syncing an added audio stream to a m2ts, answered

hi guys

what i want to do:
some Blurays don´t have all the audiotracks i would like to, so sometimes i want to add another track (from DVD or another (foreign) Bluray)
the easiest solution i can think of is to use tsmuxer to mux the seperate audio into the existing .m2ts Bluray file
when the new audio track isn´t in sync with the video, i mean they already have the same "framerate" but have a time difference, i can set a delay in tsmuxer
the downside is, i can hear the result only after the muxing is finished, when the numbers weren´t accurate i have to mux it again till i finally figure out the right delay
this method is timeconsuming and i hope there is a better solution to this?
my hope is that you guys can help me find a method to play the .m2ts and play the external audio stream, to find out the delay preferably adjustable on the fly, so that i only have to mux the streams once

tia for your ideas

can i change the delay with besweet in realtime or did you mean i have to find out the delay with mpc and then convert/delay the audio stream with besweet for later usage?
the only thing i need to get is the delay time information, i will use that in tsmuxer later

thx for your help
playing the m2ts with vlc or mpc gave me the abbility to adjust the audio delay in real time, when i found the right one, i just used this delay info in tsmuxer
works like a charm