hi, I have 2 separate parts of a movie with each part has it's own audio. I use ffmpeggui to convert from MP3 to AC3 if needed then take VirtualDubMod to Demux out the AC3 then i use TMPGEnc to encode. What would i need to do to join both parts of audio together that has been split? Since each part has different sizes i been told i had to re-encode each part in my case DVD format NTSC 720 x 480 or PAL 720 x 576? Is there any guides on joining together after encoding?