File smaller after saving with Mp3tag, With no changes made with file Options

[Just for My Memo...]

My original MP4 audio file size is 7626KB.
After saving with Mp3tag, with no changes made to file, file size is decreased to 7184KB (loss 442KB, which is pretty big for an audio file).


Can you explain what was lost in 442KB after saving with Mp3tag?
In the future releases, could Mp3tag keep the file original (with no loss of size) after saving with it?

P/S:

• This happens with every MP4 audio file
• With some other tag editors, MP4 file is still original (7626KB)

This post has been edited by Just for My Memory: Feb 10 2012, 14:04

[dano]

How was this file created?
iTunes files seem to have some big free atoms that are completely empty and Mp3tag removes them

This post has been edited by dano: Feb 10 2012, 14:33

[Just for My Memo...]

How was this file created?

Meet the Robinsons - Little Wonders.m4a

You can try this with every other MP4 audio file; and everytime, after saving with Mp3tag, there is a big loss in file size.

iTunes files seem to have some big free atoms that are completely empty and Mp3tag removes them

And Mp3tag shouldn't if user didn't specify it to do so.

This post has been edited by Just for My Memory: Feb 10 2012, 14:38

[dano]

Only empty space (padding) is removed. The files are about 5% bigger than needed.
I don't think there will be an option for that.

[Just for My Memo...]

Only empty space (padding) is removed. The files are about 5% bigger than needed.
I don't think there will be an option for that.

Again, I think there SHOULD be an option for Mp3tag to keep or delete that. Myself wanted it to be kept, and some may want to delete it.



There are tag options for MPEG (MP2, MP3 files), APE/MPC; and there should have one for MP4 too!