Synching separate audio and video

[harmsway1976]

how can i take a live concert video and a separate audio source that's not exactly the same length or may be tracked differently and get them to synch together? can someone who has done this before tell me what programs and methods are best to use?

[scopophilia]

what do you mean "may be tracked differently" -- you mean track markers on CDs? they don't matter, as long as the track cutting was done on sector boundaries. if the track cutting was done in cool edit, for example, you might have very small gaps between some tracks affecting your sync. if it was done in cdwave, for example, you're good to go.

so i'm assuming you're talking about using a source in CD to sync with the video. first you should try to find out if the CD source or the video source have any cuts during the performance. one or both might cut during encore breaks but that's not as big a problem as one or both of them cutting during songs. you said they're different lengths but you should try to find out if that difference is the result of one, two, or multiple cuts in either audio. especially if the source is on more than one CD, you'd want to know if there was any editing from disc one to disc two. you'll also want to make sure you have a clean copy of the CD without any skips or other flaws that will off-sync things. if there are too many cuts or flaws in either source, it will probably take a very long time to sync the two together.

what i do to sync CDs with video is this: rip the whole CD with EAC using secure mode & use "copy range" to get a single .wav of the entire cd. you'll then need to upsample the CDR from 44.1 to 48 using cool edit, goldwave, etc. i read previously, i do not know if it is true, that this upsampling could possibly change the speed of the audio slightly, making the sync impossible. however, i've done this without problems before, so it is possible to upsample from 44.1 to 48 without speed issues.

to sync, i use a multitrack program, such as the one in cool edit, to open both wavs at the same time. sync both sources to a drum kick or something else in the first song by either adding silence to the beginning of the track or deleting from the beginning of the track. you can then look at the peaks of the files and play both files at the same time to see for how long they stay in sync. hopefully you need only re-sync them once or twice when either audio source stops and restarts. save the synced audio track and add it to your dvd project.