System and method for raising effective velocity of changing channel by providing i-frame during channel changing time

Extracts the channel original still image at a predetermined time interval, upon a channel change a system that provides priority to the user terminal to the original still image is a predetermined time interval to extract the original still picture of each channel, and the extracted original still image the association with each channel, information including a central transmission server for transmitting an original still image index still picture extraction server and the broadcast image and the generated original still picture index file for each channel to create a file on the user terminal and the source still picture index file is buffering is always transmitted to the user terminal through a separate channel. Original still images, IPTV, multicast