Method of matching sound source for each object included in video, and computing device for performing the same

A computing device comprising:

• an input/output interface configured to display a screen where a video is reproduced, and receive an input from a user;
• a memory storing instructions;
• and a processor configured to execute the instructions to:
• separate a plurality of voices in the video;
• determine a dissimilarity between the plurality of voices;
• select a partial duration in an entire duration of the video as a matching duration, based on the dissimilarity between the plurality of voices;
• match the plurality of voices with a plurality of objects in the video respectively, based on mouth movements of the plurality of objects, within the matching duration;
• and match the plurality of voices with the plurality of objects respectively in the entire duration of the video, based on results of the matching between the plurality of voices and the plurality of objects within the matching duration.