Why are 128kbit/s MP3s usually 44,100 Hz? |
Why are 128kbit/s MP3s usually 44,100 Hz? |
 Oct 14 2012, 01:44
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#1
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Group: Members Posts: 30 Joined: 14-October 12 Member No.: 103838  |
Since 128kbit/s MP3s usually has a low-pass filter at 16,000 Hz, and the Nyquist-Shannon theorem states that all frequencies under f/2 Hz can be totally described at an f Hz sampling rate, why not encode at 32,000 Hz? Wouldn't it save more space?
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Oct 14 2012, 21:10
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#2
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 Group: Members Posts: 353 Joined: 31-March 06 From: Houston, Texas Member No.: 29046 |
Indeed, many encoders *do* resample for low bit rates. I've never seen any that do it at 128 kb/s, but once you drop below 100 kb/s it's more common. I forgot exactly where it kicks in with LAME, but LAME does this if you set the quality low enough (V6 maybe? V7?)
-------------------- http://www.last.fm/user/sls/
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eamon123 Why are 128kbit/s MP3s usually 44,100 Hz? Oct 14 2012, 01:44
splice QUOTE (eamon123 @ Oct 13 2012, 16:44) ...... Oct 14 2012, 01:53 saratoga QUOTE (eamon123 @ Oct 13 2012, 20:44) Sin... Oct 14 2012, 04:03
eamon123 QUOTE (saratoga @ Oct 14 2012, 04:03) Sin... Oct 15 2012, 05:02 saratoga QUOTE (eamon123 @ Oct 15 2012, 00:02) If ... Oct 15 2012, 05:38 Dynamic QUOTE (eamon123 @ Oct 15 2012, 05:02) Lis... Oct 16 2012, 18:07 eamon123 QUOTE (Dynamic @ Oct 16 2012, 18:07) tona... Oct 17 2012, 19:31 Dynamic QUOTE (eamon123 @ Oct 17 2012, 19:31) QUO... Oct 17 2012, 21:48 halb27 QUOTE (eamon123 @ Oct 17 2012, 20:31) I... Oct 17 2012, 22:19 halb27 Compreession is more effective when using 32 kHz. ... Oct 14 2012, 08:12 pdq A 128 kbps encoding is the same size regardless of... Oct 15 2012, 03:02 halb27 If you listen to tonal problems at 128 kbps, you... Oct 15 2012, 05:43 robert MPEG-1 Layer 3 frames consist of 2 granules a 576 ... Oct 16 2012, 18:46 Dynamic Oops, thanks Robert. If I could edit my post now, ... Oct 16 2012, 19:39 Martel The problem is - how exactly do you resample a 44.... Oct 18 2012, 15:24 halb27 Sure you can't get 16 kHz bandwidth, but somet... Oct 18 2012, 16:55 |
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