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Re: Recode to Play MP3?

bieling@terra.es wrote:

On May 25, 3:37 am, "Michael J. Mahon" <mjma...@aol.com> wrote:


Yep... The figures were right after all.


Nope.



YEP :



Non-accelerated rates would be
((6+4+2)*4+3)/4=12.75 cycles/byte -->> 78.43 KB/s (slightly unrolled)
((6+4+2)*2+3)/2=13.50 cycles/byte -->> 74.07 KB/s (non-unrolled)


OK--I wasn't looking at the formulas, just the time deltas we were
talking about--a danger of focusing too much on the details.  ;-)

These look OK except for the clock rate being 1.0205MHz and the result
is actually "kB" (1000) rather than "KB" (1024).  Since we're comparing
to a 11.025kHz sample rate, the "kB" number is actually handier, so the
clock rate correction gets to 80.04kB/sec for the 4-unrolled loop and
75.59kB/sec for the 2-unrolled loop.

Of course, neither formula takes into account the end-of-page time,
which is admittedly second order (as long as the CF card doesn't choke).

Frankly, these rates are sufficiently high that it's clear something
else is the problem.

-michael

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