internal static GifApplicationExtensionBlock Create(GifReader reader)
{
GifApplicationExtensionBlock gifApplicationExtensionBlock = new GifApplicationExtensionBlock(reader);
if (gifApplicationExtensionBlock.ApplicationIdentifier.Equals("NETSCAPE") && gifApplicationExtensionBlock.ApplicationAuthenticationCode.Equals("2.0"))
{
if ((null != gifApplicationExtensionBlock.Bytes))
{
if ((3 == gifApplicationExtensionBlock.Bytes.Length) && (1 == gifApplicationExtensionBlock.Bytes[0]))
{
gifApplicationExtensionBlock = new GifNetscapeLoopingApplicationExtensionBlock(gifApplicationExtensionBlock);
}
else if ((5 == gifApplicationExtensionBlock.Bytes.Length) && (2 == gifApplicationExtensionBlock.Bytes[0]))
{
gifApplicationExtensionBlock = new GifNetscapeBufferingApplicationExtensionBlock(gifApplicationExtensionBlock);
}
}
}
else if (gifApplicationExtensionBlock.ApplicationIdentifier.Equals("ANIMEXTS") && gifApplicationExtensionBlock.ApplicationAuthenticationCode.Equals("1.0"))
{
if ((null != gifApplicationExtensionBlock.Bytes) && (3 == gifApplicationExtensionBlock.Bytes.Length) && (1 == gifApplicationExtensionBlock.Bytes[0]))
{
gifApplicationExtensionBlock = new GifAnimextsLoopingApplicationExtensionBlock(gifApplicationExtensionBlock);
}
}
return(gifApplicationExtensionBlock);
}
internal void Read(GifReader reader)
{
Byte size = reader.ReadByte();
if (size != 4)
{
System.Diagnostics.Debug.WriteLine("Wrong size of " + ToString());
}
Byte flags = reader.ReadByte();
disposalMethod = (GifDisposalMethod)((flags & 0x1C) >> 2);
userInputExpected = 0x02 == (flags & 0x02);
transparency = 0x01 == (flags & 0x01);
delay = reader.ReadUInt16();
transparencyIndex = reader.ReadByte();
Byte terminator = reader.ReadByte();
if (terminator != 0x00)
{
throw new Exception("Unknown extension terminator: 0x" + terminator.ToString("X2"));
}
}
internal void Read(GifReader reader)
{
Byte size = reader.ReadByte();
if (size != 11)
{
System.Diagnostics.Debug.WriteLine("Wrong size of " + ToString());
}
applicationIdentifier = reader.ReadString(8);
applicationAuthenticationCode = reader.ReadString(3);
bytes = reader.ReadBinarySubBlocks();
}
internal void Read(GifReader reader)
{
left = reader.ReadUInt16();
top = reader.ReadUInt16();
width = reader.ReadUInt16();
height = reader.ReadUInt16();
Byte flags = reader.ReadByte();
localColorTableFlag = 0x80 == (flags & 0x80);
interlaced = 0x40 == (flags & 0x40);
localColorTableSorted = 0x20 == (flags & 0x20);
localColorTableSize = (UInt16)(2 << (flags & 0x07));
}
internal void Read(GifReader reader)
{
width = reader.ReadUInt16();
height = reader.ReadUInt16();
Byte flags = reader.ReadByte();
globalColorTableFlag = 0x80 == (flags & 0x80);
colorResolution = (Byte)(((flags & 0x70) >> 4) + 1);
globalColorTableSorted = 0x08 == (flags & 0x08);
globalColorTableSize = (UInt16)(2 << (flags & 0x07));
backgroundColorIndex = reader.ReadByte();
pixelAspectRatio = reader.ReadByte();
}
internal void Read(GifReader reader, GifLogicalScreenDescriptorBlock gifLogicalScreenDescriptorBlock)
{
bytes = reader.ReadBytes(gifLogicalScreenDescriptorBlock.GlobalColorTableSize * 3);
//byte[] globalColorTableBuffer = reader.ReadBytes(globalColorTableSize * 3);
//globalColorTable = new Color[globalColorTableSize];
//int baseIndex = 0;
//for (UInt16 colorIndex = 0; colorIndex < globalColorTableSize; colorIndex++)
//{
// globalColorTable[colorIndex] = Color.FromArgb(globalColorTableBuffer[baseIndex], globalColorTableBuffer[baseIndex + 1], globalColorTableBuffer[baseIndex + 2]);
// baseIndex += 3;
//}
}
internal void Read(GifReader reader)
{
String signature = reader.ReadString(3);
if (signature != "GIF")
{
throw new Exception("No GIF signature");
}
version = reader.ReadString(3);
if ((version != "87a") && (version != "89a"))
{
throw new Exception("Unsupported GIF version: " + version);
}
}
internal void Read(GifReader reader)
{
Byte size = reader.ReadByte();
if (size != 12)
{
System.Diagnostics.Debug.WriteLine("Wrong size of " + ToString());
}
left = reader.ReadUInt16();
top = reader.ReadUInt16();
width = reader.ReadUInt16();
height = reader.ReadUInt16();
cellWidth = reader.ReadByte();
cellHeight = reader.ReadByte();
foregroundColor = reader.ReadByte();
backgroundColor = reader.ReadByte();
text = reader.ReadTextSubBlocks();
}
internal void Read(GifReader reader)
{
bytes = reader.ReadBinarySubBlocks();
}
public void Read(Stream stream)
{
blocks.Clear();
// reader
GifReader reader = new GifReader(stream);
// Header
AddBlock(new GifHeaderBlock(reader));
// Logical Screen Descriptor
GifLogicalScreenDescriptorBlock gifLogicalScreenDescriptorBlock = new GifLogicalScreenDescriptorBlock(reader);
AddBlock(gifLogicalScreenDescriptorBlock);
// Global Color Table
if (gifLogicalScreenDescriptorBlock.GlobalColorTableFlag)
{
AddBlock(new GifGlobalColorTableBlock(reader, gifLogicalScreenDescriptorBlock));
}
// Segments
while (true)
{
Byte identifier = reader.ReadByte();
switch (identifier)
{
// Frames
case 0x2C:
GifImageDescriptorBlock gifImageDescriptorBlock = new GifImageDescriptorBlock(reader);
AddBlock(gifImageDescriptorBlock);
if (gifImageDescriptorBlock.LocalColorTableFlag)
{
AddBlock(new GifLocalColorTableBlock(reader, gifImageDescriptorBlock));
}
AddBlock(new GifTableBasedImageDataBlock(reader));
break;
// Extensions
case 0x21:
Byte label = reader.ReadByte();
switch (label)
{
case 0xF9:
AddBlock(new GifGraphicControExtensionBlock(reader));
break;
case 0xFE:
AddBlock(new GifCommentExtensionBlock(reader));
break;
case 0x01:
AddBlock(new GifPlainTextExtensionBlock(reader));
break;
case 0xFF:
AddBlock(GifApplicationExtensionBlock.Create(reader));
break;
default:
AddBlock(new GifExtensionBlock(label, reader));
break;
}
break;
// Trailer
case 0x3B:
AddBlock(new GifTrailerBlock());
return;
default:
throw new Exception("Unknown segment identifier: 0x" + identifier.ToString("X2"));
}
}
}
internal GifExtensionBlock(Byte label, GifReader reader)
: base(GifBlockType.Extension)
{
this.label = label;
Read(reader);
}
internal GifApplicationExtensionBlock(GifReader reader)
: base(GifBlockType.ApplicationExtension)
{
Read(reader);
}
internal GifLogicalScreenDescriptorBlock(GifReader reader)
: base(GifBlockType.LogicalScreenDescriptor)
{
Read(reader);
}
internal GifCommentExtensionBlock(GifReader reader)
: base(GifBlockType.CommentExtension)
{
Read(reader);
}
internal GifImageDescriptorBlock(GifReader reader)
: base(GifBlockType.ImageDescriptor)
{
Read(reader);
}
internal GifGraphicControExtensionBlock(GifReader reader)
: base(GifBlockType.GraphicControlExtension)
{
Read(reader);
}
internal void Read(GifReader reader)
{
comment = reader.ReadTextSubBlocks();
}
internal GifLocalColorTableBlock(GifReader reader, GifImageDescriptorBlock gifImageDescriptorBlock)
: base(GifBlockType.LocalColorTable)
{
Read(reader, gifImageDescriptorBlock);
}
internal GifHeaderBlock(GifReader reader)
: base(GifBlockType.Header)
{
Read(reader);
}
internal void Read(GifReader reader)
{
lzwMinimumCodeSize = reader.ReadByte();
imageData = reader.ReadBinarySubBlocks();
}
internal GifTableBasedImageDataBlock(GifReader reader)
: base(GifBlockType.TableBasedImageData)
{
Read(reader);
}
internal void Read(GifReader reader, GifImageDescriptorBlock gifImageDescriptorBlock)
{
bytes = reader.ReadBytes(gifImageDescriptorBlock.LocalColorTableSize * 3);
}
internal GifPlainTextExtensionBlock(GifReader reader)
: base(GifBlockType.PlainTextExtension)
{
Read(reader);
}
internal GifGlobalColorTableBlock(GifReader reader, GifLogicalScreenDescriptorBlock gifLogicalScreenDescriptorBlock)
: base(GifBlockType.GlobalColorTable)
{
Read(reader, gifLogicalScreenDescriptorBlock);
}