internal override void Write(Stream output)
{
var contents = Encoding.UTF8.GetBytes(Value);
using (var writer = new Mp4Writer(output))
{
// Write the atom header
writer.WriteBigEndian((uint)contents.Length + 24);
#if NETSTANDARD2_0
writer.Write(CodePagesEncodingProvider.Instance.GetEncoding(1252).GetBytes(_fourCc));
#else
Span <byte> fourCcBuffer = stackalloc byte[4];
CodePagesEncodingProvider.Instance.GetEncoding(1252).GetBytes(_fourCc, fourCcBuffer);
writer.Write(fourCcBuffer);
#endif
// Write the data atom header
writer.WriteBigEndian((uint)contents.Length + 16);
writer.WriteBigEndian(0x64617461); // 'data'
// Set the type flag
writer.WriteBigEndian(1);
writer.WriteZeros(4);
writer.Write(contents);
}
}
internal void Write([NotNull] Stream output)
{
if (_atoms.Count == 0)
{
return;
}
var startPosition = output.Position;
using (var writer = new Mp4Writer(output))
{
// Write the atom header, but we don't know the size yet
writer.Seek(4, SeekOrigin.Current);
writer.WriteBigEndian(0x696c7374); // 'ilst'
foreach (var atom in _atoms)
{
atom.Write(output);
}
// Update the size
var size = output.Position - startPosition;
writer.BaseStream.Position = startPosition;
writer.WriteBigEndian((uint)size);
writer.Seek((int)size - 4, SeekOrigin.Current);
}
}
void UpdateTimeStamp(
[NotNull, ItemNotNull] string[] hierarchy,
DateTime?creationTime,
DateTime?modificationTime)
{
DescendToAtom(hierarchy);
var version = _stream.ReadByte();
_stream.Seek(3, SeekOrigin.Current);
var epoch = new DateTime(1904, 1, 1);
var creationSeconds = creationTime?.Subtract(epoch).TotalSeconds ?? 0;
var modificationSeconds = modificationTime?.Subtract(epoch).TotalSeconds ?? 0;
using (var writer = new Mp4Writer(_stream))
{
if (version == 0)
{
if (creationTime.HasValue)
{
writer.WriteBigEndian((uint)creationSeconds);
}
else
{
writer.Seek(4, SeekOrigin.Current);
}
if (modificationTime.HasValue)
{
writer.WriteBigEndian((uint)modificationSeconds);
}
}
else
{
if (creationTime.HasValue)
{
writer.WriteBigEndian((ulong)creationSeconds);
}
else
{
writer.Seek(8, SeekOrigin.Current);
}
if (modificationTime.HasValue)
{
writer.WriteBigEndian((ulong)modificationSeconds);
}
}
}
}
internal override void Write(Stream output)
{
if (_size <= 8)
{
return;
}
using (var writer = new Mp4Writer(output))
{
// Write the atom header
writer.WriteBigEndian(_size);
writer.WriteBigEndian(0x66726565); // 'free'
writer.WriteZeros((int)_size - 8);
}
}
internal override void Write(Stream output)
{
using (var writer = new Mp4Writer(output))
{
// Write the atom header
writer.WriteBigEndian(32);
writer.WriteBigEndian(0x74726B6E); // 'trkn'
// Write the data atom header
writer.WriteBigEndian(24);
writer.WriteBigEndian(0x64617461); // 'data'
writer.WriteZeros(11);
writer.Write(TrackNumber);
writer.WriteZeros(1);
writer.Write(TrackCount);
writer.WriteZeros(2);
}
}
internal override void Write(Stream output)
{
using (var writer = new Mp4Writer(output))
{
// Write the atom header
writer.WriteBigEndian((uint)Value.Data.Length + 24);
writer.WriteBigEndian(0x636F7672); // 'covr'
// Write the data atom header
writer.WriteBigEndian((uint)Value.Data.Length + 16);
writer.WriteBigEndian(0x64617461); // 'data'
// Set the type flag to PNG or JPEG
writer.WriteBigEndian(Value.Lossless ? 14u : 13u);
writer.WriteZeros(4);
#if NETSTANDARD2_0
writer.Write(Value.Data.ToArray());
#else
writer.Write(Value.Data);
#endif
}
}
internal void UpdateAtomSizes(uint increase)
{
if (_atomInfoStack.Count <= 0)
{
return;
}
using (var writer = new Mp4Writer(_stream))
{
do
{
var currentAtom = _atomInfoStack.Pop();
_stream.Position = currentAtom.Start;
writer.WriteBigEndian(currentAtom.Size + increase);
} while (_atomInfoStack.Count > 0);
}
}
internal void UpdateStco(uint offset)
{
DescendToAtom("moov", "trak", "mdia", "minf", "stbl", "stco");
_stream.Seek(4, SeekOrigin.Current);
using (var reader = new Mp4Reader(_stream))
using (var writer = new Mp4Writer(_stream))
{
var count = reader.ReadUInt32BigEndian();
var dataStart = _stream.Position;
for (var i = 0; i < count; i++)
{
_stream.Position = dataStart + i * 4;
var value = reader.ReadUInt32BigEndian();
_stream.Seek(-4, SeekOrigin.Current);
writer.WriteBigEndian(value + offset);
}
}
}