Video decoding device and video decoding method

A video decoding device comprising:

• a decoder configured to decode encoded data of a plurality of pictures included in each group of pictures in an encoded stream from encoded data of each of the plurality of pictures;
• a vertical synchronization signal generation time calculator configured to calculate a generation time of a first vertical synchronization signal associated with each of the plurality of pictures in a unit of a first cycle in which a first time interval between display times of consecutive pictures among the plurality of pictures is not an integer multiple of the first cycle, based on first information on a number of pictures in the group of pictures and second information on display time of a leading picture in the group of pictures;
• a clock unit including a first oscillator with a first oscillation cycle and configured to synchronize the first oscillation cycle with the first cycle based on time synchronize information representing a time based on a first clock having the first cycle and to generate the first vertical synchronization signal for each of the pictures at the respective generation times based on a first synchronized oscillation cycle;
• and
• a synchronization signal generator including a second oscillator with a second oscillation cycle and configured to synchronize the second oscillation cycle such that an input interval of the first vertical synchronization signals coincides with a second time interval between display times of consecutive pictures among the plurality of pictures represented as an integer multiple of a second cycle and to generate a second vertical synchronization signal and a horizontal synchronization signal of each of the pictures based on a second synchronized oscillation cycle.