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Full Version: Was this track ever encoded in a lossy format?
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Borisz
What the topic says... I can't tell myself. The spectral view looks very fishy to me, but its possible that it's only because the analog to digital conversion was not too stellar.

*removed by HA staff*
molnart
There are two programs, AuCDetect and TauAnalyzer that can tell you. Can be found on www.true-audio.org
CiTay
Please do NOT offer full tracks for download, see TOS #9. Short clips only.
Borisz
My apologies. Here's a trimmed version (35 secs):

Link removed by moderation. TOS #9 states that clips should be less than 30s.
sony666
I didn't download the track, but looking at the lowpass alone means no much.

I have quite a few pressed CDs, mostly from 80s and early 90s that have 16 or 18k lowpasses.
Sunhillow
looks a bit like some kind of dynamic noise limiter, a processing that reduces the HF amplitude when there is not much HF content. But otherwise the threshold frequency of ~13 kHz is much too high for that.

Edit: Sony666, the lowpass is above 20 kHz, but on more silent parts the content above 13 kHz is attenuated by ca. 15 dB
Synthetic Soul
Link removed again. Please post a clip less than 30s in length.
greynol
FWIW, I looked at the track as originally posted.

I have no reason to suspect that it was lossy.

Spectral analysis alone does not in any way prove that a track is lossy or lossless. Looking at the frequency content over time is much more conclusive. I've seen auCDtect identify mp3 as 100% CDDA using -m 0. I've also seen it identify CDDA as mp3 on so many occasions that I've lost track.

With the caveat about auCDtect aside, I still think it's a very useful tool, the mp3 as CDDA was actually an exception. It is usually quite reliable in determining when something is CDDA.

When you combine auCDtect with how frequency changes over time and you know what to look for, you can make a pretty good case whether a track is lossy-sourced or lossless-sourced.

Are you concerned that this track may have come from a bootlegged disc or something?
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