import json
from datetime import datetime
fps = 30
frameTime = 1.0/fps
with open('Metadata.json') as jsonFile:
    data = json.load(jsonFile)
    with open('driverecorder.srt', 'w') as subFile:
        for entry in data[0]['entries']:
            frame = entry['id']
            timeFrom = datetime.fromtimestamp(( _
              frame-1)*frameTime+82800).strftime('%H:%M:%S,%f')[:-3]
            timeTo   = datetime.fromtimestamp(frame*frameTime+82800).strftime( _
            '%H:%M:%S,%f')[:-3]
            subFile.write('%i\n' % frame)
            subFile.write('%s --> %s\n' % (timeFrom, timeTo))
            subFile.write('%s %s\n' % (entry['date'], entry['time']))
            subFile.write('%.2fkm/h, lat=%.4f, long=%.4f\n\n' % ( _
              entry['velocity'], entry['latitude'], entry['longitude']))