macro for batch converting multiple mp3 files to m4a

Audacity 3 Help Forum Windows
1

I am using the Windows 10 OS (Build 18362) and Audacity 2.3.3 (build date Nov 15, 2019).
If I take them one file at a time, it is easy to convert from mp3 to m4a with Audacity.
However, I have been unable thus far to write a macro to convert multiple mp3 files to m4a.
When setting up the macro, there is no “Export as m4a” selection.
Therefore, I have tried to use Export2. Audacity’s guidance for Export2 is Spartan and it has not imparted to me what I need to make this work.

Can anyone please provide guidance on how to write the macro I desire?

If it’s not possible to automate this process with Audacity, please tell me and I will revert to converting the files one at a time.

Thanks for any help.

2

If all you are doing is converting files with no editing, I’d recommend [u]TAudioconverter[/u] (or some other special-purpose conversion program).

Once you’ve set-up the desired output-format and location it’s just drag, drop, and click, and you can drag-in multiple files at once, or multiple folders, etc.

…As you may know, this is a lossy-to-lossy conversion and the “damage” does accumulate. You may not hear any quality loss but it’s something you should be aware of and you should only make lossy-to-lossy conversions when you have a good reason or if you don’t have a choice.

3

Thanks very much for the tip. I’ve downloaded and installed it. I just have one question before I start, if you know the answer, please.

To leave the file volume settings alone during the conversion, should I just uncheck Apply ReplayGain in Settings?

Other than that, it’s straightforward.

I appreciate your comment lossy formats. I make a point of using the max quality settings for mp3 and m4a, and limiting the number of conversions to a minimum, and only when necessary.

My current project is still in the experimental stage. I always listen to the results.

4

To leave the file volume settings alone during the conversion, should I just uncheck Apply ReplayGain in Settings?

That was a good question! I tried it, and yes leave it unchecked.

ReplayGain isn’t supposed to change the actual audio level. It’s just supposed to add a tag to be used by the ReplayGain compatible player software. But, my original MP3 was over 0dB and it looks like the “Auto lower to prevent clipping” kicked-in. It lowered the volume slightly but it didn’t make the “full” ReplayGain reduction which is about -10dB for this particular loud-file.

But when I tried it with replay gain but Auto lower unchecked it was totally fouled-up!

5

Thanks for kindly checking out the effects of those settings. I appreciate you characterizing my question as a good one. I wasn’t sure.

After reading your last post, I converted a batch of 12 mp3 files to m4a with Apply ReplayGain unchecked and the following preset selected:
AAC - 320kbps - Stereo - 44100Hz.

Then, I checked the loudness of the m4a files with Adobe Audition and they were exactly the same as that of the mp3 files I started with. The final quality control step was to listen to the m4a files and I can’t hear any degradation. Pass!

Thanks to you, I now have another verified tool in my audio arsenal. Thanks!

The reason I had to take this route is that Adobe Audition’s Match Loudness batch process does not export in m4a format. I routinely use Match Loudness to level the volume of the assorted audio files I’ve collected into a musical compilation. Audition’s Match Loudness function is the best tool I’m aware of for accomplishing this essential task. iTunes is friendlier to m4a files thn mp3 files, even if you’ve diligently inserted all the metadata.

6

The next Audacity release has a new effect called “Loudness Normalization”. This allows you to normalize tracks / files to a specified “loudness” (as defined by EBU R-128 standard).

7

That will be a welcome addition to Audacity. That feature is just about the only reason I broke down and paid for Audition.

8

The reason I had to take this route is that Adobe Audition’s Match Loudness batch process does not export in m4a format. I routinely use Match Loudness to level the volume of the assorted audio files I’ve collected into a musical compilation. Audition’s Match Loudness function is the best tool I’m aware of for accomplishing this essential task.

There are several options -

There is an unofficial [u]ReplayGain plug-in[/u] for Audacity. This isn’t the “real” ReplayGain as it “permanently” changes the volume instead of writing the ReplayGain tags.

There is a free 3rd-party loudness analyzer called [u]dpMeter 4[/u] that works in Audacity. (It just measures loudness so you have to make the changes manually.)

[u]MP3Gain[/u] and [u]AACGAIN[/u] also make “permanent” changes to the actual volume and they work losslessly without decoding-recording the compressed audio.

Apple’s version of ReplayGain is called [u]SoundCheck[/u] and it’s built into iTunes.