Special files

[Cerahobbes]

I have some audio tracks that I want to manipulate but I want to make sure that the file stays intact. These tracks have info embedded in them so I can't have them compressed in any way. These files are in wav format. I would love to add music to the tracks but want to make sure that I will not compromise the embedded info.
Can anyone help?

The things I would like to do is:
crop my tracks
combine one or more tracks into a single track
add music to existing tracks

[jc836]

The safest thing you can and should do-is make a full backup of the files before working with them. Keep the copy completely off-line. Should you make an error, it can be recovered by reloading. I treat all files as irreplaceable and thus do this. The media you use for the copy is also important for long term storage/archiving.

[Cerahobbes]

Thanks for your reply but not quite the answer I was looking for.
I can't verify in any way that Audacity hasn't made any changes other than the ones I made to the new file. I just want to make sure that Audacity doesn't compress or do anything to the file if I don't ask it to.

I would start with a Wav file crop or combine, then save as a Wav.

[alatham]

Audacity won't change your original file at all unless you overwrite it.

When Audacity imports a file, it makes a second copy of all the audio data in a proprietary format (it doesn't work with the WAV file directly, in other words). As far as I know, any "extra" data that isn't audio data won't get imported into Audacity, and therefore won't get exported in the end. Your final file will not have any extra info embedded.

If you're talking about watermarking files so you can identify them later, I don't think Audacity will help you.

[AndyNewton]

Making sure Audacity does not do anything you have not asked it to do:

1) Edit / Preferences / File Formats / Uncompressed Export Format / select the WAV format that is the same as your original file. (There are four different options on my PC in Audacity 1.2.6)

2) Make sure the Audacity project rate is the same as the original WAV file data rate. (This is set automatically when I import an mp3 into Audacity but don't know if it always occurs for WAV files)


Verify that Audacity has not made any changes: Two tricks --->

When trying to learn more about how Audacity processes sounds I found that zooming in - in - in - until individual sound sample points are visible can be most instructive. I was exploring what happens when changing project rates and also the results of various effect menu items, but the same idea may be of use to Cerahobbes. If you want to be Sherlock Holmes you can actually compare the same tiny piece of sound in two tracks side by side, sample point to sample point, to see if any changes have occured.

If two tracks are absolutely identical, or if some parts of the two tracks are identical, then subtracting one from the other should give a result of zero. You can do this subtraction , as a sort of forensic test in Audacity. Select one track, use menu Effect / Invert. Make sure the track gain is the same on both tracks. Select both tracks, use menu Project / Quick Mix. The result should look like a flat zero - but just to be sure use menu Effect / Normalize - if it is still zero after that then it really was a true zero and the two original tracks must have been idential point for point.