, a pull or a live source to determine how the multimedia content is received. If the multimedia source is a push source (e.g., a streaming multimedia source), then the application (s) 240 may be notified of the rate in which the multimedia content is to be pulled or accepted from the multimedia source, otherwise data that is pushed or streamed by the multimedia source may be lost. If the multimedia source 220 is a live source, then the application (s) 240 may be given resource priority for accessing/ 50 processing the multimedia data. If the multimedia source 220 is a pull source, then the application (s) 240 may be made aware that new multimedia data will only be received when certain requests for the data are made. The application(s) 240 may also want to schedule calls for the multimedia content to be sure the multimedia is delivered and processed on time. [0055] Determining the rate at which the multimedia source 220 is configured to transmit data 240 may also be important 55 for determining when to make the buffer 264 in the storage medium 250 available to store the multimedia content. For example, when applications are unable to process data at the rate in which the multimedia content is received, the media source API may make the buffer 264 in the storage medium available so that the multimedia content may be stored until it can successfully be processed by the appropriate application (s) 240. Accordingly, in this manner the applications are

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effectively able to make calls for the buffer 264, thereby controlling the rate at which the multimedia data is received and stored. [0056] The multimedia source interface 270 provides the application (s) with the appropriate information regarding the multimedia source 220 in a standard and uniform manner, without requiring each of the applications to be programmed 5 in a duplicative manner to interpret the various formats in which the basic information may be presented to the computing system. Instead, according to the invention, the media source API obtains the information and makes it available to the application(s) 240 in a standard predetermined manner, such as, for example, by storing the basic information about the multimedia source in one or more table(s) of basic information 260 that are contained in the storage medium. The basic information about the multimedia source may also be presented immediately to the application(s) 240 without 10 being placed in the storage medium. [0057] The multimedia content interface 272 is configured to identify basic information about the multimedia content, such as, for example, the duration of each stream of multimedia data that is transmitted to the computing system 210, a unique identifier for each multimedia stream, the size of each multimedia stream, the start time and stop time assigned to each stream, and the available media types supported by each stream. 15 [0058] The duration of each stream may be provided in terms of nanoseconds or any other predetermined measurement of time. The unique identifier for each stream may be provided by the multimedia source or may be stored in the actual multimedia content or it may be synthesized by the media source API, and may include any symbol, name, letter, number or other unique identification mark. [0059] The basic information about the multimedia content may also be made available to appropriate application (s) 20 240 by providing the information directly to the application(s) or by storing the basic information within the table(s) of basic information in the storage medium 266. According to one embodiment, the basic information is provided in the form of stream descriptor objects that are stored in the table(s) of basic information 266. [0060] The basic information about the multimedia content may be required for an application to process the multimedia content. For instance, an application may need to know the available media types supported by each stream so that the 25 application can request a media type that is desired by a user or that is compatible with the application. Examples of media types include, but are not limited to, image file types (e.g., JPEG, GIF, TIFF, and so forth), streaming formats (e.g., ASF, AVI, MPEG, MP3 and so forth), and sound file types (e.g., WAV, AU, MIDI, and so forth). The basic information about the multimedia content may also include the play languages and display options supported by the individual streams. This is useful, for example, for enabling an application to select a user desired language and display of a 30 multimedia presentation, as described below. [0061] The multimedia presentation interface 274 is configured to identify basic information about an intended presentation of the multimedia content. Examples of basic information about an intended presentation include, but are not limited to, metadata regarding an intended presentation, the duration of the intended presentation, the number of stream descriptor objects (described above), and which stream descriptor objects have been selected for the intended presen- 35 tation. [0062] The multimedia presentation interface 274 also determines the default or selected stream descriptor objects that are to be included in the multimedia presentation. For example, if the default stream descriptor indicates the intended presentation is to be rendered in the English language then this information is obtained so that the appropriate application configuration can be used to process the intended presentation in the English language. 40 [0063] The basic information about intended presentations may be stored in the storage medium, as a presentation object within the table (s) of basic information 266, so that they may be accessed by appropriate application (s) 240 when it is time to for the intended presentation to be rendered, or edited. [0064] According to one embodiment, the multimedia stream interface 276 is configured to allow an application to access the multimedia content in a desired and controlled manner. For example, the multimedia stream interface 276 45 enables applications to select and deselect descriptor objects that are included in the presentation descriptor object. For example, if the multimedia source is a DVD that supports various languages and screen display formats, the multimedia presentation stream interface 276 enables the application to request a particular language and screen display format according to default settings preferred by the application, or according to user requests. According to one embodiment, the selection and deselection of descriptor objects occurs through function calls that are transmitted from the 50 application to the multimedia source through the multimedia stream interface 276. [0065] The multimedia stream interface 276 also enables applications to select desired play rates, to identify a desired output, such as rendering device 230, where the multimedia data should be transmitted during the presentation, the media type that is used of the available media types, when the buffer should be used to store multimedia content for enabling the multimedia content to be rendered at a later time, and for altering the play rate assigned to the presentation. 55 When the multimedia content is not assigned time stamps by the multimedia source, the multimedia stream interface may be used to assign time stamps to the multimedia content. [0066] The last illustrated interface of the media source API 260 is the event manager interface 278. The event manager interface 278 is configured to manage multimedia source events and multimedia content events that are received by

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the computing system by the multimedia source 220 and/or the application(s) 240. According to one embodiment, the multimedia source events and the multimedia content events are stored in an event queue 268 within the storage medium 250 of the computing system. Events are well understood by those skilled in the art. As described below in reference to Figure 4, applications can request events from the one or more event queues, which may result in an object being 5 transmitted to the requesting application. The events in the one or more event queues reference various resources, including the streams that they refer to. It will be appreciated that the event-based programming paradigm provided by the present invention for processing multimedia data via the one or more event queues is convenient and provides for the application to be truly responsive to external events. [0067] Examples of multimedia content events and corresponding objects include, but are not limited to the following: 10 events that indicate multimedia content has been received by the computing system, which may include the corresponding objects for identifying the location and attributes of the multimedia content; events indicating that a formatting change in the multimedia content has occurred, which may include the corresponding objects identifying the new format of the multimedia content; and other events, which may not have corresponding objects, such as events indicating the end of a stream, events indicating that a stream is being seeked, and events that specifiying the time stamps associated with 15 particular streams. [0068] Examples of multimedia source events and corresponding objects include, but are not limited to the following: events that indicate a start, stop and pause of streaming multimedia content, which may have corresponding objects for activating and deactivating media streams of an intended presentation; events indicating the media source has been seeked for multimedia, which may include an object for identifying the time seeked to within the multimedia content; 20 events indicating that a new presentation is available, which may include corresponding objects for starting the new presentation automatically or after the current presentation has ended; and events indicating a new stream is available in a current presentation, which may include corresponding objects for buffering the stream in the storage medium (for push media sources) or for notifying the application that a function call for the stream should be made when a current stream ends; events that indicate the end of a current presentation, which may include the corresponding objects for 25 dropping all events from the queue that are related to the presentation; and events indicating that a current presentation has new metadata available, which may include the corresponding objects for refreshing the current metadata state associated with the presentation. Other media source events may not include corresponding objects, such as, but not limited to, events indicating data transmission rate changes in the media source. [0069] Turning now to Figure 3, it is shown how the media source API 260 can help facilitate the manner in which 30 applications obtain basic multimedia information according to one embodiment of the invention. As shown, the present method includes various acts that can be performed by the media source API 260. In particular, the media source API 260 is configured to access multimedia content from a multimedia source, (act 310), to identify and make available basic information about the multimedia source, (act 320), to identify and make available basic information about the multimedia content (act 330), to provide an event queue for storing multimedia source and content events (act 340), to receive 35 function calls for events in the event queue (act 350), and to return the corresponding objects that are associated with the requested events to the requesting application(s) (act 360). In this manner, the media source API is effectively able to provide a means for the application(s) to stop, pause, and start streaming multimedia data. [0070] As indicated by the dotted line 370, the acts of accessing the multimedia content and making available basic information about the multimedia source and content (acts 310, 320, 330) can be generally described as a single step 40 for obtaining and making available basic information about the multimedia source and multimedia content to appropriate applications (step 380). Accordingly, step 380 should be interpreted in terms of the corresponding acts 310, 320, 330 and equivalents thereof. [0071] As described above, the act of accessing multimedia content from a multimedia source (act 310) may occur in a push a pull or a live communication. The acts of identifying and making available the basic information about the 45 multimedia source and content (acts 320 and 330) can occur when the computing system uses the API to obtain the basic information and either transmits the basic information directly to one or more application(s) and stores the basic information in a storage medium to be accessed by one or more applications. [0072] The act of providing an event queue for storing events (act 340) may occur directly by formatting designated memory to store events, or indirectly by simply transmitting the events to a preformatted portion of designated memory. 50 The designated memory may include the system memory of the computing system or any other local or remote memory that is volatile or non-volatile. In one embodiment, the act of providing an event queue includes the act of providing more than one event queue. [0073] The act of receiving a function call for an event (act 350) may occur passively, by waiting until an application initiates a request for an event. Alternatively, the act of receiving a function call for an event (act 350) may occur actively 55 by notifying one or more applications that an event has been queued and is ready to be requested. This alternative enables the media source API to operate as a pull system without superseding the control of the applications. For example, when a new media stream has been received or is detected. the media source API can queue the event indicating the new media stream while at the same time notifying applications that the new media stream is ready to be

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processed. This enables the applications to issue a function call for the event so that an appropriate and corresponding object can be returned (act 360), which may result in the playing of the new media stream. [0074] Figure 4 illustrates a flow chart of one method 400 which is performed by the media source API 260, of Figure 2, for facilitating the how multimedia applications access and process multimedia data and which includes the step for 5 creating a multimedia presentation object (step 410). Multimedia presentation objects, as described above, contain information that may facilitate the manner in which application (s) are able to processes multimedia content, such as, for example, to play a multimedia presentation (e.g., a DVD movie). [0075] The corresponding acts and step for creating a multimedia presentation object (step 410) include the acts of determining the multimedia content metadata that applies to the presentation. In general, the metadata of the multimedia 10 content provides information on how the multimedia content is formatted, which is used to interpret and process the multimedia content. The next act includes determining the overall duration of the presentation (act 430). Although not necessary, act (430) may be useful for synchronizing the time stamps of different media streams that are to be rendered simultaneously, for example. Synchronization may also occur with the use of the timestamps assigned to each sample from each of the media streams. 15 [0076] Next, the method 400 includes the step for creating an array of stream descriptor objects, which are described above. The corresponding acts for creating the stream descriptor objects (step 440) include the acts of determining unique identifiers for each stream (act 442), determining the start and stop time for each stream (act 444), determining the duration of each stream (act 446), and determining all supported media types of each stream (448). [0077] Upon creating the array of stream descriptor objects (step 440), which are made available to the applications, 20 as described above, the step for creating the multimedia presentation object (step 410) may further include the act of selecting a preferred media type in which the presentation is to be rendered. [0078] Upon creating a multimedia presentation object, the media source API queues an event in the event queue that a new presentation is ready. Thereafter, one or more applications issue a function call for the new presentation event, which causes the media source API to return the newly created media presentation object to the requesting 25 application(s). Upon receiving the multimedia presentation object, which includes the array of stream descriptor objects, the applications are able to activate the appropriate streams of the presentation at the appropriate times. [0079] During the presentation, when a buffer is required by one or more applications to buffer activated media streams then the buffer is presented (act 460) by the media source API to the one or more applications. In one embodiment, the applications themselves allocate space for the buffer and the media source API fills the buffer with the multimedia data. 30 In another embodiment, the media source API allocates space for the buffer and fills the buffer with the multimedia data. The media source API also enables the applications to pause, stop, and seek multimedia content during the presentation, when the media source allows this functionality. In some circumstances, for example, the media source may not allow pausing of a live presentation. [0080] As events are received during the presentation, the media source API continues to queue the events and 35 respond to requests for the events. For instance, when the events that indicate a current media stream has ended and that a new media stream is available are received by the media source API, the media source API notifies the appropriate applications and waits until a request for the new media stream is received in the form of a function call for the queued event. Then, as indicated in Figure 3, when the application provides an appropriate function call for the newly received media stream event then an object associated with the requested event is returned to the application, thereby enabling 40 the new media stream to be activated. [0081] Although the acts shown in Figures 3 and 4 are shown serially, it will be appreciated that the acts may also be performed in different orders and sequences. By way of example, and not limitation, the acts of providing an event queue (act 340), receiving a function call for an event (act 350) and accessing multimedia content (310), may occur simultaneously. 45 [0082] In summary, the methods of the invention enable an API to obtain basic multimedia information that may be required to process multimedia data. By doing this, the invention enables one or more applications to easily obtain the basic information from the API in a predetermined and standard manner, without having to individually obtain the information directly from the multimedia source. [0083] It will be appreciated by one skilled in the art upon reading this application that this invention is particularly 50 useful for reducing the functionality that has to be programmed into multimedia applications, thereby reducing the burden (e.g., cost, time, and resources) required for creating new multimedia applications. [0084] Code that may be used for creating some of the interfaces that are described herein will now be described. Nevertheless, while specific code is provided below, it will be appreciated by one of ordinary skill in the art, after having reviewed this description, that there are many software implementations that fall within the scope of the present invention. 55 Accordingly, the code provided below exhibits only possible embodiments for implementing the methods of the invention, and are provided by way of illustration only, and not to limit the scope of the invention. Accordingly, any number of the interfaces described herein may be integrated and combined into modules, computer program products, and other interfaces for implementing methods of the invention.

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[0085] According to one embodiment, the multimedia source interface 270 may include the following IMFMediaEvent- Generator interface code:

Interface IMFMediaSource: IMFMediaEventGenerator 5 { DWORD GetCharacteristics(); HRESULT GetService( [in] REFGUID guidService, [in] REFIID riid, 10 [out] IUnknown** ppunkObject ); HRESULT GetDefaultPresentation( [in] DWORD cMajorTypeFilter, [in] const GUID** aMajorTypeFilter, [out] IMFMediaPresentation** ppPresentation 15 ); HRESULT Start( [in] IMFMediaPresentation* pPresentation ); HRESULT Stop(); 20 HRESULT Pause(); HRESULT Seek( [in] IMFMediaPresentation* pPresentation, [in] const GUID* pguidTimeFormat, [in] IMFStreamDescriptor* pMasterStream, [in] LONGLONG IlTime 25 );

HRESULT GetClock( [out] IMFClock** ppClock ); 30 HRESULT GetActivePresentation( [out] IMFMediaPresentation** ppPresentation ); };

[0086] In the foregoing code, GetCharacteristics returns flags indicating interesting characteristics of the media source. 35 For example, the certain flags may be defined as follows for describing characteristics of the media source:

// Indicate that this is a live source #define MEDIASOURCE_IS_LIVE 0x00000001 // Indicate that this is a push mode source 40 #define MEDIASOURCE_IS_PUSH_MODE 0x00000002 // Indicate that this source exposes a rate control service #define MEDIASOURCE_HAS_RATE_CONTROL 0x00000004 // Indicate that this source exposes a stream selector service #define MEDIASOURCE_HAS_STREAM_SELECTOR 0x00000008 45 // Indicate that this source exposed uncompressed formats in its current presentation #define MEDIASOURCE_HAS_UNCOMPRESSED_FORMATS 0x00000010 // Indicate that this source can seek #define MEDIASOURCE_CAN_SEEK 0x00000020 // Indicate this this source can pause #define MEDIASOURCE_CAN_PAUSE 0x00000040 50 // Indicate that this source can process multiple samples per ::ProcessBuffer call // on a stream #define MEDIASOURCE_CAN_PROCESS_MULTIPLE_SAMPLES 0x00000080 // Indicate that this source can drop samples if the caller does not // supply buffers fast enough or if the source is paused 55 #define MEDIASOURCE_CAN_DROP_SAMPLES 0x00000100

[0087] GetService allows the calling application to retrieve extended services from the media source, such as MS_ RATE_CONTROL_SERVICE (supported by IMFMediaSourceRateControl ID_ interface), and MS_STREAM_

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SELECTOR_SERVICE (supported by IID_IMFStreamSelector interface). [0088] GetDefaultPresentation creates and returns a default presentation object describing the content initialized on the media source, including a default set of media streams. [0089] "Start" activates the media source with the presentation that is specified by the pPresentation input parameter. 5 If the pPresentation input parameter is NULL, and the media source is in the stopped state, the default presentation is used to active the media source streams. If the media source is in a paused state, the currently active presentation is started. If a new presentation is started on a source which already has an active presentation, then at the time the new ME_MEDIA_SOURCE_STARTED event is queued, all prior active media stream objects are shutdown. [0090] "Stop" terminates all active streams in the media source. "Pause" pauses all active streams in the media source. 10 "Seek" allows the media source to be seeked to a specified time. The pPresentation input parameter is used to specify the presentation on which the seek is being performed. If the pPresentation parameter is NULL, then the seek is performed on the current active presentation. If the parameter is non NULL, the presentation being seeked becomes the current active presentation and the presentation is started. The format of the specified time is indicated by the pguidTimeFormat input parameter and is in the format of 100ns when the pguidTimeFormat input parameter is NULL. The pMasterStream 15 parameter is used when the time format is applied in the context of a particular media stream, e.g., seek to frame. [0091] GetClock returns the clock associated with the media source, if one is available. The clock is returned as an IMFClock which is defined according to Microsoft’s Media Foundation. [0092] GetActivePresentation returns the currently active media presentation. [0093] The Media Source Events, which are described above in reference to Figure 3, are associated with correspond- 20 ing objects that are returned when the media source events are requested by a calling application. Generally, media source objects enable manipulation of particular pieces of the multimedia. For example, they may expose retrieval of the presentation, generate media events, expose source control (start, stop, pause, and so forth, and enable other services, as described above. [0094] The multimedia content interface 272 may include the following IMFStreamDescriptor interface code: 25

Interface IMFStreamDescriptor: Unknown { DWORD GetStreamIdentifier(); LONGLONG GetDuration(); 30 HRESULT GetStartTime( [in] const GUID* pguidTimeFormat, [out] LONGLONG* pUStartTime ); HRESULT GetStopTime( [in] const GUID* pguidTimeFormat, 35 [out] LONGLONG* pIlStopTime ); DWORD GetMediaTypeCount(); HRESULT GetMediaTypeByIndex( [in] DWORD dwIndex, 40 [out] IMFMediaType** ppType ); HRESULT Clone( [out] IMFStreamDescriptor** ppDescriptor ); }; 45 [0095] In the foregoing code, GetStreamldentifier returns a unique identifier for the stream that is received from the multimedia source. GetStartTime returns the start time of the stream and GetStopTime returns the stop time of the stream, both relative to the media source in the time format requested by a calling application via the input parameter guidTimeFormat. A NULL pointer as the time format requests the standard time format of 100ns units. GetMediaType- 50 Count returns the count of media types available on the media stream. GetMediaTypeByIndex returns a media type given an input dwIndex parameter which is valid in the range 0 to media type count -1. The media type is returned as an IMFMediaType object defined according to Microsoft’s Media Foundation. "Clone" makes a deep copy of the stream descriptor object. [0096] The multimedia content interface 272 may also include the following code for allowing a media source to create 55 a stream descriptor object that is initialized with a set of parameters, including media types, stream times, and so forth:

HRESULT MFCreateStreamDescriptor(

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[in] DWORD dwStreamIdentifier, [in] DWORD cStreamTimes, [in] const GUID** apguidTimeFormats, [in] LONGLONG* aStartTimes, 5 [in] LONGLONG* aStopTimes, [in] DWORD cMediaTypes, [in] IMFMediaType** apMediaTypes, [out] IMFStreamDescriptor** ppDescriptor );

10 [0097] The foregoing code includes various parameters, including the following: dwStreamIdentifier, which is the identifier for the stream; cStreamTimes, which is the count of supported stream time formats; apguidTimeFormats, which is the array of supported time format GUIDs; aStartTime, which is the array of start times for the stream that corresponds to the count of supported stream time formats; aStopTimes, which is the array of stop times corresponding to the count of supported stream time formats; cMediaTypes, which is the count of media types supported by the stream; apMedi- 15 aTypes, which is the array of media types supported by the stream; and ppPresentation, which is the location to output the presentation object pointer. [0098] The multimedia presentation interface 274 may include the following IMFMediaPresentation interface code:

Interface IMFMediaPresentation: IUnknown 20 { HRESULT GetMetadata( [in] REFIID riid, [out] IUnknown** ppunkObject ); 25 HRESULT GetDuration( [in] const GUID* pguidTimeFormat, [out] LONGLONG* pIlDuration ); DWORD GetStreamDescriptorCount(); HRESULT GetStreamDescriptorByIndex( 30 [in] DWORD dwIndex, [out] BOOL* pfSelected, [out] DWORD* pdwSelectionFlags, [out] IMFStreamDescriptor** ppStreamDescriptor [out] IMFMediaType** ppSelectedMediaType 35 ); HRESULT SelectStream( [in] DWORD dwDescriptorIndex, [in] DWORD dwSelectionFlags, [in] IMFMediaType* pSelectedMediaType 40 ); HRESULT DeselectStream( [in] DWORD dwDescriptorIndex ); HRESULT Clone( [out] IMFMediaPresentation** ppPresentation 45 ); };

[0099] In the foregoing code, GetMetadata retrieves a metadata management interface that provides access to the overall content and metadata of the presentation. GetDuration returns the duration of the presentation. If a null pointer 50 is pointer is specified, the duration returned is in the default time format of 100ns units. GetStreamDescriptorCount returns the count of stream descriptor objects in the presentation, wherein each stream descriptor object describes a stream in the media presentation. GetStreamDescriptorByIndex retrieves the stream descriptors in the presentation associated with the index specified by the dwIndex input parameter. pfSelected indicates whether the stream is selected in the presentation so that it can be activated. ppSelectedMediaType indicates the media type that is selected for the 55 stream in the presentation, which is derived from the set of supported stream media types. [0100] SelectStream allows an application to select a stream in the presentation by providing a stream selection flag (indicated by dwSelectionFlags) and a selected media type. DeselectStream allows the application to deselect a stream in the presentation. "Clone" causes a copy of all stream descriptors and associated information to be made.

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[0101] The multimedia presentation interface 274 may also include the following code for allowing a source to create a media presentation object that is initialized with a set of stream descriptors, medadata, and so forth:

HRESULT MFCreatePresentation( 5 [in] IUnknown* punkMetadata, [in] LONGLONG IlDuration, [in] DWORD cStreamDescriptors, [in] IMFStreamDescriptor** aStreamDescriptors [out] IMFMediaPresentation** ppPresentation 10 );

[0102] The parameters of the foregoing code include the following: punkMetadata, which is the metadata object to be associated with the presentation; IIDuration, which is the length of the presentation in 100ns interval units,; cStreamDe- scriptor, which is the number of stream descriptors in the presentation; aStreamDescriptors, which is the array of stream descriptors to be associated with the presentation; and ppPresentation, which is the location to output the presentation 15 object pointer. [0103] The multimedia stream interface 276 may be associated with the IMFMediaSource interface code, described above, and may further include the following IMFMediaStream interface code:

20 Interface IMFMediaStream : IMFMediaEventGenerator { HRESULT GetMediaSource( [out] IMFMediaSource** ppMediaSource ); HRESULT GetStreamDescriptor( 25 [out] IMFStreainDescriptor** ppDescriptor ); HRESULT GetCurrentMediaType( [out] IMFMediaType** ppMediaType ); 30 HRESULT SetCurrentMediaType( [in] IMFMediaType* pMediaType ); BOOL IsEndOfStream(); HRESULT ProcessBuffer( 35 [in] IMediaBuffer* pBuffer ); HRESULT Shutdown(); };

40 [0104] In the foregoing code, GetMediaSource returns the media source object to which the stream belongs. Get- StreamDescriptor returns the stream descriptor object used to activate the stream. GetCurrentMediaType returns the current media type configured on the active stream. SetCurrentMediaType allows the application to set a new current media type for the output of the multimedia. IsEndOfStream returns TRUE if all events for the stream have been emptied from the queue, otherwise it returns false.

45 [0105] ProcessBuffer presents a buffer to the media stream so it can deliver a sample into the media stream queue via an event. The buffer is presented as an ImediaBuffer via the pBuffer input parameter defined according to Microsoft’s Media Foundation. If the application would like the media stream to use its own samples, rather than the buffer’s, it may still call ProcessBuffer (to maintain flow control), while designating ProcessBuffer to NULL. [0106] "Shutdown" is used to explicitly shutdown a media stream object prior to releasing it. The application calls this

50 method when it is through with the stream. The implementation of shutdown releases waiting event generators (GetEvent, BeginEvent), destroys the queued events, and releases any references to the corresponding source objects. Shutdown may also shutdown any other resources it deems appropriate. [0107] The multimedia stream interface may also be associated with the following IMFMediaStreamArray interface code:

55 Interface IMFMediaStreamArray: IUnknown { DWORD GetMediaStreamCount();

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HRESULT GetMediaStreamByIndex( [in] DWORD dwIndex, [out] IMFMediaStream** ppMediaStream ); 5 }

[0108] In the foregoing code, GetMediaStreamCount returns the count of media stream objects in the array and GetMediaStreamByIndex returns the media stream associated with the index specified by the dwIndex input parameter. [0109] The multimedia stream interface may also be associated with the following IMFMediaStreamSelector interface

10 code:

Interface IMFStreamSelector : unknown { HRESULT SelectStreams( [in] IMFMediaPresentation* pPresentation, 15 [in] DWORD dwFlags, [in] DWORD dwBitrate, [in] LPWSTR pwszLanguage ); HRESULT GetOutputIdentifierFromStreamIdentifier( 20 [in] DWORD dwStreamIdentifier, [out] DWORD* pdwOutputIdentifier ); };

[0110] In the foregoing code, SelectStreams selects the streams in the presentation that are matched by the media 25 source specific automatic stream selection logic given in the input bitrate (dwBitrate) and language (pwszLanguage) specifiers. GetOutputIdentifierFromStreamIdentifier returns the output identifier that a particular selected stream is associated with, such that the application can map newly selected streams to the same rendering output, where appropriate. [0111] The following flags may also be used to modify the stream selection process:

30 // Use the lowest bitrate streams (dwBitrate must be zero) #define MFSTREAMSELECT_FLAG_USE_LOWEST_BTTRATE_STREAMS 0x00000001

// Use the highest bitrate streams (dwBitrate must be zero) 35 #define MFSTREAMSELECT_FLAG_USE_HIGHEST_BITRATE_STREAMS 0x00000002

// Use the default language stream (pwszLanguage must be NULL) #define MFSTREAMSELECT_FLAG_USE_DEFAULT_LANGUAGE_STREAMS 40 0x00000004

[0112] The multimedia stream interface may also be associated with the following IMFMediaSourceRateControl interface code:

45 Interface IMFMediaSourceRateControl : IUnknown { float GetMinRate(); float GetMaxRate(); float GetCurrentRate(); HRESULT SetRate( 50 [in] float fRate ); };

[0113] In the foregoing code, GetMinRate returns the minimum possible rate that can be set on the media source. 55 GetMaxRate returns the maximum possible rate that can be set on the media source. GetCurrentRate returns the current rate of the media source. SetRate changes the rate of the media source. In one embodiment, the normal rate is set at 1.0 on the rate control interface. All other rates are multipliers of the normal rate (e.g., 2.0 is twice as fast as normal). The rate change can be changed when the media source is in the started or stopped states.

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[0114] The nVIFMediaSourceRateControl interface code may be optionally implemented by media source objects to expose their own rate control, such as, for example, when a networked streaming source sends a rate change message to the server to only send key frames. [0115] The event manager interface 278 may include the following IMFMedia Event interface source code: 5

interface IMFMediaEvent : IUnknown { HRESULT GetType( [out] GUID* pguidType 10 ); HRESULT GetStatus(); HRESULT GetDataObject( [out] IUnknown** ppunkObject ); }; 15 [0116] In the foregoing source code, GetType returns the event type for a requested event. GetStatus returns the status of a specified event as an HRESULT. GetDataObject returns an object associated with the requested media event. Event types and event objects are described above in reference to Figure 3. [0117] The event manager interface 278 may also include the following IMFMediaEventGenerator interface source 20 code:

Interface IMFMediaEventGenerator: IUnknown { HRESULT GetEvent( 25 [in] DWORD dwFlags, [out] IMFMediaEvent** ppEvent ); HRESULT BeginGetEvent( [in] IMFAsyncCallback* pCallback, 30 [in] IUnknown* punkState ); HRESULT EndGetEvent( [in] IMFAsyncResult* pResult, [out] IMFMediaEvent** ppEvent ); 35 }

[0118] In the foregoing code, GetEvent allows the caller to synchronously retrieve the next event available in the event queue. If dwFlags is zero, then the function blocks until an event is available to return from the queue. BeginGetEvent allows the caller to start an asynchronous request for an event. EndGetEvent allows the calling application to retrieve 40 the media event object associated with a prior BeginGetEvent request. [0119] During use, an application may make a call to BeginGetEvent with the following:

// // The callback parameter is an IMFAsyncCallback which is 45 // implemented by the application. // // The state parameter is NULL since the app doesn’t want any // extra state variable passed to it in the callback invocation // m_pSource->BeginGetEvent( pCallback, NULL ); 50 [0120] The application callback is then invoked when an event is queued. The following source code may be used to actually retrieve the associated event:

STDMETHODIMP CAppCallback::Invoke(IMFAsyncResult* pResult) 55 { HRESULT hr; IMFMediaEvent* pEvent = NULL; hr = m_pSource->EndGetEvent( pResult, &pEvent);

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// further processing of the event can go here hr = OnSourceEvent( pEvent); // more event processing return( hr); 5 }

[0121] In order to get more events, the application may need to call BeginGetEvent again. However, according to another embodiment, multiple events can be processed with the following code:

10 HRESULT CApp::OnAsyncEvent(IMFAsyncResult* pResult) { HRESULT hr; IMFMediaEvent* pEvent = NULL; BOOL fContinue = TRUE; // If you pass in NULL for the pResult, then this all 15 // boils down to BeginGetEvent // Otherwise, it retrieves the next event via EndGetEvent // processes it, and if it should continue, it calls // BeginGetEvent if( NULL != pResult) 20 { hr = m_pSource->EndGetEvent( pResult, &pEvent); } if(NULL != pEvent ) { hr = OnSourceEvent( pEvent, &fContinue ); 25 } if( fContinue ) { hr = m_pSource->BeginGetEvent( m_pcallback, NULL ); } 30 return( hr); } HRESULT CAppCallback::Invoke(IMF AsyncResult* pResult) { HRESULT hr; hr = m_pApp->OnAsyncEvent( pResult ); 35 retum(hr); }

[0122] The foregoing code illustrates certain specific embodiments of source code and program interfaces that may be used according to the present invention for facilitating the manner in which multimedia data is accessed and processed 40 by multimedia applications. [0123] Itwill be appreciated, however,that thepresent invention may be embodied in otherspecific forms. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope. 45

Claims

1. A method in a computing system (210) that is associated with at least one application (240) configured to process 50 multimedia content that includes one or more streams of content from a multimedia source (220), the method for facilitating the at least one application to process the multimedia content by identifying and providing the application with basic multimedia source and content information, such that the at least one application does not have to be programmed to identify the basic information directly from the multimedia source, the method comprising:

55 an act of accessing multimedia content from the multimedia source; an act of using multimedia content interfaces to identify basic information about the multimedia content, and basic information about an intended presentation of the multimedia content; creating a multimedia presentation object, wherein creating the multimedia presentation object includes the

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following acts:

determining multimedia content metadata corresponding to a presentation and that identifies how the multimedia content is formatted; 5 determining a duration for the presentation; and creating an array of stream descriptor objects, wherein the stream descriptor objects include, for each stream in the multimedia content that corresponds to the intended presentation, (a) a unique identifier, (b) a start time, (c) a stop time, (d) a duration, and (e) all supported media types for each stream; and upon creating the multimedia presentation object, creating a new presentation event in a queue; 10 upon receiving a function call for the new presentation event from an application, providing the multimedia presentation object to the application, which is used by the application to process the multimedia content.

2. The method as recited in claim 1, further including an act of providing a multimedia presentation interface (274) that is configured to identify basic information about an intended presentation of the multimedia content, wherein the 15 multimedia presentation interface provides the at least one application with the basic information about the intended presentation of the multimedia content.

3. The method as recited in claim 1, further including an act of providing a multimedia stream interface (276) that is configured to allow the at least one application to access the multimedia content in a controlled manner. 20 4. The method as recited in claim 3, wherein allowing the at least one application (240) to access the multimedia content in a controlled manner includes allowing the application to change the media type of the multimedia content.

5. The method as recited in claim 1, further including an act of providing an event manager interface (278) that is 25 configured to manage multimedia source events and multimedia content events in an event management queue, and wherein the event manager interface is further configured to provide the at least one application with an object in response to receiving an appropriate function call from the at least one application for an event in the event management queue.

30 6. The method as recited in claim 5, wherein the objects enable the at least one application to process the multimedia content.

7. The method as recited in claim 1, wherein the multimedia interfaces (270-278) also identify basic information about the multimedia source that includes at least one of information indicating whether the multimedia source is a push 35 source, a pull source or a live source, information regarding the bit rate at which the multimedia source is capable of transmitting data, the formats in which the multimedia source is capable of transmitting the data, the capabilities provided by the multimedia source for seeking and pausing multimedia content, whether the multimedia source includes a clock for time stamping the multimedia content, and whether the multimedia source is capable of transmitting multiple data streams at a single time. 40 8. The method as recited in claim 1, wherein the requested event is a multimedia source event or a multimedia content event.

9. The method as recited in claim 8, wherein the requested event is a multimedia source event that includes one of 45 an event indicating that multimedia content has been received by the computing system, an event indicating that a formatting change in the multimedia content has occurred, an event indicating the end of a media stream included in the multimedia content has been reached, an event indicating that a media stream included in the multimedia content is being seeked, and an event indicating the time stamps that are associated with the multimedia content.

50 10. The method as recited in claim 9, wherein the object associated with the requested multimedia source event includes one of an object identifying the location and attributes of the multimedia content, an object identifying a new format of the multimedia content.

11. The method as recited in claim 8, wherein the requested event is a multimedia content event including one of an 55 event indicating the start or stop of receiving multimedia content from the media source, an event indicating the media source has been seeked for multimedia, an event indicating that a new presentation is available, an events indicating a new stream is available in a current presentation, an event indicating the end of a current presentation, an event indicating that a current presentation has new metadata available, and an event indicating a change in the

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rate multimedia content is received from the media source.

12. The method as recited in claim 11, wherein the object associated with the requested multimedia content event includes one of an object for activating and deactivating media streams of an intended presentation, an object for 5 identifying the time of multimedia content that is seeked to, an object for starting a new presentation automatically, an object for starting a new presentation after a current presentation has ended, an object for buffering the multimedia content, an object for refreshing a metadata state associated with the presentation.

13. The method as recited in claim 1, wherein the requested event is not present in the event management queue at 10 the time the requested event is requested.

14. The method as recited in claim 13, wherein the method further includes the act of waiting until the requested event is placed in the event queue prior to returning the object associated with the requested event.

15 15. The method as recited in claim 1, the method further comprising:

an act of providing a multimedia stream interface (276) that is configured to allow the at least one application to access the multimedia content in a controlled manner; and an act of providing an event manager interface (278) that is configured to manage multimedia source events 20 and multimedia content events in an event management queue, and wherein the event manager interface is further configured to provide the at least one application with an object in response to receiving an appropriate function call from the at least one application for an event in the event management queue, wherein the object enables the at least one application to either access or process the multimedia data.

25 16. The method as recited in claim 15, wherein the multimedia content supports multiple media types, and wherein the method further includes the act of enabling the application to select a preferred media type.

17. The method as recited in claim 16, wherein the multiple media types include audio media types including at least one of WAV, AU, and MIDI audio types. 30 18. The method as recited in claim 16, wherein the multiple media types include image media types including at least one of JPEG, GIF, and TIFF

19. The method as recited in claim 16, wherein the multiple media types include media streaming formats including at 35 least one of AVI, ASF, MPEG, MP3, Active Movie, Cinepaq, QuickTime, and Indeo.

20. The method as recited in claim 1, wherein the method further includes:

upon creating the multimedia presentation object, queuing an event in an event queue that indicates that a new 40 presentation is ready.

21. The method as receited in claim 1, wherein creation of the presentation object further includes an act of selecting a preferred media type for rendering a corresponding presentation.

45 22. The method as recited in claim 1, wherein creation of the presentation object further includes an act of synchronizing time stamps of different media streams that are to be rendered simultaneously.

23. A computer program product for use in a computing system (210) that is associated with at least one application (240), the at least one application being configured to process multimedia content from a multimedia source (220) 50 that is associated with the computing system, the computer program product comprising one or more computer- readable media having stored thereon computer-executable instructions for implementing the method of one of claims 1 to 22.

24. The computer program product as recited in claim 23, wherein the one or more computer-readable media include 55 system memory.

25. The computer program product as recited in claim 23, wherein the multimedia content comprises streamed multimedia data.

18 EP 1 376 978 B1

26. The computer program product as recited in claim 25, wherein the multimedia content includes at least one of audio data and video data.

27. The computer program product as recited in claim 26, wherein the multimedia content includes metadata that is 5 transmitted with the at least one of audio data and video data.

28. The computer program product as recited in claim 23, wherein the computing system accesses the multimedia content from the multimedia source through the Internet.

10 29. The computer program product as recited in claim 23, wherein the multimedia source includes a DVD.

30. The computer program product as recited in claim 23, wherein the basic information includes format agnostic data.

31. The computer program product as recited in claim 23, wherein the basic information includes format specific data. 15 32. A computing system associated with at least one application configured to process multimedia content from a multimedia source, the system adapted to perform the method of one of claims 1 to 22.

20 Patentansprüche

1. Verfahren in einem Computersystem (210), das mit wenigstens einer Anwendung (240) verbunden ist, die zum Verarbeiten von Multimedia-Inhalt konfiguriert ist, der einen oder mehrere Strom/Ströme von Inhalt von einer Mul- timedia-Quelle (220) enthält, wobei das Verfahren dazu dient, zu ermöglichen, dass die wenigstens eine Anwendung 25 den Multimedia-Inhalt verarbeitet, indem Grundinformationen über Multimedia-Quelle und -Inhalt identifiziert und der Anwendung bereitgestellt werden, so dass die wenigstens eine Anwendung nicht so programmiert sein muss, dass sie die Grundinformationen direkt von der Multimedia-Quelle identifiziert, und das Verfahren umfasst:

einen Vorgang des Zugreifens auf Multimedia-Inhalt von der Multimedia-Quelle; 30 einen Vorgang des Verwendens von Schnittstellen für Multimedia- Inhalt zum Identifizieren von Grundinforma- tionen über den Multimedia-Inhalt und Grundinformationen über eine geplante Präsentation des Multimedia- Inhaltes; Erzeugen eines Multimedia- Präsentationsobjektes, wobei Erzeugen des Multimedia- Präsentationsobjektes die folgenden Vorgänge einschließt: 35 Ermitteln von Multimedia-Inhalt-Metadaten, die einer Präsentation entsprechen und die identifizieren, wie der Multimedia-Inhalt formatiert ist; Ermitteln einer Dauer für die Präsentation; und Erzeugen einer Anordnung von Stream-Descriptor-Objekten, wobei die Stream-Descriptor-Objekte für je- 40 den Strom in dem Multimedia- Inhalt, der der geplanten Präsentation entspricht, a) eine eindeutige Kennung, b) eine Anfangszeit, c) eine Endzeit, d) eine Dauer und e) alle unterstützten Medientypen für jeden Strom enthalten; und nach Erzeugen des Multimedia- Präsentationsobjektes Erzeugen eines neuen Präsentationsereignisses in einer Warteschlange; 45 beim Empfangen eines Funktionsaufrufs für das neue Präsentationsereignis von einer Anwendung Bereit- stellen des Multimedia-Präsentationsobjektes für die Anwendung, das durch die Anwendung verwendet wird, um den Multimedia-Inhalt zu verarbeiten.

2. Verfahren nach Anspruch 1, das des Weiteren einen Vorgang des Bereitstellens einer Multimedia-Präsentations- 50 schnittstelle (274) einschließt, die so konfiguriert ist, dass sie Grundinformationen über eine geplante Präsentation des Multimedia-Inhaltes identifiziert, wobei die Multimedia- Präsentationsschnittstelle der wenigstens einen Anwen- dung die Grundinformationen über die beabsichtigte Präsentation des Multimedia- Inhaltes bereitstellt.

3. Verfahren nachAnspruch 1,das desWeiteren einen Vorgang des Bereitstellens einerMultimedia- Strom-Schnittstelle 55 (276) einschließt, die so konfiguriert ist, dass sie ermöglicht, dass die wenigstens eine Anwendung kontrolliert auf den Multimedia-Inhalt zugreift.

4. Verfahren nach Anspruch 3, wobei Ermöglichen, dass die wenigstens eine Anwendung (240) kontrolliert auf den

19 EP 1 376 978 B1

Multimedia-Inhalt zugreift, einschließt, dass ermöglicht wird, dass die Anwendung den Medientyp des Multimedia- Inhaltes ändert.

5. Verfahren nach Anspruch 1, das des Weiteren einen Vorgang des Bereitstellens einer Ereignis-Manager-Schnitt- 5 stelle (278) einschließt, die zum Verwalten von Multimedia- Quellen-ereignissen und Multimedia-Inhalt-Ereignissen in einer Ereignis-Verwaltungs-Warteschlange konfiguriert ist, und wobei die Ereignis- Verwaltungs-Schnittstelle des Weiteren so konfiguriert ist, dass sie der wenigstens einen Anwendung in Reaktion auf Empfang eines entsprechenden Funktionsaufrufes von der wenigstens einen Anwendung für ein Ereignis in der Ereignis-Verwaltungs- Warteschlange ein Objekt bereitstellt. 10 6. Verfahren nach Anspruch 5, wobei die Objekte die wenigstens eine Anwendung befähigen, den Multimedia-Inhalt zu verarbeiten.

7. Verfahren nach Anspruch 1, wobei die Multimedia- Schnittstellen (270-278) des Weiteren Grundinformationen über 15 die Multimedia-Quelle identifizieren, die eine Information, die anzeigt, ob die Multimedia-Quelle eine Push-Quelle, eine Pull-Quelle oder eine Live-Quelle ist, eine Information bezüglich der Bitrate, mit der die Multimedia-Quelle Daten senden kann, bezüglich der Formate, in denen die Multimedia-Quelle die Daten senden kann, bezüglich der durch die Multimedia-Quelle bereitgestellten Fähigkeiten zum Durchsuchen und Anhalten von Multimedia-Inhalt, eine Information dahingehend, ob die Multimedia- Quelle eine Uhr zum Versehen des Multimedia- Inhaltes mit einem 20 Zeitstempel enthält, oder/und eine Information dahingehend enthalten, ob die Multimedia-Quelle in der Lage ist, gleichzeitig mehrere Datenströme zu senden.

8. Verfahren nach Anspruch 1, wobei das angeforderte Ereignis ein Multimedia- Quellen-Ereignis oder ein Multimedia- Inhalt-Ereignis ist. 25 9. Verfahren nach Anspruch 8, wobei das angeforderte Ereignis ein Multimedia- Quellen-Ereignis ist, das ein Ereignis, das anzeigt, dass Multimedia-Inhalt durch das Computersystem empfangen worden ist, ein Ereignis, das anzeigt, dass eine Formatierungsänderung des Multimedia-Inhaltes stattgefunden hat, ein Ereignis, das anzeigt, dass das Ende eines in dem Multimedia- Inhalt enthaltenen Medien- Strom erreicht worden ist, ein Ereignis, das anzeigt, dass 30 ein in dem Multimedia-Inhalt enthaltener Medien- Strom durchsucht wird, oder ein Ereignis enthält, das die Zeitstem- pel anzeigt, die mit dem Multimedia-Inhalt verbunden sind.

10. Verfahren nach Anspruch 9, wobei das mit dem angeforderten Multimedia- Quellen-Ereignis verbundene Objekt ein Objekt, das den Ort und Attribute des Multimedia- Inhaltes identifiziert, oder ein Objekt enthält, das ein neues Format 35 des Multimedia-Inhaltes identifiziert.

11. Verfahren nach Anspruch 8, wobei das angeforderte Ereignis ein Multimedia-Inhalt-Ereignis ist, das ein Ereignis, das den Anfang oder das Ende des Empfangs von Multimedia- Inhalt von der Medien-Quelle anzeigt, ein Ereignis, das anzeigt, dass die Medien-Quelle nach Multimedia durchsucht worden ist, ein Ereignis, das anzeigt, dass eine 40 neue Präsentation verfügbar ist, ein Ereignis, das anzeigt, dass ein neuer Strom in einer aktuellen Präsentation verfügbar ist, ein Ereignis, das das Ende einer aktuellen Präsentation anzeigt, ein Ereignis, das anzeigt, dass in einer aktuellen Präsentation neue Metadaten verfügbar sind, oder ein Ereignis einschließt, das anzeigt, dass eine Änderung der Rate von Multimedia-Inhalt von der Medienquelle empfangen wird.

45 12. Verfahren nach Anspruch 11, wobei das mit dem angeforderten Multimedia- Inhalt-Ereignis verbundene Objekt ein Objekt zum Aktivieren und Deaktivieren von Medien-Strömen einer geplanten Präsentation, ein Objekt zum Iden- tifizieren der Zeit von Multimedia-Inhalt, nach dem gesucht wird, ein Objekt zum automatischen Beginnen einer neuen Präsentation, ein Objekt zum Beginnen einer neuen Präsentation nach Beendigung einer aktuellen Präsen- tation, ein Objekt zum Puffern des Multimedia-Inhaltes oder ein Objekt zum Aktualisieren eines mit der Präsentation 50 verbundenen Metadaten-Status einschließt.

13. Verfahren nach Anspruch 1, wobei das angeforderte Ereignis zu der Zeit, zu der das angeforderte Ereignis ange- fordert wird, in der Ereignis-Verwaltungs-Warteschlange nicht vorhanden ist.

55 14. Verfahren nach Anspruch 13, wobei das Verfahren des Weiteren den Vorgang des Wartens bis zum Positionieren des angeforderten Ereignisses in der Ereignis-Warteschlange vor dem Zurückführen des mit dem angeforderten Ereignis verbundenen Objektes einschließt.

20 EP 1 376 978 B1

15. Verfahren nach Anspruch 1, wobei das Verfahren des Weiteren umfasst:

einen Schritt des Bereitstellens einer Multimedia-Strom-Schnittstelle (276), die so konfiguriert ist, dass sie ermöglicht, dass die wenigstens eine Anwendung kontrolliert auf dem Multimedia- Inhalt zugreift; und 5 einen Schritt des Bereitstellens einer Ereignis- Manager-Schnittstelle (278), die zum Verwalten von Multimedia- Quellen-Ereignissen und Multimedia-Inhalt-Ereignissen in einer Ereignis- Verwaltungs-Warteschlange konfiguriert ist, wobei die Ereignis-Verwaltungs-Schnittstelle des Weiteren so konfiguriert ist, dass sie der wenigstens einen Anwendung in Reaktion auf Empfang eines entsprechenden Funktionsaufrufes von der wenigstens einen Anwendung für ein Ereignis in der Ereignis-Venrvaltungs-Warteschlange ein Objekt bereitstellt, wobei das 10 Objekt die wenigstens eine Anwendung befähigt, auf die Multimediadaten entweder zuzugreifen oder sie zu verarbeiten.

16. Verfahren nach Anspruch 15, wobei der Multimedia-Inhalt mehrere Medien-Typen unterstützt und das Verfahren des Weiteren den Vorgang des Befähigens der Anwendung zum Auswählen eines bevorzugten Medien-Typs ein- 15 schließt.

17. Verfahren nach Anspruch 16, wobei die mehreren Medien-Typen Audio-Medien-Typen einschließen, die WAV-, AU- oder/und MIDI-Audio-Typen einschließen.

20 18. Verfahren nach Anspruch 16, wobei die mehreren Medien- Typen Bild-Medien-Typen einschließen, die JPEG, GIF oder/und TIFF einschließen.

19. Verfahren nach Anspruch 16, wobei die mehreren Medien- Typen Medien-Streaming-Formate einschließen, die AVI, ASF, MPEG, MP3, Active Movie, Cinepaq, QuickTime oder/und Indeo einschließen. 25 20. Verfahren nach Anspruch 1, wobei das Verfahren des Weiteren einschließt:

nach Erzeugen des Multimedia-Präsentationsobjektes Einstellen eines Ereignisses in eine Ereignis-Warte- schlange, die anzeigt, dass eine neue Präsentation bereit ist. 30 21. Verfahren nach Anspruch 1, wobei Erzeugung des Präsentationsobjektes des Weiteren einen Vorgang des Aus- wählens eines bevorzugten Medien-Typs zum Wiedergeben einer entsprechenden Präsentation einschließt.

22. Verfahren nach Anspruch 1, wobei Erzeugung des Präsentationsobjekts des Weiteren einen Vorgang des Synchro- 35 nisierens von Zeitstempeln unterschiedlicher Medien-Ströme einschließt, die gleichzeitig wiedergegeben werden sollen.

23. Computerprogrammerzeugnis zum Einsatz in einem Computersystem (210), das mit wenigstens einer Anwendung (240) verbunden ist, wobei die wenigstens eine Anwendung zum Verarbeiten von Multimedia- Inhalt von einer Mul- 40 timedia-Quelle (220) konfiguriert ist, die mit dem Computersystem verknüpft ist, und das Computerprogrammer- zeugnis ein computerlesbares Medium oder mehrere computerlesbare Medien umfasst, auf denen durch Computer ausführbare Befehle zum Implementieren des Verfahrens nach einem der Ansprüche 1 bis 22 gespeichert sind.

24. Computerprogrammerzeugnis nach Anspruch 23, wobei das eine computerlesbare Medium bzw. die mehreren 45 computerlesbaren Medien Systemspeicher enthält/enthalten.

25. Computerprogrammerzeugnis nach Anspruch 23, wobei der Multimedia-Inhalt gestreamte Multimedia-Daten umfasst.

50 26. Computerprogrammerzeugnis nach Anspruch 25, wobei der Multimedia-Inhalt Audio-Daten oder/und Video-Daten enthält.

27. Computerprogrammerzeugnis nach Anspruch 26, wobei der Multimedia- Inhalt Metadaten enthält, die mit den Audio- Daten oder/und den Video-Daten gesendet werden. 55 28. Computerprogrammerzeugnis nach Anspruch 23, wobei das Computersystem auf den Multimedia-Inhalt von der Multimedia-Quelle über das Internet zugreift.

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29. Computerprogrammerzeugnis nach Anspruch 23, wobei die Multimedia-Quelle eine DVD einschließt.

30. Computerprogrammerzeugnis nach Anspruch 23, wobei die Grundinformationen formatunabhängige Daten enthalten. 5 31. Computerprogrammerzeugnis nach Anspruch 23, wobei die Grundinformationen formatspezifische Daten enthalten.

32. Computersystem, das mit wenigstens einer Anwendung verbunden ist, die zum Verarbeiten von Multimedia- Inhalt von einer Multimedia-Quelle konfiguriert ist, wobei das System zum Durchführen des Verfahrens nach einem der 10 Ansprüche 1 bis 22 eingerichtet ist.

Revendications

15 1. Procédé dans un système informatique (210) associé à au moins une application (240) configurée pour traiter un contenu multimédia qui comprend un ou plusieurs flux de contenu provenant d’une source multimédia (220), le procédé facilitant l’au moins une application pour traiter le contenu multimédia en identifiant et en procurant à l’application de l’information multimédia élémentaire de source et de contenu, de telle sorte que l’au moins une application ne doit pas être programmée pour identifier l’information élémentaire directement à partir de la source 20 multimédia, le procédé comprenant :

un acte d’accès à du contenu multimédia de la source multimédia ; un acte d’utilisation d’interfaces de contenu multimédia pour identifier de l’information élémentaire concernant le contenu multimédia, et de l’information élémentaire concernant une présentation prévue du contenu 25 multimédia ; la création d’un objet de présentation multimédia, dans lequel la création de l’objet de présentation multimédia comprend les actes suivants :

détermination de métadonnées de contenu multimédia qui correspondent à une présentation et qui iden- 30 tifient comment le contenu multimédia est formaté ; détermination d’une durée pour la présentation ; et création d’un réseau d’objets descripteurs de flux, dans lequel les objets descripteurs de flux comprennent, pour chaque flux dans le contenu multimédia qui correspond à la présentation prévue, (a) un identifiant unique, (b) un temps de démarrage, (c) un temps d’arrêt, (d) une durée, et (e) tous les types de médias 35 supportés pour chaque flux ; et lors de la création de l’objet de présentation multimédia, la création d’un nouvel événement de présentation dans une file d’attente ; lors de la réception d’un appel de fonction pour le nouvel événement de présentation provenant de l’application, la procuration à l’application de l’objet de présentation multimédia, qui est utilisé par l’application 40 pour traiter le contenu multimédia.

2. Procédé selon la revendication 1, comprenant en outre un acte consistant à procurer une interface de présentation multimédia (274) configurée pour identifier de l’information élémentaire concernant une présentation prévue du contenu multimédia, dans lequel l’interface de présentation multimédia procure à l’au moins une application l’infor- 45 mation élémentaire concernant la présentation prévue du contenu multimédia.

3. Procédé selon la revendication 1, comprenant en outre un acte consistant à procurer une interface de flux multimédia (276) configurée de manière à permettre à l’au moins une application d’accéder au contenu multimédia de manière contrôlée. 50 4. Procédé selon la revendication 3, dans lequel l’acte consistant à permettre à l’au moins une application (240) d’accéder au contenu multimédia de manière contrôlée comprend l’acte consistant à permettre à l’application de modifier le type de média du contenu multimédia.

55 5. Procédé selon la revendication 1, comprenant en outre un acte consistant à procurer une interface de gestionnaire d’événements (278) configurée pour gérer des événements de source multimédia et des événements de contenu multimédia dans une file d’attente de gestion d’événements, et dans lequel l’interface de gestionnaire d’événements est en outre configurée pour procurer un objet à l’au moins une application en réponse à la réception d’un appel de

22 EP 1 376 978 B1

fonction approprié provenant de l’au moins une application pour un événement dans la file d’attente de gestion d’événements.

6. Procédé selon la revendication 5, dans lequel les objets permettent à l’au moins une application de traiter le contenu 5 multimédia.

7. Procédé selon la revendication 1, dans lequel les interfaces multimédia (270-278) identifient également de l’information élémentaire concernant la source multimédia, comprenant au moins une information parmi de l’information indiquant si la source multimédia est une source push, une source pull ou une source live, de l’information concernant 10 le débit binaire auquel la source multimédia est capable de transmettre des données, les formats dans lesquels la source multimédia est capable de transmettre les données, les capacités procurées par la source multimédia pour chercher et mettre en pause un contenu multimédia, si la source multimédia comprend ou non une horloge pour l’horodatage du contenu multimédia, et si la source multimédia est capable ou non de transmettre simultanément des flux de données multiples. 15 8. Procédé selon la revendication 1, dans lequel l’événement demandé est un événement de source multimédia ou un événement de contenu multimédia.

9. Procédé selon la revendication 8, dans lequel l’événement demandé est un événement de source multimédia 20 comprenant un événement parmi un événement indiquant qu’un contenu multimédia a été reçu par le système informatique, un événement indiquant qu’un changement de format s’est produit dans le contenu multimédia, un événement indiquant que la fin du flux de média compris dans le contenu multimédia a été atteinte, un événement indiquant qu’un flux de média compris dans le contenu multimédia est actuellement recherché, et un événement indiquant les horodatages qui sont associés au contenu multimédia. 25 10. Procédé selonla revendication 9, danslequel l’objet associé à l’événementde source multimédiademandé comprend un objet parmi un objet identifiant l’emplacement et les attributs du contenu multimédia, et un objet identifiant un nouveau format du contenu multimédia.

30 11. Procédé selon la revendication 8, dans lequel l’événement demandé est un événement de contenu multimédia comprenant un événement parmi un événement indiquant le démarrage ou l’arrêt de la réception de contenu mul- timédia provenant de la source de média, un événement indiquant que des multimédias ont été recherchés dans la source de média, un événement indiquant qu’une nouvelle présentation est disponible, un événement indiquant qu’un nouveau flux est disponible dans une présentation en cours, un événement indiquant la fin d’une présentation 35 en cours, un événement indiquant que de nouvelles métadonnées d’une présentation en cours sont disponibles, et un événement indiquant un changement du débit de contenu multimédia reçu de la source de média.

12. Procédé selon la revendication 11, dans lequel l’objet associé à l’événement de contenu multimédia demandé comprend un objet parmi un objet pour activer et désactiver des flux de média d’une présentation prévue, un objet 40 pour identifier le temps recherché du contenu multimédia, un objet pour démarrer automatiquement une nouvelle présentation, un objet pour démarrer une nouvelle présentation après la fin d’une présentation en cours, un objet pour conserver le contenu multimédia en mémoire tampon, et un objet pour rafraîchir un état de métadonnées associé à la présentation.

45 13. Procédé selon la revendication 1, dans lequel l’événement demandé n’est pas présent dans la file d’attente de gestion d’événements au moment où l’événement demandé est demandé.

14. Procédé selon la revendication 13, dans lequel le procédé comprend en outre l’acte consistant à attendre jusqu’à ce que l’événement demandé soit placé dans la file d’attente d’événements avant de renvoyer l’objet associé à 50 l’événement demandé.

15. Procédé selon la revendication 1, le procédé comprenant en outre :

un acte consistant à procurer une interface de flux multimédia (276) configurée de manière à permettre à l’au 55 moins une application d’accéder au contenu multimédia de manière contrôlée ; et un acte consistant à procurer une interface de gestionnaire d’événements (278) configurée pour gérer des événements de source multimédia et des événements de contenu multimédia dans une file d’attente de gestion d’événements, et dans lequel l’interface de gestionnaire d’événements est en outre configurée pour procurer

23 EP 1 376 978 B1

un objet à l’au moins une application en réponse à la réception d’un appel de fonction approprié provenant de l’au moins une application pour un événement dans la file d’attente de gestion d’événements, dans lequel l’objet permet à l’au moins une application soit d’accéder aux données multimédia, soit de traiter les données multi- média. 5 16. Procédé selon la revendication 15, dans lequel le contenu multimédia prend en charge de multiples types de médias, et dans lequel le procédé comprend en outre l’acte consistant à permettre à l’application de sélectionner un type de média préféré.

10 17. Procédé selon la revendication 16, dans lequel les multiples types de média comprennent des types de médias audio comprenant au moins un type audio parmi les types WAV, AU et MIDI.

18. Procédé selon la revendication 16, dans lequel les multiples types de média comprennent des types de média d’image comprenant au moins un type parmi JPEG, GIF et TIFF. 15 19. Procédé selon la revendication 16, dans lequel les multiples types de média comprennent des formats de diffusion de média en flux comprenant au moins un format parmi les formats AVI, ASF, MPEG, MP3, Active Movie, Cinepaq, QuickTime et Indeo.

20 20. Procédé selon la revendication 1, dans lequel le procédé comprend en outre :

lors de la création de l’objet de présentation multimédia, la mise en file d’attente d’un événement dans une file d’attente d’événements qui indique qu’une nouvelle présentation est prête.

25 21. Procédé selon la revendication 1, dans lequel la création de l’objet de présentation comprend en outre un acte consistant à sélectionner un type de média préféré pour restituer une présentation correspondante.

22. Procédé selon la revendication 1, dans lequel la création de l’objet de présentation comprend en outre un acte consistant à synchroniser des horodatages de différents flux de média qui doivent être restitués simultanément. 30 23. Produit logiciel destiné à être utilisé dans un système informatique (210) associé à au moins une application (240), l’au moins une application étant configurée pour traiter un contenu multimédia provenant d’une source multimédia (220) associée au système informatique, le produit logiciel comprenant un ou plusieurs supports lisibles par un ordinateur où sont stockées des instructions exécutables par un ordinateur pour mettre en oeuvre le procédé selon 35 l’une des revendications 1 à 22.

24. Produit logiciel selon la revendication 23, dans lequel lesdits un ou plusieurs supports lisibles par un ordinateur comprennent une mémoire de système.

40 25. Produit logiciel selon la revendication 23, dans lequel le contenu multimédia comprend des données multimédia diffusées en flux.

26. Produit logiciel selon la revendication 25, dans lequel le contenu multimédia comprend au moins un type de données parmi des données audio et des données vidéo. 45 27. Produit logiciel selon la revendication 26, dans lequel le contenu multimédia comprend des métadonnées transmises avec lesdites données d’au moins un type de données parmi des données audio et des données vidéo.

28. Produit logiciel selon la revendication 23, dans lequel le système informatique accède au contenu multimédia pro- 50 venant de la source multimédia via le réseau Internet.

29. Produit logiciel selon la revendication 23, dans lequel la source multimédia comprend un DVD.

30. Produit logiciel selon la revendication 23, dans lequel l’information élémentaire comprend des données agnostiques 55 en termes de format.

31. Produit logiciel selon la revendication 23, dans lequel l’information élémentaire comprend des données spécifiques en termes de format.

24 EP 1 376 978 B1

32. Système informatique associé à au moins une application configurée pour traiter un contenu multimédia provenant d’une source multimédia, le système étant adapté pour mettre en oeuvre le procédé selon l’une des revendications 1 à 22.

25 EP 1 376 978 B1

26 EP 1 376 978 B1

27 EP 1 376 978 B1

28 EP 1 376 978 B1

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REFERENCES CITED IN THE DESCRIPTION

This list of references cited by the applicant is for the reader’s convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

Patent documents cited in the description

• US 5996025 A [0010] • US 2002065952 A1 [0012] • US 2002004355 A1 [0011]