Method computer program and driver unit for streaming gaze data packets

Patent metadata

Field	Value
Publication number	US-11716365-B2
Application number	US-202017007397-A
Country	US
Kind code	B2
Filing date	Aug 31, 2020
Priority date	Dec 12, 2018
Publication date	Aug 1, 2023
Grant date	Aug 1, 2023

Abstract

Data packets containing gaze data are streamed from an eyetracker to a client via a driver unit by receiving, repeatedly, gaze data packets in a first interface; and, providing, repeatedly, via a second interface, gaze data packets. The client sends a request message to the driver unit. The request message defines a delivery point in time in a first time frame structure at which delivery point in time in each frame of the first time frame structure the gaze data packet shall be provided to the client via the second interface. An offset is calculated between a reception point in time and the delivery point in time. The reception point in time indicates when a gaze data packet is received from the eyetracker relative to the first time structure. An adjusted data acquisition instance is assigned based on the offset. The adjusted data acquisition instance represents a modified point in time in a second time frame structure when at least one future gaze data packet shall be produced by the eyetracker. The driver unit sends a control message to the eyetracker. The control message is adapted to cause the eyetracker to produce the at least one future gaze data packet at such an adjusted acquisition instance in the second time structure that the reception point in time for the at least one future gaze data packet is expected to lie within a margin prior to the delivery point in time.

First claim

The invention claimed is:

1. A method performed in a driver unit for streaming gaze data packets containing gaze data from an eyetracker to a client, the method comprising:
receiving, repeatedly, in a first interface, gaze data packets from the eyetracker, and
providing, repeatedly, via a second interface, the gaze data packets to the client, wherein providing the gaze data packets to the client comprises:
receiving a request message from the client, which request message defines a delivery point in time at which a respective one of the gaze data packets shall be provided, in each frame of a first time frame structure, to the client via the second interface;
calculating an offset, in the first time frame structure, between (i) a reception point in time indicating when a gaze data packet is received from the eyetracker relative to the first time frame structure and (ii) the delivery point in time at which the gaze data packet shall be provided to the client;
assigning an adjusted data acquisition instance based on the offset, the adjusted data acquisition instance representing a modified point in time in a second time frame structure when at least one future gaze data packet shall be produced by the eyetracker; and
sending a control message to the eyetracker, which control message is adapted to cause the eyetracker to produce the at least one future gaze data packet at the adjusted acquisition instance in the second time frame structure, such that the reception point in time for the at least one future gaze data packet is expected to lie within a margin prior to the delivery point in time; and
synchronizing the second time frame structure to the first time frame structure such that the first time frame structure and the second time frame structure share a common time base reference,
wherein the adjusted acquisition instance in the second time frame structure when the at least one future gaze packet shall be produced by the eyetracker is such that an expected reception point in time indicating when the at least one future gaze data packet is received from the eyetracker is at least a safety time prior to the delivery point in time.

2. The method of claim 1 , wherein the synchronizing of the second time frame structure to the first time frame structure comprises adjusting an interval between consecutive data acquisition instances to match a period of the first time frame structure.

3. The method of claim 1 , wherein the first time frame structure is synchronized to a first time base reference different from a second time base reference to which the second time frame structure is synchronized, and the method further comprises:
calculating, repeatedly, an updated offset between the reception point in time and the delivery point in time; and
if the updated offset does not lie within the margin prior to the delivery point in time, sending an updated control message to the eyetracker,
wherein the updated control message is adapted to cause the eyetracker to produce the at least one future gaze data packet at the adjusted acquisition instance in the second time frame structure, such that the reception point in time for the at least one future gaze data packet is expected to lie within the margin prior to the delivery point in time.

4. The method of claim 1 , wherein assigning the adjusted data acquisition instance is further based on a latency in the eyetracker and a transmission delay between the eyetracker and the driver unit.

5. A non-transitory computer-readable storage medium comprising computer-executable instructions which when executed by a processor cause the processor to perform operations comprising:
receiving, repeatedly, in a first interface, gaze data packets from an eyetracker, and
providing, repeatedly, via a second interface, the gaze data packets to a client, wherein providing the gaze data packets to the client comprises:
receiving a request message from the client, which request message defines a delivery point in time at which a respective one of the gaze data packets shall be provided, in each frame of a first time frame structure, to the client via the second interface;
calculating an offset, in the first time frame structure, between aa reception point in time indicating when a gaze data packet is received from the eyetracker relative to the first time frame structure and (ii) the delivery point in time at which the gaze data packet shall be provided to the client;
assigning an adjusted data acquisition instance based on the offset, the adjusted data acquisition instance representing a modified point in time in a second time frame structure when at least one future gaze data packet shall be produced by the eyetracker; and
sending a control message to the eyetracker, which control message is adapted to cause the eyetracker to produce the at least one future gaze data packet at the adjusted acquisition instance in the second time structure, such that the reception point in time for the at least one future gaze data packet is expected to lie within a margin prior to the delivery point in time; and
synchronizing the second time frame structure to the first time frame structure such that the first time frame structure and the second time frame structure share a common time base reference,
wherein the adjusted acquisition instance in the second time frame structure when the at least one future gaze packet shall be produced by the eyetracker is such that an expected reception point in time indicating when the at least one gaze data packet is received from the eyetracker is at least a safety time prior to the delivery point in time.

6. A driver unit adapted to stream gaze data packets containing gaze data from an eyetracker to a client, the driver unit comprising:
a first interface configured to receive, repeatedly, gaze data packets from the eyetracker,
a second interface configured to provide, repeatedly, the gaze data packets to the client; and
processing circuitry configured to control a functioning of the driver unit, wherein the driver unit is configured to:
receive a request message from the client, which request message defines a delivery point in time at which a respective one of the gaze data packets shall be provided, in each frame of a first time frame structure, to the client via the second interface;
calculate an offset, in the first time frame structure, between (i) a reception point in time indicating when a gaze data packet is received from the eyetracker relative to the first time frame structure and (ii) the delivery point in time at which the gaze data packet shall be provided to the client;
assign an adjusted data acquisition instance based on the offset, the adjusted data acquisition instance representing a point in time in a second time frame structure when at least one future gaze data packet shall be produced by the eyetracker; and
send a control message, via a control interface, to the eyetracker, which control message is adapted to cause the eyetracker to produce the at least one future gaze data packet at the adjusted acquisition instance in the second time frame structure such that the reception point in time for the at least one future gaze data packet is expected to lie within a margin prior to the delivery point in time,
wherein the driver unit and the eyetracker are connected to a common clock generator configured to provide a common time base reference for the first and second frame structures, and
wherein the adjusted acquisition instance in the second time frame structure when the at least one future gaze packet shall be produced by the eyetracker is such that an expected reception point in time indicating when the at least one gaze data packet is received from the eyetracker is at least a safety time prior to the delivery point in t

Assignees

• Tobii Ab

Inventors

• Clausen Anders
• Tornéus Daniel

Classifications

• H04L65/60 Primary

  Network streaming of media packets · CPC title

• G02B27/0093

  with means for monitoring data relating to the user, e.g. head-tracking, eye-tracking · CPC title

• G06F3/013 Primary

  Eye tracking input arrangements (G06F3/015 takes precedence) · CPC title

• G06F3/017

  Gesture based interaction, e.g. based on a set of recognized hand gestures (interaction based on gestures traced on a digitiser G06F3/04883) · CPC title

• H04L43/0852

  Delays · CPC title