| 摘要 |
PURPOSE: To prevent the leading part of an acoustic signal from being lost by improving probability for a synchronizing pattern, which is first detected, to be a true synchronizing signal in the synchronizing detection of MPEG audio bit stream. CONSTITUTION: A bit rate 2 measured by a bit rate measuring circuit 1 is transformed to the code of the same format as a bit rate index by an encoder 3, bit stream data 50 are inputted to a shift register 103, and a synchronizing pattern and a header are extracted. Then, a bit rate index in the header is compared with a code based on the measured bit rate and by ANDing this compared result and a synchronizing pattern detect signal 105, a synchronizing pattern detect signal 7 having much higher certainty is provided. When a frequency incoming confirming circuit 107 confirms that the synchronizing pattern detect signal 7 is cyclically incoming, a synchronism establish signal 108 is outputted. |
