| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a stream converter that converts a received MPEG 2 stream into a stream, whose slice exists only to the left end of an image pattern, as demonded by the MPGE 2. SOLUTION: When a detection circuit 300 detects a picture header from the received MPEG 2 stream, a counter 305 is reset to zero. A VLD 302 decodes a variable length code and detects a macro block(MB). When the MB is detected, a count CNT of the counter 305 is incremented by one. A comparator circuit 306 discriminates whether the count CNT is zero or a multiple of 45 and outputs '1', because the MB is placed to the left end of the image frame, when the CNT is a multiple of 45. An AND circuit 307 ANDs an output of the comparator circuit 306 and a slice detection result of the detection circuit 301 and masks an enable signal indicating a valid/invalid signal, on the basis of a system clock according to the result. Since a slice header placed to the outside of the left end of the image frame is eliminated, the transmission bit rate can be reduced.</p> |
