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# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
# GBYTES -- Locally implemented bit unpacker for the NCAR extended metacode
# translator. 3 may 84 cliff stoll
# Required for the ncar/gks vdi metacode generator.
#
# Essentially this routine accepts an array which is a packed series of bits.
# [array BUFIN], and unpacks them into an array [array BUFOUT]. Received
# integer INDEX is the beginning bit in BUFIN where information is to be
# placed. INDEX is zero indexed. Received integer argument SIZE is the
# number of bits in each "information packet". Received argument SKIP is the
# number of bits to skip between bit packets. For more info, see page 4 of
# the NCAR "Implementaton details for the new metafile translator, version 1.0"
procedure gbytes (bufin, bufout, index, size, skip, count)
int bufout[ARB], bufin[ARB], index, size, skip, count
int pack
int offset
int bitupk() # Iraf function to unpack bits
begin
for (pack = 1; pack <= count ; pack = pack+1) {
# Offset is a bit offset into the input buffer bufin.
# (offset is 1- indexed; INDEX is zero indexed)
offset = (size + skip) * (pack - 1) + index + 1
bufout(pack) = bitupk(bufin, offset, size)
}
end
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