from datetime import datetime
from opendm import location, log
import re
def match_single(regexes, line, dtype=int):
if isinstance(regexes, str):
regexes = [(regexes, dtype)]
for i in range(len(regexes)):
if isinstance(regexes[i], str):
regexes[i] = (regexes[i], dtype)
try:
for r, transform in regexes:
match = re.search(r, line)
if match:
res = match.group(1)
return transform(res)
except Exception as e:
log.ODM_WARNING("Cannot parse SRT line \"%s\": %s", (line, str(e)))
return None
class SrtFileParser:
def __init__(self, filename):
self.filename = filename
self.data = []
self.gps_data = []
self.ll_to_utm = None
self.utm_to_ll = None
def get_entry(self, timestamp: datetime):
if not self.data:
self.parse()
# check min and max
if timestamp < self.data[0]["start"] or timestamp > self.data[len(self.data) - 1]["end"]:
return None
for entry in self.data:
if entry["start"] <= timestamp and entry["end"] >= timestamp:
return entry
return None
def get_gps(self, timestamp):
if not self.data:
self.parse()
# Initialize on first call
prev_coords = None
if not self.gps_data:
for d in self.data:
lat, lon, alt = d.get('latitude'), d.get('longitude'), d.get('altitude')
if alt is None:
alt = 0
tm = d.get('start')
if lat is not None and lon is not None:
if self.ll_to_utm is None:
self.ll_to_utm, self.utm_to_ll = location.utm_transformers_from_ll(lon, lat)
coords = self.ll_to_utm.TransformPoint(lon, lat, alt)
# First or new (in X/Y only)
add = (not len(self.gps_data)) or (coords[0], coords[1]) != (self.gps_data[-1][1][0], self.gps_data[-1][1][1])
if add:
self.gps_data.append((tm, coords))
# No data available
if not len(self.gps_data) or self.gps_data[0][0] > timestamp:
return None
# Interpolate
start = None
for i in range(len(self.gps_data)):
tm, coords = self.gps_data[i]
# Perfect match
if timestamp == tm:
return self.utm_to_ll.TransformPoint(*coords)
elif tm > timestamp:
end = i
start = i - 1
if start < 0:
return None
gd_s = self.gps_data[start]
gd_e = self.gps_data[end]
sx, sy, sz = gd_s[1]
ex, ey, ez = gd_e[1]
dt = (gd_e[0] - gd_s[0]).total_seconds()
if dt >= 10:
return None
dx = (ex - sx) / dt
dy = (ey - sy) / dt
dz = (ez - sz) / dt
t = (timestamp - gd_s[0]).total_seconds()
return self.utm_to_ll.TransformPoint(
sx + dx * t,
sy + dy * t,
sz + dz * t
)
def parse(self):
# SRT metadata is not standarized, we support the following formats:
# DJI mavic air 2
# 1
# 00:00:00,000 --> 00:00:00,016
# SrtCnt : 1, DiffTime : 16ms
# 2023-01-06 18:56:48,380,821
# [iso : 3200] [shutter : 1/60.0] [fnum : 280] [ev : 0] [ct : 3925] [color_md : default] [focal_len : 240] [latitude: 0.000000] [longitude: 0.000000] [altitude: 0.000000]
# DJI Mavic Mini
# 1
# 00:00:00,000 --> 00:00:01,000
# F/2.8, SS 206.14, ISO 150, EV 0, GPS (-82.6669, 27.7716, 10), D 2.80m, H 0.00m, H.S 0.00m/s, V.S 0.00m/s
# DJI Phantom4 RTK
# 36
# 00:00:35,000 --> 00:00:36,000
# F/6.3, SS 60, ISO 100, EV 0, RTK (120.083799, 30.213635, 28), HOME (120.084146, 30.214243, 103.55m), D 75.36m, H 76.19m, H.S 0.30m/s, V.S 0.00m/s, F.PRY (-5.3°, 2.1°, 28.3°), G.PRY (-40.0°, 0.0°, 28.2°)
# DJI Unknown Model #1
# 1
# 00:00:00,000 --> 00:00:00,033
# SrtCnt : 1, DiffTime : 33ms
# 2024-01-18 10:23:26.397
# [iso : 150] [shutter : 1/5000.0] [fnum : 170] [ev : 0] [ct : 5023] [color_md : default] [focal_len : 240] [dzoom_ratio: 10000, delta:0],[latitude: -22.724555] [longitude: -47.602414] [rel_alt: 0.300 abs_alt: 549.679]
# DJI Mavic 2 Zoom
# 1
# 00:00:00,000 --> 00:00:00,041
# FrameCnt : 1, DiffTime : 41ms
# 2023-07-15 11:55:16,320,933
# [iso : 100] [shutter : 1/400.0] [fnum : 280] [ev : 0] [ct : 5818] [color_md : default] [focal_len : 240] [latitude : 0.000000] [longtitude : 0.000000] [altitude: 0.000000]
with open(self.filename, 'r') as f:
iso = None
shutter = None
fnum = None
focal_len = None
latitude = None
longitude = None
altitude = None
start = None
end = None
for line in f:
# Check if line is empty
if not line.strip():
if start is not None:
self.data.append({
"start": start,
"end": end,
"iso": iso,
"shutter": shutter,
"fnum": fnum,
"focal_len": focal_len,
"latitude": latitude,
"longitude": longitude,
"altitude": altitude
})
iso = None
shutter = None
fnum = None
ct = None
focal_len = None
latitude = None
longitude = None
altitude = None
start = None
end = None
continue
# Remove html tags
line = re.sub('<[^<]+?>', '', line)
# Search this "00:00:00,000 --> 00:00:00,016"
match = re.search("(\d{2}:\d{2}:\d{2},\d+) --> (\d{2}:\d{2}:\d{2},\d+)", line)
if match:
start = datetime.strptime(match.group(1), "%H:%M:%S,%f")
end = datetime.strptime(match.group(2), "%H:%M:%S,%f")
iso = match_single([
"iso : (\d+)",
"ISO (\d+)"
], line)
shutter = match_single([
"shutter : \d+/(\d+\.?\d*)"
"SS (\d+\.?\d*)"
], line)
fnum = match_single([
("fnum : (\d+)", lambda v: float(v)/100.0),
("F/([\d\.]+)", float),
], line)
focal_len = match_single("focal_len : (\d+)", line)
latitude = match_single([
("latitude: ([\d\.\-]+)", lambda v: float(v) if v != 0 else None),
("latitude : ([\d\.\-]+)", lambda v: float(v) if v != 0 else None),
("GPS \([\d\.\-]+,? ([\d\.\-]+),? [\d\.\-]+\)", lambda v: float(v) if v != 0 else None),
("RTK \([-+]?\d+\.\d+, (-?\d+\.\d+), -?\d+\)", lambda v: float(v) if v != 0 else None),
], line)
longitude = match_single([
("longitude: ([\d\.\-]+)", lambda v: float(v) if v != 0 else None),
("longtitude : ([\d\.\-]+)", lambda v: float(v) if v != 0 else None),
("GPS \(([\d\.\-]+),? [\d\.\-]+,? [\d\.\-]+\)", lambda v: float(v) if v != 0 else None),
("RTK \((-?\d+\.\d+), [-+]?\d+\.\d+, -?\d+\)", lambda v: float(v) if v != 0 else None),
], line)
altitude = match_single([
("altitude: ([\d\.\-]+)", lambda v: float(v) if v != 0 else None),
("GPS \([\d\.\-]+,? [\d\.\-]+,? ([\d\.\-]+)\)", lambda v: float(v) if v != 0 else None),
("RTK \([-+]?\d+\.\d+, [-+]?\d+\.\d+, (-?\d+)\)", lambda v: float(v) if v != 0 else None),
("abs_alt: ([\d\.\-]+)", lambda v: float(v) if v != 0 else None),
], line)