Loop-able sounds created in Pro Tools?

Question

I am was average to moderate user of the old Social Sound Design, but since it moved to stack exchange all my info seems to have been deleted. So many imaginary points, down the drain!!

I read a tip (can't remember where for the life of me) that creating ambiences for the library that are PERFECTLY loop-able saves a TON of time in editing. I completely agree that this would be pretty amazing for the sounds I find myself using a lot.

So I brought a few sound into Pro Tools and cut some loops and then I used the "Export Selected" function to get an interleaved wav into the library. My problem is that Pro Tools is adding roughly a quarter frame of silence to the end of my file. Making it unusable as a loop.

Has anyone seem this before? Or has success with the "perfectly loop-able library" technique?

Thank you,

Chris Davis

Answer 1

Here's my process for creating loopable sound files:

1. Select a reasonable amount of audio from the tail end of the file ("reasonable" is variable and entirely dependent on the content of what you're working with), cut it off and paste it onto the front of the file. You'll need to make a crossfade from the tail end of the region you just cut onto the head of the master clip. Depending on the content of your audio file, this may be a short, medium, or long fade. Just get it sounding natural.
2. Put ProTools into "loop play" mode, select the entire edited region and hit play. If the edited region loops fine without any snaps or unwanted editorial artifacts, simply duplicate the file and viola, you have a loopable sound file.
3. Lastly, export your newly created region as something that ProTools can easily recognize, ie. a .WAV file. I would stay away from other formats such as .mp3 or others that are heavily compressed. So long as you stick with .WAV I don't know why you'd be encountering mysterious insertions of silence.

That's pretty much it. One great advantage to loopable files is creating background tracks. Say you have a 3 min scene. You can lay in your 45 second loopable traffic bed, switch the ProTools trimmer tool to "loop mode" and pull that sucker out for as long as you want; it's already looped and ready to play for the entire 3 minutes without you having to make a single edit or crossfade. Later, when you're conforming your reel to a new version of picture, you won't need to worry about retaining and fixing your old edits - simply blow away the conform damage, pull the region out again, and the file will loop itself up once again.

Happy Looping!

Answer 2

Just to add to Jay's answer, an alternative method for getting the looped tail to sound right is to take your audio loop and create two copies and place one after the other. Bounce out the two copy version and reimport. The edit by cutting off the first version of the loop and deleting, just leaving you with the second version which will include the tail from the first. This way you will get a natural sounding loop.

Also no idea why you are getting the silence on your bounce. I know Logic used to have an export option that allowed you preserve your FX tails on export. This would automatically extend the export to include your reverb or delay tails, but as far as I am aware there is no such option in Pro Tools.

Answer 3

In response to Ricardo's question (sorry, not enough rep to reply directly), you need a lossless audio codec to successfully create seamless loops. Codecs that compress audio upon export will essentially break the loop -- OGG, MP3, etc. The only other lossless format you can use would be FLAC. Since FLACs are lossless, your loops will be preserved and the file size will be significantly less than a WAV/AIF.

Answer 4

you are getting that silence because you are exporting to mp3 (ID info). I'm having the same problem because I'm designing sound for app and using wav files is too heavy. Anyone knows how to make a light loopeable audio file?