I have been preparing a large body of FLAC albums to load into an "Audio Request" media server and am running into a situation of some files corrupting.
I have prepared many CD's for loading by using EAC (Exact Audio Copy). All of the FLAC files created from CD's with EAC and tagged by Mp3tag work fine in Audio Request.
However, with about 20% of FLAC files I purchased online and tagged with Mp3tag, the FLAC files get corrupted after they are scanned by Audio Request and re-saved automatically by its internal software. For example, after Audio Request calculates a gain computation (a level setting so that songs play consistently) or rewrites metadata for storing data on cached artwork, the FLAC files often get bloated to 2x or 3x their original size and are corrupt and won't play.
In summary, all FLAC files made with EAC are totally fine and about 20% of FLAC files purchased get corrupted consistently when used with Audio Request.
I have been unable to analyze what the difference is between the EAC FLAC files and the purchased FLAC files by using exiftool and other means. I assume there is something different about them that I have not found.
I have uploaded an example of each of these files, that is, a file made with EAC and works fine after scanning, and then a purchased FLAC file that was okay, but then became corrupt after scanning.
FLAC file made with EAC, tagged with Mp3tag - OKAY
FLAC file made with EAC, tagged with Mp3tag, scanned by Audio Request - OKAY
FLAC file purchased online, tagged with Mp3tag - OKAY
FLAC file purchased online, tagged with Mp3tag, scanned by Audio Request - CORRUPT
Any insight into what is going on that would create this problem and a solution would be most appreciated.
It appears that Audio Request is both corrupting tags, and also inserting literally 30MB worth of album artwork into the corrupted file. Or something.
You might want to limit the artwork size. The files play fine, but "kamane" contains a 12.6 MB 4000x4000 px image that is inefficiently encoded to over double its size. Perhaps the reason why purchased files are affected in particular is that they come bundled with oversized digital images.
Audio Request isn't following the standard, and saves the image in the textual tags that players might attempt to load into memory.
Thank you both very much for your insight.
You were correct - if the album artwork jpg file associated with an album was too large for Audio Request to handle (about 6 MB's or more seems to be too much for it), then Audio Request was writing metadata into it that was increasing the size of the FLAC file considerably and corrupting it as well.
Because many FLAC albums I had purchased online came with large artwork files (8 MB's or more) these were the ones that were then corrupting.
Following your advice, I reloaded the original FLAC files into Audio Request without artwork or small artwork (1 MB or less). At which point all the previously "problematic" FLAC files worked perfectly.
So, the problem had nothing to do with the FLAC files but with the associated artwork files. Remarkable.
Thank you again for solving this completely for me. Most appreciated!