Is there a program anywhere to automatically synchronise tags between two mp3 files or even better between two folders of mp3 files? It would greatly simplify maintaining file copies when tags in the originals have been changed.
Why would you synchronize only the tags and not the entire file?
You can use Tag Copy and Tag Paste to accomplish this.
Open all of source and target files in MP3tag,
Highlight the files you want to copy the tags from, right click and select Tag Copy
Highlight the target files, right click and select Tag Paste
Be sure that you're copying from and pasting to the same number of files, in the same order.
Because I know that only the tags have changed.
Yes, that would work although it could still be quite tedious picking out the files whose tags have been changed from two libraries of 2000 files each. I was thinking more of something along the lines of the FileSync program which compares any number of files from a souce and a target location, identifies and filters out those whose "Dates Modified" are different and if required replaces the older version with the newer version (or indeed vice versa). In the case of tags a similar program would compare a single tag e.g. "Album", in each source and target mp3 file, indicate whether or not they are the same and then if different replace one with the other as required. Any ideas? Would it be possible in Windows to write a script for such a process?
If you look for a file synchronization program, you ma have a look at the MS SyncToy.
I don't know whether there is a program anywhere that compares tags, filename and audio and finds out which is the updated one.
Do you hope that this is faster then simply copy the changed files?
SyncToy 2.1 appears pretty much the same as FileSync. I am really only looking for a program to compare tags, display differences and allow changes to be made. It wouldn't have to find out which file is the updated one.
Basically yes, and also since tag differences are not apparent except via a tag editor such as Mp3Tag it would simplify the task of identifying any differences between the metadata of two otherwise identical mp3 files. The alternative as you suggest would be simply to copy all files, whether their tags have been changed or not.
You should copy only the files with changed tags. Mp3tag has an option to actualize the file modification time. This is enough for almost any sync program to detect changed files. Even the built-in robocopy in Windows can do that for you.
I bet that the checksum is different. Or the size because the padding was exhausted.
I think it is much easier to use OS functions for file handling than specialized programs that first have to open a file, interpret the data and then do something (or not).
I think that OS functions that look at the FAT are faster.
I think the topic wanders off to some kind of duplicate detection or list comparison - and this something that, even though it has been requested numerous times, has not been implemented.
MP3tag does not compare the data of any two or more files. Mp3tag only knows the data of the current file.