Patent ID: 8472781

Claim:
A playback method to play video data and audio data associated with the video data, the method comprising: calculating a time difference between a video playback interval and a corresponding audio playback interval, the video playback interval being based on a first unit of processing for the video data and designated by playback interval designated information, and the audio playback interval being based on a second unit of processing for the audio data which is a different length than that of the first unit of processing; converting, as a frequency conversion, the video data from a first frame frequency to a second frame frequency by performing 3:2 pull-down processing such that a plurality of three-frame groups and a plurality of two-frame groups are alternately produced, resulting in the second frame frequency having a five-to-two relationship with the first frame frequency; and after the frequency conversion, converting, as a video playback interval length conversion, the length of the video playback interval, based on the calculated time difference between the video playback interval and the audio playback interval, wherein the video playback interval length is converted by inserting one frame into a specified two-frame group, of the plurality of two-frame groups, or by deleting one frame from a specified three-frame group, of the plurality of three-frame groups, and after the video playback interval length conversion, adjacent groups of frames formed during the frequency conversion have a frame quantity difference of less than or equal to one frame.