SEGDREAD - read an SEG-D tape

segdread > stdout tape=


Required parameters:
tape= input tape device
tape=- to read from stdin

Optional parameters:
use_stdio=0 for record devices (9-track reel tape drive)
=1 for pipe, disk and fixed-block 8mm drives
verbose=0 silent operation
= 1 ; echo every 'vblock' traces
= 2 ; echo information about blocks
vblock=50 echo every 'vblock' traces under verbose option
ptmin=1 first shot to read
ptmax=INT_MAX last shot to read
gain=0 no application of gain
aux=0 no recovery of auxiliary traces
errmax=0 allowable number of consecutive tape IO errors
ns=0 override of computed ns to work around SEG-D
flaws. Not used with tape input.

type: sudoc segdread for further information

Credits:
for version 1:
IPRA, Pau, France: Dominique Rousset, rousset@iprrs1.univ-pau.fr
for version 2.2:
EOST, Strasbourg, France: Celine Girard
for versions 2.3:
EOST, Strasbourg, France: Marc Schaming, mschaming@eost.u-strasbg.fr
for version 2.4:
SEP, Stanford University: Stew Levin, stew@sep.stanford.edu
a) Changed definitions of BCD_FF/BCD_FFFF
b) Corrected decoding of general_header_1 in info_gh1.
c) Changed buff=0 to use_stdio=1 to avoid confusion (stdio
IS buffered I/O). Kept old buff= internally for backwards
compatibility.
d) Changed F8015 decoding of negative mantissas to avoid
1 part in 2^14th decoding error on 2's complement platforms.
e) Adapted F8015 to F0015 decoding routine. Unused, but now available.
f) Use AT&T sfio package for tape read.
g) Handle endian and wordsize dependencies portably (I think).
g) Allow tape=- command line argument to accept input from stdin.
h) Compute trace length explicitly from headers so that disk data
input can work.
i) Correct tape trace length calculation to account for demux
trace header extensions.
j) Fix a couple of typos in comments and selfdoc
k) Added F8022 for 1 byte quaternary exponent demux.
l) Added F8024 for 2 byte quaternary exponent demux.
m) Added F8042 for 1 byte hexadecimal exponent demux.
n) Added F8044 for 2 byte hexadecimal exponent demux.
o) Added F8048 for 4 byte hexadecimal exponent demux.
p) Added F8036 for 2 byte 2's complement integer demux.
q) Added F8038 for 4 byte 2's complement integer demux.
r) Added F8058 for 4 byte IEEE float demux.
s) Added ns= parameter to work around bad SEG-D trace
length specifications in headers.

For any problems, send message to mschaming@eost.u-strasbg.fr
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SEGDREAD: Version 2.1, 10/10/94
Version 2.2, 17/08/95
Version 2.3, 04/1997 Thu Apr 10 11:55:45 DFT 1997
Version 2.4, 10/03/98 Tue Mar 10 1998
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