Pluginmanager fails to find any plugins in linux

I have MATLAB 2024b installed on Ubuntu 24.04.1. I have gstreamer1 and mpg123:

gst-inspect-1.0  mpg123
Plugin Details:
  Name                     mpg123
  Description              mp3 decoding based on the mpg123 library
  Filename                 /usr/lib/x86_64-linux-gnu/gstreamer-1.0/libgstmpg123.so
  Version                  1.24.2
  License                  LGPL
  Source module            gst-plugins-good
  Documentation            https://gstreamer.freedesktop.org/documentation/mpg123/
  Source release date      2024-04-09
  Binary package           GStreamer Good Plugins (Ubuntu)
  Origin URL               https://launchpad.net/ubuntu/+source/gst-plugins-good1.0

  mpg123audiodec: mpg123 mp3 decoder

I have libsnd1 installed:

apt list libsndfile1 libsndfile1-dev
libsndfile1-dev/noble,now 1.2.2-1ubuntu5 amd64 [installed]
libsndfile1/noble,now 1.2.2-1ubuntu5 amd64 [installed]

In matlab, I try:

>> import multimedia.internal.audio.file.PluginManager;
>> PluginManager.getInstance.WriteableFileTypes        

ans =

  0x1 empty cell array

Exploring further, I see:

>>   PluginManager.getInstance.getPluginForWrite("test.mp3")
Error using multimedia.internal.audio.file.PluginManager/getPluginForWrite (line 58)
Audio file I/O requires libsndfile.
Install this on your system and restart MATLAB.

I have libsndfile, and I can confirm that matlab finds it:

sudo auditctl -a always,exit -F arch=b64 -S openat -S open -F dir=/usr -k usr
matlab
>> import multimedia.internal.audio.file.PluginManager;   
>> PluginManager.getInstance.getPluginForWrite("test.mp3")
>> exit
sudo ausearch -k usr | grep libsndfile
type=PATH msg=audit(1731096294.780:179509): item=0 name="/usr/local/lib/libsndfile.so.1" inode=566340 dev=fc:03 mode=0100755 ouid=0 ogid=0 rdev=00:00 nametype=NORMAL cap_fp=0 cap_fi=0 cap_fe=0 cap_fver=0 cap_frootid=0

I know this issue has been raised before, ( https://www.mathworks.com/matlabcentral/answers/1842843-how-do-i-download-gstreamer-into-matlab-it-is-on-my-computer ), and there is a suggestion that export PATH=/path/to/gstreamer/bin:$PATH might be the solution, but I've placed the location to the gstreamer libraries (/usr/lib/x86_64-linux-gnu/gstreamer-1.0) in both PATH and LD_LIBRARY_PATH without any effect. Note that on my Mac, I see:

>> import multimedia.internal.audio.file.PluginManager;
>> PluginManager.getInstance.WriteableFileTypes

ans =

  8×1 cell array

    {'flac'}
    {'m4a' }
    {'mp3' }
    {'mp4' }
    {'oga' }
    {'ogg' }
    {'opus'}
    {'wav' }

Is there something I'm missing?

[Pramil]

Working for me just fine. Are there any other reproduction steps ?

Answer 1

[Jeff Mandel]

OK, I revisited this after a few apt upgrades and reboots, and now:

>> PluginManager.getInstance.WriteableFileTypes

ans =

  6x1 cell array

    {'flac'}
    {'mp3' }
    {'oga' }
    {'ogg' }
    {'opus'}
    {'wav' }

So I try:

>> PluginManager.getInstance.getPluginForWrite("test.mp3")
Error using multimedia.internal.audio.file.PluginManager/getPluginForWrite (line 58)
The file type is not supported

Looking carefully at what you posted, I noticed single quote vs. double quotes. So:

>> PluginManager.getInstance.getPluginForWrite('test.mp3')            

ans =

    '/usr/local/MATLAB/R2024b/toolbox/shared/multimedia/bin/glnxa64/audio/libmwaudiofilesndfilewriterplugin.so'

Oddly

>> PluginManager.getInstance.getPluginForRead("test.mp3")             

ans =

    '/usr/local/MATLAB/R2024b/toolbox/shared/multimedia/bin/glnxa64/audio/libmwaudiofilesndfilereaderplugin.so'

Looking in $MATLABROOT/toolbox/shared/multimedia/+multimedia/+internal/+audio/+file/PluginManager.m, both of these routines simply call the routine matlab.internal.audioPluginManager. So why 'getPluginForRead' tolerates double quotes and 'getPluginForWrite' doesn't is a mystery to me. So returning to the original problem I was trying to solve:

>> [y,Fs] = audioread('weight.mp3') ;
>>      audiowrite('test.mp3',y,Fs); 
>>      audiowrite("test.mp3",y,Fs);

Works on both Mac and Linux. Which is fine.

So if someone at MathWorks is bothered by this, passing char(fileToRead) to matlab.internal.audioPluginManager in PluginManager.m will avoid this issue.