/// <summary>
/// This will parse list of location-size pairs
/// And parse each specific location
/// </summary>
/// <param name="g"></param>
/// <param name="file"></param>
/// <returns>list of gps points</returns>
private static List <ViofoGpsPoint> ParseGpsCatalog(Box g, MemoryMappedFileReader reader)
{
LocationsList list = new LocationsList(g);
List <ViofoGpsPoint> gpsPoints = new List <ViofoGpsPoint>();
foreach (Location loc in list.locations)
{
if (loc.Offset == 0 || loc.Length == 0)
{
continue;
}
reader.Position = loc.Offset;
ViofoGpsPoint i = ViofoGpsPoint.Parse(reader, loc.Length);
if (i == null)
{
continue;
}
gpsPoints.Add(i);
}
return(gpsPoints);
}
public static ViofoGpsPoint Parse(IBufferReader reader, uint expectedSize)
{
long start = reader.Position;
uint size = reader.ReadUintBE();
string type = reader.ReadString(4);
string magic = reader.ReadString(4);
if (expectedSize != size || type != "free" || magic != "GPS ")
{
return(null);
}
ViofoGpsPoint gps = new ViofoGpsPoint();
//# checking for weird Azdome 0xAA XOR "encrypted" GPS data.
//This portion is a quick fix.
int payload_size = 254;
byte c = reader.ReadByte();
if (c == 0x05)
{
if (size < 254)
{
payload_size = (int)+size;
}
reader.Position += 5; //???
byte[] payload = reader.ReadBuffer(payload_size);
}
else if ((char)c == 'L')
{
const uint OFFSET_V2 = 48, OFFSET_V1 = 16;
reader.Position = start + OFFSET_V2;
//# Datetime data
int hour = (int)reader.ReadUintLE();
int minute = (int)reader.ReadUintLE();
int second = (int)reader.ReadUintLE();
int year = (int)reader.ReadUintLE();
int month = (int)reader.ReadUintLE();
int day = (int)reader.ReadUintLE();
try { gps.Date = new DateTime(2000 + year, month, day, hour, minute, second); }
catch (Exception err) { Debug.WriteLine(err.ToString()); return(null); }
//# Coordinate data
char active = (char)reader.ReadByte();
gps.IsActive = (active == 'A');
gps.Latitude_hemisphere = (char)reader.ReadByte();
gps.Longtitude_hemisphere = (char)reader.ReadByte();
gps.Unknown = reader.ReadByte();
float lat = reader.ReadFloatLE();
gps.Latitude = FixCoordinate(lat, gps.Latitude_hemisphere);
float lon = reader.ReadFloatLE();
gps.Longtitude = FixCoordinate(lon, gps.Longtitude_hemisphere);
gps.Speed = reader.ReadFloatLE();
gps.Bearing = reader.ReadFloatLE();
return(gps);
}
return(null);
}