Hello

Sorry to be so ignoramus (this name tells me something... Radi... ) but i want to kown is there is a bond between the time resolution and the frequency of a sound.
IHMO increasing the last improves the first in that way you can reduce the pre-echo artefact.
My question is very simple: is it better to convert to 48 kHz before encoding ? (even with codecs what use 192 samples for short blocks).

Thank you for your precious help.
Have a merry christmas !


Sincerely,
Nick

Edit: I'm sorry but as you can imagine, the title is not "the" but "Relation between Time res. and frequency".
Sorry

There's been some discussion here about this. IIRC the results were this:

mp3 (lame)
- lame (especially alt-presets) is tuned for 44.1kHz and performs audibly worse on some samples at 48kHz (but not better anywhere IIRC).
- pre-echo could be reduced somewhat using 48kHz theoretically, but OTH there are more frames/blocks per second, so more bits are needed to encode the same - that's why for low bitrates resampling to e.g. 36kHz is recommended.

musepack
There are a few problem samples that improve using 48kHz.

There is a relation between the time resolution t and the maximum frequency Fmax of a sound :

Fmax=1/(2t)

But the pre echo artifact in encoding don't directly depend on this.



Can you find a link ? I know that resampling to 48 kHz is not recommended, but I don't remember about tests showing problems.

Here I found:


I don't know anymore which songs/positions I ABXed. (It was from this DVD, a classical/world music live concert.)

Now I've done a new test using Desmond_1 sample (from 24/96 vs CD quality sample suite):
Original vs.
Original, converted to 44.1kHz/24bit with fb2k resampler (slow) + diskwriter, encoded with lame 3.90.3 --alt-preset standard and
Original, converted to 48kHz/24bit with fb2k resampler (slow) + diskwriter, encoded with lame 3.90.3 --alt-preset standard

Focussing on 1-4s I was able to ABX successfully [Original vs. 48kHz mp3] and [44.1 mp3 vs. 48kHz mp3] but not [Original vs. 44.1kHz mp3]. (The difference I heard was fluttering/bumping of the cymbals/hihats).

To find other similar samples, using music with lots of high pitched, noise-like content should be promising (e.g. live recordings, metal with distorted guitars + cymbals).