Methods, systems, and computer program products for providing video call service

1. An operation method of a server, the operation method comprising:

identifying whether matching between a first user of a first terminal and a second user of a second terminal is completed;

relaying a preliminary call between the first terminal and the second terminal based on the matching, wherein the duration of the preliminary call is pre-determined to be a preset time;

allowing conversation between the first user and the second user during the preliminary call;

terminating the conversation of the preliminary call after the preset time elapses;

asking each of the first terminal and the second terminal whether to proceed with a main call after the preset time has elapsed during the preliminary call;

receiving, from each of the first terminal and the second terminal, a response as to whether to proceed with the main call after the preset time has elapsed during the preliminary call;

determining whether to proceed with the main call, based on the response,

wherein a first graphical user interface is displayed on a display of each of the first terminal and the second terminal during the preset time and a second graphical user interface is displayed on the display of each of the first terminal and the second terminal while the main call is in progress, and

wherein the first graphical user interface and the second graphical user interface are different from each other; and

resuming the conversation between the first user and the second user if proceeding to the main call.

2. The operation method of claim 1 , wherein

the determining of whether to proceed with the main call comprises:

when a response accepting proceeding with the main call is received from each of the first terminal and the second terminal, proceeding with the main call; and

when a response rejecting proceeding with the main call is received from at least one of the first terminal and the second terminal, not proceeding with the main call.

3. The operation method of claim 1 , wherein

the first graphical user interface comprises an image area of a counterpart terminal performing the preliminary call and a blocking area covering at least a part of the image area, wherein visibility of the image area changes over time.

4. The operation method of claim 3 , wherein

the second graphical user interface does not include the blocking area when the main call is proceeded.

5. The operation method of claim 3 , wherein

as the preset time is sequentially counted down, width of the blocking area gradually increases or opacity of the blocking area gradually increases.

6. The operation method of claim 3 , wherein

when a countdown of the preset time ends, the blocking area completely covers the image area of the counterpart terminal.

7. The operation method of claim 1 , wherein

the first graphical user interface comprises a graphical user interface for sequentially counting down the preset time.

8. The operation method of claim 1 , wherein

the identifying of whether the matching is completed comprises:

receiving a first like signal transmitted by the first terminal, based on profile information about the second user; and

receiving a second like signal transmitted by the second terminal, based on profile information about the first user.

9. The operation method of claim 1 , wherein

the preliminary call corresponds to a voice call and the main call corresponds to a video call.

10. A computer-readable recording medium having recorded thereon a program for executing, on a computer, the operation method of claim 1 .

11. The operation method of claim 1 , wherein

after the preset time elapsed, a message window requesting the response as to whether to proceed with the main call is displayed on the display of the first terminal and the second terminal.

12. A device for relaying a call, the device comprising:

a processor; and

a memory storing at least one program containing instructions that when read by the processor direct the processor to perform operations including:

identifying whether matching between a first user of a first terminal and a second user of a second terminal is completed;

relaying a preliminary call between the first terminal and the second terminal based on the matching, wherein the duration of the preliminary call is pre-determined to be a preset time;

allowing conversation between the first user and the second user during the preliminary call;

terminating the conversation of the preliminary call after the preset time elapses;

asking each of the first terminal and the second terminal whether to proceed with a main call after the preset time has elapsed during the preliminary call;

receiving, from each of the first terminal and the second terminal, a response as to whether to continue the main call after the preset time has elapsed during the preliminary call;

determining whether to proceed with the main call based on the response,

wherein a first graphical user interface is displayed on a display of each of the first terminal and the second terminal during the preset time and a second graphical user interface is displayed on the display of each of the first terminal and the second terminal while the main call is in progress, and

wherein the first graphical user interface and the second graphical user interface are different from each other; and

resuming the conversation between the first user and the second user if proceeding to the main call.

13. The device of claim 12 , wherein

the at least one processor

proceeds with the main call when a response accepting proceeding with the main call is received from each of the first terminal and the second terminal, and

does not proceed with the main call when a response rejecting the proceeding with the main call is received from at least one of the first terminal and the second terminal.

14. The device of claim 12 , wherein

after the preset time elapsed, a message window requesting the response as to whether to proceed with the main call is displayed on the display of the first terminal and the second terminal.

15. The device of claim 12 , wherein

the first graphical user interface comprises an image area of a counterpart terminal performing the preliminary call and a blocking area covering at least a part of the image area, wherein visibility of the image area changes over time.

16. The device of claim 15 , wherein

as the preset time is sequentially counted down, width of the blocking area gradually increases or opacity of the blocking area gradually increases, and

when a countdown of the preset time ends, the blocking area completely covers the image area of the counterpart terminal.

17. A first terminal comprising:

a communication unit configured to

receive a like signal transmitted from a second user of a second terminal to a server,

transmit a like signal regarding the second user of the second terminal to the server, and

receive a request for establishing a communication connection between the first terminal and the second terminal; and

a control unit configured to perform a preliminary call with the second terminal, according to the request, wherein the duration of the preliminary call is pre-determined to be a preset time and the preliminary call is terminated after the preset time elapses,

wherein the communication unit receives, from the server, a request for input as to whether to proceed with a main call with the second terminal after the preset time has elapsed,

wherein the communication unit transmits, to the server, a response as to whether to proceed with the main call with the second terminal after the preset time has elapsed during the preliminary call,

wherein a first graphical user interface displayed on a display during the preset time and a second graphical user interface displayed on the display while the main call is in progress, and

wherein the first graphical user interface and the second graphical user interface are different from each other.

18. The terminal of claim 17 , wherein

the first graphical user interface comprises an image area of a counterpart terminal performing the preliminary call and a blocking area covering at least a part of the image area, wherein visibility of the image area changes over time, and

the second graphical user interface displays only the image area when the main call is proceeded.

19. The terminal of claim 18 , wherein

as the preset time is sequentially counted down, width of the blocking area gradually increases or opacity of the blocking area gradually increases, and

when a countdown of the preset time ends, the blocking area completely covers the image area of the counterpart terminal.

20. The terminal of claim 17 , wherein

after the preset time elapsed, a message window requesting the response as to whether to proceed with the main call is displayed on the display.