Audacity Forum

I have a series of 2 GB MP3 Files (each represent about 40 hrs of continuous audio) that I would like to edit. When I open these files the audacity temp file grows to about 40 GB and there appears to be some challenges getting Audacity to work or at least respond quickly. I have moved the temp file directory to an esata external hard drive given space requirements. This is the same drive the MP3's are stored on.

I have Windows 7
4 GB RAM with 32 GB flash drive (ReadyBoost)
Seagate 1 TB GoFlex w/ e-sata connection
Downloaded Audacity 1 week ago

Is there a more appropriate tool to work with very large MP3 files? Any tips for doing so with Audacity?

The expansion in the temp folder is because Audacity decompresses the MP3 files. Unless the files are 11025 Hz or lower (look above the Mute / Solo buttons on the track), you won't be able to save Audacity projects without breaking the track up into smaller projects. The storage limit is 13.5 hours at 44100 Hz, 27 hours at 22050 Hz and so on. There could be problems editing - most of this is untested.

If you just want to do cuts and pastes or volume edits, try the tools listed here instead which work directly on the file:
http://wiki.audacityteam.org/wiki/Lame_ ... tion#lossy .

If you want to do things like equalisation then you may be better to split the MP3's to a more manageable size in those tools, edit them in Audacity then rejoin them in those tools.


Gale

I'd use MP3Split or mp3DirectCut before anything else.
If you just want to make simple cut/trim type edits then you can probably do the job using only one or other of these.

If you want to do more complex editing I'd recommend splitting the MP3s into more manageable size chunks, say 1 hour of audio, and then use Audacity to edit them.
If you are applying the same processing to each file, you may be able to "batch" process the files using the Audacity "Chains" feature:
http://manual.audacityteam.org/man/Edit_Chains
and
http://manual.audacityteam.org/man/File ... pply_Chain...

Gale Andrews wrote:The expansion in the temp folder is because Audacity decompresses the MP3 files.

Just for the avoidance of doubt ...

Audacity doesn't actually "decompress" the files in that the compression damage that was incurred when the original MP3 was compressed will still be there in the Audacity project.

But as Gale says it does take the Mp3 and turns it into an Audacity project which is an uncompressed format.

So if you import an MP3 into Audacity, edit the project and then export to an MP3 then the edited MP3 will acquire a second dose of compression damage (it's a bit like taking a packet of chicken soup, reconstituting it with watr, where it isn't "real" chicken soup, and then drying it out again - when it will taste even worse when that is reconstituted).

That's why Steve recommended MP3Split etc.

WC

waxcylinder wrote: Audacity doesn't actually "decompress" the files in that the compression damage that was incurred when the original MP3 was compressed will still be there in the Audacity project.

OK, I clarified that on http://wiki.audacityteam.org/wiki/Lame_ ... tion#lossy .

Thanks,


Gale