Re: linear PCM
Re: linear PCM
- Subject: Re: linear PCM
- From: Brian Willoughby <email@hidden>
- Date: Sun, 13 Jan 2008 15:21:48 -0800
On Jan 13, 2008, at 15:04, Roland Silver wrote:
Given a signal with amplitude A at time t, is the value of the
corresponding linear PCM signal at time t just A itself,
No. Amplitude is the maximum value over an entire period of a
waveform. There is only one time t per cycle where the value would
be the maximum. At all other time t, the value will be less than A.
Perhaps, when you said "amplitude," you really meant "instantaneous
value."
or is a conversion required?
A conversion is always either implied or explicit. Signals can
either be pure mathematical functions, software algorithms, or
sampled signals. Functions and algorithms may have an infinite
range, and need to be scaled (converted) to fit within the allowed
range. Sampled signals also need to be scaled before digitization.
Linear PCM signals can be float or fixed, and they can have varying
numbers of bits of precision. As such, an equivalent value can have
many different specific numerical values. The most important
difference is between linear float PCM and fixed linear PCM.
Or, in short, you have neither defined "signal" nor "linear PCM
signal" enough for anyone to answer. Both terms are vague enough
that there is no way to say.
Brian Willoughby
Sound Consulting
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| | >linear PCM (From: Roland Silver <email@hidden>) |