private void ReadMdia(ref TrakInfo trackData, BoxInfo mdiaBox)
{
var maxLen = mdiaBox.BoxOffset + mdiaBox.Offset;
BoxInfo?box = null;
do
{
box = NextBox(maxLen);
if (box != null)
{
if (box.Value.Type.Check(mdhd))
{
ReadMdhd(ref trackData);
}
if (box.Value.Type.Check(hdlr))
{
ReadHdlr(ref trackData);
}
if (box.Value.Type.Check(minf))
{
ReadMinf(ref trackData, box.Value);
}
SeekNext(box.Value);
}
} while (!(box == null || box.Value.Last));
}
private void ReadChaptersText(TrakInfo textBox)
{
if (textBox.Durations != null && textBox.Samples != null)
{
var len = Math.Min(textBox.Durations.Length, textBox.Samples.Length);
if (len > 0)
{
Chapters = new ChapterInfo[len];
var pos = TimeSpan.FromSeconds(0);
var tps = (double)textBox.TimeUnitPerSecond;
if (tps <= 0.1)
{
tps = 600;
}
for (int i = 0; i < len; i++)
{
var ci = new ChapterInfo();
ci.Time = pos;
var d = (double)textBox.Durations[i];
pos += TimeSpan.FromSeconds(d / tps);
stream.Seek(SeekOrigin.Begin, textBox.Samples[i]);
ci.Name = ReadPascalString(Encoding.UTF8);
Chapters[i] = ci;
}
}
}
}
private TrakInfo ReadTrak(BoxInfo trakBox)
{
var maxLen = trakBox.BoxOffset + trakBox.Offset;
var trakData = new TrakInfo();
BoxInfo?box = null;
do
{
box = NextBox(maxLen);
if (box != null)
{
if (box.Value.Type.Check(tkhd))
{
ReadTkhd(ref trakData);
}
if (box.Value.Type.Check(mdia))
{
ReadMdia(ref trakData, box.Value);
}
if (box.Value.Type.Check(tref))
{
ReadTref(ref trakData, box.Value);
}
SeekNext(box.Value);
}
} while (!(box == null || box.Value.Last));
return(trakData);
}
private void ReadTkhd(ref TrakInfo trakData)
{
var v = new byte[1];
stream.Read(v, 1);
var isv8 = v[0] == 1;
stream.Seek(SeekOrigin.Current, 3 + (isv8 ? 8 + 8 : 4 + 4));
trakData.Id = ReadUint32();
}
private void ReadHdlr(ref TrakInfo trakData)
{
stream.Seek(SeekOrigin.Current, 4 + 4);
var b = new byte[4];
stream.Read(b, 4);
var bc = new char[4];
AsciiEncoding.Current.GetDecoder().GetChars(b, 0, 4, bc, 0);
trakData.Type = new string(bc);
}
private void ReadChap(ref TrakInfo trakData, BoxInfo box2)
{
var len = (box2.Offset - 8) / 4;
if (len > 0 && len < 1024)
{
trakData.Chaps = new uint[len];
for (uint i = 0; i < len; i++)
{
trakData.Chaps[i] = ReadUint32();
}
}
}
private void ReadStco(ref TrakInfo trakData)
{
stream.Seek(SeekOrigin.Current, 4);
var len = ReadUint32();
if (len > 1024)
{
len = 0;
}
trakData.Samples = new long[len];
for (uint i = 0; i < len; i++)
{
trakData.Samples[i] = ReadUint32();
}
}
private void ReadStts(ref TrakInfo trakData)
{
stream.Seek(SeekOrigin.Current, 4);
var len = ReadUint32();
if (len > 1024)
{
len = 0;
}
trakData.Durations = new uint[len];
trakData.FrameCount = new uint[len];
for (uint i = 0; i < len; i++)
{
trakData.FrameCount[i] = ReadUint32();
trakData.Durations[i] = ReadUint32();
}
}
private void ReadMinf(ref TrakInfo trakData, BoxInfo box2)
{
var maxLen = box2.BoxOffset + box2.Offset;
BoxInfo?box = null;
do
{
box = NextBox(maxLen);
if (box != null)
{
if (box.Value.Type.Check(stbl))
{
ReadStbl(ref trakData, box.Value);
}
SeekNext(box.Value);
}
} while (!(box == null || box.Value.Last));
}
