Apparatus, method, and recording medium implementing audio gap information for an audio presentation discontinuous period

A medium having a bitstream carrying machine readable information, said medium comprising:

• a first system stream comprising:
• a plurality of video packets operable to carry first encoded video data of video frames in a compressed manner;
• and
• a plurality of audio packets operable to carry first encoded audio data of audio frames in a compressed manner, wherein a time length of an audio frame is different from that of a video frame in said first system stream;
• and
• a second system stream comprising:
• a plurality of video packets operable to carry second encoded video data of video frames in a compressed manner;
• and
• a plurality of audio packets operable to carry second encoded audio data of audio frames in a compressed manner, wherein a time length of an audio frame is different from that of a video frame in said second system stream;
• wherein said second system stream is played after said first system stream such that video data decoded from the second encoded video data is played seamlessly after the play of video data decoded from the first encoded video data, and audio data decoded from the second encoded audio data is played after the play of audio data decoded from the first encoded audio data with an audio discontinuous part appearing in, or at the end of, the audio data decoded from the first encoded audio data;
• and
• wherein said first system stream further comprises audio gap information used for controlling the audio discontinuous part.