I've found this document: http://www.rmworkshop.com/dvd_info/related_info/ac3hdr.html According to it, 0x0B77 is the beginning of an AC3 frame. I opened up my AC3 file in hexedit and, lo and behold, there were 0x0B77 strings at regular intervals in the file. Using dd, I cut a chunk of the file from the beginning until right before the second occurrence of 0x0B77. Apparently, that chunk is a single AC3 frame and a valid AC3 stream on its own. Using cat and a bit of shell scripting, I concatenated this chunk 69 times at the beginning of the existing file. The result, according to a52dec, mplayer and mplex, was a valid AC3 file with just the right amount of delay at the beginning (69 times the duration of one frame was what I determined experimentally to be needed). -- Florin Andrei http://florin.myip.org/
