1# http://pyrocko.org - GPLv3
2#
3# The Pyrocko Developers, 21st Century
4# ---|P------/S----------~Lg----------
6from struct import unpack
7import os
8import re
9import math
10import logging
12from pyrocko import trace
13from pyrocko.util import reuse, ensuredirs
14from .io_common import FileLoadError, FileSaveError
16logger = logging.getLogger('pyrocko.io.mseed')
18MSEED_HEADER_BYTES = 64
19VALID_RECORD_LENGTHS = tuple(2**exp for exp in range(8, 20))
22class CodeTooLong(FileSaveError):
23 pass
26def iload(filename, load_data=True, offset=0, segment_size=0, nsegments=0):
27 from pyrocko import mseed_ext
29 have_zero_rate_traces = False
30 try:
31 isegment = 0
32 while isegment < nsegments or nsegments == 0:
33 tr_tuples = mseed_ext.get_traces(
34 filename, load_data, offset, segment_size)
36 if not tr_tuples:
37 break
39 for tr_tuple in tr_tuples:
40 network, station, location, channel = tr_tuple[1:5]
41 tmin = float(tr_tuple[5])/float(mseed_ext.HPTMODULUS)
42 tmax = float(tr_tuple[6])/float(mseed_ext.HPTMODULUS)
43 try:
44 deltat = reuse(1.0/float(tr_tuple[7]))
45 except ZeroDivisionError:
46 have_zero_rate_traces = True
47 continue
49 ydata = tr_tuple[8]
51 tr = trace.Trace(
52 network.strip(),
53 station.strip(),
54 location.strip(),
55 channel.strip(),
56 tmin,
57 tmax,
58 deltat,
59 ydata)
61 tr.meta = {
62 'offset_start': offset,
63 'offset_end': tr_tuple[9],
64 'last': tr_tuple[10],
65 'segment_size': segment_size
66 }
68 yield tr
70 if tr_tuple[10]:
71 break
73 offset = tr_tuple[9]
74 isegment += 1
76 except (OSError, mseed_ext.MSeedError) as e:
77 raise FileLoadError(str(e)+' (file: %s)' % filename)
79 if have_zero_rate_traces:
80 logger.warning(
81 'Ignoring traces with sampling rate of zero in file %s '
82 '(maybe LOG traces)' % filename)
85def as_tuple(tr, dataquality='D'):
86 from pyrocko import mseed_ext
87 itmin = int(round(tr.tmin*mseed_ext.HPTMODULUS))
88 itmax = int(round(tr.tmax*mseed_ext.HPTMODULUS))
89 srate = 1.0/tr.deltat
90 return (tr.network, tr.station, tr.location, tr.channel,
91 itmin, itmax, srate, dataquality, tr.get_ydata())
94def save(traces, filename_template, additional={}, overwrite=True,
95 dataquality='D', record_length=4096, append=False, steim=1):
96 from pyrocko import mseed_ext
98 assert record_length in VALID_RECORD_LENGTHS
99 assert dataquality in ('D', 'E', 'C', 'O', 'T', 'L'), 'invalid dataquality'
100 overwrite = True if append else overwrite
102 fn_tr = {}
103 for tr in traces:
104 for code, maxlen, val in zip(
105 ['network', 'station', 'location', 'channel'],
106 [2, 5, 2, 3],
107 tr.nslc_id):
109 if len(val) > maxlen:
110 raise CodeTooLong(
111 '%s code too long to be stored in MSeed file: %s' %
112 (code, val))
114 fn = tr.fill_template(filename_template, **additional)
115 if not overwrite and os.path.exists(fn):
116 raise FileSaveError('File exists: %s' % fn)
118 if fn not in fn_tr:
119 fn_tr[fn] = []
121 fn_tr[fn].append(tr)
123 for fn, traces_thisfile in fn_tr.items():
124 trtups = []
125 traces_thisfile.sort(key=lambda a: a.full_id)
126 for tr in traces_thisfile:
127 trtups.append(as_tuple(tr, dataquality))
129 ensuredirs(fn)
130 try:
131 mseed_ext.store_traces(trtups, fn, record_length, append, steim)
132 except mseed_ext.MSeedError as e:
133 raise FileSaveError(
134 str(e) + ' (while storing traces to file \'%s\')' % fn)
136 return list(fn_tr.keys())
139tcs = {}
142def get_bytes(traces, dataquality='D', record_length=4096, steim=1):
143 from pyrocko import mseed_ext
145 assert record_length in VALID_RECORD_LENGTHS
146 assert dataquality in ('D', 'E', 'C', 'O', 'T', 'L'), 'invalid dataquality'
148 nbytes_approx = 0
149 rl = record_length
150 trtups = []
151 for tr in traces:
152 for code, maxlen, val in zip(
153 ['network', 'station', 'location', 'channel'],
154 [2, 5, 2, 3],
155 tr.nslc_id):
157 if len(val) > maxlen:
158 raise CodeTooLong(
159 '%s code too long to be stored in MSeed file: %s' %
160 (code, val))
162 nbytes_approx += math.ceil(
163 tr.ydata.nbytes / (rl-MSEED_HEADER_BYTES)) * rl
164 trtups.append(as_tuple(tr, dataquality))
166 return mseed_ext.mseed_bytes(trtups, nbytes_approx, record_length, steim)
169def detect(first512):
171 if len(first512) < 256:
172 return False
174 rec = first512
176 try:
177 sequence_number = int(rec[:6])
178 except Exception:
179 return False
180 if sequence_number < 0:
181 return False
183 type_code = rec[6:7]
184 if type_code in b'DRQM':
185 bads = []
186 for sex in '<>':
187 bad = False
188 fmt = sex + '6s1s1s5s2s3s2s10sH2h4Bl2H'
189 vals = unpack(fmt, rec[:48])
190 fmt_btime = sex + 'HHBBBBH'
191 tvals = unpack(fmt_btime, vals[7])
192 if tvals[1] < 1 or tvals[1] > 367 or tvals[2] > 23 or \
193 tvals[3] > 59 or tvals[4] > 60 or tvals[6] > 9999:
194 bad = True
196 bads.append(bad)
198 if all(bads):
199 return False
201 else:
202 if type_code not in b'VAST':
203 return False
205 continuation_code = rec[7:8]
206 if continuation_code != b' ':
207 return False
209 blockette_type = rec[8:8+3].decode()
210 if not re.match(r'^\d\d\d$', blockette_type):
211 return False
213 try:
214 blockette_length = int(rec[11:11+4])
215 except Exception:
216 return False
218 if blockette_length < 7:
219 return False
221 return True