High picture quality video streaming service method and system

A user terminal, comprising:

• a video download unit for downloading a first encoding video;
• a video streaming unit for receiving a streaming video in real time;
• a playback video generation unit for generating a video for playback using the first encoding video and the streaming video;
• and
• a video playback unit for playing the first encoding video or playing back the video for playback
• wherein the user terminal generating the video for playback by recombining frames of the first encoding video and frames of the streaming video and
• wherein the first encoding video is encoded at a constant bit rate, the streaming video having a 1/N of a frame rate of the first encoding video,
• wherein the user terminal communicates with a content server which predicts structural similarity values and generates the preliminary streaming video by selecting the frame of the first encoding video or the second encoding video based on both difference between the predicted structural similarity values and threshold.