Import Failure - Does not recognize MP3 files

Audacity 3.1.3, MacOS 11.6.1

I’m importing a set of MP3 files to build a single mixed MP3 file. Some of the files import and some do not. There does not seem to be any rhyme or reason.

Audacity did not recognize the type of file

Try installing FFmpeg.

FWIW ffmpeg is installed. I know the files on which Audacity balked are good .mp3 files. I’ve never seen this error before.

I use home brew, and coincidentally, brew upgrade installed a new version of audacity yesterday. It had been awhile since I used audacity so I can’t say which prior version was the first to have this error.

Should I fall back on an earlier audacity? Should I not use brew to install Audacity upgrades? This has not been a problem before.

Thanks in advance.

EDIT - Uninstalled the home brew installation, downloaded the .dmg, installed new from the .dmg … same thing, no help.

Audacity trips over the same files, saying they are not recognized.

Do other programs (e.g. VLC, Quicktime Player, Firefox) have trouble with any of the files?
– Bill

What does this webpage say about the files?

Complete name                            : 40-sophie_zelmani-to_know_you.mp3
Format                                   : MPEG Audio
File size                                : 2.38 MiB
Duration                                 : 2 min 34 s
Overall bit rate mode                    : Constant
Overall bit rate                         : 128 kb/s
Album                                    : Road Mix 1
Album/Performer                          : Various
Track name                               : To Know You
Track name/Position                      : 40
Grouping                                 : Various
Performer                                : Sophie Zelmani
Publisher                                : Sophie Zelmani
Genre                                    : Alt Rock
Cover                                    : Yes
Cover type                               : Cover (front)
Cover MIME                               : image/png
Initial key                              : 1536

Format                                   : MPEG Audio
Format version                           : Version 1
Format profile                           : Layer 3
Format settings                          : Joint stereo / MS Stereo
Duration                                 : 2 min 34 s
Bit rate mode                            : Constant
Bit rate                                 : 128 kb/s
Channel(s)                               : 2 channels
Sampling rate                            : 44.1 kHz
Frame rate                               : 38.281 FPS (1152 SPF)
Compression mode                         : Lossy
Stream size                              : 2.36 MiB (99%)

Other apps do not have trouble with the files. On a lark I used the file command against the .mp3 and got this –

40-sophie_zelmani-to_know_you.mp3: Audio file with ID3 version 2.3.0

which looks ok to me but other files show more details –

29-folk_implosion-gravity_decides.mp3: Audio file with ID3 version 2.3.0, contains:MPEG ADTS, layer III, v1, 192 kbps, 44.1 kHz, Stereo

It’s notable that the ones Audacity does not like have the additional layer, rate, kHz, and stereo information missing. It must be in how those .mp3’s were originally written.

Perhaps you could open the problematic files in VLC (or some other program) and save them, thus stripping the extra layers?
– Bill

I haven’t been able to look at this for awhile, but tonight I had some time to explore it again.

The problem is not stripping the extra layers. Those files (with the extra layers) are fine and Audacity is ok with them. It’s the files that do not have the layers.

They open fine in VLC (and when copied to my Android), but opening them and saving them back is a heavy time-consuming process and I’m finding more and more files with this problem, thus rendering this solution sub-optimal.

This has to be a problem with a recent version Audacity. I’ve never had problems with it opening any .mp3 before.


I don’t understand what this means. What are the additional layers that are added and where did they come from? The .mp3 files in question were produced by Total Recorder in a process similar to each other. It’s not like I consciously chose some files to have the layers and some not.

Maybe this is on ffmpeg? I could look there and see if there is a conversion argument that will strip, add, or reorder the layers in an agreeable manner.

Your earlier statement:

It’s notable that the ones Audacity does not like have the additional layer

Then your later statement:

Those files (with the extra layers) are fine and Audacity is ok with them.

appear to directly contradict each other.

Converting them all to .flac fixes the problem. I can work around that but I still believe there is an error somewhere in Audacity and/or ffmpeg that won’t process the .mp3 files.

Thanks, I’m going to close this one.

Thanks for your reply Steve, Maybe I was fat-fingering my statements earlier. To clarify, the info I got on the files came from the Unix-level ‘file’ command. If the file output showed

Audio file with ID3 version 2.3.0

Audacity would not recognize it or import it. But if it showed

Audio file with ID3 version 2.3.0, contains:MPEG ADTS, layer III, v1, 128 kbps, 44.1 kHz, JntStereo

then it was imported. I’m just going to use ffmpeg to convert to .flac and call it a day.

If you are interested in finding out what’s different between the “good” files and the “bad”, you could try analyzing them with and look for common factors and differences.