public static FlvTag ReadFlvTag(Stream stream)
{
const string Message = "输入数据不是 FLV Tag";
if ((stream.Length - stream.Position) < 11)
{
throw new FlvException(Message);
}
byte[] b = new byte[4];
FlvTag tag = new FlvTag
{
Position = 0,
TagType = (TagType)stream.ReadByte()
};
if (tag.TagType != TagType.Audio && tag.TagType != TagType.Video && tag.TagType != TagType.Script)
{
throw new FlvException(Message);
}
// ----------------------------- //
b[0] = 0;
if (3 != stream.Read(b, 1, 3))
{
throw new FlvException(Message);
}
tag.TagSize = BitConverter.ToInt32(b.ToBE(), 0);
// ----------------------------- //
if (3 != stream.Read(b, 1, 3))
{
throw new FlvException(Message);
}
var temp = stream.ReadByte();
if (temp == -1)
{
throw new FlvException(Message);
}
b[0] = (byte)temp;
tag.TimeStamp = BitConverter.ToInt32(b.ToBE(), 0);
// ----------------------------- //
switch (tag.TagType)
{
case TagType.Audio:
{
if (4 != stream.Read(b, 0, 4))
{
throw new FlvException(Message);
}
tag.Flag = stream.ReadByte() == 0 ? TagFlag.Header : TagFlag.None;
var totalSkip = tag.TagSize - 2;
if (totalSkip != stream.SkipBytes(totalSkip))
{
throw new FlvException(Message);
}
}
break;
case TagType.Video:
{
if (3 != stream.Read(b, 0, 3))
{
throw new FlvException(Message);
}
if (stream.ReadByte() == 0x17)
{
tag.Flag |= TagFlag.Keyframe;
}
switch (stream.ReadByte())
{
case 0:
tag.Flag |= TagFlag.Header;
break;
case 2:
tag.Flag |= TagFlag.End;
break;
}
var totalSkip = tag.TagSize - 2;
if (totalSkip != stream.SkipBytes(totalSkip))
{
throw new FlvException(Message);
}
}
break;
default:
{
var totalSkip = 3 + tag.TagSize;
if (totalSkip != stream.SkipBytes(totalSkip))
{
throw new FlvException(Message);
}
}
break;
}
// ----------------------------- //
return(tag);
}
private static FlvTag[] ReadAllTagsFromstream(Stream stream, uint tagNum)
{
List <FlvTag> tags = new List <FlvTag>(1024);
byte[] b = new byte[4];
do
{
FlvTag tag = new FlvTag();
// ----------------------------- //
if (4 != stream.Read(b, 0, 4))
{
break;
}
// ----------------------------- //
tag.Position = stream.Position;
tag.TagType = (TagType)stream.ReadByte();
if (tag.TagType != TagType.Audio && tag.TagType != TagType.Video && tag.TagType != TagType.Script)
{
break;
}
// ----------------------------- //
b[0] = 0;
if (3 != stream.Read(b, 1, 3))
{
break;
}
tag.TagSize = BitConverter.ToInt32(b.ToBE(), 0);
// ----------------------------- //
if (3 != stream.Read(b, 1, 3))
{
break;
}
var temp = stream.ReadByte();
if (temp == -1)
{
break;
}
b[0] = (byte)temp;
tag.TimeStamp = BitConverter.ToInt32(b.ToBE(), 0);
// ----------------------------- //
switch (tag.TagType)
{
case TagType.Audio:
{
if (4 != stream.Read(b, 0, 4))
{
goto break_out;
}
tag.Flag = stream.ReadByte() == 0 ? TagFlag.Header : TagFlag.None;
var totalSkip = tag.TagSize - 2;
if (totalSkip != stream.SkipBytes(totalSkip))
{
goto break_out;
}
}
break;
case TagType.Video:
{
if (3 != stream.Read(b, 0, 3))
{
goto break_out;
}
if (stream.ReadByte() == 0x17)
{
tag.Flag |= TagFlag.Keyframe;
}
switch (stream.ReadByte())
{
case 0:
tag.Flag |= TagFlag.Header;
break;
case 2:
tag.Flag |= TagFlag.End;
break;
}
var totalSkip = tag.TagSize - 2;
if (totalSkip != stream.SkipBytes(totalSkip))
{
goto break_out;
}
}
break;
default:
{
var totalSkip = 3 + tag.TagSize;
if (totalSkip != stream.SkipBytes(totalSkip))
{
goto break_out;
}
}
break;
}
// ----------------------------- //
tags.Add(tag);
} while (tagNum == 0 ? true : tags.Count < tagNum);
break_out:
return(tags.ToArray());
}
