def get_video_start_time_blackvue(video_file):
fd = open(video_file, 'rb')
fd.seek(0, io.SEEK_END)
eof = fd.tell()
fd.seek(0)
while fd.tell() < eof:
box = Box.parse_stream(fd)
if box.type.decode('utf-8') == "moov":
fd.seek(box.offset + 8, 0)
size = struct.unpack('>I', fd.read(4))[0]
typ = fd.read(4)
fd.seek(4, os.SEEK_CUR)
creation_time = struct.unpack('>I', fd.read(4))[0]
modification_time = struct.unpack('>I', fd.read(4))[0]
time_scale = struct.unpack('>I', fd.read(4))[0]
duration = struct.unpack('>I', fd.read(4))[0]
# from documentation
# in seconds since midnight, January 1, 1904
video_start_time_epoch = creation_time * 1000 - duration
epoch_start = datetime.datetime(year=1904, month=1, day=1)
video_start_time = epoch_start + \
datetime.timedelta(milliseconds=video_start_time_epoch)
return video_start_time
def ismt_to_ttml(ismt_data):
fd = io.BytesIO(ismt_data)
while True:
x = Box.parse_stream(fd)
if x.type == b'mdat':
return x.data
def get_video_start_time_blackvue(video_file):
with open(video_file, 'rb') as fd:
fd.seek(0, io.SEEK_END)
eof = fd.tell()
fd.seek(0)
while fd.tell() < eof:
box = Box.parse_stream(fd)
if box.type.decode('utf-8') == "moov":
fd.seek(box.offset + 8, 0)
size = struct.unpack('>I', fd.read(4))[0]
typ = fd.read(4)
fd.seek(4, os.SEEK_CUR)
creation_time = struct.unpack('>I', fd.read(4))[0]
modification_time = struct.unpack('>I', fd.read(4))[0]
time_scale = struct.unpack('>I', fd.read(4))[0]
duration = struct.unpack('>I', fd.read(4))[0]
# from documentation
# in seconds since midnight, January 1, 1904
video_start_time_epoch = creation_time * 1000 - duration
epoch_start = datetime.datetime(year=1904, month=1, day=1)
video_start_time = epoch_start + \
datetime.timedelta(milliseconds=video_start_time_epoch)
return video_start_time
def decrypt(key, inp, out):
"""
decrypt()
@param key: AES-128 CENC key in bytes
@param inp: Open input file
@param out: Open output file
"""
with BufferedReader(inp) as reader:
senc_boxes = deque()
trun_boxes = deque()
while reader.peek(1):
box = Box.parse_stream(reader)
fix_headers(box)
for stsd_box in BoxUtil.find(box, b'stsz'):
sample_size = stsd_box.sample_size
if box.type == b'moof':
senc_boxes.extend(BoxUtil.find(box, b'senc'))
trun_boxes.extend(BoxUtil.find(box, b'trun'))
elif box.type == b'mdat':
senc_box = senc_boxes.popleft()
trun_box = trun_boxes.popleft()
clear_box = b''
with BytesIO(box.data) as box_bytes:
for sample, sample_info in zip(
senc_box.sample_encryption_info,
trun_box.sample_info):
counter = Counter.new(64,
prefix=sample.iv,
initial_value=0)
cipher = AES.new(key, AES.MODE_CTR, counter=counter)
if sample_size:
cipher_bytes = box_bytes.read(sample_size)
clear_box += cipher.decrypt(cipher_bytes)
elif not sample.subsample_encryption_info:
cipher_bytes = box_bytes.read(
sample_info.sample_size)
clear_box += cipher.decrypt(cipher_bytes)
else:
for subsample in sample.subsample_encryption_info:
clear_box += box_bytes.read(
subsample.clear_bytes)
cipher_bytes = box_bytes.read(
subsample.cipher_bytes)
clear_box += cipher.decrypt(cipher_bytes)
box.data = clear_box
out.write(Box.build(box))
return
def dump():
parser = argparse.ArgumentParser(description='Dump all the boxes from an MP4 file')
parser.add_argument("input_file", type=argparse.FileType("rb"), metavar="FILE", help="Path to the MP4 file to open")
args = parser.parse_args()
fd = args.input_file
fd.seek(0, io.SEEK_END)
eof = fd.tell()
fd.seek(0)
while fd.tell() < eof:
box = Box.parse_stream(fd)
print(box)
def find_camera_model(videos_folder):
from mapillary_tools.uploader import get_video_file_list
file_list = get_video_file_list(videos_folder)
fd = open(file_list[0], "rb")
fd.seek(0, io.SEEK_END)
eof = fd.tell()
fd.seek(0)
while fd.tell() < eof:
box = Box.parse_stream(fd)
if box.type.decode("utf-8") == "free": # or 'ftyp':
return box.data[29:39]
def find_camera_model(videos_folder) -> bytes:
from mapillary_tools.uploader import get_video_file_list
file_list = get_video_file_list(videos_folder)
if not file_list:
raise RuntimeError(f"No video found in {videos_folder}")
fd = open(file_list[0], "rb")
fd.seek(0, io.SEEK_END)
eof = fd.tell()
fd.seek(0)
while fd.tell() < eof:
box = Box.parse_stream(fd)
if box.type.decode("utf-8") == "free": # or 'ftyp':
return box.data[29:39]
raise RuntimeError(f"camera model not found in {file_list[0]}")
def test_parse_video_samples(self):
infile = open('3.cmfv', 'rb')
moov_box = []
moof_box = []
for i in range(5):
t = Box.parse_stream(infile)
if (t["type"] == b"moov"):
moov_box = t
if (t["type"] == b"moof"):
moof_box = t
res = BoxUtil.find_samples_fragmented(moov_box, moof_box, 1)
self.assertEqual(res[0]["decode_time"], 12288)
self.assertEqual(res[1]["decode_time"], 12800)
self.assertEqual(res[2]["decode_time"], 13312)
self.assertEqual(res[0]["offset_mdat"], 8)
self.assertEqual(res[1]["offset_mdat"], 2223)
self.assertEqual(res[2]["offset_mdat"], 2400)
def find_camera_model(videos_folder):
from mapillary_tools.uploader import get_video_file_list
file_list = get_video_file_list(videos_folder)
fd = open(file_list[0], 'rb')
fd.seek(0, io.SEEK_END)
eof = fd.tell()
fd.seek(0)
while fd.tell() < eof:
try:
box = Box.parse_stream(fd)
except RangeError:
print('error parsing blackvue GPS information, exiting')
sys.exit(1)
except ConstError:
print('error parsing blackvue GPS information, exiting')
sys.exit(1)
if box.type.decode('utf-8') == 'free':# or 'ftyp':
return box.data[29:39]
def find_camera_model(videos_folder):
from mapillary_tools.uploader import get_video_file_list
file_list = get_video_file_list(videos_folder)
fd = open(file_list[0], 'rb')
fd.seek(0, io.SEEK_END)
eof = fd.tell()
fd.seek(0)
while fd.tell() < eof:
try:
box = Box.parse_stream(fd)
except RangeError:
print('error parsing blackvue GPS information, exiting')
sys.exit(1)
except ConstError:
print('error parsing blackvue GPS information, exiting')
sys.exit(1)
if box.type.decode('utf-8') == 'free': # or 'ftyp':
return box.data[29:39]
def get_points_from_bv(path, use_nmea_stream_timestamp=False):
points = []
fd = open(path, 'rb')
fd.seek(0, io.SEEK_END)
eof = fd.tell()
fd.seek(0)
date = None
first_gps_date = None
first_gps_time = None
found_first_gps_date = False
found_first_gps_time = False
while fd.tell() < eof:
try:
box = Box.parse_stream(fd)
except RangeError:
print('error parsing blackvue GPS information, exiting')
sys.exit(1)
except ConstError:
print('error parsing blackvue GPS information, exiting')
sys.exit(1)
if box.type.decode('utf-8') == 'free':
length = len(box.data)
offset = 0
while offset < length:
newb = Box.parse(box.data[offset:])
if newb.type.decode('utf-8') == 'gps':
lines = newb.data
# Parse GPS trace
for l in lines.splitlines():
m = l.lstrip('[]0123456789')
# this utc millisecond timestamp seems to be the camera's
# todo: unused?
# match = re.search('\[([0-9]+)\]', l)
# if match:
# utcdate = match.group(1)
#By default, use camera timestamp. Only use GPS Timestamp if camera was not set up correctly and date/time is wrong
if use_nmea_stream_timestamp == False:
if "$GPGGA" in m:
match = re.search('\[([0-9]+)\]', l)
if match:
epoch_in_local_time = match.group(1)
camera_date = datetime.datetime.utcfromtimestamp(
int(epoch_in_local_time) / 1000.0)
data = pynmea2.parse(m)
if (data.is_valid):
if found_first_gps_time == False:
first_gps_time = data.timestamp
found_first_gps_time = True
lat, lon, alt = data.latitude, data.longitude, data.altitude
points.append((camera_date, lat, lon, alt))
if use_nmea_stream_timestamp == True or found_first_gps_date == False:
if "GPRMC" in m:
try:
data = pynmea2.parse(m)
if data.is_valid:
date = data.datetime.date()
if found_first_gps_date == False:
first_gps_date = date
except pynmea2.ChecksumError as e:
# There are often Checksum errors in the GPS stream, better not to show errors to user
pass
except Exception as e:
print(
"Warning: Error in parsing gps trace to extract date information, nmea parsing failed"
)
if use_nmea_stream_timestamp == True:
if "$GPGGA" in m:
try:
data = pynmea2.parse(m)
if (data.is_valid):
lat, lon, alt = data.latitude, data.longitude, data.altitude
if not date:
timestamp = data.timestamp
else:
timestamp = datetime.datetime.combine(
date, data.timestamp)
points.append(
(timestamp, lat, lon, alt))
except Exception as e:
print(
"Error in parsing gps trace to extract time and gps information, nmea parsing failed due to {}"
.format(e))
#If there are no points after parsing just return empty vector
if points == []:
return []
#After parsing all points, fix timedate issues
if use_nmea_stream_timestamp == False:
# If we use the camera timestamp, we need to get the timezone offset, since Mapillary backend expects UTC timestamps
first_gps_timestamp = datetime.datetime.combine(
first_gps_date, first_gps_time)
delta_t = points[0][0] - first_gps_timestamp
if delta_t.days > 0:
hours_diff_to_utc = round(delta_t.total_seconds() /
3600)
else:
hours_diff_to_utc = round(
delta_t.total_seconds() / 3600) * -1
utc_points = []
for idx, point in enumerate(points):
delay_compensation = datetime.timedelta(
seconds=-1.8
) #Compensate for solution age when location gets timestamped by camera clock. Value is empirical from various cameras/recordings
new_timestamp = points[idx][0] + datetime.timedelta(
hours=hours_diff_to_utc) + delay_compensation
lat = points[idx][1]
lon = points[idx][2]
alt = points[idx][3]
utc_points.append((new_timestamp, lat, lon, alt))
points = utc_points
points.sort()
else:
#add date to points that don't have it yet, because GPRMC message came later
utc_points = []
for idx, point in enumerate(points):
if type(points[idx][0]) != type(
datetime.datetime.today()):
timestamp = datetime.datetime.combine(
first_gps_date, points[idx][0])
else:
timestamp = points[idx][0]
lat = points[idx][1]
lon = points[idx][2]
alt = points[idx][3]
utc_points.append((timestamp, lat, lon, alt))
points = utc_points
points.sort()
offset += newb.end
break
return points
def get_points_from_bv(path,use_nmea_stream_timestamp=False):
points = []
with open(path, 'rb') as fd:
fd.seek(0, io.SEEK_END)
eof = fd.tell()
fd.seek(0)
date = None
first_gps_date = None
first_gps_time = None
found_first_gps_date = False
found_first_gps_time = False
while fd.tell() < eof:
try:
box = Box.parse_stream(fd)
except RangeError:
print('error parsing blackvue GPS information, exiting')
sys.exit(1)
except ConstError:
print('error parsing blackvue GPS information, exiting')
sys.exit(1)
if box.type.decode('utf-8') == 'free':
length = len(box.data)
offset = 0
while offset < length:
newb = Box.parse(box.data[offset:])
if newb.type.decode('utf-8') == 'gps':
lines = newb.data
# Parse GPS trace
for l in lines.splitlines():
m = l.lstrip('[]0123456789')
# this utc millisecond timestamp seems to be the camera's
# todo: unused?
# match = re.search('\[([0-9]+)\]', l)
# if match:
# utcdate = match.group(1)
#By default, use camera timestamp. Only use GPS Timestamp if camera was not set up correctly and date/time is wrong
if use_nmea_stream_timestamp==False:
if "$GPGGA" in m:
match = re.search('\[([0-9]+)\]', l)
if match:
epoch_in_local_time = match.group(1)
camera_date=datetime.datetime.utcfromtimestamp(int(epoch_in_local_time)/1000.0)
data = pynmea2.parse(m)
if(data.is_valid):
if found_first_gps_time == False:
first_gps_time = data.timestamp
found_first_gps_time = True
lat, lon, alt = data.latitude, data.longitude, data.altitude
points.append((camera_date, lat, lon, alt))
if use_nmea_stream_timestamp==True or found_first_gps_date==False:
if "GPRMC" in m:
try:
data = pynmea2.parse(m)
if data.is_valid:
date = data.datetime.date()
if found_first_gps_date == False:
first_gps_date=date
except pynmea2.ChecksumError as e:
# There are often Checksum errors in the GPS stream, better not to show errors to user
pass
except Exception as e:
print(
"Warning: Error in parsing gps trace to extract date information, nmea parsing failed")
if use_nmea_stream_timestamp==True:
if "$GPGGA" in m:
try:
data = pynmea2.parse(m)
if(data.is_valid):
lat, lon, alt = data.latitude, data.longitude, data.altitude
if not date:
timestamp = data.timestamp
else:
timestamp = datetime.datetime.combine(
date, data.timestamp)
points.append((timestamp, lat, lon, alt))
except Exception as e:
print(
"Error in parsing gps trace to extract time and gps information, nmea parsing failed due to {}".format(e))
#If there are no points after parsing just return empty vector
if points == []:
return []
#After parsing all points, fix timedate issues
if use_nmea_stream_timestamp==False:
# If we use the camera timestamp, we need to get the timezone offset, since Mapillary backend expects UTC timestamps
first_gps_timestamp = datetime.datetime.combine(first_gps_date, first_gps_time)
delta_t = points[0][0]-first_gps_timestamp
if delta_t.days>0:
hours_diff_to_utc = round(delta_t.total_seconds()/3600)
else:
hours_diff_to_utc = round(delta_t.total_seconds()/3600) * -1
utc_points=[]
for idx, point in enumerate(points):
delay_compensation = datetime.timedelta(seconds=-1.8) #Compensate for solution age when location gets timestamped by camera clock. Value is empirical from various cameras/recordings
new_timestamp = points[idx][0]+datetime.timedelta(hours=hours_diff_to_utc)+delay_compensation
lat = points[idx][1]
lon = points[idx][2]
alt = points[idx][3]
utc_points.append((new_timestamp, lat, lon, alt))
points = utc_points
points.sort()
else:
#add date to points that don't have it yet, because GPRMC message came later
utc_points=[]
for idx, point in enumerate(points):
if type(points[idx][0]) != type(datetime.datetime.today()):
timestamp = datetime.datetime.combine(
first_gps_date, points[idx][0])
else:
timestamp = points[idx][0]
lat = points[idx][1]
lon = points[idx][2]
alt = points[idx][3]
utc_points.append((timestamp, lat, lon, alt))
points = utc_points
points.sort()
offset += newb.end
break
return points
def get_points_from_bv(path):
points = []
fd = open(path, 'rb')
fd.seek(0, io.SEEK_END)
eof = fd.tell()
fd.seek(0)
date = None
while fd.tell() < eof:
try:
box = Box.parse_stream(fd)
except RangeError:
print('error parsing blackvue GPS information, exiting')
sys.exit(1)
except ConstError:
print('error parsing blackvue GPS information, exiting')
sys.exit(1)
if box.type.decode('utf-8') == 'free':
length = len(box.data)
offset = 0
while offset < length:
newb = Box.parse(box.data[offset:])
if newb.type.decode('utf-8') == 'gps':
lines = newb.data
for l in lines:
if "GPRMC" in l:
m = l.lstrip('[]0123456789')
try:
data = pynmea2.parse(m)
date = data.datetime.date()
except Exception as e:
print(
"Error in extracting the gps trace, nmea parsing failed due to {}"
.format(e))
break
# Parse GPS trace
for l in lines.splitlines():
# this utc millisecond timestamp seems to be the camera's
# todo: unused?
# match = re.search('\[([0-9]+)\]', l)
# if match:
# utcdate = match.group(1)
m = l.lstrip('[]0123456789')
if "GPRMC" in m:
try:
data = pynmea2.parse(m)
date = data.datetime.date()
except Exception as e:
print(
"Error in parsing gps trace to extract date information, nmea parsing failed due to {}"
.format(e))
if "$GPGGA" in m:
try:
if not date:
print(
"Error, could not extract date from the video gps trace, exiting..."
)
sys.exit(1)
data = pynmea2.parse(m)
timestamp = datetime.datetime.combine(
date, data.timestamp)
lat, lon, alt = data.latitude, data.longitude, data.altitude
points.append((timestamp, lat, lon, alt))
except Exception as e:
print(
"Error in parsing gps trace to extract time and gps information, nmea parsing failed due to {}"
.format(e))
points.sort()
offset += newb.end
break
return points
def dump(file, dump_embedded, dump_raw_blocks, extended_scan, verbose):
""" Extract GPS and Acceleration data from BlackVue MP4 recordings.
BlackVue extracts data embedded in the MP4 recordings of a BlackVue Dashcam.
"""
for filename in file:
filebase = os.path.splitext(filename)[0]
with open(filename, 'rb') as fd:
fd.seek(0, io.SEEK_END)
eof = fd.tell()
fd.seek(0)
while fd.tell() < eof:
try:
box = Box.parse_stream(fd)
# print(box)
content = dict(box.__getstate__())
ctype = content['type'].decode('utf8')
if 'data' in content and ctype == 'free':
offset = content['offset']
end = content['end']
data = content['data']
if verbose:
print(
"Found container of type '{}', data has length {}."
.format(ctype, len(data)))
if dump_embedded:
with open(
filename +
"-{:012d}-{}.bin".format(offset, ctype),
"wb") as ofd:
ofd.write(data)
idx = 0
while idx < len(data):
block_len = int.from_bytes(data[idx:idx + 4],
'big')
block_data = data[idx + 4:idx + block_len]
if verbose:
print("Found block with len {}".format(
block_len))
if block_len == 0:
break
if dump_raw_blocks:
with open(
filebase +
"-{:012d}-{}-{:08d}.bin".format(
offset, ctype, idx), "wb") as ofd:
ofd.write(block_data)
if block_data[0:4] in emb_file_def:
first, has_length, termination, ext = emb_file_def[
block_data[0:4]]
# some data like thmb indicates the length:
last = first + int.from_bytes(
block_data[4:8],
'big') if has_length else block_len
# other data like gps is zero terminated:
last = block_data.find(
termination
) if termination is not None else last
if ext is not None:
with open(filebase + ext, "wb") as ofd:
ofd.write(block_data[first:last])
if ext == '.3gf':
with open(filebase + ext + ".txt",
"wt") as ofd:
n = 0
while first < last:
chunk = block_data[first:first +
10]
time_ms = int.from_bytes(
chunk[0:4], 'big')
if time_ms == 0xffffffff:
break
acc_1u = int.from_bytes(
chunk[4:6], 'big')
acc_2u = int.from_bytes(
chunk[6:8], 'big')
acc_3u = int.from_bytes(
chunk[8:10], 'big')
acc_1s = int.from_bytes(
chunk[4:6], 'big', signed=True)
acc_2s = int.from_bytes(
chunk[6:8], 'big', signed=True)
acc_3s = int.from_bytes(
chunk[8:10],
'big',
signed=True)
ofd.write(
("{:8d} " +
"{:08x} {:04x} {:04x} {:04x} "
+ "{:6d} {:6d} {:6d} {:6d}\n"
).format(
n, time_ms, acc_1u,
acc_2u, acc_3u, time_ms,
acc_1s, acc_2s, acc_3s))
first += 10
n += 1
idx += block_len
if verbose:
("Got to idx {}.".format(idx))
if not extended_scan:
break
except construct.core.ConstError:
break
except Exception as e:
print(e)
raise
def detect_file_type(input_file):
device = "X"
make = "unknown"
model = "unknown"
if input_file.lower().endswith(".ts"):
with open(input_file, "rb") as f:
device = "A"
input_packet = f.read(188) #First packet, try to autodetect
if bytes("\xB0\x0D\x30\x34\xC3", encoding="raw_unicode_escape"
) in input_packet[4:20] or args.device_override == "V":
device = "V"
make = "Viofo"
model = "A119 V3"
if bytes("\x40\x1F\x4E\x54\x39", encoding="raw_unicode_escape"
) in input_packet[4:20] or args.device_override == "B":
device = "B"
make = "Blueskysea"
model = "B4K"
while device == "A":
currentdata = {}
input_packet = f.read(188)
if not input_packet:
break
#Autodetect camera type
if device == 'A' and input_packet.startswith(
bytes("\x47\x03\x00", encoding="raw_unicode_escape")):
bs = list(input_packet)
active = chr(bs[156])
lathem = chr(bs[157])
lonhem = chr(bs[158])
if lathem in "NS" and lonhem in "EW":
device = "B"
make = "Blueskysea"
model = "B4K"
print("Autodetected as Blueskysea B4K")
break
if device == 'A' and input_packet.startswith(
bytes("\x47\x43\x00", encoding="raw_unicode_escape")):
bs = list(input_packet)
active = chr(bs[34])
lathem = chr(bs[35])
lonhem = chr(bs[36])
if lathem in "NS" and lonhem in "EW":
device = "V"
print("Autodetected as Viofo A119 V3")
make = "Viofo"
model = "A119 V3"
break
if input_file.lower().endswith(
".mp4"): #Guess which MP4 method is used: Novatek, Subtitle, NMEA
with open(input_file, "rb") as fx:
if True:
fx.seek(0, io.SEEK_END)
eof = fx.tell()
fx.seek(0)
lines = []
while fx.tell() < eof:
try:
box = Box.parse_stream(fx)
except:
pass
#print (box.type.decode("utf-8"))
if box.type.decode("utf-8") == "free":
length = len(box.data)
offset = 0
while offset < length:
inp = Box.parse(box.data[offset:])
#print (inp.type.decode("utf-8"))
if inp.type.decode("utf-8") == "gps": #NMEA-based
lines = inp.data
for line in lines.splitlines():
m = str(line).lstrip("[]0123456789")
if "$GPGGA" in m:
device = "N"
make = "NMEA-based video"
model = "unknown"
break
offset += inp.end
if box.type.decode(
"utf-8") == "gps": #has Novatek-specific stuff
fx.seek(0)
largeelem = fx.read()
startbytes = [
m.start()
for m in re.finditer(b'freeGPS', largeelem)
]
del largeelem
if len(startbytes) > 0:
make = "Novatek"
model = "MP4"
device = "T"
break
if box.type.decode("utf-8") == "moov":
try:
length = len(box.data)
except:
length = 0
offset = 0
while offset < length:
inp = Box.parse(box.data[offset:])
#print (inp.type.decode("utf-8"))
if inp.type.decode("utf-8") == "gps": #NMEA-based
lines = inp.data
print(len(inp.data))
for line in lines.splitlines():
m = str(line).lstrip("[]0123456789")
if "$GPGGA" in m:
device = "N"
make = "NMEA-based video"
model = "unknown"
#break
offset += inp.end
else:
pass
if device == "X":
fx.seek(0)
largeelem = fx.read()
startbytes = [
m.start() for m in re.finditer(
b'\x00\x14\x50\x4E\x44\x4D\x00\x00\x00\x00', largeelem)
]
del largeelem
if len(startbytes) > 0:
make = "Garmin"
model = "unknown"
device = "G"
if device == "X":
fx.seek(0)
largeelem = fx.read()
startbytes = [
m.start() for m in re.finditer(b'GPGGA', largeelem)
]
del largeelem
if len(startbytes) > 0:
make = "NEXTBASE"
model = "unknown"
device = "NB"
return device, make, model
def get_gps_data_nmea(input_file, device):
packetno = 0
locdata = {}
with open(input_file, "rb") as fx:
if True:
fx.seek(0, io.SEEK_END)
eof = fx.tell()
fx.seek(0)
prevts = 0
lines = []
while fx.tell() < eof:
try:
box = Box.parse_stream(fx)
except:
pass
if box.type.decode("utf-8") == "free":
try:
length = len(box.data)
except:
length = 0
offset = 0
while offset < length:
inp = Box.parse(box.data[offset:])
#print (inp.type.decode("utf-8"))
if inp.type.decode("utf-8") == "gps": #NMEA-based
lines = inp.data
for line in lines.splitlines():
m = str(line)
if "$GPRMC" in m:
currentdata = {}
currentdata["ts"] = int(m[3:13])
#print (m)
try:
currentdata["lat"] = float(
m.split(",")[3][0:2]) + float(
m.split(",")[3][2:]) / 60
currentdata["latR"] = m.split(",")[4]
if currentdata["latR"] == "S":
currentdata[
"lat"] = -currentdata["lat"]
currentdata["lon"] = float(
m.split(",")[5][0:3]) + float(
m.split(",")[5][3:]) / 60
currentdata["lonR"] = m.split(",")[6]
if currentdata["lonR"] == "N":
currentdata[
"lon"] = -currentdata["lon"]
except:
pass
try:
currentdata["bearing"] = float(
m.split(",")[9])
currentdata["speed"] = float(
m.split(",")[8]) * 1.6 / 3.6
except:
currentdata["bearing"] = 0
currentdata["speed"] = 0
active = (m.split(",")[2])
nts = currentdata["ts"]
currentdata["metric"] = 0
currentdata["prevdist"] = 0
try:
currentdata["mx"], currentdata[
"my"] = lonlat_metric(
currentdata["lon"],
currentdata["lat"])
except:
pass
if active == "A" and nts > prevts:
locdata[packetno] = currentdata
prevts = nts
packetno += 1
del currentdata
offset += inp.end
return locdata, packetno
def get_points_from_bv(path,use_nmea_stream_timestamp=False):
points = []
fd = open(path, 'rb')
fd.seek(0, io.SEEK_END)
eof = fd.tell()
fd.seek(0)
date = None
while fd.tell() < eof:
try:
box = Box.parse_stream(fd)
except RangeError:
print('error parsing blackvue GPS information, exiting')
sys.exit(1)
except ConstError:
print('error parsing blackvue GPS information, exiting')
sys.exit(1)
if box.type.decode('utf-8') == 'free':
length = len(box.data)
offset = 0
while offset < length:
newb = Box.parse(box.data[offset:])
if newb.type.decode('utf-8') == 'gps':
lines = newb.data
# Parse GPS trace
for l in lines.splitlines():
# this utc millisecond timestamp seems to be the camera's
# todo: unused?
# match = re.search('\[([0-9]+)\]', l)
# if match:
# utcdate = match.group(1)
#By default, use camera timestamp. Only use GPS Timestamp if camera was not set up correctly and date/time is wrong
if use_nmea_stream_timestamp==False:
m = l.lstrip('[]0123456789')
if "$GPGGA" in m:
match = re.search('\[([0-9]+)\]', l)
if match:
utcdate = match.group(1)
date=datetime.datetime.utcfromtimestamp(int(utcdate)/1000.0)
data = pynmea2.parse(m)
if(data.is_valid):
lat, lon, alt = data.latitude, data.longitude, data.altitude
points.append((date, lat, lon, alt))
else:
if "GPRMC" in m:
try:
data = pynmea2.parse(m)
date = data.datetime.date()
except Exception as e:
print(
"Error in parsing gps trace to extract date information, nmea parsing failed due to {}".format(e))
if "$GPGGA" in m:
try:
if not date:
#discarding Lat/Lon messages if date has not been set yet. TODO: we could save the messages and add the date later
continue
data = pynmea2.parse(m)
if(data.is_valid):
timestamp = datetime.datetime.combine(
date, data.timestamp)
lat, lon, alt = data.latitude, data.longitude, data.altitude
points.append((timestamp, lat, lon, alt))
except Exception as e:
print(
"Error in parsing gps trace to extract time and gps information, nmea parsing failed due to {}".format(e))
points.sort()
offset += newb.end
break
return points
def read(self) -> Telemetry:
tel = Telemetry()
with open(self.source, 'rb') as fd:
fd.seek(0, io.SEEK_END)
eof = fd.tell()
fd.seek(0)
while fd.tell() < eof:
try:
box = Box.parse_stream(fd)
except RangeError:
print('error parsing blackvue GPS information, exiting')
sys.exit(1)
except ConstError:
print('error parsing blackvue GPS information, exiting')
sys.exit(1)
if box.type.decode('utf-8') == 'free':
length = len(box.data)
offset = 0
while offset < length:
newb = Box.parse(box.data[offset:])
if newb.type.decode('utf-8') == 'gps':
lines = newb.data.decode('utf-8')
# Parse GPS trace
timestamp = None
packet = None
for l in lines.splitlines():
m = l.lstrip('[]0123456789')
if not m:
continue
match = re.search('\[([0-9]+)\]', l)
# If new timestamp found
if match and match.group(1) != timestamp:
if packet:
tel.append(packet)
packet = Packet()
timestamp = match.group(1)
packet[TimestampElement.
name] = TimestampElement(
float(timestamp) * 1e-3)
#remove timestamp on tail if it exists
try:
m = m[:m.rindex('[')]
except:
pass
try:
m = m[:m.index("\x00")]
except:
pass
try:
nmea_data = pynmea2.parse(m)
if nmea_data and nmea_data.sentence_type == 'GGA':
packet[LatitudeElement.
name] = LatitudeElement(
nmea_data.latitude)
packet[LongitudeElement.
name] = LongitudeElement(
nmea_data.longitude)
if nmea_data.altitude:
packet[AltitudeElement.
name] = AltitudeElement(
nmea_data.altitude)
if nmea_data and nmea_data.sentence_type == 'VTG':
packet[
SpeedElement.name] = SpeedElement(
nmea_data.spd_over_grnd_kmph /
3.6) #convert to m/s
except:
self.logger.warn(
"Couldn't parse nmea sentence. Skipping..."
)
if packet:
tel.append(packet)
offset += newb.end
break
return tel
