Method and system of image processing with power reduction while using a universal serial bus camera
A method, system, and article provide image processing with power reduction while using universal serial bus cameras.
1 . A method comprising:
activating a power savings mode of a universal serial bus (USB) camera to cause the USB camera to switch from empty data transmissions to negative acknowledgement (NAK) transmissions to respond to data requests from a compute device when there is no image data for the USB camera to transmit, the data requests according to an isochronous mode of a USB protocol;
receiving, based on the data requests, image data transmissions associated with frames of a video from the USB camera at intervals based on the USB protocol; and
receiving, based on the data requests, the NAK transmissions between the image data transmissions associated with consecutive frames of the video without triggering an awakening from an enabled low power state of the compute device.
2 . The method of claim 1 , wherein the activating of the power savings mode includes setting a device isochronous interrupt handler setting of a USB protocol kit of the USB camera to cause the USB camera to send the NAK transmissions when there is no image data exists to send.
3 . The method of claim 1 , wherein the compute device has package power states of PC0 to PC10, the PC0 state corresponds to an active power state, the PC1 state to PC10 states correspond to low power states, and the enabled low power state is one of the PC3 state, the PC6 state, the PC8 state, or the PC10 state.
4 . The method of claim 1 , wherein the power savings mode of the USB camera is to cause the compute device to remain in the PC3 state or a deeper package power state for up to 30 milliseconds with the image data provided by the USB camera at 720p resolution and 30 frames-per-second (fps).
5 . The method of claim 1 , wherein the compute device has core power states of CC0 to CC6, the CC0 state corresponds to an active power state, the CC1 to CC6 states correspond to low power states, and the enabled low power state is one of the CC3 to CC6 states.
6 . The method of claim 1 , including detecting power consumption of the compute device, wherein the activating of the power savings mode of the USB camera is based on the detected power consumption.
7 . The method of claim 1 , wherein the activating of the power savings mode of the USB camera is based on a setup parameter.
8 . The method of claim 1 , wherein the activating of the power savings mode of the USB camera is based on a detected condition of the compute device.
9 . A system comprising:
a universal serial bus (USB) camera; and
a compute device including:
memory;
instructions;
at least one processor circuit to be programmed based on the instructions to activate a power savings mode of the USB camera, the power savings mode to cause the USB camera to switch from empty data responses to negative acknowledgement (NAK) responses to respond to data requests from the compute device when there is no image data for the USB camera to transmit, the data requests according to an isochronous mode of a USB protocol; and
a USB host controller to:
receive image data responses associated with frames of a video from the USB camera at intervals based on the USB protocol, the image data responses based on the data requests; and
receive the NAK responses from the camera between the image data responses associated with consecutive frames of the video without triggering an awakening from an enabled low power state of the compute device, the NAK responses based on the data requests.
10 . The system of claim 9 , wherein one or more of the at least one processor circuit is to:
detect power consumption of the compute device; and
activate the power savings mode of the USB camera based on the detected power consumption.
11 . The system of claim 9 , wherein one or more of the at least one processor circuit is to activate the power savings mode of the USB camera based on a setup parameter.
12 . The system of claim 9 , wherein one or more of the at least one processor circuit is to activate the power savings mode of the USB camera based on a detected condition of the compute device.
13 . A compute device comprising:
memory;
instructions;
at least one processor circuit to be programmed based on the instructions to activate a power savings mode of a universal serial bus (USB) camera, the power savings mode to cause the USB camera to switch from empty data transmissions to negative acknowledgement (NAK) transmissions to respond to data requests from the compute device when there is no image data for the USB camera to transmit, the data requests according to an isochronous mode of a USB protocol; and
a USB host controller to:
receive image data transmissions associated with frames of a video from the USB camera at intervals based on the USB protocol, the image data transmissions based on the data requests; and
receive the NAK transmissions between the image data transmissions of consecutive frames of the video without triggering an awakening from an enabled low power state of the compute device, the NAK transmissions based on the data requests.
14 . The compute device of claim 13 , wherein one or more of the at least one processor circuit is to:
detect power consumption of the compute device; and
activate the power savings mode of the USB camera based on the detected power consumption.
15 . The compute device of claim 13 , wherein one or more of the at least one processor circuit is to activate the power savings mode of the USB camera based on a setup parameter.
16 . The compute device of claim 13 , wherein one or more of the at least one processor circuit is to activate the power savings mode of the USB camera based on a detected condition of the compute device.
17 . At least one non-transitory article comprising instructions to cause a universal serial bus (USB) host controller of a compute device to at least:
activate a power savings mode of a USB camera to cause the USB camera to switch from empty data transmissions to negative acknowledgement (NAK) transmissions to respond to data requests from a compute device when there is no image data for the USB camera to transmit, the data requests according to an isochronous mode of a USB protocol;
receive image data transmissions associated with frames of a video from the USB camera at intervals and based on the USB protocol, the image data transmissions based on the data requests; and
receive the NAK transmissions between the image data transmissions of consecutive frames of the video without triggering an awakening from an enabled low power state the compute device, the NAK transmissions based on the data requests.
18 . The at least one non-transitory article of claim 17 , wherein the instructions are to cause the USB host controller to activate the power savings mode of the USB camera based on detected power consumption of the compute device.
19 . The at least one non-transitory article of claim 17 , wherein the instructions are to cause the USB host controller to activate the power savings mode of the USB camera based on a setup parameter.
20 . The at least one non-transitory article of claim 17 , wherein the instructions are to cause the USB host controller to activate the power savings mode of the USB camera based on a detected condition of the compute device.