Posted by: "Aaron Ximm"
>> > So, I'm noticing that when I USB-transfer a standard MD to
>> > my computer -- I'm assuming that the compressed MD is
>> > reconstituted as a now, lossy AIFF file -- the file size is
>> > around 737mb. How big will the file be from a HiMD disc?
It is incorrect to call it a lossy AIFF file, the loss occurred when the
piece was recorded, both by sampling loss in the A/D and by the
compression. There was also a small loss due to the error rate of the
recording medium. There will be another change when the file is passed
through the D/A so we can hear it.
> To clarify, AIFF (and the PC equivalent WAV) is not lossy(!). These
> files are full-resolution uncompressed renderings of either compressed
> MD (or HiMD) files, or perfect copies of uncompressed PCM HiMD files.
Well, not very lossy. When you start digging around in how programmers
handle data transfers and processing those files, you often find
resampling and such like going on. And we have talked about how all
storage media has a error rate. These are generally tiny and
insignificant changes, but not always.
And one should always remember that word sampling, you have a bunch of
samples of that original analog sound. If it was completely non lossy
compared to the original analog sound then there would be no reason to
increase the sampling rate. Full resolution is the original analog
before the equipment starts messing with it. Sure, the sampling works
well, but it still represents a loss of data.
In terms of lossy you might also think about how the mic converted the
analog sound pressure to a electrical signal. Each mic converts that
sound differently. That's a form of loss too, probably larger than the
digital data compression people worry about. Certainly it's easy to hear
the differences between different mics.
Walt
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