This value is never a constant, I'll give my method for calculating. DVD9 capacity (8152mb) - minus - audio size (in m2ts) / divided by 1.05 (approx h264 m2ts overhead for DVD9) = re-encode file size. For example if your audio file size is 2000mb... BTW, to calculate the audio file size you should first mux the audio alone to m2ts using tsMuxeR. Then right click the audio m2ts, and use the value in brackets... this value will be in bytes. eg. If the value is 2,000,000 bytes, use 2000mb as the file size. So... 8152mb (DVD9 capacity) - 2000mb (audio in m2ts) / 1.05 (h264 overhead) = 5859mb. I usually round down to the nearest 100th... in this case I would use 5800mb. The file size input for the re-encode would be 5.8GB (not 5800mb). Hopefully this isn't to hard to follow, this works for me 99.9% of the time.
