Unwanted silence being added to exported files...

[quiet0ne]

Hello!

I'm prettymuch a newb with Audacity (and audio in general). I'm using it to clean up some seemless audio loops I'll be using on a private website. The original audio loops had a small bit of silence followed by a snap/crackle at the beginning of the track. I imported the file as MP3, saved it as an Audacity project, and carefully deleted the portions I wanted to. When I viewed the file, before exporting it as a WAV, there was NO silence or dead space at the beginning of the track. However, when I played the file back, there's an audible gap in the file. Opening the same file back up in Audacity, there is now a .025 second silence added at the very beginning of my track.

I've tried exporting as WAV and MP3 using the Lame encoder, and both ways seem to create this problem. It even happens when I try the "export selection as..." feature, when I've selected the whole track minus the silent space.

Any help would be greatly appreciated. Thank you!

~quiet0ne

[kozikowski]

<<<The original audio loops had a small bit of silence followed by a snap/crackle at the beginning of the track. I imported the file as MP3, saved it as an Audacity project>>>

Taking bets the original sound file wasn't an MP3. Audacity can act a little funny if it's not really sure what the file is. Particularly since you mentioned damage at the top of the question.

http://www.kozco.com/tech/soundtests.html

Pull either of those MP3s down and see if they edit OK.

Koz

[quiet0ne]

Thanks kozikowski.

The original audio files came from a free Flash audio loops page - they're MP3s now, but I'm not sure what the native format was to begin with. I may be able to get the wav files from that site - would that make any difference?

I downloaded piano2-CoolEdit.mp3 from the link you provided. Deleted the first 1.5 seconds or so and saved it as an AUP file. Then I exported it as an MP3 and opened the new MP3 up in Audacity. Unfortunately, it's still adding that little snip of blank space.

Here's a screenshot of the AUP file


And here's what the file looks like after exporting as MP3


I realized I forgot to mention what kind of computer I'm on. I'm running Windows XP on a 4 year old Dell laptop. Don't know if that makes any sort of difference or not! Just downloaded Audacity today, version 1.2.6

[L_Libza]

I thought I would try to duplicate the same test.

I got the same results that quietOne did, so it's not just his system. This happens both with Version 1.2.6 and 1.3.6 when exporting as MP3. However exporting as .wav does not seem to have this problem.

[kozikowski]

I haven't gone through all the variations yet, but mine seem to do it, too.

Koz

[L_Libza]

I tried it with GoldWave. The same thing happens there, so its not just Audacity. Maybe its the Lame encoding.

[quiet0ne]

Aha. I tried it again with the same piano MP3, and exported as WAV. Bingo, no weird extra space. Looks like it may very well be the Lame encoding.

Thank you everyone who tested this as well!

[steve]

MP3's always have a little snip of silence at the beginning - it is one of the limitations of the MP3 format and is one reason that MP3's are unsuitable for (seamless) audio loops. It is not due to any particular encoder, it is due to the format specification.
In Audacity (formerly Cool Edit Pro) they get round this by using a modification of the MP3 format that they call ".CEL" files.

WAV, FLAC and OGG files do not have this limitation.