I discovered that files I ripped into ALAC format were mysteriously converted to m4a format days or months later for reasons unknown to me. Is this something that the mac OSX does automatically? Does it do this if I use the hard drive optimization that is built into the operating system. If anyone can help or point to a thread on this, it would be appreciated. More details below.
So I prefer rip my CDs into FLAC format. However, for family reasons (Macs in the house), I do rip about 25% of my files into ALAC. I have a Roon lifetime subscription and use it as my primary player, with the Roon core and file storage on a mac-mini.
Since I have Tidal, when I select music to listen to, it will play from local files or from Tidal. However, one day when my internet connection was down, I realized I couldnât access files that I should have on my local drive, as they did not show up in my Roon library. I eventually discovered that the ALAC files had been converted to M4a files! WTF???!!!
Of course Roon does not play M4a files, and I would never choose this format. Even my hi-res HDTracks were converted. I discovered that my ALAC files were converted anywhere from hours to months after they were ripped, according to the âmodified dateâ shown in the file manager. It looks like they were likely converted in batches.
Is this something that the Mac OSX does automatically? Is it possible that it happens if the OSX hard drive optimization is run from the services menu? Or, is there some other reason this might happen on a Mac? Finally, is there anyway to prevent this in the future (because ALAC is needed for the family idevices that wonât run FLAC)?
Apple Lossless Audio Codec (ALAC) encoded data is stored in a MP4 container, and these files have the filename extension .m4a. This is not to be confused with lossy AAC-encoded data stored in a similar MP4 container, having also filename extension .m4a.
All my rips, done on a Mac and encoded with ALAC, are files with .m4a extension, and Roon plays them all back just fine.
I first noticed that the ALAC/m4a files were not showing up in my library a few months ago. Did all my research at that time, and eventually moved the files out of my Music folder. I didnât get around to asking about it until now.
Andreas, after your reply, I moved some ALAC files back into the Music folder and took another look for them in Roon. HmmmâŚthey now show up in the library as they should! I guess the problem was temporary. Perhaps was a bug after an update that was fixed?
Anyway, thanks very much for the reply. It looks all good now. Whew, I was about to re-rip them all as FLAC files. The only thing Iâm still curious about is why the files would show as âmodifiedâ many months to years after they were âcreatedâ/ripped on the mac.
No to Apple Music. Nor do we use iTunes. I had another thought that maybe if we open iTunes it auto-converts them. But from Andreasâ reply above, I think he is saying they are not actually converted. Perhaps, just an extension change?
Again, no. Before using Roon, for several years I played back my ripped ALAC files in iTunes, without ever seeing them touched or changed. From the first day of ripping, all had the filename extension .m4a. This is how it is. There probably must have happened something else which made you think that the files had been changed, even if they had not. One thing to keep in mind, though, is that editing a fileâs metadata will change its modification timestamp.
You can check the m4a container contents with MediaInfo, but not being able to tell lossless from lossy by just looking at the file extension is the reason I switched to Flac.
Thinking back, Roon was unable to âseeâ my ALAC/M4a files around the time I was also having issues with the update to Roon build 783. Perhaps this was all part of the same issue. Roonâs tech department solved my issues by remotely accessing Roon.
Maybe this issue was also solved as a by-product of those fixes, but I wasnât aware of this because I had already removed my ALAC/M4a files from my Roon library to a separate location. Anyway, since Andreasâ initial reply, I have discovered that my ALAC/M4a files do indeed work in Roon now, so I am good to go. If only just a little puzzled as to why âFinderâ shows those files as modified.