METHOD AND SYSTEM FOR DISPLAYING PIXELS ON DISPLAY DEVICES

• US 20150340009A1
• Filed: 06/24/2013
• Published: 11/26/2015
• Est. Priority Date: 06/22/2012
• Status: Abandoned Application

• Current Assignee: Universität des Saarlandes
• Original Assignee: Universität des Saarlandes
• Inventors: LOEFFLER, Alexander, LUCIANO, Pica, MIROLL, Jochen, HERFET, Thorsten, SLUSALLEK, Philipp
• Application Number:
  US14/409,751
• Publication Number:
  US 20150340009A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 3/1438 using more than one graphics controller
• CPC Class Codes: G06F 3/1446 display composed of modules, e.g. video walls
• CPC Class Codes: G09G 2300/026 Video wall, i.e. juxtaposition of a plurality of screens to create a display screen of bigger dimensions
• CPC Class Codes: G09G 2352/00 Parallel handling of streams of display data
• CPC Class Codes: G09G 2360/04 Display device controller operating with a plurality of display units
• CPC Class Codes: G09G 2370/025 LAN communication management
• CPC Class Codes: G09G 2370/10 Use of a protocol of communication by packets in interfaces along the display data pipeline
• CPC Class Codes: G09G 2370/22 Detection of presence or absence of input display information or of connection or disconnection of a corresponding information source
• CPC Class Codes: G09G 5/008 Clock recovery
• CPC Class Codes: G09G 5/04 using circuits for interfacing with colour displays
• CPC Class Codes: G09G 5/12 Synchronisation between the display unit and other units, e.g. other display units, video-disc players

Abstract

A method for displaying pixels on display devices, comprising: generating one or more pixels by one or more pixel sources; Providing one or more display devices for displaying pixels; transmitting the one or more generated pixels to one or more display devices for displaying the pixels via a network based on a network transmission protocol; and displaying the pixels on the display devices, wherein a plurality of the display devices are synchronized with each other for displaying the pixels and that preferably based on the synchronized display devices a plurality of the pixel sources are synchronized with the plurality of synchronized display devices via the network for synchronous displaying the pixels on the plurality of the display devices. The present invention further relates to a system for displaying pixels on display devices.

Claims

1. A method for displaying pixels on display devices, comprising the steps of:

a) generating one or more pixels by one or more pixel sources,

b) providing one or more display devices for displaying pixels,

c) transmitting the one or more generated pixels to one or more display devices for displaying the pixels via a network based on a network transmission protocol, and

d) displaying the pixels on the display devices.

characterized in that

a plurality of the display devices are synchronized with each other for displaying the pixels and that, preferably based on the synchronized display devices a plurality of the pixel sources are synchronized with the plurality of synchronized display devices via the network for synchronous displaying the pixels on the plurality of the display devices.

2. The method according to claim 1, characterized in that display device information representing at least one characteristic parameter of one or more of the display devices is announced via the network.

3. The method according to claim 1, characterized in that the plurality of display devices are synchronized with respect to their refresh rates and/or their phases.

4. The method according to claim 1, characterized in that a sync reference device (CMD) is selected, preferably out of the display devices for providing synchronization information.

5. The method according to claim 1, characterized in that a clock signal is determined by a clock master device (CMD) and the clock signal is included into the synchronization information.

6. The method according to claim 5, characterized in that an internal clock signal of the clock master device (CMD) is determined, preferably based on observing interrupts, and used as the clock signal.

7. The method according to claim 1 characterized in that vertical display refresh interrupts are observed, preferably via an OpenGL swap buffer event and/or by a SGI video sync extension API.

8. The method according to claim 1, characterized in that synchronization information, preferably including the internal clock signal, is announced in display clock reference messages via multicast and/or broadcast in the network.

9. The method according to claim 1, characterized in that synchronization information is announced to the network with a frequency smaller or equal than the frequency of updates, preferably via periodic Internet Protocol packets.

10. The method according to claim 9, characterized in that virtual timestamps, preferably an increasing tick counter, are included in the synchronization information, preferably in the display clock reference messages.

11. The method according to claim 9, characterized in that the displaying rates of the display devices other than the sync reference device (CMD) are adapted according to the announced synchronization information for synchronization.

12. The method according to claim 9, characterized in that the displaying rates of the display devices other than the sync reference device (CMD), preferably of all display devices, are determined by a phase-locked-loop (PLL) procedure.

13. The method according to claim 12, characterized in that a round-trip time of the announced synchronization information is estimated, preferably by using network-based protocols, in particular by using ICMP echo messages.

14. The method according to claim 1, characterized in that for synchronizing display devices with the sync reference device (CMD) a frequency synthesizer used to generate a video clock signal, preferably a DVI and/or HDMI clock signal, is parameterized and modified.

15. The method according to claim 1, characterized in that for synchronizing a display device with a sync reference device (CMD) a voltage of a voltage controlled crystal oscillator (VXCO) is adapted.

16. The method according to claim 4, characterized in that the internal displaying rates of all display devices are determined and based on the determined displaying rates the sync reference device (CMD) is selected out of all display devices based on the minimal difference between a middle frequency of the internal displaying rates and the corresponding displaying rates.

17. The method according to claim 16, characterized in that a distributed coordination mechanism for selecting the sync reference device (CMD) out of the display devices is used.

18. The method according to claim 17, characterized in that based on the transmitted synchronization information each of the pixel sources estimates the internal displaying rates of the display devices relative to its own pixel source system clock.

19. The method according to claim 1, characterized in that in case of a stream of frames generated by the pixel sources, the pixel sources estimate the time when to send a corresponding frame to the display devices for a synchronized stream displayed on the display devices, preferably wherein estimating includes a determination of a deadline for each of the frames based on frame propagation time and/or inter-process communication latency.

20. The method according to claim 1, characterized in that the transmission of the generated pixels is encoded.

21. The method according to claim 1, characterized in that each display device is assigned its own unique identifier in the network, preferably in form of an IP-address.

22. The method according to claim 1, characterized in that the internal clock signal is transmitted within the network via the NTP and/or PTP protocol and/or MPEG program clock reference time stamps.

23. The method according to claim 1, characterized in that before displaying the pixels the visualization of these pixels is adapted based on quality level data (QL) for visualizing one or more pixels.

24. A system for displaying pixels on display devices, preferably for performing with a method according to claim 1, comprising:

one or more pixel sources for generating pixels to be displayed; and

one or more display devices for displaying the pixels, wherein the one or more pixel sources are connected to the one or more displays for transmitting the generated pixels to the one or more display devices for displaying the pixels via a network based on a network transmission protocol,

characterized in that

a plurality of the display devices are operable to be synchronized with each other for displaying the pixels and that, preferably based on synchronized display devices, a plurality of the pixel sources are operable to be synchronized with the plurality of synchronized display devices via the network for synchronous displaying the pixels an the plurality of the display devices.