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View Full Version : 32kHz upsampled to 44.1kHz - lossy?


GRC
2008-06-24, 05:03 PM
Couple of Zep torrents posted over at ABT, and one of them has the lineage -
Analogue -> 32kHz DAT multiple times -> upsampled to 44.1kHz

It's been sampled from analogue at 32kHz, any 'upsampling' to bring it back up to 44.1kHz can only be based on an algorithm which will 'guess' what to put in..... and such algorithm is every bit as bad as those which 'guess' what to throw away when forming an mp3, ATRAC, or similar lossy file.

Discuss.

paddington
2008-06-24, 05:14 PM
trying to discuss it in that thread, already..

I agree with you.. I might be inclined to call for an exception if it was all there is and needed to be 44.1 for CD burning, obviously.

GRC
2008-06-24, 06:09 PM
trying to discuss it in that thread, already..

I agree with you.. I might be inclined to call for an exception if it was all there is and needed to be 44.1 for CD burning, obviously.

Doesn't that make a case for allowing mp3 or ATRAC if they're 'all there is' of a particular show....? :hmm:

Regards, Graham

paddington
2008-06-24, 06:17 PM
We do allow ATRAC if it is all there is, and recorded before 2008. We do not allow MP3 for any reason.

This one is 33 years old, so if the 32kHz DAT is as good as it gets, I might be inclined to allow it.. but we always discuss things like that first and make a joint decision.

There is supposed to be a source that is 44.1 transfer, anyway, but I'm awiting conformation. The one I have is the same as the first one posted (still running) and it looks to be 44.1kHz (no 16hKhz chop) - but the ST5s all match the one that was listed as 32kHz...

something posted is false.

Five
2008-06-26, 11:54 AM
32kHz DAT cuts off at a similar place to 128kbps cbr mp3 ... however it doesn't introduce slurry mp3 artifacts into the lower frequencies.

I'm not saying 32kHz DAT is ideal but it is a lot better than mp3 imo. hopefully a better source will show up at some point.

As for converting to 16bit/44.1kHz that's just what happens since we're still fixated on compatability with audio cdr format. There's no rule against posting 48kHz FLAC but its rare, rare, rare to see that (and always causes a lot of confusion to the average user...).

GRC
2008-06-26, 05:00 PM
Yeah, but my point is that if you

a) sample analogue to 44.1kHz directly, or
b) sample analogue at 48kHz, then sample-rate-convert it to 44.1kHz

you haven't gone below the final resolution.

If you sample analogue at 32kHz, then upsample it to 44.1kHz, you've gone 'below the line' as it were, and you'll never get back what you lost when you went to 32kHz. In the same way as you never get back what was lost in conversion to mp3, except with mp3 you've lost it when you convert it to mp3; with the 32kHz upsampling, I see it as the upsampling, whilst not necessarily 'losing' data, is having to fill in for what wasn't captured in the 32kHz transfer.

I see a parallel between lineages of

Analogue -> 32kHz -> 44.1kHz and
Analogue -> mp3 -> 44.1kHz
Analogue -> post-2008 ATRAC -> 44.1kHz

and suggest that if the second and third aren't permitted, there might be a case for the first being declined also.