def get_data(cap, file, t0, out, name):
dt = 1 / cap.get(cv2.CAP_PROP_FPS)
cur_time = 0
prev_vel = 0
prev_altitude = 0
prev_time = 0
start = False
dropped_frames = 0
frame_index = 1
prev_stage = None
time_file = open(name + '.meta', 'w')
with open(CONFIG_FILE_PATH, 'r') as spacex_dict_file:
spacex_dict = json.load(spacex_dict_file)
session = general_extract.RelativeExtract(
spacex_dict, anchor_range=spacex_dict['anchor'][0])
util = Util(session)
if util.find_anchor(cap,
start=ANCHOR_SEARCH_START_TIME_FRACTION,
end=ANCHOR_SEARCH_END_TIME_FRACTION):
util.skip_from_launch(cap, 'sign', t0)
_, frame = cap.read()
_, t0 = session.extract_number(frame, 'time')
_, v0 = session.extract_number(frame, 'velocity')
dec, a0 = session.extract_number(frame, 'altitude')
if dec:
a0 /= DECIMAL_CONVERSION
if t0 is not None:
prev_time = t0 - dt
prev_vel = v0
prev_altitude = a0
cur_time = rtnd(t0, 3)
while frame is not None:
_, velocity = session.extract_number(frame, 'velocity')
dec, altitude = session.extract_number(frame, 'altitude')
if dec and altitude is not None:
altitude /= DECIMAL_CONVERSION
show_frame(frame)
if cv2.waitKey(1) & 0xff == ord('q'):
break
cur_stage = session.get_template_index(frame, 'stage') + 1
if velocity is not None and altitude is not None and \
(check_data(prev_vel, prev_time, velocity/KMH, cur_time, prev_altitude, altitude)
or check_stage_switch(cur_stage, prev_stage)):
velocity /= KMH
if cur_stage is not None and cur_stage != prev_stage:
prev_stage = cur_stage
time_file.write(
json.dumps(
OrderedDict([('time', rtnd(cur_time, PRECISION)),
('stage', cur_stage)])) + '\n')
time_file.flush()
json_data = data_to_json(cur_time, velocity, altitude)
if out:
print(data_to_json(cur_time, velocity, altitude))
if start:
write_to_file(file, json_data)
prev_vel = velocity
prev_altitude = altitude
prev_time = cur_time
if velocity > LAUNCH_VELOCITY:
start = True
else:
dropped_frames += 1
if dropped_frames % DROPPED_FRAME_THRESH == 0:
print(
'Frame number {} was dropped ({}) which is {:.2f}% of the total frames'
.format(frame_index, dropped_frames,
100 * dropped_frames / frame_index))
_, frame = cap.read()
if start:
cur_time += dt
frame_index += 1
cv2.destroyAllWindows()
time_file.close()
def data_to_json(time, velocity, altitude):
return json.dumps(
OrderedDict([('time', rtnd(time, PRECISION)),
('velocity', rtnd(velocity, PRECISION)),
('altitude', altitude)]))