Method of and apparatus for supporting and enabling the selection and mixing of multiple streams of audio/video data from multiple sources within a receiving device allowing external control

A method of and apparatus for supporting and enabling the selection and mixing of multiple input data streams from multiple sources within a receiving device allowing external control includes a receiving device, a control device and one or more source devices. The receiving device receives input data streams from the source devices. The input data streams are provided as inputs to selectors within the receiving device. The selectors output selective ones of the input data streams to a mixer, based on control information received from a control device. The mixer then combines the selected input data streams into an output stream, based on control information received from the control device. The interfaces and functions of the selectors and the mixer are provided to the control device in response to a request from the control device. As the control device receives control inputs, the control device provides control information to the selectors and the mixer within the receiving device to control the output of the input data streams.

FIELD OF THE INVENTION

The present invention relates to the field of selecting and mixing data at a receiving device. More particularly, the present invention relates to the field of selecting and mixing streams of audio/video data at a receiving device to provide an output stream of data under control from an external device.

BACKGROUND OF THE INVENTION

The IEEE standard, “IEEE 1394-2000 Standard For A High Performance Serial Bus,” Draft ratified in 2000, is an international standard for implementing an inexpensive high-speed serial bus architecture which supports both asynchronous and isochronous format data transfers. Isochronous data transfers are real-time transfers which take place such that the time intervals between significant instances have the same duration at both the transmitting and receiving applications. Each packet of data transferred isochronously is transferred in its own time period. Ali example of an ideal application for the transfer of data isochronously would be from a video recorder to a television set. The video recorder records images and sounds and saves the data in discrete chunks or packets. The video recorder then transfers each packet, representing the image and sound recorded over a limited time period, during that time period, for display by the television set. The IEEE 1394-2000 serial bus architecture provides multiple channels for isochronous data transfer between applications. A six bit channel number is broadcast with the data to ensure reception by the appropriate application. This allows multiple applications to simultaneously transmit isochronous data across the bus structure. Asynchronous transfers are traditional data transfer operations which take place as soon as possible and transfer an amount of data from a source to a destination.

The IEEE 1394-2000 standard provides a high-speed serial bus for interconnecting digital devices thereby providing a universal I/O connection. The IEEE 1394-2000 standard defines a digital interface for the applications thereby eliminating the need for an application to convert digital data to analog data before it is transmitted across the bus. Correspondingly, a receiving application will receive digital data from the bus, not analog data, and will therefore not be required to convert analog data to digital data. The cable required by the IEEE 1394-2000 standard is very thin in size compared to other bulkier cables used to connect such devices. Devices can be added and removed from an IEEE 1394-2000 bus while the bus is active. If a device is so added or removed the bus will then automatically reconfigure itself for transmitting data between the then existing nodes. A node is considered a logical entity with a unique address on the bus structure. Each node provides a configuration ROM, a standardized set of control registers and its own address space. Because of these advantages the IEEE 1394-2000 standard provides for a unique networking structure that is capable of incorporating audio/video devices, media play/record devices, computing devices and display devices.

The IEEE 1394-2000 standard defines a protocol as illustrated inFIG. 1. This protocol includes a serial bus management block10coupled to a transaction layer12, a link layer14and a physical layer16. The physical layer16provides the electrical and mechanical connection between a device or application and the IEEE 1394-2000 cable. The physical layer16also provides arbitration to ensure that all devices coupled to the IEEE 1394-2000 bus have access to the bus as well as actual data transmission and reception. The link layer14provides data packet delivery service for both asynchronous and isochronous data packet transport. This supports both asynchronous data transport, using an acknowledgement protocol, and isochronous data transport, providing real-time guaranteed bandwidth protocol for just-in-time data delivery. The transaction layer12supports the commands necessary to complete asynchronous data transfers, including read, write and lock. The transaction layer12also provides a path for isochronous management data to be transferred to the serial bus management block10via read operations with isochronous control compare-swap registers. The serial bus management block10contains an isochronous resource manager for managing isochronous data transfers. The serial bus management block also provides overall configuration control of the serial bus in the form of optimizing arbitration timing, guarantee of adequate electrical power for all devices on the bus, assignment of the cycle master, assignment of isochronous channel and bandwidth resources and basic notification of errors.

A diverse range of products can be implemented with the ability to connect to an IEEE 1394-2000 serial bus network. These devices can have capabilities and functionality ranging from very simple to very complex. Specifically, a variety of audio/video devices, media play/record devices and computing/display devices are capable of being linked together over an IEEE 1394-2000 serial bus networking structure to support asynchronous and isochronous data transfers between the devices.

The IEEE 1394-2000 cable environment is a network of nodes connected by point-to-point links, including a port on each node's physical connection and the cable between them. The physical topology for the cable environment of an IEEE 1394-2000 serial bus is a non-cyclic network of multiple ports, with finite branches. The primary restriction on the cable environment is that nodes must be connected together without forming any closed loops.

A block diagram of a conventional home audio/video network including a television and an analog video cassette recorder (VCR) is illustrated inFIG. 2. The television20is coupled to the analog VCR40. Video data and associated data are sent between the analog VCR40and the television20in a known manner.

Relevant internal components of the television20and the analog VCR40are also illustrated inFIG. 2. The television20includes an interface32which sends and receives audio and video signals to and from the analog VCR40. The interface32is coupled to an audio/video switch26for directing audio/video signals to and from the analog VCR40. A cable/antenna interface circuit30is coupled to receive input signals from a coaxial cable or an antenna and to pass those signals through a tuner28to the audio/video switch26. The audio/video switch26is coupled to a video random access memory (VRAM) circuit24for providing the video signals from the cable/antenna interface30or the analog VCR40to the display22.

The analog VCR40includes a video source46, such as a video tape which is being played by the analog VCR40or a television input. The analog VCR40also includes a graphics source48which generates on-screen-display graphics to be displayed by the television20when the analog VCR40is sending data to be displayed by the television20. Such on-screen-display graphics include words or symbols representing commands being executed by the analog VCR40, such as PLAY, STOP, REWIND, FAST-FORWARD, PAUSE and RECORD. The on-screen-display graphics generated by the graphics source48typically also include a menu or menus displayed on the television20for the user which allow the user to program the analog VCR40. On-screen-display graphics generated by the graphics source48are provided to a mixer circuit44. The mixer circuit44also receives video data from the video source46. The mixer circuit44then combines the on-screen-display graphics from the graphics source48and the video data from the video source46into a video output which is transmitted through the interface circuit42to the television20. The video output from the analog VCR40is then processed by the television20and shown on the display22. The mixer circuit44will, as appropriate, either overlay the on-screen-display graphics onto the video data to form the video output or cause the video output to include only on-screen-display graphics from the graphics source48or video data from the video source46.

In an audio/video network including a digital television and a digital VCR coupled together by an IEEE 1394-1995 serial bus network, the video data from the digital VCR is typically transmitted in a digital format such as MPEG. The digital VCR is not typically responsible for encoding the video data in an MPEG format, but will record and transmit data previously encoded in a MPEG format by another source. In order for the digital VCR to have the ability to combine on-screen-display graphics with the video data, as described above, the digital VCR would have to include an MPEG encoder and have the ability to encode the on-screen-display graphics into an MPEG format and then combine the streams of data into a video output stream of data. Due to the cost of MPEG encoders, such a requirement is cost prohibitive in competitive consumer VCRs.

Some video source devices have the ability to generate a very high bandwidth graphics output which is sent to a display device, such as a television, for on-screen-display to the user. This graphics output can be of very high resolution and color depth, including dynamic animation effects with multiple portions of the graphics data changing on a frequent basis. This graphics data is typically mixed with, or overlaid on top of, a video signal. As described above, it is relatively easy and inexpensive to provide capability within an analog device to combine on-screen-display graphics with a video stream of data and send the combined stream of data to a television or other display device for display to a user or users. It is also relatively easy and inexpensive for a device, such as a video game console to generate a pure graphics output stream and send this output stream over an analog video connection to the television. However, for digital devices, it is quite expensive, to include within the device, the capability to generate graphics data or on-screen-display data and encode this data into a format such as MPEG video in which digital data is typically transmitted. It is cost prohibitive for most consumer devices such as VCRs and video game consoles to include the ability to generate on-screen-display graphics for combination with video and/or transmission to a digital display device as an MPEG stream of video.

The EIA-775, DTV 1394 Interface Specification, draft Nov. 30, 1998, is a standard which defines a specification for a baseband digital interface to a digital television that provides a level of functionality that is similar to the analog system illustrated inFIG. 2and described above. Within the EIA-775 specification, an audio/video source capable of producing analog audio and video and also an MPEG transport stream, is coupled to a digital television receiver. The analog signal is transmitted over a standard coaxial cable and the MPEG data is transmitted isochronously over an IEEE 1394 serial bus. Bitmaps of the source on-screen-display data are sent by asynchronous connections separately over the IEEE 1394 serial bus and are mixed with the decoded MPEG video in the digital television prior to being presented on the display. This process removes the need for the audio/video source to perform the additional MPEG video decodes and re-encodes, described above. However, the process of the EIA-775 specification, requires the audio/video source and the digital television to be connected together by the IEEE 1394 serial bus. The process of the EIA-775 specification does not work with connections other than the IEEE 1394 serial bus.

SUMMARY OF THE INVENTION

A method of and apparatus for supporting and enabling the selection and mixing of multiple input data streams from multiple sources within a receiving device allowing external control includes a receiving device, a control device and one or more source devices. The receiving device receives input data streams from the source devices. The input data streams are provided as inputs to selectors within the receiving device. The selectors output selective ones of the input data streams to a mixer, based on control information received from a control device. The mixer then combines the selected input data streams into an output stream, based on control information received from the control device. The interfaces and functions of the selectors and the mixer are provided to the control device in response to a request from the control device. As the control device receives control inputs, the control device provides control information to the selectors and the mixer within the receiving device to control the output of the input data streams.

In one aspect of the present invention, a method of providing an output data stream comprises receiving one or more input data streams from one or more source devices at a receiving device, receiving control information from a control device, including information regarding selected ones of the one or more input data streams, thereby providing selected input data streams, and mixing information, selecting the selected input data streams based on the control information from the control device and mixing the selected input data streams into the output data stream based on the control information from the control device. The method further comprises sending a request from the control device to the receiving device regarding selection and mixing functions and controls at the receiving device and providing the selection and mixing functions and controls from the receiving device to the control device. The input data streams include one or more of audio/video data streams, on-screen-display data streams and graphics data streams. The control device is preferably external of the receiving device. Alternatively, the control device is internal to the receiving device. The method further comprises outputting the output data stream. The method further comprises receiving control input at the control device and generating the control information based on the control input. The one or more input streams are received over one or more of a network which substantially complies with a version of the IEEE 1394 standard, a connection which substantially complies with a version of universal serial bus standard and a connection which substantially complies with a version of universal plug-and-play standard. The control information is received over one or more of a network which substantially complies with a version of the IEEE 1394 standard, a connection which substantially complies with a version of universal serial bus standard and a connection which substantially complies with a version of universal plug-and-play standard.

In a further aspect of the present invention, a method of controlling a receiving device providing a combination of one or more input data streams as ail output data stream comprises sending a request from a control device to the receiving device regarding selection and mixing functions and controls at the receiving device, providing the selection and mixing functions and controls from the receiving device to the control device and providing control information from the control device to the receiving device, including information regarding selected ones of the one or more input data streams, thereby providing selected input data streams, and mixing information, wherein the selected input data streams are selected and mixed based on the control information. The method further comprises receiving the one or more input data streams from one or more source devices at the receiving device, selecting the selected input data streams based on the control information from the control device and mixing the selected input data streams into the output data stream based on the control information from the control device. The method further comprises outputting the output data stream. The input data streams include one or more of audio/video data streams, on-screen-display data streams and graphics data streams. Preferably, the control device is external of the receiving device. The method further comprises receiving control information at the control device and generating the control information based on the control input. The one or more input streams are received over one or more of a network which substantially complies with a version of the IEEE 1394 standard, a connection which substantially complies with a version of universal serial bus standard and a connection which substantially complies with a version of universal plug-and-play standard. The control information is received over one or more of a network which substantially complies with a version of the IEEE 1394 standard, a connection which substantially complies with a version of universal serial bus standard and a connection which substantially complies with a version of universal plug-and-play standard.

In still a further aspect of the present invention, a receiving device for providing an output data stream comprises means for receiving one or more input data streams configured for coupling to one or more source devices, means for receiving control information configured for coupling to a control device, wherein the control information includes information regarding selected ones of the one or more input data streams, thereby providing selected input data streams, and mixing information, means for selecting coupled to the means for receiving one or more input data streams and the means for receiving control information for selecting the selected input data streams based on the control information from the control device and means for mixing coupled to the means for selecting and to the means for receiving control information for mixing the selected input data streams into the output data stream based on the control information from the control device. The means for receiving control information provides selection and mixing functions and controls to the control device in response to a request from the control device. The receiving device further comprises means for outputting coupled to the means for mixing for outputting the output data stream. The input data streams include one or more of audio/video data streams, on-screen-display data streams and graphics data streams. Preferably, the control device is external of the receiving device. Alternatively, the control device is internal of the receiving device. The means for receiving one or more input data streams is coupled to the source devices by one or more of a network which substantially complies with a version of the IEEE 1394 standard, a connection which substantially complies with a version of universal serial bus standard and a connection which substantially complies with a version of universal plug-and-play standard. The means for receiving control information is coupled to the control device by one or more of a network which substantially complies with a version of the IEEE 1394 standard, a connection which substantially complies with a version of universal serial bus standard and a connection which substantially complies with a version of universal plug-and-play standard.

In a further aspect of the present invention, a receiving device to provide an output data stream comprises a first interface to receive one or more input data streams configured to couple to one or more source devices, a second interface to receive control information configured to couple to a control device, wherein the control information includes information regarding selected ones of the one or more input data streams, thereby providing selected input data streams, and mixing information, one or more selectors coupled to the first interface and to the second interface to select the selected input data streams based on the control information from the control device and a mixer coupled to the selectors and the second interface to mix the selected input data streams into the output data stream based on the control information from the control device. The second interface provides functions and controls of the selectors and the mixer to the control device in response to a request from the control device. The receiving device further comprises an output device coupled to the mixer to output the output data stream. The input data streams include one or more of audio/video data streams, on-screen-display data streams and graphics data streams. Preferably, the control device is external to the receiving device. Alternatively, the control device is internal to the receiving device. The first interface is coupled to the source devices by one or more of a network which substantially complies with a version of the IEEE 1394 standard, a connection which substantially complies with a version of universal serial bus standard and a connection which substantially complies with a version of universal plug-and-play standard. The second interface is coupled to the control device by one or more of a network which substantially complies with a version of the IEEE 1394 standard, a connection which substantially complies with a version of universal serial bus standard and a connection which substantially complies with a version of universal plug-and-play standard.

In still a further aspect of the present invention, a control device to provide control information to a receiving device receiving one or more input data streams to control selection and mixing of the input data streams into an output data stream comprises an interface configured to couple to the receiving device to request selection and mixing function and control information from the receiving device and a control circuit coupled to the interface to receive the selection and mixing function and control information and to provide output control information to the receiving device, wherein the output control information includes information regarding selected ones of the one or more input data streams and a selected combination of the selected ones of the one or more input data streams. The input data streams include one or more of audio/video data streams, on-screen-display data streams and graphics data streams. Preferably, the receiving device is external to the control device. Alternatively, the receiving device is internal to the control device. The interface is coupled to the receiving device by one or more of a network which substantially complies with a version of the IEEE 1394 standard, a connection which substantially complies with a version of universal serial bus standard and a connection which substantially complies with a version of universal plug-and-play standard.

In yet another aspect of the present invention a network of devices to provide an output data stream comprises one or more source devices configured to provide one or input data streams, a control device configured to provide control information regarding selection and mixing of the input data streams into the output data stream, the control device including a control interface configured to provide the control information and a control circuit coupled to the control interface to generate the control information and a receiving device comprising a first receiving interface coupled to the source devices to receive the one or more input data streams, a second receiving interface coupled to the control interface to receive the control information, one or more selectors coupled to the first receiving interface and the second receiving interface to select selected input data streams based on the control information and a mixer coupled to the selectors and the second receiving interface to mix the selected input data streams into the output data stream based on the control information from the control device. The second receiving interface provides functions and controls of the selectors and the mixer to the control device in response to a request from the control device. The receiving device further comprises an output device coupled to the mixer to output the output data stream. The input data streams include one or more of audio/video data streams, on-screen-display data streams and graphics data streams. Preferably, the control device is external to the receiving device. Alternatively, the control device and the receiving device are integrated together. The first receiving interface is coupled to the source devices by one or more of a network which substantially complies with a version of the IEEE 1394 standard, a connection which substantially complies with a version of universal serial bus standard and a connection which substantially complies with a version of universal plug-and-play standard. The second receiving interface is coupled to control interface by one or more of a network which substantially complies with a version of the IEEE 1394 standard, a connection which substantially complies with a version of universal serial bus standard and a connection which substantially complies with a version of universal plug-and-play standard.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The method of and apparatus for supporting and enabling the selection and mixing of multiple input data streams from multiple sources within a receiving device allowing external control of the preferred embodiment of the present invention includes a receiving device, a control device and one or more source devices. The receiving device receives input data streams from the source devices. Preferably, the input data streams are streams of audio/video data and on-screen-display/graphics data. Alternatively, the input data streams are streams of any appropriate data type to be selected and mixed into an output stream by the receiving device. The input data streams are provided as inputs to selectors within the receiving device. The selectors output selective ones of the input data streams to a mixer, based on control input received from a control device. The selectors are turned off or on. When a selector is turned off, the selector will not output any input data stream. When a selector is turned on, the selector will output a selected one of the input data streams provided as inputs to the selector. The outputs from the selectors are provided to a mixer. The mixer then combines the selected input data streams into an output stream, based on control input received from the control device. The mixer can select one of the input data streams or can output some combination of the input data streams.

Upon request from the control device, the receiving device exposes the functionality and controls of the selectors and the mixer to the control device, allowing the control device to provide control information to control the selectors and the mixer within the receiving device. As the control device receives control inputs, the control device provides control information to the selectors and the mixer within the receiving device to control the output of the input data streams. The control device receives the control inputs from any appropriate input devices including a remote control, keyboard, mouse or other devices coupled to the control device either by a wired or wireless connection. This allows the control device to control which input data streams are output, how the input data streams are output and how the input data streams are combined for output, if appropriate. Accordingly, for video data streams, the display of multiple input data streams can be selected, displayed together in a tiled format or in separate windows, such as a picture-in-picture format, and on-screen-display/graphics data can be overlaid on video input data streams. For audio data streams, the output of one or more audio source streams can be selected or the audio source streams can be combined together for output.

A functional block diagram of an exemplary network of devices including a first digital VCR80, a second digital VCR100, a computer system120and a digital television50is illustrated inFIG. 3. Relevant functional components of the first digital VCR80, the second digital VCR100and the digital television50are also illustrated inFIG. 3. The digital television50includes an IEEE 1394-2000 interface circuit76through which data and commands are sent to and received from the digital VCR80, the digital VCR100and the computer120, over the IEEE 1394-2000 serial bus cables126,128and130, respectively. The IEEE 1394-2000 interface circuit76includes a physical interface circuit78. At the physical interface circuit78, the IEEE 1394-2000 serial bus cables126,128and130are coupled to the plug A, the plug B and the plug C, respectively.

The IEEE 1394-2000 interface circuit76is coupled to a control circuit74. The control circuit74is coupled to provide audio/video data received from the digital VCRs80and100on the plugs A and B, to a decoder circuit72. The control circuit74is coupled to provide on-screen-display and graphics data to a decompressor circuit66. The control circuit74is also coupled to an on-screen-display selector58, a secondary selector60, a primary selector62and a mixer56to provide control information to the on-screen-display selector58, the secondary selector60, the primary selector62and the mixer56.

The decoder circuit72includes an output A and an output B, which are both coupled to inputs of the primary selector62. The primary selector62includes a third input which is configured for coupling to another connection. The decompressor circuit66is coupled to provide decompressed on-screen-display and graphics data to a buffer64. The buffer64is coupled to an input of the on-screen-display selector58.

The digital television50includes a cable/antenna interface circuit70which is coupled to receive input signals from a coaxial cable or an antenna and to pass those signals through a tuner68to an input of the secondary selector60. The outputs of the on-screen-display selector58, the secondary selector60and the primary selector62are coupled to inputs of the mixer56. An output of the mixer56is coupled to a VRAM circuit54for providing video and on-screen-display and graphics data to the display52.

The digital VCR80includes an IEEE 1394-2000 interface circuit88through which data and commands are sent to and received from the digital television50. The IEEE 1394-2000 interface circuit88includes a physical interface circuit90. The physical interface circuit90is coupled to the digital television50, over the IEEE 1394-2000 serial bus cable126. The digital VCR80includes a video source82, such as a video tape, which is being played by the VCR80, or a television input. The video source82is coupled to the IEEE 1394-2000 interface circuit88for transmitting video streams of data over the IEEE 1394-2000 serial bus cable126to the digital television50. The digital VCR80also includes a graphics source84which generates on-screen-display graphics to be displayed by the television50. The graphics source84is preferably coupled to a compression circuit86which compresses the graphics data generated by the graphics source84. The compression circuit86is coupled to the IEEE 1394-2000 interface circuit88for transmitting the compressed graphics data over the IEEE 1394-2000 serial bus cable126to the digital television50.

The digital VCR100includes an IEEE 1394-2000 interface circuit108through which data and commands are sent to and received from the digital television50. The IEEE 1394-2000 interface circuit108includes a physical interface circuit110. The physical interface circuit110is coupled to the digital television50, over the IEEE 1394-2000 serial bus cable128. The digital VCR100includes a video source102, such as a video tape, which is being played by the digital VCR100, or a television input. The video source102is coupled to the IEEE 1394-2000 interface circuit108for transmitting video streams of data over the IEEE 1394-2000 serial bus cable128to the digital television50. The digital VCR100also includes a graphics source104which generates on-screen-display graphics to be displayed by the digital television50. The graphics source104is preferably coupled to a compression circuit106which compresses the graphics data generated by the graphics source104. The compression circuit106is coupled to the IEEE 1394-2000 interface circuit108for transmitting the compressed graphics data over the IEEE 1394-2000 serial bus cable128to the digital television50.

The computer system120includes an IEEE 1394-2000 interface circuit122through which data and commands are sent to and received from the digital television50. The IEEE 1394-2000 interface circuit122includes a physical interface circuit124. The physical interface circuit124is coupled to the digital television50, over the IEEE 1394-2000 serial bus cable130. The additional details and exemplary components of the computer system120will be described below in detail in reference toFIG. 4.

The configuration illustrated inFIG. 3is exemplary only. It should be apparent that an audio/video network could include many different combinations of components. It should also be recognized that data, commands and parameters can be sent in either direction between the devices within the IEEE 1394-2000 network, as appropriate.

A block diagram of the internal components of the computer system120is illustrated inFIG. 4. The computer system120includes a central processor unit (CPU)156, a main memory150, a video memory158, a mass storage device152and an IEEE 1394-2000 interface circuit122, all coupled together by a conventional bidirectional system bus154. The interface circuit122includes the physical interface circuit124for sending and receiving communications over the IEEE 1394-2000 serial bus. The physical interface circuit124is coupled to the digital television50over the IEEE 1394-2000 serial bus cable130. In the preferred embodiment of the present invention, the interface circuit122is implemented on an IEEE 1394-2000 interface card within the computer system120. However, it should be apparent to those skilled in the art that the interface circuit122can be implemented within the computer system120in any other appropriate manner, including building the interface circuit onto the motherboard itself. The mass storage device152may include both fixed and removable media using any one or more of magnetic, optical or magneto-optical storage technology or any other available mass storage technology. The system bus154contains an address bus for addressing any portion of the memory150and158. The system bus154also includes a data bus for transferring data between and among the CPU156, the main memory150, the video memory158, the mass storage device152and the interface circuit122.

The computer system120is also coupled to a number of peripheral input and output devices including the keyboard166, the mouse168and the associated display164. The keyboard166is coupled to the CPU156for allowing a user to input data and control commands into the computer system120. A conventional mouse168is coupled to the keyboard166for manipulating graphic images on the display164as a cursor control display. It should be apparent to those skilled in the art, that the mouse168could also be coupled to the CPU156.

A port of the video memory158is coupled to a video multiplex and shifter circuit160, which in turn is coupled to a video amplifier162. The video amplifier162drives the display164. The video multiplex and shifter circuitry160and the video amplifier162convert pixel data stored in the video memory158to raster signals suitable for use by the display164.

The digital television50is a receiving device, which receives input streams of data from source devices coupled to the digital television50. In the example illustrated inFIG. 3, the source devices80and100are coupled to the digital television50by the IEEE 1394-2000 cables126and128and the cable input is coupled to the cable/antenna interface70. It should be apparent however that the source devices80and100could be coupled to the digital television50by any appropriate connection means including wired and wireless connections and by any appropriate protocol, including other versions of the IEEE 1394 protocol, universal serial bus, and universal plug-and-play. It should also be apparent that input streams of data could originate from sources within the digital television50.

In the example illustrated inFIG. 3, the computer system120is a control device for controlling the operation of the selectors58,60and62and the mixer56of the present invention, within the digital television50. In the example illustrated inFIG. 3, the control device120is coupled to the digital television50by the IEEE 1394-2000 cable130. It should also be apparent however that the control device120could be coupled to the digital television50by any appropriate connection means including wired and wireless connections and by any appropriate protocol, including other versions of the IEEE 1394 protocol, universal serial bus, and universal plug-and-play. Also, in the example illustrated inFIG. 3, the control device120is an external device implemented by a computer system. It should be apparent to those skilled in the art that the control device can be any appropriate connected device with the capability to discover and control the selectors58,60and62and the mixer56, including an external control device, an internal control device, a source device and a remote control device.

The input data streams from the sources coupled to the digital television50are provided as inputs to the digital television50. The cable input is provided through the cable/antenna interface70to the tuner68. After being tuned by the tuner68, the cable input is then provided as an input to the secondary selector60. The input data streams from the source devices coupled to the digital television through the IEEE 1394-2000 serial bus network are provided through the IEEE 1394 interface circuit76to the control circuit74. The control circuit74is coupled to provide the on-screen-display/graphics input data streams to the decompressor66. The decompressor66decompresses the on-screen-display/graphics input data streams and provides the data to the buffer64. From the buffer64, the decompressed on-screen-display/graphics input data is provided as an input to the OSD selector58. As will be discussed in detail below, the OSD selector58selects input data to be output based on a URL address. The control circuit74is coupled to provide encoded audio/video data from the IEEE 1394-2000 source devices to the decoder72. The decoder72then decodes the encoded audio/video data and provides the decoded data from the outputs A and B as inputs to the primary selector62. The outputs A and B from the decoder72correspond to the input plugs A and B of the IEEE 1394-2000 physical interface circuit78. The primary selector62has a third input for other connections.

The control input stream from the computer system120is provided through the IEEE 1394-2000 interface circuit76to the control circuit74. The control circuit74is coupled to provide control signals to the selectors58,60and62and to the mixer56to control the operation of the selectors58,60and62and the mixer56. Under the control of the control device120, the control circuit74controls the operation of the selectors58,60and62to10select one or none of the inputs coupled to each of the selectors58,60and62. In the example ofFIG. 3, the OSD selector58can be controlled to output the input on-screen-display/graphics input data stream or to provide no output, the secondary selector60can be controlled to output the cable input data stream or to provide no output, and the primary selector62can be controlled to output the input data streams corresponding to the IEEE 1394-2000 input plugs A and B, the other connections or to provide no output. When not turned off, the selectors58,60and62preferably will only output one of the input data streams at a time.

The outputs from the selectors58,60and62are provided as inputs to the mixer circuit56. Under the control of the control device120, the control circuit74controls the operation of the mixer56to provide a mix of the input data streams from the selectors58,60and62. The output of the mixer56is then provided to the VRAM54to be displayed on the display52. Under the control of the control device120, the control74controls the operation of the mixer56to combine the input data streams from the selectors58,60and62into a combined output data stream to be displayed on the display52. In this manner, the input data streams from the source devices coupled to the digital television50are selected, mixed and displayed, thereby providing opportunities for overlaying input data streams or displaying multiple input data streams at the same time in a tiled or picture-in-picture arrangement. Preferably, the output data stream from the mixer56is displayed on the display52within the receiving device50. It should be understood by those skilled in the art, that alternatively, the output data stream from the mixer56can be stored for later display or transmitted from the receiving device50to another device for display or output at that device.

Utilizing the selectors and mixer of the present invention, the control device120controls the operation and display of the digital television50to select input data streams at each of the selectors58,60and62and to then mix the selected input data streams at the mixer56for display on the display62. In the example ofFIG. 3, the selectors58,60and62and the mixer56are shown as separate blocks within the digital television50. It should be understood that the functions of the selectors58,60and62and the mixer56are preferably implemented within software within the digital television50. Alternatively, the selectors58,60and62and the mixer56are preferably implemented within firmware, hardware or some combination of software, firmware and hardware.

To provide control inputs to control the operation of the selectors58,60and62and the mixer62, the control device120first must discover each of the selectors58,60and62and their respective inputs and the mixer56. To discover the selectors58,60and62, the mixer56and their respective inputs, the control device120communicates with the digital television50over the IEEE 1394-2000 serial bus network to request this information from the digital television50. In response to this request for information from the control device120, the digital television50then exposes the functionality of the selectors58,60and62and the mixer56to the control device120.

The functionality and control of the selectors58,60and62is preferably exposed to the control device120, through an XML document that describes the selectors58,60and62and their inputs to the control device120. An example of such an XML document corresponding to the selectors58,60and62of the example illustrated inFIG. 3is included below in Table I:

In the example ofFIG. 3and of Table I, the primary selector62outputs the input data stream corresponding to the IEEE 1394-2000 input plug A, the input data stream corresponding to the IEEE 1394-2000 input plug B, the input data stream corresponding to the other connections or is turned off and does not output ally data stream. The secondary selector60outputs the input data stream corresponding to the cable/antenna interface70or is turned off and does not output any data stream. The OSD selector58outputs the input data stream corresponding to the specified URL or is turned off and does not output ally data stream.

The mixer56is utilized to combine the inputs that have been selected by the selectors58,60and62. The functionality and control of the mixer56is preferably exposed to the control device120, through an XML document that describes the mixer56and its inputs to the control device120. An example of such an XML document corresponding to the mixer56of the example illustrated inFIG. 3is included below in Table II:

TABLE IIVideo Mixer:<process><name>Mixer</name><dataType>string</dataType><defaultValue>default</defaultValue><currentValue>current</currentValue><allowedValueList><allowedValue>Off</allowedValue><allowedValue>Primary on top</allowedValue><control><name>windowControl</name><dataType>string</dataType><defaultValue>default</defaultValue><currentValue>current</currentValue><allowedValueList><allowedValue>maximum</allowedValue><allowedValue>minimum</allowedValue><allowedValue>size</allowedValue><allowedValue>restore</allowedValue></allowedValueList></control><allowedValue>Secondary on top</allowedValue><control><name>windowControl</name><dataType>string</dataType><defaultValue>default</defaultValue><currentValue>current</currentValue><allowed ValueList><allowedValue>maximum</allowedValue><allowedValue>minimum</allowedValue><allowedValue>size</allowedValue><allowedValue>restore</allowedValue></allowedValueList></control><allowedValue>OSD selector on top</allowedValue><control><name>windowControl</name><dataType>string</dataType><defaultValue>default</defaultValue><currentValue>current</currentValue><allowedValueList><allowedValue>maximum</allowedValue><allowedValue>minimum</allowedValue><allowedValue>size</allowedValue><allowedValue>restore</allowedValue></allowedValueList></control></allowedValueList></process>
The mixer56combines the input data streams from the primary selector62, the secondary selector60and the OSD selector58into an output data stream to be displayed on the display52. Based on the values input to the mixer56from the control device120, the mixer is either turned off or turned on. Preferably, when the mixer56is turned off, only the input data stream from the primary selector62is output from the mixer56. When the mixer56is not turned off, the mixer56combines the input data streams provided from the selectors58,60and62, according to the values received from the control device120. The mixer56can combine the input data streams in any appropriate manner, under the control of the control device120. As apparent from the XML document of Table II, the mixer56can combine the input data streams from the selectors58,60and62in many different combinations, including with the input from the primary selector62on top, with the input from the secondary selector60on top and with the input from the OSD selector58on top. Also, in these combinations, the size and placement of the input data streams from the selectors58.60and62within the display can also be controlled.

There is also preferably coordination between the OSD selector58and the mixer56, such that when the OSD selector58is turned off, the mixer56will not attempt to perform an overlay function.

A flowchart showing the preferred steps followed by the control device120when controlling the functions of the selectors58,60and62and the mixer56within the receiving device50is illustrated inFIG. 5. The process begins at the step200. At the step202, the control device sends a request to the receiving device50to request the functions and data from the receiving device50, regarding the selectors and the mixer implemented within the receiving device50, as well as the inputs to the selectors and the mixer. At the step204, the control device120receives the requested functions and data from the receiving device50, thereby exposing the interface and functions of the selectors58,60and62and the mixer56to the control device120.

At the step206, it is determined if the control device120has received control input from a user or from a device coupled to the control device120, regarding the display of the input data streams by the receiving device50. This control input can be input to the control device120by any appropriate means, including through a keyboard, mouse, a remote control or other appropriate device. Once control input regarding the display of the input data streams by the receiving device50has been received by the control device120, the control device120then generates control instructions and values based on this control input, at the step208. At the step210, the control device120then transmits these control instructions and values to the receiving device50. The process then returns to the step206to wait until further control inputs are received by the control device.

A flowchart showing the preferred steps followed by the receiving device50to provide an output data stream based on control instructions received from the control device120, is illustrated inFIG. 6. The process begins at the step250. At the step252, it is determined if a request for functions and data has been received from the control device120. Once it is determined at the step252that a request for functions and data has been received from the control device120, then the functions of the selectors58,60and62and the mixer56are exposed to the control device120at the step254.

At the step256, it is determined if control instructions regarding the selection of and mixing of the input data streams has been received from the control device120. Once it is determined that control instructions have been received from the control device120regarding the selection of and mixing of the input data streams at the step256, then the receiving device50provides the control instructions to the selectors58,60and62and the mixer56to appropriately control the selection and mixing of the input data streams based on the control instructions. The output data stream from the mixer56is then displayed by the receiving device50on the display52. The process then returns to the step256to wait until further control instructions are received from the control device120.

As an example of the operation of the present invention within the audio/video network illustrated inFIG. 3, the digital television50selects and mixes input data streams from the source devices80and100, from the cable/antenna interface70and on-screen-display/graphics data received from the address specified by a URL. Regarding the example illustrated inFIG. 3, the computer system120first requests the functions and data for the selectors58,60and62and the mixer56from the digital television50. The digital television50then exposes the functions and data representing the selectors58,60and62, the mixer56and their respective inputs to the computer system120, preferably through the XML documents of Table I and Table II, as described above. Alternatively, the functions and data representing the selectors, the mixer and their respective inputs are exposed to the computer system120in any appropriate manner.

Once the computer system120has been exposed to the functions and data representing the selectors58,60and62and the mixer56, the computer system120can then provide control information to the digital television50to control the output of the input data streams. As an example, the computer system120provides control information to the digital television50to initially select the input data stream from the digital VCR80through the primary selector62, to turn the secondary selector60off and to turn the OSD selector58off. The mixer56is then only provided the input data stream from the primary selector62to output and display on the display52. If the computer system120then receives a control input to display on-screen-display/graphics information, such as the current time, the computer system120generates the appropriate control information and provides this control information to the digital television50to turn on the OSD selector58and select a URL address corresponding to the current time. This input data stream is then output from the OSD selector58and provided to the mixer56. The mixer56will then combine the input data stream from the primary selector62and from the OSD selector58to display the current time with the input data stream from the digital VCR80on the display52.

The method of and apparatus for supporting and enabling the selection and mixing of multiple input data streams from multiple sources within a receiving device allowing external control of the preferred embodiment of the present invention includes a receiving device, a control device and one or more source devices. The receiving device receives input data streams from the source devices. Preferably, the input data streams are streams of audio/video data and on-screen-display/graphics data. Alternatively, the input data streams are streams of any appropriate data type to be selected and mixed into an output stream by the receiving device. The input data streams are provided as inputs to selectors within the receiving device. The selectors output selective ones of the input data streams to a mixer, based on control input received from a control device. The mixer then combines the selected input data streams into an output stream, based on control input received from the control device.

Upon request from the control device, the receiving device exposes the functionality and controls of the selectors and the mixer to the control device, allowing the control device to provide control information to control the selectors and the mixer within the receiving device. As the control device receives control inputs, the control device provides control information to thee selectors and the mixer within the receiving device to control the output of the input data streams. This allows the control device to control which input data streams are output, how the input data streams are output and how the input data streams are combined for output. Accordingly, for video data streams, the display of multiple input data streams can be selected, displayed together in a tiled format or in separate windows, such as a picture-in-picture format, and on-screen-display/graphics data can be overlaid on video input data streams. For audio data streams, the output of one or more audio source streams can be selected or the audio source streams can be combined together for output.

The combination of the selector and mixer functions of the present invention, allow a control device to discover and control these functions within a receiving device using any appropriate protocol, not just the IEEE 1394-2000 serial bus protocol. Using the present invention, the interfaces and functions of the selectors and the mixer are exposed to external control devices or control points for external control of those functions within a receiving device.

The present invention has been described in terms of specific embodiments incorporating details to facilitate the understanding of principles of construction and operation of the invention. Such reference herein to specific embodiments and details thereof is not intended to limit the scope of the claims appended hereto. It will be apparent to those skilled in the art that modifications may be made in the embodiment chosen for illustration without departing from the spirit and scope of the invention. Specifically, it will be apparent to those skilled in the art that while the illustrated embodiment utilizes an IEEE 1394-2000 serial bus structure, the present invention could also be implemented on any other appropriate digital interfaces or bus structures, or with any other appropriate protocols, including other or later versions of the IEEE 1394 serial bus, other local area network protocols or device connection protocols, including current or later versions of the USB protocol and universal plug-and-play protocol. It will also be apparent to those skilled in the art that while the illustrated embodiment utilizes video input data streams, the present invention could also be implemented with any appropriate input data streams, including audio data streams.