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Old 22nd October 2016, 19:33   #1390  |  Link
LoRd_MuldeR
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Quote:
Originally Posted by digitaltoast View Post
During install, it wants to install to folder 4.11 and won't let me change path.
That's because the installer will "upgrade" the existing installation - which is located wherever you originally installed LameXP.

Quote:
Originally Posted by digitaltoast View Post
When encoding mp3, even when I override the samplerate and enforce 44.1KHz, it downgrades to 32KHz etc, at anything above VBR compression level 6.
And that's because of LAME's psycho-acoustic model.

The sampling rate determines the highest frequency that can be retained (cf. Nyquist–Shannon sampling theorem). So, by reducing the sampling rate from 44.1 kHz to 32 kHz, you are effectively low-pass filtering the audio. In other words, the highest frequencies are discarded before the actual encoding. At a sampling frequency of 44.1 kHz the highest audio frequency that can be retained (without aliasing) is 22.05 kHz; at a sampling frequency of 32 kHz, the highest audio frequency that can be retained is 16 kHz. Low-pass filtering the audio makes a lot of sense at very low bitrates (or the lowest VBR quality levels), because loosing the highest frequencies is way less disturbing than the compression artifacts that arise otherwise.

Note: It's possible to "force" LAME to encode at the original sampling rate, by explicitly specifying the "--resample" option with the original sampling rate. But you almost always do not want this!
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Last edited by LoRd_MuldeR; 22nd October 2016 at 19:39.
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