1 Oct
2014
1 Oct
'14
11:56 a.m.
[Egor Sanin]
Now the question is whether it is possible to analyze
an
audio file encoded in a lossless format and
determine if it existed as a lossy file in a
previous life?
The lowpass/antialiasing filters used for most audio productions
usually operate very close to the Nyquist limit. Those employed in
lossy audio data compression often (but not always) are set to a lower
cutoff frequency. On a spectrogram, their effect is visible as a
total absence of energy above, say, 20kHz or lower.
Cheers, Tim