def read_reel_header(f, filename, endian='>'):
"""
reel_header = read_reel_header(filename)
"""
#data = open(filename, 'rb').read()
reel_header = {'filename': filename}
for key in SH_def.keys():
pos = SH_def[key]["pos"]
format = SH_def[key]["type"]
reel_header[key], index = read_binary_value(f, pos, format, endian)
logger.debug(str(pos) + " " + str(format) + " Reading " + key + "=" + str(reel_header[key]))
# SET NUMBER OF BYTES PER DATA SAMPLE
bps = getBytePerSample(reel_header)
file_size = file_length(f)
ntraces = (file_size - REEL_HEADER_NUM_BYTES) / (reel_header['ns'] * bps + TRACE_HEADER_NUM_BYTES)
reel_header["ntraces"] = ntraces
logger.debug('read_reel_header : successfully read ' + filename)
return reel_header
def read_reel_header(f, filename, endian='>'):
"""
reel_header = read_reel_header(filename)
"""
#data = open(filename, 'rb').read()
reel_header = {'filename': filename}
for key in SH_def.keys():
pos = SH_def[key]["pos"]
format = SH_def[key]["type"]
reel_header[key], index = read_binary_value(f, pos, format, endian)
logger.debug(
str(pos) + " " + str(format) + " Reading " + key + "=" +
str(reel_header[key]))
# SET NUMBER OF BYTES PER DATA SAMPLE
bps = getBytePerSample(reel_header)
file_size = file_length(f)
ntraces = (file_size - REEL_HEADER_NUM_BYTES) / (reel_header['ns'] * bps +
TRACE_HEADER_NUM_BYTES)
reel_header["ntraces"] = ntraces
logger.debug('read_reel_header : successfully read ' + filename)
return reel_header
def getDefaultSegyHeader(ntraces=100, ns=100):
"""
SH = getDefaultSegyHeader()
"""
# TraceSequenceLine
SH = {"Job": {"pos": 3200, "type": "int32", "def": 0}}
for key in SH_def.keys():
tmpkey = SH_def[key]
if tmpkey.has_key("def"):
val = tmpkey["def"]
else:
val = 0
SH[key] = val
SH["ntraces"] = ntraces
SH["ns"] = ns
return SH
def getDefaultSegyHeader(ntraces=100, ns=100):
"""
SH = getDefaultSegyHeader()
"""
# TraceSequenceLine
SH = {"Job": {"pos": 3200, "type": "int32", "def": 0}}
for key in SH_def.keys():
tmpkey = SH_def[key]
if tmpkey.has_key('def'):
val = tmpkey['def']
else:
val = 0
SH[key] = val
SH["ntraces"] = ntraces
SH["ns"] = ns
return SH
def writeSegyStructure(filename, Data, SH, STH, endian='>'): # modified by A Squelch
"""
writeSegyStructure(filename, Data, SegyHeader, SegyTraceHeaders)
Write SEGY file using SegyPy data structures
See also readSegy
(c) 2005, Thomas Mejer Hansen
"""
logger.debug("writeSegyStructure : Trying to write " + filename)
f = open(filename, 'wb')
# VERBOSE INF
revision = SH["SegyFormatRevisionNumber"]
dsf = SH["DataSampleFormat"]
try: # block added by A Squelch
DataDescr = SH_def["DataSampleFormat"]["descr"][revision][dsf]
except KeyError:
logging.critical(" An error has ocurred interpreting a SEGY binary header key")
logging.critical(" Please check the Endian setting for this file: {0}".format(SH["filename"]))
sys.exit()
logger.debug("writeSegyStructure : SEG-Y revision = " + str(revision))
logger.debug("writeSegyStructure : DataSampleFormat = " + str(dsf) + "(" + DataDescr + ")")
# WRITE SEGY HEADER
for key in SH_def.keys():
pos = SH_def[key]["pos"]
format = SH_def[key]["type"]
value = SH[key]
putValue(value, f, pos, format, endian)
# SEGY TRACES
ctype = SH_def['DataSampleFormat']['datatype'][revision][dsf]
bps = SH_def['DataSampleFormat']['bps'][revision][dsf]
sizeT = TRACE_HEADER_NUM_BYTES + SH['ns'] * bps
for itrace in range(SH['ntraces']):
index = REEL_HEADER_NUM_BYTES + itrace * sizeT
logger.debug('Writing Trace #' + str(itrace + 1) + '/' + str(SH['ntraces']))
# WRITE SEGY TRACE HEADER
for key in STH_def.keys():
pos = index + STH_def[key]["pos"]
format = STH_def[key]["type"]
value = STH[key][itrace]
logger.debug(str(pos) + " " + str(format) + " Writing " + key + "=" + str(value))
putValue(value, f, pos, format, endian)
# Write Data
cformat = endian + ctype
for s in range(SH['ns']):
strVal = struct.pack(cformat, Data[s, itrace])
f.seek(index + TRACE_HEADER_NUM_BYTES + s * struct.calcsize(cformat))
f.write(strVal)
f.close()
def writeSegyStructure(filename,
Data,
SH,
STH,
endian='>'): # modified by A Squelch
"""
writeSegyStructure(filename, Data, SegyHeader, SegyTraceHeaders)
Write SEGY file using SegyPy data structures
See also readSegy
(c) 2005, Thomas Mejer Hansen
"""
logger.debug("writeSegyStructure : Trying to write " + filename)
f = open(filename, 'wb')
# VERBOSE INF
revision = SH["SegyFormatRevisionNumber"]
dsf = SH["DataSampleFormat"]
try: # block added by A Squelch
DataDescr = SH_def["DataSampleFormat"]["descr"][revision][dsf]
except KeyError:
logging.critical(
" An error has ocurred interpreting a SEGY binary header key")
logging.critical(
" Please check the Endian setting for this file: {0}".format(
SH["filename"]))
sys.exit()
logger.debug("writeSegyStructure : SEG-Y revision = " + str(revision))
logger.debug("writeSegyStructure : DataSampleFormat = " + str(dsf) + "(" +
DataDescr + ")")
# WRITE SEGY HEADER
for key in SH_def.keys():
pos = SH_def[key]["pos"]
format = SH_def[key]["type"]
value = SH[key]
putValue(value, f, pos, format, endian)
# SEGY TRACES
ctype = SH_def['DataSampleFormat']['datatype'][revision][dsf]
bps = SH_def['DataSampleFormat']['bps'][revision][dsf]
sizeT = TRACE_HEADER_NUM_BYTES + SH['ns'] * bps
for itrace in range(SH['ntraces']):
index = REEL_HEADER_NUM_BYTES + itrace * sizeT
logger.debug('Writing Trace #' + str(itrace + 1) + '/' +
str(SH['ntraces']))
# WRITE SEGY TRACE HEADER
for key in STH_def.keys():
pos = index + STH_def[key]["pos"]
format = STH_def[key]["type"]
value = STH[key][itrace]
logger.debug(
str(pos) + " " + str(format) + " Writing " + key + "=" +
str(value))
putValue(value, f, pos, format, endian)
# Write Data
cformat = endian + ctype
for s in range(SH['ns']):
strVal = struct.pack(cformat, Data[s, itrace])
f.seek(index + TRACE_HEADER_NUM_BYTES +
s * struct.calcsize(cformat))
f.write(strVal)
f.close()
