VEHICLE HEAD UNIT AND METHOD FOR OPERATING THE SAME

Abstract

A method of operating a vehicle head unit (100) having a processor executing an application associated with a connection service, the method comprising:determining, by the processor, whether a current frame of video stream data transmitted from a user terminal (200) corresponds to a black screen based on at least one line included in the current frame;determining, by the processor, whether the black screen persists for a predetermined time after determining that the current frame corresponds to the black screen; andnotifying, by the processor, that the user terminal (200) needs to be reconnected or rerun after determining that the black screen persists for the predetermined time.

Description

TECHNICAL FIELDThe present disclosure relates to a vehicle head unit and a method for operating the same.BACKGROUNDThe statements in this section merely provide background information related to the present disclosure and do not constitute prior art.The vehicle connection technology relates to a technique for easily and conveniently using communication and personalization information services in a vehicle based on connectivity between a vehicle head unit (vehicle head unit) and a user terminal (e.g., smartphone). It is expected that a combination of a user terminal, which is considered very important for most people, and a vehicle head unit will be very widely used.For example, the content stored in a user terminal can be output by a display of a vehicle head unit. Further, the user terminal and the vehicle head unit are remotely connected through a mobile communication network, so that the corresponding vehicle can be located in real time even if the vehicle is stolen or towed.If the user terminal is not operating properly while an application program executed in the user terminal sends video data to the vehicle head unit and an image corresponding to the video data is displayed, normal video data may not be transmitted to the vehicle head unit. Here, the content to be displayed is not displayed on the display of the vehicle head unit, and a black screen whose larger part is displayed in black appears on the display of the vehicle head unit, and thus the user may not recognize that the black screen is caused by the vehicle head unit.In this case, the user may be unsatisfying with the quality of the vehicle head unit and may have difficulty solving the problem immediately because the user cannot know which device has a problem. Further, when the user takes measures during driving to solve the problem, safe driving cannot be expected.In KR 10 2017 0 047 918 A, there is provided an apparatus and a method capable of recognizing and restoring a situation in which a screen in an AVN security device of a vehicle does not normally function due to an internal problem of the portable terminal in a cooperation function between the portable terminal and an audio video navigation device (AVN) in a system operating system (OS) in the portable terminal.SUMMARYIt is an object of the present disclosure to provide a vehicle head unit capable of detecting a failure in a user terminal and informing a user of the failure of the user terminal when the connection service / connectivity service is provided, and a method of operating the same.The object is achieved by a method for operating a vehicle head unit having the features of claim 1 and a vehicle head unit having the features of claim 7.The present disclosure provides a method of operating a vehicle head unit executing an application related to a connection service. The method may include: determining whether a current frame of video stream data transmitted from a user terminal corresponds to a black screen based on at least one line included in the current frame; determining whether the black screen continues for a predetermined time when it is determined that the current frame corresponds to the black screen; and notifying / informing that the user terminal needs to be reconnected or executed again when it is determined that the black screen continues for the predetermined time.In another form of the present disclosure, a vehicle head unit executing an application related to a connection service includes: decoding logic for storing, in an analysis buffer, data corresponding to a current frame of video stream data transmitted from a user terminal; and black screen detection logic for determining whether the current frame corresponds to a black screen based on at least one line included in the current frame with respect to the analysis buffer, determining whether the black screen continues for a predetermined time when it is determined that the current frame corresponds to the black screen, and notifying / informing that the user terminal needs to be reconnected or executed again when it is determined that the black screen continues for the predetermined time.The above-mentioned vehicle head unit and the method of operating the same according to the present disclosure may notify a user that the display of a black screen is caused by a failure of a user terminal when the black screen is displayed due to the failure of the user terminal, thereby improving the user-friendliness and the quality index of the vehicle head unit.Moreover, the time and the CPU operation load required for detecting / detecting the black screen can be reduced by performing black screen detection only for some lines of the current frame.The effects / effects of the present disclosure are not limited to the above-described effects / effects, and other effects / effects not described herein will become apparent to those skilled in the art from the following description.BRIEF DESCRIPTION OF THE DRAWINGSIn order to make the disclosure well understood, various forms thereof will now be described as examples, with reference to the accompanying drawings. The figures show: FIG. 1 is a block diagram of a connection system; FIG. 2 is a block diagram of a vehicle head unit shown in FIG. 1 ; FIG. 3 is a flow chart illustrating a method of operating the vehicle head unit shown in FIG. 2 ; and FIG. 4 is a diagram illustrating step S 20 shown in FIG. 3.The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the present disclosure in any way.DETAILED DESCRIPTIONIt should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.Although the suffixes "module" and "unit" are used for constituent elements described in the following description, this is provided only for convenience of description.FIG. 1 is a block diagram of a connection system, and FIG. 2 is a block diagram of a vehicle head unit shown in FIG. 1.Referring to FIGS. 1 and 2, a connection system 10 may include a vehicle head unit 100 and a user terminal 200 (e.g., a smartphone, a portable computer, etc.), and provide a connection service through which the vehicle head unit 100 and the user terminal 200 may operate as other-side input / output devices using connectivity between the vehicle head unit 100 and the user terminal 200.For example, the vehicle head unit 100 functions as an input / output device of the user terminal 200.The vehicle head unit 100 may be installed or installed in the dashboard of a vehicle, and may provide multiple services such as air conditioning, audio, video, and navigation services of the vehicle, and the connection service with respect to any terminal.A connection between the vehicle head unit 100 and the user terminal 200 for the connection service may be implemented as a wired connection such as MHL (Mobile High Definition Link) or a wireless connection such as Bluetooth.The user terminal 200 may be implemented as a mobile phone, a smartphone, a tablet PC, a notebook PC, or the like. The user terminal 200 provides a plurality of services as well as a calling service by being equipped with a mobile platform and various kinds of applications executed at an upper application level / application layer of the mobile platform. As the mobile platform, iOS of Apple, Android of Google, Symbian of Nokia, Blackberry of RIM, Windows Mobile of Microsoft, Li-Mo of LiMo Foundation, or the like can be used.An application (e.g., CarLay from Apple or Andriod Auto from Google) that provides the connection service is installed and executed in the user terminal 200 so that the user terminal 200 can use the vehicle head unit 100 as an input / output device based on data communication with the vehicle head unit 100.When the application is executed and the data communication is established between the vehicle head unit 100 and the user terminal 200, the vehicle head unit 100 may output video data and audio data transmitted from the user terminal 200 via a display ( 140 of FIG. 2 ) and a speaker ( 190 of FIG. 2 ) thereof after receiving the video data and audio data.FIG. 2 shows a configuration of the vehicle head unit 100. The vehicle head unit 100 may include: a wired / wireless communication module 110, a decoding buffer (decoding buffer) 120, a decoding logic 130, a display 140, a detection timer 150, an analysis buffer (analysis buffer) 160, a black screen detection logic 170, a detection counter 180, and a speaker 190.The wired / wireless communication module 110 may support a wired connection with the user terminal 200 using MHL or a wireless connection with the user terminal 200 using Bluetooth, and convert the protocol of the video stream data received from the user terminal 200.The decoding cache 120 may store video stream data from the wired / wireless communication module 110. Here, the decoding cache 120 may store the video stream data on a frame, line (line), or pixel basis in accordance with control of the decoding logic 130. To this end, the video stream data may include information about the start and end of a frame and a line size.The decoding buffer 120 may be a part of a memory included in the vehicle head unit 100, and the analysis buffer 160 described below may be implemented as another part of the memory.The decoding logic 130 may operate as a decoder that decodes video stream data compressed by a particular codec into a format that may be output by the display 140. The decoding logic 130 may be used as a workspace for decoding operation of the decoding cache 120.The decoding logic 130 may be implemented as part of a central processing unit (CPU) included in the vehicle head unit 100 together with the sensing logic 170. That is, the decoding logic 130 and the black screen sensing logic 170 may be executed or operated in independent threads in the CPU. A thread refers to an operation processing unit. Although the number of threads may correspond to the number of cores, the scope of the present disclosure is not limited thereto.The decoding logic 130 decodes the video stream data and sends the decoded video stream data to the display 140 so that the user can view the video stream data sent from the user terminal 200 via the display 140.In addition, the decoding logic 130 may duplicate or transmit data corresponding to the current frame of video stream data stored in the decoding buffer 120 to the analysis buffer 160 according to a timer completion signal of the acquisition timer 150. According to another form, the decoding logic 130 may duplicate or transmit data corresponding to at least one particular line included in the current frame to the analysis cache 160 according to the timer completion signal instead of the data of the current frame. In this case, the storage capacity to be allocated to the analysis buffer 160 can be reduced.After transmission or duplication of the data, the decoding logic 130 may activate the black screen capture logic 170.The display 140 is a display device such as a liquid crystal display (LCD) capable of visually outputting video data, and may output the video stream data sent from the decoding logic 130. In addition, the display 140 may output a pop-up window generated by the black screen detection logic 170 described later.The detection timer 150 may generate the timer completion signal and transmit the timer completion signal to the decoding logic 130 whenever a detection period set / set by the decoding logic 130 expires. In one form, the sensing timer 150 may determine whether the sensing period expires by counting an internal clock signal of the vehicle head unit 100.For example, when the acquisition period is set to one second, the acquisition timer 150 may generate the timer completion signal and transmit the same to the decoding logic 130 every second.Moreover, the detection period may be set / adjusted in consideration of the CPU load. For example, when a normal sensing period is one second, when a load related to an operation having higher thread priority than the black screen sensing logic 170 is generated, the decoding logic 130 may set the sensing period to 2 to 3 seconds. The thread priority refers to a priority for occupying threads of the CPU of the in-vehicle head unit 100, and an operation having a higher thread priority may be regarded as an operation of higher importance.The analysis buffer 160 may store the data (or data corresponding to at least one specific line of the current frame) corresponding to the current frame transmitted from the decoding buffer 120.The black screen acquisition logic 170 is activated according to control of the decoding logic 130, and may determine whether the current frame corresponds to a black screen (screen mainly displayed in black instead of displaying contents to be displayed thereon) based on the data (or data corresponding to at least one specific line of the current frame) corresponding to the current frame.Upon determining that the current frame corresponds to a black screen, the black screen detection logic 170 may increase a counter value stored in the detection counter 180 by a certain value (e.g., 1). Conversely, the black screen detection logic 170 may initialize the counter value stored in the detection counter 180 to an initial value (e.g., 0) when it is determined that the current frame does not correspond to a black screen.The black screen detection logic 170 may determine whether the counter value reaches a threshold value (e.g., 20) with respect to the counter value stored in the detection counter 180. When the count value reaches the threshold, the black screen detection logic 170 may generate a pop-up window, transmit the pop-up window to the display 140, and transmit a warning sound to the speaker 190.The pop-up window and the warning sound may include information indicating that the user terminal 200 needs to be reconnected or re-executed because normal images are not currently received by the user terminal 200.The sensing counter 180 may store a counter value according to a determination of the black screen sensing logic 170.The speaker 190 may amplify an audio signal, remove noise therefrom, and output the audio signal. Specifically, the speaker 190 may output the warning sound transmitted from the black screen detection logic 170.FIG. 3 is a flowchart illustrating a method of operating the vehicle head unit shown in FIG. 2, and FIG. 4 is a diagram illustrating step S 20 shown in FIG. 3.Referring to FIGS. 1 to 4, when the application providing the connection service is executed and data communication is established between the vehicle head unit 100 and the user terminal 200, video stream data may be received by the wired / wireless communication module 110 and stored in the decoding buffer 120 (S 10).The decoding logic 130 may periodically transmit or duplicate data (or data corresponding to at least one specific line included in the current frame) corresponding to the current frame of the video stream data stored in the decoding buffer 120 to the analysis buffer 160 according to the timer completion signal of the acquisition timer 150.The black screen acquisition logic 170 is activated according to the control of the decoding logic 130, and may determine whether the current frame corresponds to a black screen based on the data (or data corresponding to at least one specific line included in the current frame) corresponding to the current frame (S 20).FIG. 4 shows the current frame CF. It is assumed that the current frame has a resolution of 800x480.Moreover, it is assumed that the data corresponding to the current frame includes color data corresponding to 800 x 480 pixels. The color of a pixel may be RGBA (red, green, blue, and alpha). Accordingly, color data corresponding to one pixel may have a size of 4 bytes.The black screen detection logic 170 may determine whether the current frame corresponds to a black screen based on data included in only some lines of the current frame instead of the total data corresponding to the current frame. The data included in some lines may be referred to as example data / sample data, as the data represents a portion of a frame.Figure 4 shows an example based only on 12 out of 480 lines of the current frame with the resolution of 800x480.That is, the 12 lines are divided into first to fourth line groups L1 to L4, each of which includes 3 lines.For example, the first group L 1 may include Y-coordinate lines (coordinates set sequentially / sequentially from the top of the current frame CF in the Y-axis direction) 45, 51, and 57, and the second group L 2 may include Y-coordinate lines 195, 201, and 207.The third row group L 3 may include Y-coordinate rows 372, 378, and 384, and the fourth row group may include Y-coordinate rows 430, 436, and 448.Here, a distance (e.g., 6) of the lines included in each line group may be determined in consideration of the resolution of the current frame CF.The current frame CF may be divided into a plurality of areas in consideration of a menu screen of the application providing the connection service supported by the vehicle head unit 100.That is, in the example of FIG. 4, the current frame CF is divided into a first area A 1 and a second area A 2.The first area A1 displays content (e.g., video reproduction, music related images, and the like), while the second area A1 displays main menu icons regardless of the content.When a black screen is transmitted, all pixels in the first area A1 are displayed in black, while in the second area A2 with a background color with transparency (related to an alpha value) changed, all pixels are not displayed in black and the main menu icons are not displayed.Accordingly, it is desirable to separate a determination as to whether the first area A 1 displays a black screen from a determination as to whether the second area A 2 displays a black screen.Accordingly, the black screen detection logic 170 determines whether color data of all pixels included in each of the lines belonging to the first, second, and third line groups L 1, L 2, and L 3 of the first area A 1 is black (0, 0, 0, 255).However, the black screen detection logic 170 determines whether color data of all pixels included in each of the lines belonging to the fourth line group L 4 of the second area A 2 are identical, instead of determining whether the color data is black ((0, 0, 0, 255). This is because it is more suitable to determine whether the main menu icons are displayed in the second area A 2 by checking whether all the color data are identical, because the second area A 2 is highly likely to have a background color with transparency (related to the alpha value) that changes from black.The above process is merely an example of dividing the current frame CF into a plurality of areas and determining whether the current frame CF corresponds to a black screen in consideration of a user interface of the application, and the scope of the present disclosure is not limited thereto.The first area A1 includes 9 black screen detection lines and the second area A2 includes 3 black screen detection lines. The number of lines included in the first area A 1 and the second area A 2 may be determined based on the ratios of the Y coordinate lengths of the first area A 1 and the second area A 2 to the Y coordinate length of the current frame.Further, while the first to fourth line groups L 1 to L 4 may be equally spaced, the black screen detection logic 170 may acquire information on an area in which icons or content of normal video stream data sent from the decoding logic 130 are displayed, and determine the positions of the first to fourth line groups L 1 to L 4 based on the acquired information.The black screen detection logic 170 sequentially determines whether the first to fourth line groups correspond to a black screen for the current frame CF. When the black screen detection logic 170 determines that a line does not correspond to a black screen during a sequential determination, the black screen detection logic 170 does not perform a determination for the following lines.When one of the pixels belonging to the lines included in the first to third line groups L 1 to L 3 is not black, or when one of the pixels belonging to the lines included in the fourth line group L 4 has a different color from other pixels, it is determined that the current frame does not correspond to a black screen.In addition, black screen detection for the first to fourth line groups L 1 to L 4 may be independently performed, and an order of detection may be changed. For example, after black screen detection for the fourth line group L 4, black screen detection for the first to third line groups L 1 to L 3 may be performed.Upon determining that the current frame CF does not correspond to a black screen (No of S 20), the black screen detection logic 170 may initialize the detection counter 180, and may then be activated to enter a sleep mode so as to reduce the operation load.After determining that the current frame CF corresponds to a black screen (Yes of S 20), that is, when all pixels belonging to the lines included in the first to third line groups L 1 to L 3 are black and when all pixels belonging to lines included in the fourth line group L 4 have the same color, the black screen detection logic 170 may increase the counter value of the detection counter 180 by a certain value (e.g., 1). Moreover, the black screen detection logic 170 may determine whether the black screen continues for a predetermined time T (e.g., 20 seconds) by checking whether the incremented counter value is equal to a threshold value (e.g., 20) (S 30).The threshold value is set to a value greater than 1 to determine the current frame as a black screen only when the black screen continues for a predetermined time or longer because a delay time required for a screen change may be generated due to a load of the vehicle head unit 100 or a load of the user terminal 200.When the black screen does not continue for the predetermined time (No of S 30), the black screen detection logic 170 may be disabled to enter a sleep mode so as to reduce an operation load.When the black screen continues for the predetermined time (Yes of S 30), the black screen detection logic 170 may generate a pop-up window, transmit the pop-up window to the display 140, and transmit a warning sound to the speaker 190 (S 40).The user can recognize through the pop-up window or the warning sound that the user terminal 200 needs to be reconnected or executed again because normal images cannot be currently received from the user terminal 200. That is, the user can know that the currently generated fault is caused by the user terminal 200 that cannot transmit normal data instead of a problem in the vehicle head unit 100, and a method of operating the user terminal 200 to remedy the fault can be provided.Since a case where it is determined that the current frame CF does not correspond to a black screen (No of S 20), a case where the black screen does not continue for the predetermined time (No of S 30), and a case where the user is notified of the error (S 40) correspond to a state where determination of the black screen detection logic 170 is completed, the black screen detection logic 170 may initialize the analysis buffer 160 so that data corresponding to the next frame may be stored therein.The algorithm shown in FIG. 4 can be executed only when video stream data is received from the user terminal 200.The vehicle head unit and the method of operating the same according to the present disclosure may notify the user that a display of a black screen is caused by a problem in the user terminal when the black screen is displayed due to the problem in the user terminal, thereby improving user-friendliness and quality index of a vehicle head unit.In addition, time and a CPU operation load required for detecting the black screen can be reduced by performing black screen detection only for some lines of the current frame.The above-mentioned method of operating the vehicle head unit 100 may be implemented as computer readable code stored in a computer readable recording medium. The computer readable recording medium includes all types of recording media that store data readable by a computer system. Examples of the computer readable recording medium include ROM, RAM, a magnetic tape, a magnetic disk, a flash memory, an optical data storage device, and the like. Moreover, the computer readable recording medium can be stored and executed on computer systems connected through a computer communication network and as code readable in a distributed manner.

Claims

A method of operating a vehicle head unit (100) having a processor executing an application related to a connection service, the method comprising: determining, by the processor, whether a current frame of video stream data transmitted from a user terminal (200) corresponds to a black screen based on at least one line included in the current frame; determining, by the processor, whether the black screen continues for a predetermined time after determining that the current frame corresponds to the black screen; and notifying, by the processor, that the user terminal (200) needs to be reconnected or executed again after determining that the black screen continues for the predetermined time.The method of claim 1, wherein determining whether the current frame corresponds to the black screen comprises determining whether all pixels belonging to lines included in a first area in which content is displayed are black.The method of claim 1, wherein determining whether the current frame corresponds to the black screen comprises determining whether all pixels belonging to lines included in a second area in which menu icons are displayed have the same color.The method of claim 1, wherein the determining whether the current frame corresponds to the black screen is periodically performed according to a timer completion signal of a detection timer (150).The method of claim 1, wherein determining whether the black screen continues for the predetermined time comprises: incrementing a count value of a capture counter (180) by a predetermined value; and determining whether the incremented count value equals a threshold value.The method of claim 1, wherein notifying that the user terminal (200) needs to be reconnected or re-executed comprises: outputting a pop-up window through a display (140); and outputting a warning sound through a speaker (190).A vehicle head unit (100) configured to execute an application related to a connection service, the vehicle head unit (100) comprising: a processor configured to store, in an analysis buffer (160), data corresponding to a current frame of video stream data transmitted from a user terminal (200), configured to determine whether the current frame corresponds to a black screen based on at least one line included in the current frame with respect to the analysis buffer (160), configured to determine whether the black screen continues for a predetermined time after determining that the current frame corresponds to the black screen, and configured to notify, the user terminal (200) needs to be reconnected or executed again after determining that the black screen continues for the predetermined time.The vehicle head unit (100) according to claim 7, wherein the processor is configured to determine whether all pixels belonging to lines included in a first area in which content is displayed are black.The vehicle head unit (100) according to claim 7, wherein the processor is configured to determine whether all pixels belonging to lines included in a second area in which menu icons are displayed have the same color.The vehicle head unit (100) according to claim 7, wherein the processor is configured to periodically store the data corresponding to the current frame in the analysis buffer (160) according to a timer completion signal of a detection timer (150).The vehicle head unit (100) of claim 7, wherein the processor is configured to increment a counter value of a detection counter (180) by a certain value and determine whether the incremented counter value equals a threshold value.The vehicle head unit (100) according to claim 7, wherein the processor is configured to control a pop-up window to be output via a display (140) and to control a warning sound to be output via a speaker (190).The vehicle head unit (100) of claim 7, wherein the storing and the determining are performed in different threads in a central processing unit (CPU) of the vehicle head unit (100).A vehicle head unit (100) configured to execute an application related to a connection service, the vehicle head unit (100) comprising: a processor configured to periodically store, in an analysis buffer (160), data corresponding to a current frame of video stream data transmitted from a user terminal (200) according to a timer completion signal of a detection timer (150), to determine whether the current frame corresponds to a black screen and whether the black screen continues for a predetermined time based on example data included in the current frame with respect to the analysis buffer (160), and to notify that the user terminal (200) needs to be reconnected or executed again after determining, the black screen continues for the predetermined time.The vehicle head unit (100) of claim 14, wherein black screen detection logic (170) executed by the processor is disabled to enter a sleep mode upon determining that the current frame does not correspond to the black screen.The vehicle head unit (100) of claim 14, wherein a black screen detection logic (170) executed by the processor increases a counter value of a detection counter (180) by a certain value, and is disabled to enter a sleep mode after determining that the black screen does not continue for the predetermined time.The vehicle head unit (100) according to claim 14, wherein the processor is configured to determine whether all pixels belonging to lines included in a first area in which content is displayed are black.The vehicle head unit (100) according to claim 14, wherein the processor is configured to determine whether all pixels belonging to lines included in a second area in which menu icons are displayed have the same color.

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