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include <mii.h>
include <mach.h>
include <fset.h>
# CAM_INIT_READ_PIXELS and READ_PIXELS -- Read pixel data with record buffering
# and data type conversion. The input data must meet the MII standard
# except for possibly having the least significant byte first.
#
# Read data in records of len_record and convert to the specified IRAF
# data type. Successive calls of cam_read_pixels returns the next npix pixels.
# Read_pixels returns EOF or the number of pixels converted.
# Cam_init_read_pixels must be called before cam_read_pixels.
#
# Error conditions are:
# 1. A short input record
# 2. Error in converting the pixels by miiup.
#
# This routine is based on the MII unpack routine which is machine dependent.
# The bitpix must correspond to an MII type. If the lsbf (least significant
# byte first) flag is YES then the pixels do not satisfy the MII standard.
# In this case the bytes are first swapped into most significant byte first
# before the MII unpack routine is called.
#
# This version has been modified for the CAMERA format in that byte data
# is also swapped if lsbf = YES and a new record is read if only a
# partial line of data is in the buffer.
int procedure cam_init_read_pixels (npix_record, bitpix, spp_type)
long npix_record # Number of pixels per input record
int bitpix # Bits per pixel (must correspond to an MII type)
int spp_type # SPP data type to be returned
# entry cam_read_pixels (fd, buffer, npix)
int cam_read_pixels
int fd # Input file descriptor
char buffer[1] # Output buffer
int npix # Number of pixels to read
int ty_mii, ty_spp
int npix_rec, nch_rec, sz_rec, nchars, len_mii
int i, n, ip, op
int swap
pointer mii, spp
int read(), sizeof(), miilen()
include "rcamera.com"
errchk miilen, mfree, malloc, read, miiup
data mii/NULL/, spp/NULL/
begin
swap = lsbf
ty_mii = bitpix
ty_spp = spp_type
npix_rec = npix_record
nch_rec = npix_rec * sizeof (ty_spp)
len_mii = miilen (npix_rec, ty_mii)
sz_rec = len_mii * SZ_INT
if (mii != NULL)
call mfree (mii, TY_INT)
call malloc (mii, len_mii, TY_INT)
if (spp != NULL)
call mfree (spp, TY_CHAR)
call malloc (spp, nch_rec, TY_CHAR)
ip = nch_rec
return (OK)
entry cam_read_pixels (fd, buffer, npix)
op = 0
nchars = npix * sizeof (ty_spp)
repeat {
# If data is exhausted read the next record
if (ip + nchars > nch_rec) { # Modified for CAMERA data
# flush the tape buffers, only needed to handle
# camera tapes created with 7-to-9 conversions
if (tape == YES)
call fseti (fd, F_CANCEL, YES)
# Read a data record
i = read (fd, Memi[mii], sz_rec)
if (i == EOF)
return (EOF)
else if ( i < sz_rec - SZ_INT + 1)
call error (0, "Short record encountered")
# Convert from MII format to SPP format
if (swap == YES)
switch (ty_mii) {
# Modified for CAMERA data #
case MII_BYTE: #
call bswap2 (Memi[mii], 1, Memi[mii], 1, #
sz_rec * SZB_CHAR) #
case MII_SHORT:
call bswap2 (Memi[mii], 1, Memi[mii], 1,
sz_rec * SZB_CHAR)
case MII_LONG:
call bswap4 (Memi[mii], 1, Memi[mii], 1,
sz_rec * SZB_CHAR)
}
call miiupk (Memi[mii], Memc[spp], npix_rec, ty_mii, ty_spp)
ip = 0
}
n = min (nch_rec - ip, nchars - op)
call amovc (Memc[spp + ip], buffer[1 + op], n)
ip = ip + n
op = op + n
} until (op == nchars)
return (npix)
end
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