Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[d_pert]

Updated and continued in MC26 forum:
https://yabb.jriver.com/interact/index.php/topic,124054.msg858879.html#msg858879

SHORT VERSION

Convert Format > FLAC-to-ALAC (no DSP) produces LOUDER files with occasional clipping "ticks", most noticeable on, e.g., solo piano.

Try it yourself: 1) get a FLAC, 2) convert it with JRiver (no DSP!), 3) convert it with another tool (e.g. dBpoweramp, EZ-CD), 4) compare in any player.

LONG VERSION

I routinely convert FLAC files to ALAC files using JRiver v.25, with no DSP(s) engaged.

Recently, I noticed some of the albums I've converted have occasional, clipped-sounding "ticks" encoded in them.

When I compare to original FLACs, it confirms that the ALACs generally sound louder, to varying degrees.

To investigate further ... I did some careful comparisons:

I stripped any ReplayGain and/or R128 tags out of all the test/compare files, and turned off any DSP at playback; sure enough the ALACs created with JRiver consistently sounded louder!

I performed new conversions using a different software application (a popular converter), and the resulting ALACs were NOT louder; they subjectively sound the same volume as the original input FLACs, unlike JRiver's converts.

When I ran JRiver Audio Analysis on all the test files, many of the JRiver-created ALACs received +0.0 +0.0 +0.0 "across the board" in the resulting tags, whereas the original FLACs and/or the 3rd party converts received tags only in the range of approx. -10 to -2.

I surveyed all my JRiver FLAC-to-ALAC convert albums/files: where the phenomenon affects a track on an album, it affects all the the tracks on that album.

Questions:

Does JRiver's ALAC conversion normalize or add gain (inadvertently or otherwise), unbeknownst to the user?

Do the louder-sounding ALACs actually have changed, uncompressed 16/24-bit words compared to thier original counterparts? I've converted approx. 10,000 files FLAC-to-ALAC (no DSP) using JRiver over the last few years and dearly hope this is not the case.

Should I stop using JRiver to do FLAC-to-ALAC conversion in order to avoid this phenomenon?

In case it matters:

Sometimes I convert (always with no DSP) one album at a time, using the Playing Now queue for convenience.

Other times I convert (always with no DSP) several albums at a time, using the Playing Now queue for convenience.

Thank you for any light that can be shed.

[tij]

There are tools that compare lossless compress formats ... they extract pcm data and compare their hashtags ... this will definitely provide you with info if MC has modified original data

[tij]

Quick search on net suggest that ffmpeg can do it

https://ffmpeg.org/ffmpeg-formats.html#framemd5-1