First post, long time user, but now I’ve got a question about something that’s bugging me.
Lately I’ve been busy mixing A LOT of wav-files, with a length of 3 to 15 seconds. Although I’ve selected “Read uncompressed audio files directly from the original” in the Import / Export Preferences, I’ve noticed for a track of ± 6 minutes I made the _data folder to be a staggering 268MB in size. After some searching I found out this setting doesn’t apply to “Uncompressed files shorter than 30 seconds long”… 268MB is completely madness as the wav-file source directory is only 17MB.
Is there perhaps already a way to override this secret setting to read uncompressed files shorter than 30 seconds long directly from the original as well?! If not, can I hereby make a feature request? Thanks a lot.
It doesn’t just read in the file. Depending on your settings, Audacity also converts to 32 bit-floating bit depth no matter how it arrived. It’s the only way to be able to apply multiple effects and tools and even damage the sound a little by accident with multiple, wildly different style files without seriously effecting the music in the final show.
As soon as you do any edits or apply any effects the audio will be effectively copied in anyway. Audacity has to do this since effects are not applied in real time but instead alter the file permanently (barring Undo) and immediately. Since you are referencing the original file Audacity has to create “block files” to store the changed audio.
As Koz points out, if you have not changed your preferences then Audacity stores audio data in 32-bit float. 6 minutes of stereo would be 120 MB. That’s a far cry from the 268 MB you report. Was this folder size determined while the project was open or after you quit Audacity? Audacity stores comprehensive Undo information which can cause the project _data folder to balloon in size while the project is open.
Ok, I thought all the changes and effects you apply to a project are stored in the aup-file (like a realtime AviSynth-script). Guess I was wrong.
Because of 32-bit float I expected it to be a bit larger in size, but now that you mention all the undo-information is stored in those au-files as well, that explains a lot. But are you saying the _data folder will only grow in size this much as long as the project is open and shrink upon closing the project? Because the 268MB as it so happens is of a closed project.
Thanks for your input. I guess I have to resign to it.
The _data folder will grow to reflect that you copy in (or make a changed copy of) lossless PCM data with every edit.
When you close the project, the size of the _data folder will reduce because the PCM data required will only relate to the project content as saved, without any undo data being stored. This will still be much larger than if you had done no edits at all, in which case the _data folder would be populated only with small .auf summary files which are not real audio data.
If you still have multiple tracks in this project that may explain the large size of the saved and closed project _data folder.
I should clarify that unless you make an edit on the entire track, you still need the “read directly” WAV or AIFF file to remain available. You still need the WAV or AIFF file to remain available if you undo back to a state where the project depended on that file. For example, if you faded in the start of the track, amplified the whole track then undid the Amplify, the project will still fail if the file is unavailable. So the simple rule is, just keep the original file available if reading directly.