internal DataStruct(int blockSize,Stream stream)
{
StreamHelper streamHelper = new StreamHelper(stream);
_blockSize = (byte)blockSize;
if (_blockSize > 0)
{
_data = streamHelper.ReadByte(_blockSize);
}
}
internal static void Encode(GifImage gifImage, string gifPath)
{
FileStream fs = null;
try
{
fs = new FileStream(gifPath, FileMode.Create);
StreamHelper streamHelper = new StreamHelper(fs);
streamHelper.WriteHeader(gifImage.Header);
streamHelper.WriteLSD(gifImage.LogicalScreenDescriptor);
if (gifImage.LogicalScreenDescriptor.GlobalColorTableFlag)
{
streamHelper.SetGlobalColorTable(gifImage.GlobalColorTable);
}
streamHelper.SetApplicationExtensions(gifImage.ApplictionExtensions);
streamHelper.SetCommentExtensions(gifImage.CommentExtensions);
SetFrames(gifImage.Frames, streamHelper, fs);
}
catch
{
throw;
}
finally
{
if (fs != null)
{
fs.Close();
}
}
}
static void SetFrames(List<GifFrame> frames,StreamHelper streamHelper,Stream fs)
{
foreach (GifFrame f in frames)
{
List<byte> list = new List<byte>();
if (f.GraphicExtension != null)
{
list.AddRange(f.GraphicExtension.GetBuffer());
}
f.ImageDescriptor.SortFlag = false;
f.ImageDescriptor.InterlaceFlag = false;
list.AddRange(f.ImageDescriptor.GetBuffer());
if (f.ImageDescriptor.LctFlag)
{
list.AddRange(f.LocalColorTable);
}
streamHelper.WriteBytes(list.ToArray());
int transIndex = -1;
if (f.GraphicExtension.TransparencyFlag)
{
transIndex = f.GraphicExtension.TranIndex;
}
byte[] indexedPixel = GetImagePixels(f.Image, f.LocalColorTable, transIndex);
LZWEncoder lzw = new LZWEncoder(indexedPixel, (byte)f.ColorDepth);
lzw.Encode(fs);
streamHelper.WriteBytes(new byte[] { 0 });
}
streamHelper.WriteBytes(new byte[] { 0x3B });
}
internal static GifImage Decode(Stream stream)
{
StreamHelper streamHelper = null;
GifImage gifImage = new GifImage();
List <GraphicEx> graphics = new List <GraphicEx>();
int frameCount = 0;
try
{
streamHelper = new StreamHelper(stream);
//读取文件头
gifImage.Header = streamHelper.ReadString(6);
//读取逻辑屏幕标示符
gifImage.LogicalScreenDescriptor = streamHelper.GetLCD(stream);
if (gifImage.LogicalScreenDescriptor.GlobalColorTableFlag)
{
//读取全局颜色列表
gifImage.GlobalColorTable = streamHelper.ReadByte(gifImage.LogicalScreenDescriptor.GlobalColorTableSize * 3);
}
int nextFlag = streamHelper.Read();
while (nextFlag != 0)
{
if (nextFlag == GifExtensions.ImageLabel)
{
ReadImage(streamHelper, stream, gifImage, graphics, frameCount);
frameCount++;
}
else if (nextFlag == GifExtensions.ExtensionIntroducer)
{
int gcl = streamHelper.Read();
switch (gcl)
{
case GifExtensions.GraphicControlLabel:
{
GraphicEx graphicEx = streamHelper.GetGraphicControlExtension(stream);
graphics.Add(graphicEx);
break;
}
case GifExtensions.CommentLabel:
{
CommentEx comment = streamHelper.GetCommentEx(stream);
gifImage.CommentExtensions.Add(comment);
break;
}
case GifExtensions.ApplicationExtensionLabel:
{
ApplicationEx applicationEx = streamHelper.GetApplicationEx(stream);
gifImage.ApplictionExtensions.Add(applicationEx);
break;
}
case GifExtensions.PlainTextLabel:
{
PlainTextEx textEx = streamHelper.GetPlainTextEx(stream);
gifImage.PlainTextEntensions.Add(textEx);
break;
}
}
}
else if (nextFlag == GifExtensions.EndIntroducer)
{
//到了文件尾
break;
}
nextFlag = streamHelper.Read();
}
gifImage.Texture = new Texture2D(gifImage.Width, gifImage.Height, TextureFormat.ARGB32, false);
}
catch
{
throw;
}
finally
{
stream.Close();
}
return(gifImage);
}
/// <summary>
/// ��gifͼ���ļ����н���
/// </summary>
/// <param name="gifPath">gif�ļ�·��</param>
internal static GifImage Decode(string gifPath)
{
FileStream fs=null;
StreamHelper streamHelper=null;
GifImage gifImage = new GifImage();
List<GraphicEx> graphics = new List<GraphicEx>();
int frameCount = 0;
try
{
fs = new FileStream(gifPath,FileMode.Open);
streamHelper = new StreamHelper(fs);
//��ȡ�ļ�ͷ
gifImage.Header = streamHelper.ReadString(6);
//��ȡ����Ļ��ʾ��
gifImage.LogicalScreenDescriptor = streamHelper.GetLCD(fs);
if (gifImage.LogicalScreenDescriptor.GlobalColorTableFlag)
{
//��ȡȫ����ɫ�б�
gifImage.GlobalColorTable = streamHelper.ReadByte(gifImage.LogicalScreenDescriptor.GlobalColorTableSize * 3);
}
int nextFlag = streamHelper.Read();
while (nextFlag != 0)
{
if (nextFlag == GifExtensions.ImageLabel)
{
ReadImage(streamHelper, fs, gifImage, graphics, frameCount);
frameCount++;
}
else if (nextFlag == GifExtensions.ExtensionIntroducer)
{
int gcl = streamHelper.Read();
switch (gcl)
{
case GifExtensions.GraphicControlLabel:
{
GraphicEx graphicEx = streamHelper.GetGraphicControlExtension(fs);
graphics.Add(graphicEx);
break;
}
case GifExtensions.CommentLabel:
{
CommentEx comment = streamHelper.GetCommentEx(fs);
gifImage.CommentExtensions.Add(comment);
break;
}
case GifExtensions.ApplicationExtensionLabel:
{
ApplicationEx applicationEx = streamHelper.GetApplicationEx(fs);
gifImage.ApplictionExtensions.Add(applicationEx);
break;
}
case GifExtensions.PlainTextLabel:
{
PlainTextEx textEx = streamHelper.GetPlainTextEx(fs);
gifImage.PlainTextEntensions.Add(textEx);
break;
}
}
}
else if (nextFlag == GifExtensions.EndIntroducer)
{
//�����ļ�β
break;
}
nextFlag = streamHelper.Read();
}
}
catch
{
throw;
}
finally
{
fs.Close();
}
return gifImage;
}
static void ReadImage(StreamHelper streamHelper, Stream fs, GifImage gifImage, List<GraphicEx> graphics, int frameCount)
{
ImageDescriptor imgDes = streamHelper.GetImageDescriptor(fs);
GifFrame frame = new GifFrame();
frame.ImageDescriptor = imgDes;
frame.LocalColorTable = gifImage.GlobalColorTable;
if (imgDes.LctFlag)
{
frame.LocalColorTable = streamHelper.ReadByte(imgDes.LctSize*3);
}
LZWDecoder lzwDecoder = new LZWDecoder(fs);
int dataSize = streamHelper.Read();
frame.ColorDepth = dataSize;
byte[] piexel = lzwDecoder.DecodeImageData(imgDes.Width, imgDes.Height, dataSize);
frame.IndexedPixel = piexel;
int blockSize = streamHelper.Read();
DataStruct data = new DataStruct(blockSize, fs);
GraphicEx graphicEx = graphics[frameCount];
frame.GraphicExtension = graphicEx;
Bitmap img = GetImageFromPixel(piexel, frame.Palette, imgDes.InterlaceFlag, imgDes.Width, imgDes.Height);
frame.Image = img;
gifImage.Frames.Add(frame);
}
/// <summary>
/// 对gif图像文件进行解码
/// </summary>
/// <param name="gifPath">gif文件路径</param>
public static GifImage Decode(string gifPath)
{
FileStream fs = null;
StreamHelper streamHelper = null;
GifImage gifImage = new GifImage();
List <GraphicEx> graphics = new List <GraphicEx>();
int frameCount = 0;
// try
// {
fs = new FileStream(gifPath, FileMode.Open);
streamHelper = new StreamHelper(fs);
//读取文件头
gifImage.Header = streamHelper.ReadString(6);
//读取逻辑屏幕标示符
gifImage.LogicalScreenDescriptor = streamHelper.GetLCD(fs);
if (gifImage.LogicalScreenDescriptor.GlobalColorTableFlag)
{
//读取全局颜色列表
gifImage.GlobalColorTable = streamHelper.ReadByte(gifImage.LogicalScreenDescriptor.GlobalColorTableSize * 3);
}
int nextFlag = streamHelper.Read();
while (nextFlag != 0)
{
if (nextFlag == GifExtensions.ImageLabel)
{
ReadImage(streamHelper, fs, gifImage, graphics, frameCount);
frameCount++;
}
else if (nextFlag == GifExtensions.ExtensionIntroducer)
{
int gcl = streamHelper.Read();
switch (gcl)
{
case GifExtensions.GraphicControlLabel:
{
GraphicEx graphicEx = streamHelper.GetGraphicControlExtension(fs);
graphics.Add(graphicEx);
break;
}
case GifExtensions.CommentLabel:
{
CommentEx comment = streamHelper.GetCommentEx(fs);
gifImage.CommentExtensions.Add(comment);
break;
}
case GifExtensions.ApplicationExtensionLabel:
{
ApplicationEx applicationEx = streamHelper.GetApplicationEx(fs);
gifImage.ApplictionExtensions.Add(applicationEx);
break;
}
case GifExtensions.PlainTextLabel:
{
PlainTextEx textEx = streamHelper.GetPlainTextEx(fs);
gifImage.PlainTextEntensions.Add(textEx);
break;
}
}
}
else if (nextFlag == GifExtensions.EndIntroducer)
{
//到了文件尾
break;
}
nextFlag = streamHelper.Read();
}
// }
// catch
// {
// throw;
// }
// finally
// {
fs.Close();
// }
return(gifImage);
}
internal CommentEx GetCommentEx(Stream stream)
{
CommentEx cmtEx = new CommentEx();
StreamHelper streamHelper = new StreamHelper(stream);
cmtEx.CommentDatas = new List<string>();
int nextFlag = streamHelper.Read();
cmtEx.CommentDatas = new List<string>();
while (nextFlag != 0)
{
int blockSize = nextFlag;
string data = streamHelper.ReadString(blockSize);
cmtEx.CommentDatas.Add(data);
nextFlag = streamHelper.Read();
}
return cmtEx;
}
