jellyfin/MediaBrowser.Server.Implementations/LiveTv/TunerHosts/SatIp/Utils.cs

/*  
    Copyright (C) <2007-2016>  <Kay Diefenthal>

    SatIp.RtspSample is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    SatIp.RtspSample is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with SatIp.RtspSample.  If not, see <http://www.gnu.org/licenses/>.
*/
using System;
using System.Text;

namespace MediaBrowser.Server.Implementations.LiveTv.TunerHosts.SatIp
{
    public class Utils
    {
        public static int Convert2BytesToInt(byte[] buffer, int offset)
        {
            int temp = (int)buffer[offset];
            temp = (temp * 256) + buffer[offset + 1];

            return (temp);
        }
        public static int Convert3BytesToInt(byte[] buffer, int offset)
        {
            int temp = (int)buffer[offset];
            temp = (temp * 256) + buffer[offset + 1];
            temp = (temp * 256) + buffer[offset + 2];

            return (temp);
        }
        public static int Convert4BytesToInt(byte[] buffer, int offset)
        {
            int temp =(int)buffer[offset]; 
            temp = (temp * 256) + buffer[offset + 1];
            temp = (temp * 256) + buffer[offset + 2];
            temp = (temp * 256) + buffer[offset + 3];
            
            return (temp);
        }
        public static long Convert4BytesToLong(byte[] buffer, int offset)
        {
            long temp = 0;

            for (int index = 0; index < 4; index++)
                temp = (temp * 256) + buffer[offset + index];

            return (temp);
        }
        public static long Convert8BytesToLong(byte[] buffer, int offset)
        {
            long temp = 0;

            for (int index = 0; index < 8; index++)
                temp = (temp * 256) + buffer[offset + index];

            return (temp);
        }
        public static string ConvertBytesToString(byte[] buffer, int offset, int length)
        {
            StringBuilder reply = new StringBuilder(4);
            for (int index = 0; index < length; index++)
                reply.Append((char)buffer[offset + index]);
            return (reply.ToString());
        }
        public static DateTime NptTimestampToDateTime(long nptTimestamp) { return NptTimestampToDateTime((uint)((nptTimestamp >> 32) & 0xFFFFFFFF), (uint)(nptTimestamp & 0xFFFFFFFF),null); }

        public static DateTime NptTimestampToDateTime(uint seconds, uint fractions, DateTime? epoch )
        {
            ulong ticks =(ulong)((seconds * TimeSpan.TicksPerSecond) + ((fractions * TimeSpan.TicksPerSecond) / 0x100000000L));
            if (epoch.HasValue) return epoch.Value + TimeSpan.FromTicks((Int64)ticks);
            return (seconds & 0x80000000L) == 0 ? UtcEpoch2036 + TimeSpan.FromTicks((Int64)ticks) : UtcEpoch1900 + TimeSpan.FromTicks((Int64)ticks);
        }

        //When the First Epoch will wrap (The real Y2k)
        public static DateTime UtcEpoch2036 = new DateTime(2036, 2, 7, 6, 28, 16, DateTimeKind.Utc);

        public static DateTime UtcEpoch1900 = new DateTime(1900, 1, 1, 0, 0, 0, DateTimeKind.Utc);

        public static DateTime UtcEpoch1970 = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);

    }
}