private static fdAT Read_fdAT(string png, int i)
{
BinaryReader br = new BinaryReader(new FileStream(png, FileMode.Open));
fdAT fdat = new fdAT();
fdat.id = Encoding.ASCII.GetBytes(new char[] { 'f', 'd', 'A', 'T' });
fdat.sequence_number = BitConverter.GetBytes(i).Reverse().ToArray();
bool encontrado = false;
string c = "\0\0\0\0";
while (!encontrado)
{
c = c.Remove(0, 1);
c += (char)br.ReadByte();
if (c == "IDAT")
{
encontrado = true;
}
}
br.BaseStream.Position -= 8;
int length = BitConverter.ToInt32(br.ReadBytes(4).Reverse().ToArray(), 0);
fdat.length = BitConverter.GetBytes(length + 4).Reverse().ToArray();
br.BaseStream.Position += 4;
fdat.data = br.ReadBytes(length);
List <Byte> stream = new List <byte>();
stream.AddRange(fdat.id);
stream.AddRange(fdat.sequence_number);
stream.AddRange(fdat.data);
fdat.crc = Helper.CRC32.Calculate(stream.ToArray());
br.Close();
return(fdat);
}
private static void Write(string apng, byte[] signature, IHDR ihdr, acTL actl, byte[] idat,
fcTL[] fctl, fdAT[] fdat, IEND iend)
{
BinaryWriter bw = new BinaryWriter(new FileStream(apng, FileMode.Create));
bw.Write(signature);
bw.Write(ihdr.length);
bw.Write(ihdr.id);
bw.Write(ihdr.width);
bw.Write(ihdr.height);
bw.Write(ihdr.depth);
bw.Write(ihdr.colour_type);
bw.Write(ihdr.compression);
bw.Write(ihdr.filter);
bw.Write(ihdr.interlace);
bw.Write(ihdr.crc);
bw.Write(actl.length);
bw.Write(actl.id);
bw.Write(actl.num_frames);
bw.Write(actl.num_plays);
bw.Write(actl.crc);
bw.Write(fctl[0].length);
bw.Write(fctl[0].id);
bw.Write(fctl[0].sequence_numer);
bw.Write(fctl[0].width);
bw.Write(fctl[0].height);
bw.Write(fctl[0].x_offset);
bw.Write(fctl[0].y_offset);
bw.Write(fctl[0].delay_num);
bw.Write(fctl[0].delay_den);
bw.Write(fctl[0].dispose_op);
bw.Write(fctl[0].blend_op);
bw.Write(fctl[0].crc);
bw.Write(idat);
for (int i = 0; i < fdat.Length; i++)
{
bw.Write(fctl[i + 1].length);
bw.Write(fctl[i + 1].id);
bw.Write(fctl[i + 1].sequence_numer);
bw.Write(fctl[i + 1].width);
bw.Write(fctl[i + 1].height);
bw.Write(fctl[i + 1].x_offset);
bw.Write(fctl[i + 1].y_offset);
bw.Write(fctl[i + 1].delay_num);
bw.Write(fctl[i + 1].delay_den);
bw.Write(fctl[i + 1].dispose_op);
bw.Write(fctl[i + 1].blend_op);
bw.Write(fctl[i + 1].crc);
bw.Write(fdat[i].length);
bw.Write(fdat[i].id);
bw.Write(fdat[i].sequence_number);
bw.Write(fdat[i].data);
bw.Write(fdat[i].crc);
}
bw.Write(iend.length);
bw.Write(iend.id);
bw.Write(iend.crc);
bw.Flush();
bw.Close();
}
private static fdAT Read_fdAT(string png, int i)
{
BinaryReader br = new BinaryReader(new FileStream(png, FileMode.Open));
fdAT fdat = new fdAT();
fdat.id = Encoding.ASCII.GetBytes(new char[] { 'f', 'd', 'A', 'T' });
fdat.sequence_number = BitConverter.GetBytes(i).Reverse().ToArray();
bool encontrado = false;
string c = "\0\0\0\0";
while (!encontrado)
{
c = c.Remove(0, 1);
c += (char)br.ReadByte();
if (c == "IDAT")
encontrado = true;
}
br.BaseStream.Position -= 8;
int length = BitConverter.ToInt32(br.ReadBytes(4).Reverse().ToArray(), 0);
fdat.length = BitConverter.GetBytes(length + 4).Reverse().ToArray();
br.BaseStream.Position += 4;
fdat.data = br.ReadBytes(length);
List<Byte> stream = new List<byte>();
stream.AddRange(fdat.id);
stream.AddRange(fdat.sequence_number);
stream.AddRange(fdat.data);
fdat.crc = Helper.CRC32.Calculate(stream.ToArray());
br.Close();
return fdat;
}
