# http://pyrocko.org - GPLv3
#
# The Pyrocko Developers, 21st Century
# ---|P------/S----------~Lg----------
from struct import unpack
import os
import re
import math
import logging
from pyrocko import trace
from pyrocko.util import reuse, ensuredirs
from .io_common import FileLoadError, FileSaveError
logger = logging.getLogger('pyrocko.io.mseed')
MSEED_HEADER_BYTES = 64
VALID_RECORD_LENGTHS = tuple(2**exp for exp in range(8, 20))
def iload(filename, load_data=True, offset=0, segment_size=0, nsegments=0):
from pyrocko import mseed_ext
have_zero_rate_traces = False
try:
isegment = 0
while isegment < nsegments or nsegments == 0:
tr_tuples = mseed_ext.get_traces(
filename, load_data, offset, segment_size)
if not tr_tuples:
break
for tr_tuple in tr_tuples:
network, station, location, channel = tr_tuple[1:5]
tmin = float(tr_tuple[5])/float(mseed_ext.HPTMODULUS)
tmax = float(tr_tuple[6])/float(mseed_ext.HPTMODULUS)
try:
deltat = reuse(1.0/float(tr_tuple[7]))
except ZeroDivisionError:
have_zero_rate_traces = True
continue
ydata = tr_tuple[8]
tr = trace.Trace(
network.strip(),
station.strip(),
location.strip(),
channel.strip(),
tmin,
tmax,
deltat,
ydata)
tr.meta = {
'offset_start': offset,
'offset_end': tr_tuple[9],
'last': tr_tuple[10],
'segment_size': segment_size
}
yield tr
if tr_tuple[10]:
break
offset = tr_tuple[9]
isegment += 1
except (OSError, mseed_ext.MSeedError) as e:
raise FileLoadError(str(e)+' (file: %s)' % filename)
if have_zero_rate_traces:
logger.warning(
'Ignoring traces with sampling rate of zero in file %s '
'(maybe LOG traces)' % filename)
def as_tuple(tr, dataquality='D'):
from pyrocko import mseed_ext
itmin = int(round(tr.tmin*mseed_ext.HPTMODULUS))
itmax = int(round(tr.tmax*mseed_ext.HPTMODULUS))
srate = 1.0/tr.deltat
return (tr.network, tr.station, tr.location, tr.channel,
itmin, itmax, srate, dataquality, tr.get_ydata())
def save(traces, filename_template, additional={}, overwrite=True,
dataquality='D', record_length=4096, append=False, steim=1):
from pyrocko import mseed_ext
assert record_length in VALID_RECORD_LENGTHS
assert dataquality in ('D', 'E', 'C', 'O', 'T', 'L'), 'invalid dataquality'
overwrite = True if append else overwrite
fn_tr = {}
for tr in traces:
for code, maxlen, val in zip(
['network', 'station', 'location', 'channel'],
[2, 5, 2, 3],
tr.nslc_id):
if len(val) > maxlen:
raise CodeTooLong(
'%s code too long to be stored in MSeed file: %s' %
(code, val))
fn = tr.fill_template(filename_template, **additional)
if not overwrite and os.path.exists(fn):
raise FileSaveError('File exists: %s' % fn)
if fn not in fn_tr:
fn_tr[fn] = []
fn_tr[fn].append(tr)
for fn, traces_thisfile in fn_tr.items():
trtups = []
traces_thisfile.sort(key=lambda a: a.full_id)
for tr in traces_thisfile:
trtups.append(as_tuple(tr, dataquality))
ensuredirs(fn)
try:
mseed_ext.store_traces(trtups, fn, record_length, append, steim)
except mseed_ext.MSeedError as e:
raise FileSaveError(
str(e) + " (while storing traces to file '%s')" % fn)
return list(fn_tr.keys())
tcs = {}
def get_bytes(traces, dataquality='D', record_length=4096, steim=1):
from pyrocko import mseed_ext
assert record_length in VALID_RECORD_LENGTHS
assert dataquality in ('D', 'E', 'C', 'O', 'T', 'L'), 'invalid dataquality'
nbytes_approx = 0
rl = record_length
trtups = []
for tr in traces:
for code, maxlen, val in zip(
['network', 'station', 'location', 'channel'],
[2, 5, 2, 3],
tr.nslc_id):
if len(val) > maxlen:
raise CodeTooLong(
'%s code too long to be stored in MSeed file: %s' %
(code, val))
nbytes_approx += math.ceil(
tr.ydata.nbytes / (rl-MSEED_HEADER_BYTES)) * rl
trtups.append(as_tuple(tr, dataquality))
return mseed_ext.mseed_bytes(trtups, nbytes_approx, record_length, steim)
def detect(first512):
if len(first512) < 256:
return False
rec = first512
try:
sequence_number = int(rec[:6])
except Exception:
return False
if sequence_number < 0:
return False
type_code = rec[6:7]
if type_code in b'DRQM':
bads = []
for sex in '<>':
bad = False
fmt = sex + '6s1s1s5s2s3s2s10sH2h4Bl2H'
vals = unpack(fmt, rec[:48])
fmt_btime = sex + 'HHBBBBH'
tvals = unpack(fmt_btime, vals[7])
if tvals[1] < 1 or tvals[1] > 367 or tvals[2] > 23 or \
tvals[3] > 59 or tvals[4] > 60 or tvals[6] > 9999:
bad = True
bads.append(bad)
if all(bads):
return False
else:
if type_code not in b'VAST':
return False
continuation_code = rec[7:8]
if continuation_code != b' ':
return False
blockette_type = rec[8:8+3].decode()
if not re.match(r'^\d\d\d$', blockette_type):
return False
try:
blockette_length = int(rec[11:11+4])
except Exception:
return False
if blockette_length < 7:
return False
return True
