private object ReadObject(BinaryReader br)
{
var obj = new MetaObject();
while (offset < size)
{
var byts = br.ReadBytes(3);
if (byts[0] == 0 && byts[1] == 0 && byts[2] == 9)
{
offset += 3;
break;
}
br.BaseStream.Seek(-3, SeekOrigin.Current);
string key = ReadString(br);
if (key[0] == 0)
break;
obj[key] = ReadElement(br);
}
return obj;
}
private MetaObject ReadArray(BinaryReader br)
{
var array = new MetaObject();
br.ReadBytes(4);
offset += 4;
while (offset < size)
{
var byts = br.ReadBytes(3);
if (byts[0] == 0 && byts[1] == 0 && byts[2] == 9)
{
offset += 3;
break;
}
br.BaseStream.Seek(-3, SeekOrigin.Current);
string key = ReadString(br);
//if (key[0] == 0)
// break;
array[key] = ReadElement(br);
}
return array;
//var len = br.ReadBytes(4).ToUInt32(false);
//offset += 4;
//var array = new MetaObject();
//for (uint i = 0; i < len; i++)
//{
// string key = ReadString(br);
// array[key] = ReadElement(br);
//}
//br.ReadBytes(3); // 00 00 09表示object的结束
//offset += 3;
//return array;
}
private MetaObject GetSegments(MetaArray filepositions, MetaArray times)
{
var timeLine = 0d;
var segments = new MetaObject();
segments["extension"] = ".dat";
var positions = new MetaArray();
var files = new MetaArray();
if (filepositions.Length != times.Length)
{
throw new InvalidDataException("keyframes data is invalid");
}
for (int i = 0, len = times.Length; i < len; i++)
{
var time = Convert.ToDouble(times[i]);
if (time - timeLine >= INTERNAL)
{
positions.Add(Convert.ToDouble(filepositions[i]));
files.Add(positions.Length.ToString());
timeLine = time;
}
}
positions.Add(Convert.ToDouble(this.endPosition));
files.Add(positions.Length.ToString());
segments["positions"] = positions;
segments["files"] = files;
return segments;
}
private uint WriteObjct(Stream st, MetaObject content)
{
var keys = content.Keys;
var total = 0u;
foreach (var key in keys)
{
total += this.WriteString(st, key);
total += this.WriteElement(st, content[key]);
}
st.WriteByte(0x00);
st.WriteByte(0x00);
st.WriteByte(0x09);
return total + 3;
}
private MetaObject GetKeyFrames(MetaObject obj)
{
var vTags = info.Body.Tags.Where(t => t.TagType == TagType.Video && ((t as VideoTag).Data as VideoData).Type == FrameType.KeyFrame);
this.startPosition = info.Body.Tags[0].Start + info.Body.Tags[0].Size + 4;
//this.endPosition = info.Body.Tags.Last().Start + info.Body.Tags.Last().Size + 4;
this.endPosition = info.Body.Start + info.Body.Size;
if (obj.Contains("keyframes"))
{
hasKeyFrames = true;
return obj["keyframes"] as MetaObject;
}
hasKeyFrames = false;
var filepositions = new MetaArray();
var times = new MetaArray();
foreach (var tag in vTags)
{
filepositions.Add(Convert.ToDouble(tag.Start));
times.Add(tag.Header.Timestamp / 1000d);
}
var keyFrames = new MetaObject();
keyFrames["filepositions"] = filepositions;
keyFrames["times"] = times;
return keyFrames;
}