FFMPEG version vs audio quality

[Jeffry67]

I recently explored HDCD transcoding and to do this I had to install the ffmpeg package from SynoCommunity (that’s version 4.2.1-23 of ffmpeg). I finally abandoned the HDCD transcoding because it wasn’t worth it.

Since then I’m using this version of ffmpeg transcoder on my Synology NAS instead of the built-in DSM version (I don’t know which version number they are using).

In short, I’m using this:

Stream.converter = /volume1/@appstore/ffmpeg/bin/ffmpeg

Instead of:

Stream.converter = ffmpeg

I haven’t done full comparison but it seems that the SynoCommunity version of ffmpeg has a better sound, it seems to be softer, richer and with more minute details.

Should there be audible differences when using different versions of ffmpeg? If so, why? I thought that the decoding was bit-perfect!

The drawback with using ffmpeg v 4.2.1 is that the aac transcoding (aac:wav24 doesn’t work anymore. The tracks can’t be played and the log shows: Converter program ended unexpectedly with exit value 1

Thank you,
Jean-François