Method of and apparatus for handling high bandwidth on-screen-display graphics data over a distributed IEEE 1394 network utilizing an isochronous data transmission format
First Claim
1. A method of transmitting on-screen-display graphics data from a source device to a display device separate from a video stream of data comprising:
- a. generating on-screen-display graphics to be displayed on the display device;
b. combining the on-screen-display graphics into a stream of data packets, each including an address value corresponding to a memory location within the display device; and
c. transmitting the data packets from the source device to the display device separate from the video stream of data.
1 Assignment
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Accused Products
Abstract
On-screen-display graphics data is transmitted from a source device to a display device over an IEEE 1394-1995 serial bus network utilizing an isochronous data format. The on-screen-display graphics data is generated by the source device and transmitted to a display device, as a stream of isochronous data, separate from video data. Each packet of isochronous data within the stream of on-screen-display graphics data includes an address value corresponding to a memory address within the display device forming a buffer. When received by the display device the on-screen-display graphics data is loaded into the appropriate memory locations within the buffer corresponding to the address values. At the display device, an embedded stream processor is utilized to strip the header information from each packet and determine the appropriate memory location that the data is to be stored. A trigger packet is sent at the end of the data stream for a screen of on-screen-display graphics. The trigger packet includes a presentation time value corresponding to a display time for the screen of on-screen-display graphics. When the trigger packet is received, the display device transfers the data stored in the buffer to a VRAM circuit for display at the specified presentation time. The on-screen-display graphics data can be overlaid on video data for display and also displayed separately. Differential encoding is used when transferring frames of data wherein only a portion of data changes from the previous frame.
107 Citations
50 Claims
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1. A method of transmitting on-screen-display graphics data from a source device to a display device separate from a video stream of data comprising:
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a. generating on-screen-display graphics to be displayed on the display device;
b. combining the on-screen-display graphics into a stream of data packets, each including an address value corresponding to a memory location within the display device; and
c. transmitting the data packets from the source device to the display device separate from the video stream of data. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method of transmitting on-screen-display graphics data from a source device to a display device comprising:
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a. generating on-screen-display graphics to be displayed on the display device;
b. combining the on-screen-display graphics into a stream of isochronous data packets, each including an address value corresponding to a memory location within the display device;
c. transmitting the isochronous data packets from the source device to the display device over an isochronous channel; and
d. transmitting a trigger packet on the occurrence of a trigger event, the trigger packet including a trigger address value corresponding to a trigger memory location within the display device. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
a. receiving the isochronous data packets at the display device; and
b. storing data included within each of the isochronous data packets at the memory location specified by the address value included within the isochronous data packet.
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9. The method as claimed in claim 8 further comprising:
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a. compressing the on-screen-display graphics before the isochronous data packets are formed; and
b. decompressing the data at the display device before the storing is completed.
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10. The method as claimed in claim 7 wherein the trigger packet further includes a presentation time value specifying a display time for the on-screen-display graphics.
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11. The method as claimed in claim 10 wherein the trigger event occurs when all isochronous data packets for a screen of the on-screen-display graphics have been transmitted.
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12. The method as claimed in claim 11 further comprising:
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a. receiving the isochronous data packets at the display device;
b. storing data included within each of the isochronous data packets at the memory location specified by the address value included within the isochronous data packet;
c. receiving the trigger packet at the display device;
d. storing the trigger packet at the trigger memory location; and
e. displaying the screen of on-screen-display graphics at the display time.
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13. The method as claimed in claim 12 wherein the memory locations and the trigger memory location within the display device are included within an on-screen-display graphics buffer.
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14. The method as claimed in claim 13 wherein the memory locations are included within an on-screen-display graphics buffer and the trigger memory location is included within a trigger buffer.
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15. The method as claimed in claim 13 wherein the trigger packet includes a trigger bit, which when written into the trigger memory location, signals that storage of a current frame of on-screen-display graphics data is complete.
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16. The method as claimed in claim 15 wherein the trigger packet also includes an overlay bit specifying whether or not the on-screen-display graphics are to be combined with video data.
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17. The method as claimed in claim 13 wherein the isochronous data packets and the trigger packet are transmitted from the source device to the display device over a high speed serial interface.
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18. The method as claimed in claim 17 wherein the high speed serial interface is an IEEE 1394 serial bus network.
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19. The method as claimed in claim 11 further comprising:
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a. generating a subsequent screen of on-screen-display graphics to be displayed on the display device;
b. determining changed pixels within the subsequent screen as compared to a previous screen of on-screen-display graphics;
c. combining the on-screen-display data representing only the changed pixels into a differential stream of isochronous data packets, each differential isochronous packet including an address value corresponding to the memory location related to represented changed pixels; and
d. transmitting the isochronous data packets from the source device to the display device over the isochronous channel.
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20. A method of receiving on-screen-display graphics data, generated by a source device and transmitted in isochronous data packets over an isochronous channel to a display device, each isochronous data packet including an address value corresponding to a memory location within the display device, comprising:
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a. receiving an isochronous data packet including on-screen-display graphics data and the address value;
b. storing the on-screen-display graphics data included within the isochronous data packet at the memory location within the display device;
c. receiving a trigger packet including a trigger address value, corresponding to a trigger memory location within the display device, and presentation time value specifying a display time for the on-screen-display graphics; and
d. displaying the on-screen-display graphics at the display time. - View Dependent Claims (21, 22, 23, 24, 25, 26)
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27. An apparatus for transmitting on-screen-display graphics data from a source device to a display device comprising:
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a. a graphics source for generating on-screen-display graphics to be displayed by the display device;
b. an interface circuit coupled to the graphics source and configured for coupling to the display device for combining the on-screen-display graphics into a stream of isochronous data packets each including an address value corresponding to a memory location within the display device and transmitting the isochronous data packets from the source device to the display device over an isochronous channel;
wherein the graphics source also generates a trigger packet which is transmitted by the interface circuit on the occurrence of a trigger event, the trigger packet including a trigger address value corresponding to a trigger memory location within the display device. - View Dependent Claims (28, 29, 30, 31, 32, 33, 34)
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35. An apparatus for receiving on-screen-display graphics data generated by a source device and transmitted in isochronous data packets over an isochronous channel, each isochronous data packet including an address value corresponding to a memory location, comprising:
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a. an interface circuit configured for coupling to the source device for receiving the isochronous data packets from the source device over the isochronous channel;
b. a processing device coupled to the interface circuit for receiving the isochronous data packets and separating the address value from the on-screen-display graphics data;
c. a memory device coupled to the processing device to store the on-screen-display graphics data in a memory location corresponding to the address value; and
d. a display device coupled to the memory device for displaying the on-screen-display graphics at a display time, wherein the display time is received in a trigger packet. - View Dependent Claims (36, 37, 38, 39, 40)
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41. A system for transmitting on-screen-display graphics data comprising:
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a. a source device including;
i. a graphics source for generating on-screen-display graphics to be displayed by a display device; and
ii. a source interface circuit coupled to the graphics source and configured for coupling to the display device for combining the on-screen-display graphics into a stream of isochronous data packets each including an address value corresponding to a memory location within the display device and transmitting the isochronous data packets from the source device to the display device over an isochronous channel; and
b. a display device including;
i. a display interface circuit coupled to the source interface circuit for receiving the isochronous data packets from the source device over the isochronous channel;
ii. a processing device coupled to the display interface circuit for receiving the isochronous data packets and separating the address value from the on-screen-display graphics data;
iii. a memory device coupled to the processing device to store the on-screen-display graphics data in a memory location corresponding to the address value; and
iv. a display device coupled to the memory device for displaying the on-screen-display graphics at a display time;
wherein the graphics source also generates a trigger packet which is transmitted by the interface circuit on the occurrence of a trigger event, the trigger packet including a trigger address value corresponding to a trigger memory location within the display device. - View Dependent Claims (42, 43, 44, 45, 46, 47, 48, 49, 50)
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Specification