Cannot edit large MP4 files (> 2 GiB)


I have a bunch of large MP4 (MPEG-4-AVC) files between 4 GB and 25 GB, and this program never writes metadata to those files.

After re-reading my files from disk again, I find out that nothing was saved. It seems to work with small MP4 files, under 2 GB.

Can you check out why ?

v2.78 on Win7 x64.


Depending on tag type, file needs to be rewritten when changing tags.

Your problem sounds like mp3tag would read whole file in memory for rewriting instead of reading/writing block by block... but I can not believe that...

Check memory usage when mp3tag is processing an large single file.
Can you post a sceenshot of taskmanager or sysinternal process monitor?

Well, this happens.
Sometimes it takes a long time - 3% CPU usage. (few minutes) Sometimes this is instant.
But NOTHING gets saved Just try it.