C#获取 Flv视频文件信息

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;

namespace _30edu.Common
{
    public class FlvInfo
    {
        public FlvInfo()
        {
            Header = new FLVHeader();
            TagList = new List<FLVTag>();
        }
        public FLVHeader Header { get;private set; }
        public List<FLVTag> TagList { get; private set; }
        public TimeSpan Time
        {
            get
            {
                int time=0;
                //foreach (FLVTag tag in this.TagList.Where(p=>p.Type))
                //{ 
                //    byte[] tmp = new byte[4];
                //    tmp[3] = tag.TimeEx;
                //    tmp[0] = tag.Time[2];
                //    tmp[1] = tag.Time[1];
                //    tmp[2] = tag.Time[0];
                //    time += BitConverter.ToInt32(tmp,0);
                //}
                FLVTag tag = this.TagList.Where(p => p.Type == 9).Last();
                byte[] tmp = new byte[4];
                tmp[3] = tag.TimeEx;
                tmp[0] = tag.Time[2];
                tmp[1] = tag.Time[1];
                tmp[2] = tag.Time[0];
                return new TimeSpan(0, 0, 0, 0, BitConverter.ToInt32(tmp, 0));
            }
        }
    }

    /**//// <summary>
    /// 文件头
    /// </summary>
    public class FLVHeader
    {
        public FLVHeader()
        {
            this.Type = new byte[3];
            this.Length = new byte[4];
        }
        /**//// <summary>
        /// 3byte 总是FLV（0x46 0x4C 0x56）
        /// </summary>
        public byte[] Type { get; set; }

        /**//// <summary>
        /// 版本 一般是0x01，表示FLV version 1
        /// </summary>
        public byte Version{ get; set; }

        /**//// <summary>
        /// 流信息 倒数第一bit是1表示有视频，倒数第三bit是1表示有音频
        /// </summary>
        public byte Stream { get; set; }

        /**//// <summary>
        /// 长度 4byte
        /// </summary>
        public byte[] Length { get; set; }
    }

    public class FLVTag
    {
        public FLVTag()
        {
            this.PreviousTagSize = new byte[4];
            this.DataLength = new byte[3];
            this.Time = new byte[3];
            this.streamsID = new byte[3];

        }
        /**//// <summary>
        /// 前一个Tag长度 4byte
        /// </summary>
        public byte[] PreviousTagSize { get; set; }
        /**//// <summary>
        ///  8 -- 音频tag 9 -- 视频tag 18 -- 脚本tag
        /// </summary>
        public byte Type { get; set; }

        /**//// <summary>
        /// 数据区长度 3byte
        /// </summary>
        public byte[] DataLength { get; set; }

        /**//// <summary>
        /// 时间戳 3byte 毫秒
        /// </summary>
        public byte[] Time { get; set; }

        /**//// <summary>
        /// 扩展时间戳 3byte 毫秒 作为时间戳的高位
        /// </summary>
        public byte TimeEx { get; set; }

        /**//// <summary>
        /// 一般为0 3byte
        /// </summary>
        public byte[] streamsID { get; set; }

        /**//// <summary>
        /// 
        /// </summary>
        public byte[] Data { get; set; }
    }

    public static class FlvInfoHelper
    {
        public static FlvInfo Read(string Path)
        {
            using (FileStream fs = File.OpenRead(Path))
            {
                FlvInfo aFlvInfo = new FlvInfo();
                fs.Read(aFlvInfo.Header.Type, 0, aFlvInfo.Header.Type.Length);
                aFlvInfo.Header.Version=(byte)fs.ReadByte();
                aFlvInfo.Header.Stream = (byte)fs.ReadByte();
                fs.Read(aFlvInfo.Header.Length, 0, aFlvInfo.Header.Length.Length);
                byte[] previoustagsize=new byte[4];
                while (fs.Read(previoustagsize, 0, previoustagsize.Length) != 0)
                {
                    FLVTag Tag = new FLVTag();
                    Tag.PreviousTagSize = previoustagsize;
                    Tag.Type = (byte)fs.ReadByte();
                    fs.Read(Tag.DataLength, 0, Tag.DataLength.Length);
                    fs.Read(Tag.Time, 0, Tag.Time.Length);
                    Tag.TimeEx = (byte)fs.ReadByte();
                    fs.Read(Tag.streamsID, 0, Tag.streamsID.Length);

                    byte[] tmp = new byte[4];
                    tmp[3] = 0;
                    tmp[2] = Tag.DataLength[0];
                    tmp[1] = Tag.DataLength[1];
                    tmp[0] = Tag.DataLength[2];
                    int n=System.BitConverter.ToInt32(tmp, 0);
                    fs.Seek(n, SeekOrigin.Current);
                    aFlvInfo.TagList.Add(Tag);

                }
                return aFlvInfo;
            }
            return null;
        }
    }

}