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- Version:
- 1.1, November 1991
- Hardware / OS requirements:
- Low Level SESAM Workstation
- Description:
-
- The RESAM software package contains a program for changing
sample rates of signal files, RESAMP, and a program for adding
two signal files, ADD.
- The RESAMP program changes a signal's sample rate from a
sample
frequency Fa to a sample frequency Fb by up-sampling from Fa to
the least common multiple of both Fa and Fb, and subsequently
down-sampling to Fb. When up-sampling a signal k times, each
sample is multiplied by adding (k-1) zeros. The up-sampled
signal is interpolated using a low-pass filter and down-sampled
m times by extracting each m-th sample.
- For example, when resampling noise signals (derived from
Noise-Rom 0) from 20kHz (up 4 times, down 5 times) into 16kHz
(Eurom 0 standard), a lowpass fir filter with a cutoff frequency
of 16/2=8kHz at a sample rate of 20*4=80kHz has been defined
(0.1 fs).
- Resampling a signal from 20kHz into 16kHz using the 1024
taps
FIR filter will take about one hour per megabyte on a 286-12 mHz
with co-processor. A program for designing `windowed FIR
filters' named WFIRDESN is also supplied. More details on the
use of these programs can be found in the readme file on the
distribution diskette.
- The program ADD allows to add signals with a specified
gain
factor and an offset value, which both can be determined with
the SLM program. Also for the first signal, a time-offset
measured in samples can be specified. This feature allows for a
random start point in the noise files.
- Each i-th output-sample is calculated according to the
following expression:
Out[i] =
Gain0 * (Input0[i + SampleOffset0] - Offset0)
+ Gain1 * (Input1[i] - Offset1)
No indication is given if the 16 bits dynamic range is exceeded.
- Developing lab:
-
TNO Institute for Perception
P.O. Box 23
3769 ZG Soesterberg
Netherlands
Tel: (31) 34 63 56 230
Fax: (31) 34 63 53 977
- Contact:
- Jan A. Verhave
Next: SAMITPRO (SAM Iterative Proportional
Up: SAM software tools
Previous: PTS (Progiciel de Traitement
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