Method and apparatus for modifying a transport packet stream to provide concatenated synchronization bytes at interleaver output

Apparatus for modifying a transport packet stream to provide concatenated synchronization bytes at an output of an interleaver receiving the modified packet stream, comprising:

• means coupled to receive said transport packet stream for locating particular byte positions in successive transport packets;
• means responsive to said locating means for replacing a conventional sync byte located in a first transport packet with a first substitute sync byte;
• means responsive to said locating means for deleting a conventional sync byte located in a conventional sync byte position of a second transport packet and moving another byte from said second transport packet to said conventional sync byte position, thereby opening a desired byte position in the second transport packet;
• and
• means responsive to said locating means for inserting a second substitute sync byte into said desired byte position;
• wherein said first and second transport packets and said desired byte position provide said first and second substitute sync bytes at locations in the modified packet stream where said first substitute sync byte will be concatenated with said second substitute sync byte at the output of said interleaver.

Apparatus for reconstructing an original transport packet stream with conventional sync bytes from a modified transport packet stream in which interleaved, modified transport packets provide concatenated substitute sync bytes, comprising:

• means for detecting said concatenated substitute sync bytes in the modified transport packet stream;
• means responsive to the detected concatenated substitute sync bytes for synchronizing a deinterleaver, said deinterleaver being coupled to deinterleave the modified transport packets;
• means for locating a first substitute sync byte in a conventional sync byte position of a first deinterleaved transport packet and replacing the first substitute sync byte with a first conventional sync byte;
• means for locating a second substitute sync byte in a nonconventional sync byte position of a second deinterleaved transport packet and replacing the second substitute sync byte with another byte from said second deinterleaved transport packet to open up a conventional sync byte position in said second deinterleaved transport packet;
• and
• means for inserting a second conventional sync byte into the opened up conventional sync byte position of said second deinterleaved transport packet.