Audacity and MP3 file trimming.

garryspicer

garryspicer

Southpaw
Hello all,

Would appreciate any help.

I make loops for some of my friends so that they can practise scales, try out vocal ideas etc. A few are very, very, new to using a computer so I need to
keep everything as simple as possible for them. I use Audacity for quick editing and have installed copies of the program on their system.

I record in Pro Tools 8 and mix down to WAVE format and make copies into FLAC & MP3 formats. I find that if I convert from FLAC to MP3 (using FreeRIP) it stops the annoying pumping I get on some MP3 files.

When I import a loop in MP3 format into Audacity it always puts a space at the front and back of the music. This means that the music does not loop perfectly.
For me this is not a problem as I just edit the loop by deleting the spaces and then hitting SHIFT / PLAY to loop in Audacity.
However the people I email these files too, find it challenging just to download the file and saving it.

If I try to export the trimmed file it will put the spaces back. It only does this in MP3 format. If I import WAVE or FLAC format it loops perfectly. I cannot e-mail it to them in WAVE format as they would have a nervous breakdown with the file size (ditto for FLAC). For my computer savvy friends I upload the WAVE to the cloud and they can access it from there

I do not do it directly from Pro Tools (I know there is a patch to let me mix down in MP3) as I have set up a laptop to run all my recording gear and have disabled the Internet after an episode with an update that left me unable to record for 3 months.

Is there a trick to getting a perfect loop in Audacity?

Thanks in advance.
 
If it happens when you convert to mp3 with FreeRip, it sounds like FreeRip is the problem.
Try using another mp3 converter or look at see if there are any preferences in FreeRip that add the spaces....
 
If they can operate Audacity they can learn to download a file from a file sharing site. Mp3 is for casual listening and is not really suitable for any part of music production.
 
Hi garryspicer,

I think the silence padded at the beginning and end of the song in inherent in the MP3 encoder, and possibly even all MP3 encoders. Audacity uses LAME, and this is the technical explanation:
http://lame.sourceforge.net/tech-FAQ.txt

There is probably no easy way around it, and that's why most audio players that support "gapless MP3 playback" actually use noise gate of sorts to truncate MP3 audio in order to achieve "gapless playback". Perhaps you can try OGG or WMA formats?
I'm not sure if they can be truly gapless, but worth a shot. Most computers are capable of playing these formats anyway, so it should be as idiot-proof as MP3s :)
 
Why not just send them the FLACs? A several second loop in FLAC is only going to be a couple KB, not too difficult to transfer or store on modern networks and PCs.
 
godchuanz said:
Hi garryspicer,

I think the silence padded at the beginning and end of the song in inherent in the MP3 encoder, and possibly even all MP3 encoders. Audacity uses LAME, and this is the technical explanation:
http://lame.sourceforge.net/tech-FAQ.txt

There is probably no easy way around it, and that's why most audio players that support "gapless MP3 playback" actually use noise gate of sorts to truncate MP3 audio in order to achieve "gapless playback". Perhaps you can try OGG or WMA formats?
I'm not sure if they can be truly gapless, but worth a shot. Most computers are capable of playing these formats anyway, so it should be as idiot-proof as MP3s :)
Click to expand...

I think you're pretty spot on with your diagnosis. I'll probably use the FLAC option as suggested by VomitHatSteve.

Thanks again guys.
 
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