Dari PC Mag, Februari 2000
http://www.zdnet.com/pcmag/stories/reviews/0,6755,2414820,00.html
potongannya:
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MP3 is a "lossy" compression scheme�meaning some quality is lost during
compression. But MP3 achieves perceptually "lossless" compression through
psychoacoustics. The compression technique cuts out all the audio
information that we can't perceive or that isn't needed.
Dynamic range and sample rate are the two major factors that affect the
quality of digital audio. As you lower the bit rate, you give up one or a
little of both. A good dynamic range is required to reproduce faint sounds
accurately and not clip the loud parts. A high sample rate enables the
accurate reproduction of the original recording across a wide range of
instruments.
Based on our listening tests, we found that a 128-Kbps MP3 clip (sampled at
44.1 kHz) is almost impossible to distinguish from the music on CD. This is
the bit rate you should use for classical music. If you prefer pop or
contemporary vocals without high-pitched instruments, then the 64-Kbps
encoding (typically sampled at 22.05 kHz) is likely to be just as good at
preserving the dynamic range. And the lower bit rate produces files that
are half the size.
As an alternative to MP3, Microsoft's Windows Media Format (WMF) 4.0 is
designed to store twice as much music as MP3. Most players will soon
support WMF, which can encode at 64 Kbps with the full 44.1-kHz sampling
rate in stereo. 128-Kbps MP3 files are typically encoded at 44 kHz stereo.
They can also be encoded at 64 Kbps, but most MP3 encoders sample at 22.05
kHz, limiting the frequency range to 11 kHz. We found that Microsoft's
proprietary algorithms produce near-CD�quality music files at 64 Kbps,
compared with the 128 Kbps required by MP3 for such quality.
To test Microsoft's claim that its 64-Kbps encoding is a better way to go,
we encoded three types of music (rock, jazz, and classical) with MP3 at 128
Kbps stereo and WMF at 64 Kbps stereo (at 44.1-kHz sampling rates). Only
WMF-encoded jazz (with a lot of cymbals) produced annoying artifacts. For
the other clips, we found it difficult to distinguish the MP3- and WMF-
encoded files from the originals.
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Dimana bisa dapet atau URL untuk encoding WMF?
Garind P
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"oc ur mobo not urself or anybody else"
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