Premiere Pro 2024 MP3 audio lags

While Mr. Stegner gave an awesome and deep technical response, which by the way is incredibly informative, thanks! ... there is a simple practical thing to do with mp3 files.

As you noted, you had opened in Audition. Well, you can quickly save that file out of Audition as a .wav file, and then it will work better in any NLE or DAW, realistically.

I know a number of sound mixer types who simply do that with all mp3 files, and who work in other apps "natively".

It's like so many colorists simply t-coding all long-GOP H.264/5 files to an intraframe file for grading. Because ... that just works better on the timeline, always.

Hi,

I’ll answer this and answer it broadly for any user that come across this thread in the future so it might be able to help.

The quick answer is that you will want to delete your media cache to fix this.  Yes I know it is a pain to rebuild, but it is the quick and easy answer.  The easiest way to do this is to hold the shift key on launch of Premiere and select “Delete Media Cache” Option.  The next time the any project is opened the required files will automatically be rebuilt.

Now, Why?

MP3’s in Premiere need to be converted from the perceptual encoding format that they are stored in, into uncompressed audio data (PCM data, like the common .wav format).  In Premiere, that is done automatically when importing Mp3’s.  This is stored in the Media Cache files location as a .CFA file, and the Media Cache database makes a 1:1 connection between the .mp3 you imported and the uncompressed .cfa file.  So when you play back an MP3 in Premiere, you are actually playing back the .cfa file from disk.

That .cfa to .mp3 connection is held and stored in the Media Cache Database, and used in all Premiere Pro projects from that point on.  The same CFA files is also used in After Effects, as you are finding out.

So, now you know how the Media Cache system handles MP3’s.  Now, for some reason, and I don’t know why, I wish I did know why, your CFA file had errors introduced into it when you first imported it to Premiere and Premiere was doing the conversion from the encoded MP3 data to the uncompressed CFA data.  How this happened I don’t know, but it could be something as simple as your disk was unable to keep up with the write speed of the CFA data and chunks of the CFA file are missing.  Or a whole myriad of other reasons.

Once a CFA file is corrupted, there is no mechanism to correct it in Premiere with out deleting the CFA file from disk.  The corrupted CFA file will be used over and over, again and again in Premiere until it is regenerated.

Luckily, regenerating a CFA file is usually not error prone, so deleting the media cace and regenerating it will almost always fix the issue.

Deeper dive Info:  If you really want to just regenerate the single CFA file that is corrupt, you can go into the location of your Media Cache Files location (you can find it in your preferences) and search for the file name of the original MP3.  In this case it will be “ES_Crazy like That - Lofive”.  Locate the file with the same name and the sample rate apended onto it, with the extension .CFA.  In this case it will be literally “ES_Crazy like That - Lofive.mp3 48000.cfa”.  Close Premiere, delete that single file and then reopen the project or reimport the MP3.  A new CFA file will be created.

Please let me know if there are any questions.