[Not a bug] Gap on looping MP3s

Post by **Gambit37** » Thu Mar 09, 2006 2:54 am

If you use a MP3 as a looping ambient sound, there is a noticeable silent pause between each loop. This doesn't happen with PCM WAV.

I imagine this is due to continually decompressing the sound or something? Can it be fixed?

EDIT: I opened my MP3 to view it and some empty space has been added to the start and end! If I remove this and resave as MP3, it comes back!

Anyone know how to avoid this?

Post by **Gambit37** » Thu Mar 09, 2006 2:57 am

Seems as if OGG doesn't have this problem! Guess I'll stick with that -- it's files are smaller too!

Post by **Sophia** » Thu Mar 09, 2006 7:03 am

You can't avoid it. It's an artifact of the MP3 encoding process.

beowuuf · Post by **beowuuf** » Thu Mar 09, 2006 8:26 am

yup, always annoying on listening to albums where the songs are supposed to be a continuous flow

Post by **Gambit37** » Thu Mar 09, 2006 9:48 am

Guess I've never noticed it using Windows Media Player as it has intelligent read-ahead buffering.

I noticed this on iTunes though and simply thought the software sucked. Guess it was the files themselves afterall.

Des · Post by **Des** » Sat Mar 11, 2006 8:56 pm

I've just been playing with this and even using a WAV I get a "blip" between each repetition. I was hoping to create a seamless continuous sound using just a short sound clip.

This is the one I used (made with Nero Wave Editor) Takk Snippet - about a second of Sigur Ros.

I was wondering if it's not possible to get a totally seamless loop or if my file actually has a very short period of silence. I guess maybe the answer is to use a longer snippet with a fade-in and fade-out?

Post by **Gambit37** » Sat Mar 11, 2006 9:04 pm

The looping works for me -- you probably have a small gap of silence at the end beginning. Should be easily spottable in any decent sound editor.

George Gilbert · Post by **George Gilbert** » Sat Mar 11, 2006 9:09 pm

For looped sounds, RTC detects that it's stopped once per frame (so about every 1/60th of a second) and restarts it if necessary. If something complex is happening in the dungeon, then I guess it could take up to 1/10th of a second to detect the loop.

I would have thought that that was a short enough gap to be inaudible. If you have a very short sample (much less than a second) however, I could just about believe that the rapid on / off of the sound could be audible.

As Gambit suggests, it's probably the sound itself that has a gap at the start / end. As you suggest, you could always just have a longer sample and fade loop sounds at the start and end so that if there's a tiny silence then it won't be noticed. Realistically though, that shouldn't be needed.