Display device

1. A display device comprising:

a display configured to display a video;

an audio output configured to output sound;

a wireless transceiver configured to establish a wireless connection with at least one external speaker; and

a controller configured to generate a first sound source and a second sound source,

wherein the controller is configured to:

set a sound mode of the display device to a surround mode or a non-surround mode according to the displayed video, wherein the surround mode is a mode that each of the audio output and the at least one external speaker outputs different sounds, the non-surround mode comprises a speaker extension mode in which the audio output and the at least one external speaker output a same sound at a same time as the video is being displayed,

transmit the first sound source to the audio output and transmit the second sound source to the at least one external speaker when the sound mode of the display device is set to the surround mode, and

transmit the first sound source to the audio output and the at least one external speaker when the sound mode of the display device is set to the speaker extension mode,

wherein the controller is further configured to display a setting screen including a list of a genre of a video and a channel number to which the surround mode is applied, and

wherein the controller is further configured to set at least one genre of the video or channel number from the list based on a selection signal from a user or automatically set at least one genre of the video or channel number from the list by analyzing a pattern for selecting the surround mode when the user watches the video.

2. The display device of claim 1 , wherein the controller is further configured to:

cause an output of a 2-channel sound through the audio output and the at least one external speaker in the surround mode, and

cause an output of a 1-channel sound through at least one of the audio output or the at least one external speaker in the non-surround mode.

3. The display device of claim 1 , wherein the controller is further configured to:

determine whether the displayed video corresponds to a video set to apply a surround function based on a determination that a display time of the displayed video exceeds a set time; and

set the display device to the surround mode based on a determination that the displayed video corresponds to the video set to apply the surround function.

4. The display device of claim 1 , wherein the controller is further configured to cause the display to display a message for determining whether to set the display device to the surround mode based on a determination that the displayed video corresponds to a video set to apply a surround function.

5. The display device of claim 4 , wherein the controller is further configured to:

set the display device to the surround mode based on a determination that a command for performing the surround mode is received, and

set the display device to the non-surround mode based on a determination that the command for performing the surround mode is not received within a particular time period.

6. The display device of claim 5 , wherein the controller is further configured to:

set the display device to the surround mode based on a determination that the displayed video corresponds to a video set to apply a surround function, and

set the display device to the non-surround mode based on a determination that the displayed video does not correspond to the video set to apply the surround function.

7. The display device of claim 1 , further comprising a storage configured to store surround environment information used in the surround mode,

wherein the controller is further configured to cause an output sound according to the surround environment information based on establishing the wireless connection with the at least one external speaker.

8. The display device of claim 1 , wherein the controller is further configured to set the display device to at least one of the surround mode, the TV speaker mode, the wireless speaker mode, or the speaker extension mode according to the displayed video.