United States Patent [19J
`Crites et al.
`
`I 1111111111111111 11111 1111111111 1111111111 11111 1111111111 111111111111111111
`US006097380A
`[11] Patent Number:
`[45] Date of Patent:
`
`6,097,380
`Aug. 1, 2000
`
`[54] CONTINUOUS MEDIA STREAM CONTROL
`
`[75]
`
`Inventors: Brian D. Crites, Redmond; Edward J.
`Praitis, Woodinville, both of Wash.
`
`[73] Assignee: Microsoft Corporation, Redmond,
`Wash.
`
`[21] Appl. No.: 08/669,983
`
`[22] Filed:
`
`Jun. 24, 1996
`
`Int. Cl.7 ...................................................... G06F 3/100
`[51]
`[52] U.S. Cl. .............................................................. 345/302
`[58] Field of Search ..................................... 345/302, 326,
`345/333, 334, 335
`
`[56]
`
`References Cited
`
`PUBLICATIONS
`
`Primary Examiner-Phu K. Nguyen
`Assistant Examiner-Cliff N. Vo
`Attorney, Agent, or Firm-Lee & Hayes, PLLC
`
`[57]
`
`ABSTRACT
`
`A network system includes one or more network servers and
`a plurality of available media streams. The media streams
`are formatted differently. Some are file-based streams, sup(cid:173)
`plied by the network servers. Others are supplied by local
`tuners from digital and/or analog signal broadcasts. A net(cid:173)
`work client executes an application program that is to
`control rendering of the media streams. Each media stream
`is represented by a programming object. Each programming
`object has identical interface functions that can be invoked
`by the application program to control playback of the
`different media streams even though such media streams are
`of different media types.
`
`Microsoft® Media Player Version 4.0 (Trademark of
`Microsoft Corp.) Screen Display pp. 1-10, 1981-1996.
`
`32 Claims, 6 Drawing Sheets
`
`40
`
`47
`
`48
`
`PROCESSOR
`
`NETWORK
`INTERFACE
`
`TUNER
`
`/20
`
`5,26
`
`INPUT DEVICES
`
`46
`
`42
`
`MEMORY
`
`APPLICATION
`PROGRAM
`
`OPERATING
`SYSTEM
`
`MEDIA STREAM
`CONTROLLER
`
`52
`
`50
`
`53
`
`24
`
`DISPLAY
`
`Ex.1010
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`

`

`U.S. Patent
`
`Aug. 1, 2000
`
`Sheet 1 of 6
`
`6,097,380
`
`12
`
`18
`
`NETWORK
`SERVER
`
`DATA
`STORAGE
`
`12
`
`NETWORK
`SERVER
`
`18
`
`DATA
`STORAGE
`
`14
`
`/
`
`D .
`
`I
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`I
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`~~~~~~~~~ ~
`~e
`
`14
`
`14
`
`D
`
`Ex.1010
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`

`

`U.S. Patent
`
`Aug. 1, 2000
`
`Sheet 2 of 6
`
`6,097,380
`
`20
`
`/
`
`24
`
`22
`
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`I
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`I
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`
`Ex.1010
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`

`

`U.S. Patent
`
`Aug. 1, 2000
`
`Sheet 3 of 6
`
`6,097,380
`
`40
`
`47
`
`48
`
`PROCESSOR
`
`NETWORK
`INTERFACE
`
`TUNER
`
`/20
`
`5,26
`
`INPUT DEVICES
`
`46
`
`42
`
`MEMORY
`
`APPLICATION
`PROGRAM
`
`OPERATING
`SYSTEM
`
`MEDIA STREAM
`CONTROLLER
`
`52
`
`50
`
`53
`
`24
`
`DISPLAY
`
`Ex.1010
`APPLE INC. / Page 4 of 13
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`

`

`U.S. Patent
`
`Aug. 1, 2000
`
`Sheet 4 of 6
`
`6,097,380
`
`OBJECT
`
`INTERFACES
`
`60
`
`GENERAL
`MEDIA
`OBJECT
`
`!OBJECT
`!PLAY
`!VIDEO
`!AUDIO
`!EVENTS
`
`SERVER
`FILE
`SOURCE
`
`70
`
`76
`
`DATA
`
`DATASOURCE
`
`ANALOG
`BROADCAST
`SOURCE
`
`DATA
`
`DATASOURCE
`
`82
`
`88
`
`AV/ FILE
`SOURCE
`
`DATA
`
`DATASOURCE
`
`DIGITAL
`BROADCAST
`SOURCE
`
`DATA
`
`DATASOURCE
`
`Ex.1010
`APPLE INC. / Page 5 of 13
`
`

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`STREAM OBJECT
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`LOCAL FILE
`
`STREAM OBJECT
`
`SERVER FILE
`
`62
`
`APPL/CATION PROGRAM
`
`52
`
`Ex.1010
`APPLE INC. / Page 6 of 13
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`

`

`U.S. Patent
`
`Aug. 1, 2000
`
`Sheet 6 of 6
`
`6,097,380
`
`i
`
`00
`/1
`
`I
`
`REC£/VE SOURCE
`DESIGNATION
`
`,
`INSTANTIATE MEDIA
`MANAGER
`
`I
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`/1
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`104
`
`MEDIA
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`106
`MANAGER
`
`Ex.1010
`APPLE INC. / Page 7 of 13
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`

`6,097,380
`
`1
`CONTINUOUS MEDIA STREAM CONTROL
`
`TECHNICAL FIELD
`This invention relates to computer and network systems
`that render continuous media information such as audio and 5
`video information from sources such as network servers and
`analog tuners.
`
`2
`FIG. 3 is a functional block diagram of the computer
`shown in FIG. 2.
`FIG. 4 shows a conventional representation of a program(cid:173)
`ming object and its interfaces.
`FIG. 5 shows a general-media programming object and
`preferred interfaces.
`FIG. 6 shows examples of media-specific programming
`objects.
`FIG. 7 shows the interactions of various components in
`accordance with the invention.
`FIG. 8 shows preferred steps in accordance with the
`invention.
`FIG. 9 shows a media manager object in accordance with
`15 the invention.
`
`DETAILED DESCRIPTION OF THE
`PREFERRED EMBODIMENT
`
`FIG. 1 shows a computer network system in accordance
`with one embodiment of the invention. The system includes
`one or more network servers 12 and a plurality of network
`client computers 14. The client computers preferably com(cid:173)
`municate with the servers through local-area or wide-area
`networks 16, and/or are connected for communication with
`servers 12 by on-demand or dial-up connections such as
`conventional modem connections. For example, a particular
`client computer 14 might be connected to the Internet
`through a modem connection to a local Internet service
`provider. Servers 12 in this case would typically have
`dedicated, high-speed connections to the Internet. As
`another example, a client computer 14 might be connected
`to a server 12-such as an online service provider like
`Compuserve or the Microsoft Network-by a direct, dial-up,
`modem connection.
`The network servers 12 have access to mass storage
`devices 18 on which are stored a plurality of continuous
`media data streams. In this case, the continuous media
`streams consist of sequences of digital data that are intended
`40 to be supplied serially to client computers and rendered by
`the client computers in a form that is useful to users of the
`client computers. For example, a continuous media stream
`might consist of a sequence of audio samples which are to
`be converted to analog format by the client computer and
`45 rendered as audible sound. As another example, a continu(cid:173)
`ous media stream might consist of a sequence of video
`frames that are to be rendered sequentially by the client
`machine. In many cases, the data streams will be com-
`pressed.
`These continuous media data streams are typically stored
`as files on mass storage devices 18, and are referenced by
`conventional file names. A client can specify a particular
`media stream by indicating its file name in combination with
`a unique name or ID that has been assigned to the server
`having access to the mass storage device on which the file
`resides.
`FIG. 2 shows a client computer 20 in the form of a
`conventional desktop IBM-compatible computer. Client
`computer 20 has a central processing unit (CPU) 22, a
`display monitor 24, a keyboard 25, and a mouse 26. The
`computer 20 also has a floppy disk drive 28 for interfacing
`with a compatible floppy memory diskette 30 (e.g., 3.5"
`form factor), and an optical disk drive 32 for interfacing with
`a compatible CD-ROM 34. The computer 20 might also
`65 include another input device in addition to, or in lieu of, the
`keyboard 25 and mouse 26 including such devices as a track
`ball, stylus, or the like.
`
`BACKGROUND OF THE INVENTION
`There was a time when information presented by a 10
`computer was limited to numbers and/or text. With modern
`personal computers, however, a wide variety of information
`can be presented, including graphics, audio, and video.
`The number of information sources has also multiplied.
`Multimedia information is now available from local digital
`storage such as CD-ROMs, from remote providers and
`online services, and even from local analog sources such as
`television and radio receivers.
`While such variety allows application programs to pro-
`vide much richer content, it also creates a degree of com(cid:173)
`plexity for programmers. Such complexity is a result pri(cid:173)
`marily of the different ways in which application programs
`must interact with different computer and network elements
`to render information of various kinds from different
`sources.
`It is possible to relieve application programs of some of
`the details of information rendering by providing APis
`(application programming interfaces) that take care of such
`details. Even with such APis, however, application programs
`must be aware of the types of information they are rendering
`and must be able to determine the correct APis for rendering
`such information. This approach makes it difficult to add
`new media types to a system. In order to take advantage of
`a new media type, each application program has to be
`rewritten so that it is aware of the proper APis to use for
`rendering the media type.
`
`35
`
`20
`
`25
`
`30
`
`SUMMARY OF THE INVENTION
`The invention described below enables application pro(cid:173)
`grams to render continuous media streams of different types
`and from different sources without being aware of the details
`of the media streams such as format or location or how it is
`rendered. Each media stream is represented as an object with
`a plurality of interfaces. The interfaces have functions or
`methods for adjusting the volume of a media stream, for
`setting display parameters for video streams, and for per(cid:173)
`forming other functions with regard to the rendering of
`media streams.
`In the embodiment described below, an application pro- 50
`gram learns of a media stream by receiving a pointer to a
`media-specific object representing the media stream. The
`application program passes this pointer to an object creation
`function that implements a general-media programming
`object, resulting in a general-media object that has a similar 55
`or identical set of interfaces regardless of the type of media
`stream the general-media object represents. Using this
`scheme, the application program is never required to be
`aware of the details of the media stream. Rather, the general(cid:173)
`media programming object performs any lower-level func-
`tions necessary to control the rendering of the media stream.
`
`60
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`FIG. 1 shows a computer network system in accordance
`with one embodiment of the invention.
`FIG. 2 shows a client computer in accordance with the
`invention.
`
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`6,097,380
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`5
`
`20
`
`3
`FIG. 3 shows a functional block diagram of the computer
`20, revealing components that are not shown in FIG. 2. The
`computer 20 has a processor 40 and computer-readable
`storage media 42 including volatile memory (e.g., RAM)
`and non-volatile memory. The various components are inter(cid:173)
`connected by an internal bus 46. Non-volatile memory can
`be implemented as integrated circuit chips (e.g., ROM,
`EEPROM), disk drive(s) (e.g., floppy, optical, hard), or a
`combination of both. The volatile memory will typically
`comprise electronic DRAM (dynamic random access
`memory). Display 24 is connected to bus 46 through appro(cid:173)
`priate hardware interface drivers (not shown). Additionally,
`input devices 25 and 26 are connected to supply data to bus
`46 via appropriate 1/0 ports, such as serial RS-232 ports.
`Computer 20 includes a network interface 47 for connec(cid:173)
`tion to a remote network server. As discussed above, the
`connection to the server can be through a local-area or
`wide-area network. Network interface 47 therefore com(cid:173)
`prises a conventional Ethernet network card, a modem, or
`another device that provides communications with a server.
`The computer also includes one or more local analog
`tuners 48. The tuners are connected to receive analog
`broadcast signals from one or more sources. A tuner might
`be a radio tuner for receiving radio broadcasts or paging
`messages. Alternatively, such a tuner might be a television 25
`receiver for receiving television broadcasts that include both
`video and sound. An example of such a tuner is manufac(cid:173)
`tured by Zenith Electronics Corp. of Glenview, Ill., as model
`number #ST5612.
`The analog data received from the tuner is considered a
`continuous media stream for purposes of this description.
`Computer 20 runs an operating system 50 which supports
`multiple applications. Operating system 50 is stored in
`memory 42 and executed on processor 40. The operating
`system is preferably a multitasking operating system which
`allows simultaneous execution of multiple applications,
`although aspects of this invention may be implemented
`using a single-tasking operating system. The operating sys(cid:173)
`tem preferably employs a graphical user interface window- 40
`ing environment which presents the applications or docu(cid:173)
`ments in specially delineated areas of the display screen
`called "windows." Each window has its own adjustable
`boundaries which enable the user to enlarge or shrink the
`application or document relative to the display screen. Each
`window can act independently, optionally including its own
`menu, toolbar, pointers, and other controls, as if it were a
`virtual display device. One preferred operating system is the
`Windows® operating system sold by Microsoft Corporation,
`such as Windows® 95 or Windows NT™ or other derivative
`versions of Windows®. However, other operating systems
`which provide windowing environments may be employed,
`such as the Macintosh Finder from Apple Corporation and
`the OS/2 Presentation Manager from IBM.
`An application program 52 is stored in memory 42. When
`activated, the application program 52 runs under operating
`system 50 while executing on processor 40. The application
`program 52 can be loaded into electronic memory from the
`floppy diskette 30 or CD-ROM 34 or, alternatively, down(cid:173)
`loaded from network 16 via network interface 47.
`In addition, a media stream controller 53 is stored in
`memory 42 and executed by processor 40. Media stream
`controller 53 allows application program 52 to create pro(cid:173)
`gramming objects representing the different media streams.
`Because of this, the application program does not need to be
`aware of the specifics of the media streams. In fact, the
`application program controls the rendering of each media
`
`4
`stream using the same procedures regardless of the format or
`source of the media stream.
`The programming objects created by media stream con(cid:173)
`troller 53 have common interface functions that can be
`invoked by the application program to control playback of
`different media streams even though such media streams are
`of different media types. For example, each programming
`object has a volume control interface having identical meth(cid:173)
`ods or functions that can be invoked by the application
`10 program to determine and set the rendered volume level of
`a particular media stream-whether the media stream is a
`digital audio stream or an analog television broadcast.
`The invention is described within the context of a familiar
`desktop computer that typically includes an Intel-based or
`15 Intel-compatible microprocessor, with four to sixteen mega(cid:173)
`bytes of RAM. Such a computer is capable of running a
`multitasking operating system with a windowing environ(cid:173)
`ment. However, aspects of this invention might also be
`employed in other forms of computing devices, such as
`laptop computers, hand-held computers, portable personal
`information managers (PIMs), and the like. In these devices,
`the application program may be configured to run on a
`single-tasking operating system which does not support a
`windowing environment.
`In addition, the invention will be useful in non-traditional
`network environments other than the wide-area network
`environment shown. For example, the invention will be
`useful in the interactive TV environment, where the server
`will consist of a cable headend and the client will consist of
`30 a set-top box or other device performing a similar function.
`In many proposed interactive TV systems, the headend will
`be capable of supplying media streams in a variety of
`different formats, such as file-based digital formats and
`broadcast digital and analog formats. Some media streams
`35 will be supplied on demand to individual clients, while
`others will be broadcast on a pre-determined schedule. In
`this environment, the client will include both a digital
`network interface and an analog tuner for receiving televi-
`sion or other audio/visual broadcasts.
`The configuration of FIGS. 1-3 includes several media
`sources, which are capable of supplying media streams in a
`variety of different formats. For example, the local non(cid:173)
`volatile storage of computer 20 is a potential source of media
`streams. Audio and/or video streams are available from local
`45 hard disks, floppy disks, and CD-ROMs. Similar streams
`might be available from Internet sources or other network
`sources such as a server 12. Tuners 48 also supply media
`streams. In some cases, the tuner itself will render the media
`streams, without participation by processor 40 of computer
`50 20. In other cases, a tuner will supply a digital data stream
`for rendering by processor 40. In many cases, processor 40
`or application program 52 can control the channel or fre(cid:173)
`quency of the tuner, to select a particular broadcast signal.
`Typical file-based digital media formats include ".wav"
`55 audio files and ".avi" video files commonly used in the
`Windows® operating environment. "MPEG" is another file
`or media stream format for video information. Available
`media formats also include analog formats including analog
`radio and TV broadcast formats.
`In this document, the "type" of a media stream includes
`both its format and its source. In the prior art, even media
`streams having the same data format must often be treated
`differently by an application program if they originate from
`different sources. For example, the steps for obtaining a
`65 ".wav" media stream from a local source might be quite
`different from obtaining an identical media stream from a
`remote network server.
`
`60
`
`Ex.1010
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`6,097,380
`
`5
`
`5
`As mentioned above, media stream controller 53 allows
`application program 52 to create and use programming
`objects to represent different media streams. Such objects
`are implemented in the Microsoft Windows® programming
`environment using features of Object Linking and Embed-
`ding (OLE), also referred to as ActiveX technology. OLE is
`based on a protocol referred to as the Component Object
`Model (COM). COM specifies how objects interact with
`each other using interfaces. OLE and COM have been well
`documented and will not be explained in detail here. For 10
`more information regarding OLE and COM, refer to "OLE
`2 Programmer's Reference" and "Inside OLE 2, Second
`Edition," by Kraig Brockschmidt, both published by
`Microsoft Press of Redmond, Wash., and both of which are
`hereby incorporated by reference.
`Objects and their interfaces are conventionally illustrated
`as shown in FIG. 4. A circle is used to represent each
`interface.
`The services or functions of an object can be used by both
`in-process clients and by out-of-process clients. In addition,
`an object interface can be used by a client executing on a
`different computer. The COM protocol covers all of these
`situations. Calling a remote interface ( one that is in a
`different address space than the calling process) requires the
`use of "stubs" and "proxies," and involves topics such as
`"marshalling" and "unmarshalling" of procedure param(cid:173)
`eters. These mechanisms are well understood and are docu(cid:173)
`mented in the books mentioned above. Also refer to
`"X/Open DCE: Remote Procedure Call," published by
`X/Open Company Ltd., U.K. In addition, the Microsoft 30
`Development Library CD (April 1996), available from
`Microsoft® of Redmond, Wash., contains a Specification
`entitled "Component Object Model Specification 0.9" that
`discusses distributed COM programming. Both of these
`references are incorporated by reference.
`FIG. 5 shows a general-media programming object 60
`implemented by media stream controller 53. Such an object
`is created for every desired media stream and/or source,
`including both analog and digital sources. It includes the
`following interfaces, which are common to all general- 40
`media programming objects; regardless of whether they
`represent analog or digital media services, and regardless of
`whether they represent file-based sources or tuner-type
`sources:
`!Object. This interface has functions for initializing,
`activating, and deactivating the media object.
`!Play. This interface has functions for controlling play(cid:173)
`back of the media object, including functions for
`starting, stopping, and pausing rendering of media
`streams. Additionally, for media sources that have the
`capability, this interface also supports fast-forward and
`rewind operations.
`!Video. The video control interface has functions for
`determining and controlling the size, position, and
`visibility of video output generated by a video media
`object. This interface is not available for media streams
`that do not include video.
`!Audio. This interface, also referred to as the volume
`control interface, has functions for determining and
`controlling the volume levels and audio channel of
`audio produced by the media object.
`!Events. This interface allows an application program to
`receive and respond to events generated by media
`objects.
`These interfaces, and the functions implemented by the
`interfaces, are the same for each instance of a general-media
`
`6
`programming object 60, regardless of the type of media
`source or media stream represented by the object. For
`instance, a general-media programming object representing
`a remote network source has the same interfaces and func-
`tions as a general-media programming object representing
`an analog broadcast source. To control any aspect of the
`rendering from a particular media source, an application
`program invokes the proper interface function of the object
`representing the media source. The application program
`follows the same procedure regardless of the type of the
`media source.
`Underlying each general-media programming object is a
`media-specific object that may be created under the direction
`of application program 52, by some other process in com-
`15 puter 20, or by a remote server. The media-specific object
`has interfaces that allow the general-media object to locate
`the corresponding media source. For instance, for a remote
`server source, the media-specific object allows the general(cid:173)
`media object to determine the server ID and filename of the
`20 media stream that is to be rendered. For a local tuner source,
`the media-specific object indicates the channel number or
`frequency of the subject media stream.
`FIG. 6 shows exemplary media-specific objects. Each of
`these objects has a "Data" interface that returns an identifier
`25 that allows the object to be uniquely identified, and a
`DataSource interface with the functions mentioned above
`that can be invoked to reveal source information. Object 70
`corresponds to a server file source. Object 76 corresponds to
`an AVI (audio-video interleaved) file source. An AVI file
`uses an interleaved format in which video and audio that are
`to be played at the same time are located at the same place
`in the file.
`Object 82 corresponds to an analog broadcast source such
`as an RF (radio frequency) tuner. Object 88 corresponds to
`35 a digital broadcast source such as might be used in some
`foreign countries like Japan
`For the first two types of media-specific objects (server
`file source and AVI source), the DataSource interface has
`functions that return the server ID and filename for a
`particular data file. For the second two types of media(cid:173)
`specific objects (analog and digital broadcast sources), the
`DataSource interface has functions that simply return a
`frequency or channel number for a broadcast media stream.
`FIG. 7 shows how the various objects and components
`45 interact with each other. Application program 52 is shown at
`the top of the diagram. It interacts with one or more
`general-media objects 60, which in turn interact with media(cid:173)
`specific objects 62. Objects 60 interact with the various
`media sources 64, which pass data or signals to appropriate
`50 rendering devices 66. FIG. 7 illustrates rendering audio and
`video from a remote network server, from a local file source,
`from an analog tuner source, and from a digitally-broadcast
`audio/visual source.
`In the present embodiment, an application program fol-
`55 lows the procedure of FIG. 8 to set up a general-media
`programming object. First, the application program per(cid:173)
`forms a step 100 of receiving a source designation that
`specifies a media stream. The source designation indicates a
`filename, a server ID and filename, a channel number, or a
`60 frequency, depending on the type of media source from
`which the media stream will be supplied. In this embodiment
`of the invention, a source designation is literally a reference
`or pointer to an interface of a media-specific object. The
`media-specific object, which may be located locally or
`65 remotely (using OLE and COM), has one or more functions
`that can be invoked to reveal the source information
`(filename, server ID, channel number, frequency, etc.).
`
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`6,097,380
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`7
`It should be noted that the application program itself will
`often not be concerned with the details of the media-specific
`objects. Rather, the application program will simply receive
`source designations in the form of references or pointers to
`media-specific objects. In some cases, the application pro(cid:173)
`gram may be responsible for creating a media-specific
`object. In the preferred embodiment, APis are provided for
`this purpose, for different types of media formats and
`sources. The application program can call such an API while
`providing required information about a desired media
`stream, and the API will return a pointer to a media-specific
`object representing the media stream.
`A step 102, performed by an application program, com(cid:173)
`prises instantiating a media manager object. An exemplary
`media manager object 104 is shown in FIG. 9. In includes a 15
`"Manager" interface 106. The Manager interface is the
`central mechanism for accessing any type of media object.
`General-media objects are created using this interface.
`A step 110 comprises passing the received source desig(cid:173)
`nation to an object creation function. The object creation 20
`function is implemented as a method of the Manager inter(cid:173)
`face 106 of media manager object 104. The object creation
`function accepts a pointer to a media-specific object, and
`utilizes methods of that object to determine the source of a
`desired continuous media stream. Based on the source 25
`designation, the object creation function creates a general(cid:173)
`media object such as shown in FIG. 5, representing a media
`source. The same object creation function is invoked by the
`application program regardless of the type of media source
`represented by any particular media-specific object. Regard(cid:173)
`less of the media type, a pointer to the media-specific object
`is passed to the object creation function, and the object
`creation function creates a general-media programming
`object having interfaces as shown in FIG. 5 for controlling
`various aspects of multimedia playback. The general-media 35
`programming object is responsible for dealing with the
`underlying specifics of media sources and rendering
`hardware, or it can utilize lower-level software components
`for handling these responsibilities. The application program
`simply receives a pointer to the general-media programming 40
`object from the object creation function.
`Step 112 comprises invoking the interfaces of the general(cid:173)
`media programming objects to control media rendering from
`the media sources represented by the programming objects.
`At this point, controlling these objects is totally independent 45
`of the media type being manipulated. Changing the volume
`of a file-based media stream is no different than adjusting the
`volume of an analog broadcast, even though different hard(cid:173)
`ware may be manipulated at a lower level.
`As a specific example, suppose that an application pro- 50
`gram will oversee rendering of two different media
`streams-one from a server- and file-based digital media
`source and another from a local analog media source such as
`a tuner. In this case, the application would first either create
`or receive media-specific objects representing the two media 55
`streams-one for the digital data stream and one for the
`analog broadcast stream. It would then pass pointers to these
`objects to a general-media object creation function. The
`object creation function would then create a general-media
`programming object for each of the two media streams. The 60
`general-media programming objects would have identical
`interfaces, and the application program would invoke them
`as necessary to determine or set parameters relating to
`rendering of the media streams.
`Although the invention has been described primarily in 65
`terms of its computer hardware and methodology, the inven(cid:173)
`tion also includes computer readable storage media, such as
`
`8
`electronic memory and non-volatile optical- or magnetic(cid:173)
`based removable mass storage components, containing
`instructions for carrying out the steps described above.
`Furthermore, it is to be understood that the invention is
`5 not limited to the specific features described, since the
`means herein disclosed comprise preferred forms of putting
`the invention into effect. The invention is, therefore, claimed
`in any of its forms or modifications within the proper scope
`of the appended claims appropriately interpreted in accor-
`10 dance with the doctrine of equivalents.
`What is claimed is:
`1. In a computer system that includes a plurality of media
`sources of different types, a method comprising the follow(cid:173)
`ing steps:
`creating programming objects representing the respective
`media sources, the programming objects having com(cid:173)
`mon object interfaces regardless of the types of media
`sources represented by the respective programming
`objects;
`invoking the interfaces of the programming objects to
`control media rendering from the media sources rep(cid:173)
`resented by the programming objects.
`2. A method as recited in claim 1, wherein the common
`object interfaces include:
`a play interface for starting and pausing rendering of
`media streams from the media sources;
`a volume control interface for setting volume levels of
`media streams from the media sources.
`3. A method as recited in claim 1, wherein the common
`30 object interfaces include:
`a play control interface for starting and pausing rendering
`of media streams from the media sources;
`a volume control interface for setting volume levels of
`media streams from the media sources;
`a video control interface for setting position and size
`parameters of video media streams from the media
`sources.
`4. A method as recited in claim 1, wherein the step of
`creating a programming object comprises:
`creating a media-specific programming object represent(cid:173)
`ing a specific media source;
`invoking a general-media object creation function with
`reference to the media-specific programming object,
`the general-media object creation function creating a
`general-media programming object representing the
`specific media source regardless of the type of the
`media source, the general-media programming object
`having the common object interfaces.
`5. A method as recited in claim 1, wherein the step of
`creating programming objects comprises:
`creating programming objects representing digital data
`streams;
`creating programming objects representing analog broad(cid:173)
`casts;
`the programming objects having common object inter(cid:173)
`faces regardless of whether they represent digital data
`streams or analog broadcasts.
`6. In a computer network having a plurality of media
`streams available from one or more network servers, a
`method of playing the media streams at a network client, the
`method comprising:
`receiving a source designation from one of the network
`servers, the source designation specifying a media
`stream;
`creating a programming object representing the media
`source based on the source designation, the program-
`
`Ex.1010
`APPLE INC. / Page 11 of 13
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`5
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`20
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`9
`ming object having common interfaces regardless of
`the