Audio File Length Discrepancy Between Bounce & Real Time

[sdemott]

Can anyone help shed some light on this: Editing a dialogue track for a video & ran into this curious issue. Delivered audio is an M-S track, so I do the following:

[1] take the M-S track & process it to a standard L/R track via direct recording to a new stereo audio track (not a bounce...just set it's output to the audio track's input & record in real time). In this case I used an MS Decoded & muted the sides and added gain to the mid.

[2]I pop into the Finder, copy the newly recorded track out of the Audio Files folder and do some cleaning in RX6. Save the cleaned file with a new name (append RX to it)

[3] Import the cleaned track into DP via drag & drop into the Soundbites sidebar.

Now, when I pull the newly imported & cleaned track into a new track it's longer by 3+ (it was like 3.26 or 3.62...I forget now) seconds. The extra time is all up front (at the head).

Has anyone experienced this before? Could this be because of the pre-record buffer? If so, is there a workaround that doesn't involve remembering to turn off/on the record buffer?

I hope to do some tests myself, but you know the drill...projects lining up & just cranking to stay on top of things. When I get some free time I'm going to try a full test including comparing to a bounce and a Freeze Tracks option as well as real time stem record with & without the record buffer. I was just hoping someone has some experience with this issue and can say definitively what it is that's causing the problem.

Thanks!

DP 8.07
macOS 10.12.6 (Sierra)

[FMiguelez]

It could be the buffer. To be sure, set a different length for the pre-record buffer, and repeat your test. If it matches the new lenght, then it's very likely you found your culprit.

I always keep that thing off (0 lenght), and I've never seen this.

[MIDI Life Crisis]

What kind of “cleaning” are you talking about? Noise reduction, in particular, has been responsible for altering file length- both in internal bounces from DP and stand alone apps. I don’t know why, it just is. You should be able to do a clean bounce from DP that matches but be careful that your start and end times match the original tracks exactly. Just hitting “select all”
Is not a precise way of setting those parameters.

[HCMarkus]

I'm thinking, yes, the pre-record buffer.

[sdemott]

What kind of “cleaning” are you talking about? Noise reduction, in particular, has been responsible for altering file length- both in internal bounces from DP and stand alone apps. I don’t know why, it just is. You should be able to do a clean bounce from DP that matches but be careful that your start and end times match the original tracks exactly. Just hitting “select all”
Is not a precise way of setting those parameters.

Nope, just checked. The pre-cleaned & cleaned are the exact same length. So it's happening during the recording. I haven't had time to try a bounce or freeze yet...hoping to get to that next week.

I'd be really shocked if RX6 was adding time to a file, considering how much it's used in serious audio post situations for TV & movies.

[cuttime]

Could any of the tracks have a different SMPTE frame rate?

[sdemott]

for those wondering - a bounce to disk yields the expected file length. So I'm nearly certain it's the pre-record buffer setting.

What I haven't done yet was to disable that & try the exact same thing to see if there's a file length difference. I also was wondering if I could get what I want (trim off the pre-record "hidden" stuff) if I freeze the track after doing the record process.

Just waiting for some breathing room to test things...probably not this month! And I'm not complaining...it's great to be this busy. I can test when I slow down over the summer.