Posted by Mark Lloyd on 07/18/06 23:11

On Tue, 18 Jul 2006 13:41:43 -0700, Joe Smith <joe@inwap.com> wrote:

>Peter H. Coffin wrote:
>> On Mon, 17 Jul 2006 02:52:02 -0700, Joe Smith wrote:
>>> Summercoolness@gmail.com wrote:
>>>
>>>> I always wonder if Mpeg1 at 352 x 240 is quite clear with 600MB and is
>>>> for 1 hour of video, then for Mpeg2, the size quadruple, and it is 2GB
>>>> for an hour...
>>> MPEG1 was designed to work with 1x CD-ROM drives - 1.4 Mbps.
>>
>> ... but 1x CD speed is 330 Kbps... Perhaps you meant 4x?
>
>Where did you get 330 Kbps? That's not the CD's speed.
>
>2 samples (L + R) of 16 bits each, with a sampling frequency of 44.100 KHz
> = 4 bytes * 44100 = 176,400 bytes per sec = 1.411200 megabits per second.
>
>Trivia question: Do you know where 44.1 KHz came from?
> -Joe

The high end of the range of human hearing is supposed to be 20 KHz.
The sampling rate needs to be at least double that to prevent alias
distortion. The extra is to allow for the fact that filters don't cut
off completely at the exact frequency they're designed for.
--
Mark Lloyd
has a Replay 5xxx
http://notstupid.laughingsquid.com

"The idea that there is an invisible being who
created and still runs this old universe is so
childish, so obviously contrived, that it is hard to
believe anyone with even a modicum of education can
still fall for that scam."

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