Corrupted FLAC files after tag edit

[cd_paul]

If I edit the comment tag of a FLAC file it is then corrupted and fails a FLAC frontend test procedure.

After reading various treads in the forums I have tried a new flac dll and then installed MM 2.5.5.998. But, my FLAC files still get corrupted after an edit.

Please help!

[Teknojnky]

Unless you re-rip or do a flac to flac conversion (via MM), then the file will still show corrupted with flac -t. (ie it does not get automatically fixed, you must do FLAC to FLAC conversion, or less appealingly you can re-rip)

I have not had any further flac problems with 998.

Please confirm whether or not your using a re-flac'd or re-ripped file.

[cd_paul]

I have kept a copy of the original ripped file which passes the FLAC frontend test. If I make a copy of it ( re-tested and still passes ) then edit this copy ( with 998 ) it is then corrupted.
Also, if I do a FLAC to FLAC convertion ( with 998 ) on a corrupted file it remains corrupted.

[tbessie]

I have kept a copy of the original ripped file which passes the FLAC frontend test. If I make a copy of it ( re-tested and still passes ) then edit this copy ( with 998 ) it is then corrupted.
Also, if I do a FLAC to FLAC convertion ( with 998 ) on a corrupted file it remains corrupted.

Yes, if you're tagging a clean file that passes the FLAC test, and then it doesn't pass, and you tagged it with 998, then there is a problem and the developers should look into it.

Email Jiri with a link to that file - that's what I did when I was having troubles with my files. I don't know that he'll have the time to try to fix it (since they're working on MM 3.0, full FLAC tagging support with album art, etc., now), but it's worth a try.

- Tim

[jiri]

Certainly, if you have a consistent way how to reproduce this problem with the latest MM version, send me the file.

Thanks,
Jiri

[cd_paul]

Thanks for your advice Tim ( tbessie ).

I will email Jiri with a copy of the original and corrupted files.

[cd_paul]

As recommended by Jiri I have made a clean new install of MM 998 on my computer. Since then all files tested can be repaired by doing a FLAC to FLAC conversion and new edits do not corrupt the files.

My first try at installing 998 apperaed to be OK. The 'help about' announced it as 998 and the flac dll was identical ( checked using file compare ) to the version currently on my computer. So, anybody moving to 998 from an earlier version should make a clean new install to be sure.

I have a very large number of files to check and repair. If I get any problems I will post on this forum.

The issue of 'corrupted FLAC files after tag edit' should now be considered as resolved.

[rusty]

just an fyi in case you're interested. MM 3.0 alpha 3 now supports Album Art tagging for flac.

-Rusty

[kdo]

I would like to point out, that converting FLACs which have been corrupted by previous MM version does not fix the files -- the new converted FLACs are a bit shorter (the first audio frame is obviously lost).

It's good I noticed this now in the very beginning. Immediately downloaded 2.5.5.998. Now the flacs are encoded OK, it seems.

[tbessie]

Kdo...

Do you mean, when I take a flag that was corrupted by tagging via an older version of MediaMonkey, then re-encoded with FLAC (FLAC->FLAC) with v998 of MediaMonkey, I lose the first audio frame?

What have you found this sounds like? I finished ripping my ENTIRE library
with MM (pre-998) awhile back, and went back and checked for bad FLAC files (had a whole bunch of 'em, several hundred at least) that I reencoded FLAC->FLAC. I'm curious if I can here degredation on these files, so maybe you can relate what differences you noticed?

I'd hate to have to go back and RE-RIP all the damn things!

- Tim

[kdo]

Do you mean, when I take a flac that was corrupted by tagging via an older version of MediaMonkey, then re-encoded with FLAC (FLAC->FLAC) with v998 of MediaMonkey, I lose the first audio frame?

Yes, unfortunately.

I'm curious if I can here degredation on these files, so maybe you can relate what differences you noticed?

Well, if you ripped tracks to separate flacs then these are no longer gapless. (it is not an issue for flac images of whole cds).

Most songs begin and end with pure silence, so hopefully it is not going to be audible.

How bad it is for you really depends on what was your goal of creating flac archive and how anal are you about this business of archiving.

If it is just for convenient transcoding to mp3 afterwards, then perhaps it is not so important, as mp3 themselves are not gapless.

Another issue: if you later decide to burn these flacs to audio CDs, then you will have to use smart burning software capable of padding the tracks to the standard cdda-sectors. If you burn such corrupted flacs to a cd without special care there will be audible clicks between tracks.

/Konstantin

[kdo]

By the way, if you still have the original wrongly-encoded flacs, it could make sense to keep them for a while.
Maybe someone can program a tool to recover such flacs. It might be possible to guess correct values of the header of the first frame to reconstruct it.

[tbessie]

By the way, if you still have the original wrongly-encoded flacs, it could make sense to keep them for a while.
Maybe someone can program a tool to recover such flacs. It might be possible to guess correct values of the header of the first frame to reconstruct it.

I still have all of the FLACs I ever ripped, although most were re-FLAC'd and some had been corrupted. I don't recall which ones had which problems, though I DO have a list of all the files that had to be re-FLAC'd, I think.

I'll listen to a few of them to see.

How can you tell if a FLAC has lost it's gapless-ness, by listening, or looking at a graph of the waveform?

- Tim

[kdo]

How can you tell if a FLAC has lost it's gapless-ness, by listening, or looking at a graph of the waveform?

Well, when a bit of audio is chopped off from the file it is by definition not gapless.

Take a CD which you know should have some tracks with continuous music playing without a pause between tracks, e.g. the last tracks from Pink Floyd DSOM.

Compare listening to the transition between such tracks.

Or even better: take a random track and cut it in the middle with some wave editor -- there you have your perfect gapless files to experiment with.


/Edit: Wait a second, was that your question or did you want to know how to find out the exact length of a flac file?

[Guest]

How can you tell if a FLAC has lost it's gapless-ness, by listening, or looking at a graph of the waveform?

Well, when a bit of audio is chopped off from the file it is by definition not gapless.

Take a CD which you know should have some tracks with continuous music playing without a pause between tracks, e.g. the last tracks from Pink Floyd DSOM.

Compare listening to the transition between such tracks.

Or even better: take a random track and cut it in the middle with some wave editor -- there you have your perfect gapless files to experiment with.


/Edit: Wait a second, was that your question or did you want to know how to find out the exact length of a flac file?

No, you answered my question, kind of - I was just wondering if there was more to it - i.e. if there was a characteristic look to the waveform in this particular case of FLAC file truncation, that's all.

- Tim