Patent Application
20050120374
The present invention relates generally to video signals. More specifically, the present invention relates to methods and apparatus for passing an on-screen display (OSD) from a source device, such as a television terminal, to a sink device, such as a high definition television (HDTV), over a serial interface, such as an IEEE-1394 interface.
Prior art IEEE-1394 networks require that an on-screen display be transmitted from a source device to a sink device as bit map data using asynchronous methods, such as those defined in Electronic Industries Association standards EIA-775 and EIA-799. These methods are very CPU intensive and are not widely supported. Therefore, there is no reliable prior art mechanism for passing an on-screen display (e.g., an electronic programming guide (EPG), video on demand capabilities, diagnostic capabilities) from a source device (e.g., a cable/satellite/off-air television receiver terminal) to a sink device (e.g., a high definition television (HDTV)) over an IEEE-1394 connection.
The present invention overcomes the disadvantages of the prior art by enabling the on-screen display to be passed over an IEEE-1394 interface as an isochronous MPEG data stream.
The methods and apparatus of the present invention provide the foregoing and other advantages.
The present invention provides methods and apparatus for passing an on-screen display from a source device, such as a cable/satellite/off-air television receiver terminal, to a sink device, such as a high definition television (HDTV), over a serial interface, such as an IEEE-1394 interface.
In an example embodiment of the invention, a source device capable of passing an on-screen display over a serial interface is provided. The source device includes a tuner adapted for receiving an active isochronous MPEG data stream and graphic data for an OSD. A serial interface at the source device enables communication with a sink device. A processor at the source device is adapted for detecting an action requiring an on-screen display at the sink device. The source device also includes an MPEG encoder adapted for encoding the graphic data as an isochronous MPEG data stream carrying the OSD (also referred to herein as “OSD data stream”). The isochronous MPEG data stream carrying the OSD may then be passed to the sink device via the serial interface.
Corresponding methods and apparatus are provided in accordance with the present invention.
The present invention will hereinafter be described in conjunction with the appended drawing figures, wherein like reference numerals denote like elements, and:
The ensuing detailed description provides exemplary embodiments only, and is not intended to limit the scope, applicability, or configuration of the invention. Rather, the ensuing detailed description of the exemplary embodiments will provide those skilled in the art with an enabling description for implementing an embodiment of the invention. It should be understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the invention as set forth in the appended claims.
Although the invention is described in connection with an IEEE-1394 interface, those skilled in the art will appreciate that the present invention is compatible with any type of serial interface now known in the art or that will be developed in the future.
The present invention provides methods and apparatus by which the source device passes the on-screen display (OSD) through an MPEG encoder to produce an isochronous MPEG data stream, which can be passed over an IEEE-1394 connection to the sink device. The source device includes means to determine when a user has activated the OSD (e.g., an EPG) and to “switch” the current active isochronous stream, which provides a video service (e.g., a tuned television channel, digitally recorded content, and the like) to the isochronous stream containing the OSD. The source device also contains means to determine when the user has deactivated the OSD and switched back to the isochronous stream providing the video service.
With the present invention, any sink device that is capable of processing an isochronous MPEG data stream has the capability to provide the user with an OSD over an IEEE-1394 interface.
The isochronous MPEG data stream carrying the OSD 31 may be received at the sink device 500 from serial interface 100. Once received, the isochronous MPEG data stream carrying the OSD 31 may then be decoded at the sink device 500 to provide the on-screen display as if it were a regular MPEG video stream. This enables a near real-time OSD, where cursor moves, screen highlights and the like are visible to the user as if the OSD were being displayed via analog outputs.
The serial interface 100 may comprise an IEEE-1394 interface, or any other type of serial interface.
In the example embodiment of the invention shown in
Alternatively, the program map table of the multiplexed transport stream 112 may be modified to identify the isochronous data stream carrying the on-screen display 110 as a secondary video source, wherein a video component of the active isochronous MPEG data stream 108 comprises a primary video source. For example, the program map table may be modified to contain a descriptor or unique stream identifier which identifies the OSD data stream 110. In this example embodiment, the sink device 500 may alpha blend the primary and secondary video sources (i.e., the video component of the active data stream 108 and the OSD data stream 110). In addition, providing the OSD data stream as a secondary video source enables the sink device 500 to display the OSD over a portion of the active video. For example, as shown in
A further example embodiment of the invention is shown in
Another example embodiment of the invention is shown in
The source device 10 may comprise a television terminal or similar device. The sink device 500 may comprise a high definition television.
In general, the OSD may comprise almost any type of non-video graphic that is displayed on a screen of a high definition television on top of and/or in place of the video. For example, the on-screen display may comprise an electronic programming guide (EPG), a diagnostic menu, a video on demand menu, an advertisement, a pop-up graphic, an alert, a notice (e.g., an email notification or incoming telephone call notification), a web page, a stock ticker, a sports ticker, information menus, barkers associated with the electronic program guide, or the like.
The action requiring the OSD may comprise a user driven action or a software driven action. A user driven action may be a remote control input received via user interface 55, for example a request for an EPG or the like. A software driven action may be an alert, a notification, or an unsolicited pop-up advertisement. An alert may advise a viewer of a connection problem, a hardware failure, or the like. A notification may advise a viewer of an incoming email, an incoming telephone call, or the like.
The processor 41 may also detect an action at the sink device 500 deactivating the on-screen display. In response, the source device 10 may disable the passing of the isochronous MPEG data stream carrying the OSD to the sink device 500 and provide in its place the active isochronous MPEG data stream 108. For example, once a user turns off the EPG, the source device will resume sending active video containing television programming in place of the OSD data stream 110.
It should now be appreciated that the present invention provides advantageous methods and apparatus for passing an on-screen display from a source device, such as a television terminal, to a sink device, such as a high definition television (HDTV), over a serial interface, such as an IEEE-1394 interface.
Although the invention has been described in connection with various illustrated embodiments, numerous modifications and adaptations may be made thereto without departing from the spirit and scope of the invention as set forth in the claims.
