Playlist - audio "tick" problem

robwood wrote on 6/10/2008, 6:05 AM
i've been using DVD-A 4.0 / 4.5 and been having a problem with a brief audio "tick" between files in a playlist that is quite audible... the tick varies in volume from barely audible to quite loud.

0) not that it should matter, but just in case, the video is m2v format.
1) i use PCM audio (16bit, 48kHz, Stereo) (between 30-50 tracks): some of the pieces have a strong music focus and I need to preserve audio quality.
2) every WAV file used is rendered in Vegas with fades in/out (there is no audio "tick" when playing back from the Vegas timeline)
3) if i burn another DVD direct from DVD-A, the tick(s) will be in the same location, same volume.
4) if i replace both files (before / after) with clips of a different length, the tick is gone... but a different (louder or quieter) one may appear there.. or maybe not.

and this is the one that discourages me...

5) if i render all the files as one massive WAV from the Vegas timeline and use that instead, there is no tick.


"5" was an experiment to see if the problem was in the audio files themselves. The DVD needs to play individual files as well as provide a "play all" button. I don't have the time to create a "special" dvd.

I've done a search for this problem on a variety of forums and found nothing. This gives me hope I guess that maybe I'm missing something obvious.

Anyone know what's going on, what I'm doing wrong, or a definitive way to avoid the problem?

Comments

MPM wrote on 6/10/2008, 8:18 AM
I've never put pcm on a DVD, so this is purely a guess...

DVDA has an unfortunate habit of adding a garbage frame or two to the end of any video [maybe the way it times whatever?]. Normally this was only a problem with separate intro videos showing a black frame(s) before displaying the 1st menu, & possibly when the menu looped. I used to render an extra video frame, keeping the audio the same length, then trim that last frame in DVDA.

Could DVDA be performing similar shenanigans with your titles? &/or could your PCM tracks be just a bit short or long?... Even if nothing's being altered, would it work to trim the end of the titles, & thus the wav file anyway?

I'd think you'd want to do this trimming in DVDA, with the effect that the true end of the title's never played... the DVD player just reaches the point you trimmed and skips to the next step. Something else you could try, though it wouldn't fix anything, would be to demux the audio tracks out of a DVDA prepared DVD to see if there's something added onto the end of the wav files - should be apparent in the waveform of any editor.
robwood wrote on 6/10/2008, 12:53 PM
"...would it work to trim the end of the titles, & thus the wav file anyway?" - MPM

i don't know, but it won't hurt to try... i'll see what happens. thx for the suggestion.

l8r
rob
robwood wrote on 6/13/2008, 3:51 PM
tried a one-frame trim in DVD-A... less than 1/2 the ticks we had before... think i'm gonna try 2 or 3 frame trim for next round see if that drops the amount of pops more.

thx again for the suggestion.

l8r
rob