u-law |
u-law |
Dec 16 2012, 01:50
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#1
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Group: Members Posts: 84 Joined: 14-December 12 Member No.: 105171 |
How come u-law was not used with high sample rates in the old days of computing? A quick search here says u-law is not good for sampling above 16 khz because of high frequency distortion, but when I encoded a 320 kbps mp3 44.1 khz into an 8-bit u-law 44.1 khz format it actually sounded quite ok especially compared to 8-bit linear PCM and even 4-bit ADPCM. So how come it was not used in games and multimedia at good sample rates before mp3 came? I understand that it distorts the sound slightly however this distortion is much less hearable on my samples created with audacity than in the same sample encoded to either linear 8-bit PCM or 4-bit ADPCM. And that encoded music was a 1980s OMD track with high dynamic range, not a modern day overcopressed/clipped sample. I am kind of interested in old formats and computing, so that's why I'm asking. I would insert short sound samples, but I don't know how to add them on this forum.
EDIT - I uploaded some sample files here http://www.hydrogenaudio.org/forums/index....showtopic=98358 . This post has been edited by Neuron: Dec 16 2012, 02:09 |
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Dec 18 2012, 19:47
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#2
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Group: Members Posts: 240 Joined: 14-October 05 Member No.: 25099 |
A little something more to read regarding CPU usage (namely cache). I'm not saying this means that μ-law was too much for CPUs from back in the day, I'm just linking to something I found and might be interesting for this discussion.
-------------------- lame -V 0
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Dec 29 2012, 02:22
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#3
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Group: Members Posts: 84 Joined: 14-December 12 Member No.: 105171 |
A little something more to read regarding CPU usage (namely cache). I'm not saying this means that μ-law was too much for CPUs from back in the day, I'm just linking to something I found and might be interesting for this discussion. Thanks but I think the CPU usage would be high only on primitive microcontrollers, considering televisions since early 1990s were able to decode NICAM http://en.wikipedia.org/wiki/NICAM easily, and NICAM is basically a much better form of what u-law is (10 to 14 bit companding instead of 8 to 12, adaptively increasing or decreasing bit rate etc.). Most 8-bit samplers of the 1980s also used conpanding. In PC situations, it would really help sample storage in the Sound Blaster 16 era as many games back then used raw 8-bit samples that could have sounded a lot better with u-law/other companding algorithms. |
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Neuron u-law Dec 16 2012, 01:50
[JAZ] You should probably take yourself back to the soun... Dec 16 2012, 11:49
Neuron Well, that would be a good reason to use u-law. So... Dec 16 2012, 11:59
psycho Hm, very interesting question, Neuron. I don't... Dec 16 2012, 12:28
Neuron u-law takes the same amount of CPU time (meaning p... Dec 16 2012, 13:02
Kujibo As a game audio developer that lived through 8-bit... Dec 18 2012, 04:33
nu774 Well, I think not that super critical listening is... Dec 18 2012, 05:29
Kujibo A sine wave sweep is the worst possible sample you... Dec 18 2012, 09:37
Neuron Amiga could do 4-bit ADPCM so it definitely could ... Dec 18 2012, 12:03![]() ![]() |
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Lo-Fi Version | Time is now: 20th May 2013 - 08:45 |