public static void CreateAnimatedGif(List <string> gifFiles, int delay, string outputFile)
{
BinaryWriter writer = new BinaryWriter(new FileStream(outputFile, FileMode.Create, FileAccess.ReadWrite));
byte[] gif_Signature = new byte[] { (byte)'G', (byte)'I', (byte)'F', (byte)'8', (byte)'9', (byte)'a' };
writer.Write(gif_Signature);
for (int i = 0; i < gifFiles.Count; i++)
{
GifClass gif = new GifClass();
gif.LoadGifPicture(gifFiles[i]);
if (i == 0)
{
writer.Write(gif.m_ScreenDescriptor.ToArray());
}
writer.Write(GifCreator.CreateGraphicControlExtensionBlock(delay));
writer.Write(gif.m_ImageDescriptor.ToArray());
writer.Write(gif.m_ColorTable.ToArray());
writer.Write(gif.m_ImageData.ToArray());
}
writer.Write(GifCreator.CreateLoopBlock());
writer.Write((byte)0x3B); //End file
writer.Close();
}
private void WriteAnimatedGif(Bitmap src, Stream output, IEncoder ios, ResizeSettings queryString)
{
//http://www.fileformat.info/format/gif/egff.htm
//http://www.fileformat.info/format/gif/spec/44ed77668592476fb7a682c714a68bac/view.htm
//Heavily modified and patched from comments on http://bloggingabout.net/blogs/rick/archive/2005/05/10/3830.aspx
MemoryStream memoryStream = null;
BinaryWriter writer = null;
//Variable declaration
try
{
writer = new BinaryWriter(output);
memoryStream = new MemoryStream(4096);
//Write the GIF 89a sig
writer.Write(new byte[] { (byte)'G', (byte)'I', (byte)'F', (byte)'8', (byte)'9', (byte)'a' });
//We parse this from the source image
int loops = GetLoops(src.PropertyItems);
int[] delays = GetDelays(src.PropertyItems);//20736 (delays) 20737 (loop);
int frames = src.GetFrameCount(FrameDimension.Time);
for (int frame = 0; frame < frames; frame++)
{
//Select the frame
src.SelectActiveFrame(FrameDimension.Time, frame);
// http://radio.weblogs.com/0122832/2005/10/20.html
//src.MakeTransparent(); This call makes some GIFs replicate the first image on all frames.. i.e. SelectActiveFrame doesn't work.
bool transparent = ios.SupportsTransparency;
using (Bitmap b = c.CurrentImageBuilder.Build(src, queryString, false)){
//Useful to check if animation is occurring - sometimes the problem isn't the output file, but the input frames are
//all the same.
//for (var i = 0; i < b.Height; i++) b.SetPixel(frame * 10, i, Color.Green);
// b.Save(memoryStream, ImageFormat.Gif);
if (ios is DefaultEncoder)
{
//For both WIC Builder and DefaultBuilder
//We assume no transparency
transparent = false;
}
ios.Write(b, memoryStream); //Allows quantization and dithering
}
GifClass gif = new GifClass();
gif.LoadGifPicture(memoryStream);
if (frame == 0)
{
//Only one screen descriptor per file. Steal from the first image
writer.Write(gif.m_ScreenDescriptor.ToArray());
//How many times to loop the image (unless it is 1) IE and FF3 loop endlessly if loop=1
if (loops != 1)
{
writer.Write(GifCreator.CreateLoopBlock(loops));
}
}
//Restore frame delay
int delay = 0;
if (delays != null && delays.Length > frame)
{
delay = delays[frame];
}
writer.Write(GifCreator.CreateGraphicControlExtensionBlock(delay, 0, transparent)); //The delay/transparent color block
writer.Write(gif.m_ImageDescriptor.ToArray()); //The image desc
writer.Write(gif.m_ColorTable.ToArray()); //The palette
writer.Write(gif.m_ImageData.ToArray()); //Image data
memoryStream.SetLength(0); //Clear the mem stream, but leave it allocated for now
memoryStream.Seek(0, SeekOrigin.Begin); //Reset memory buffer
}
writer.Write((byte)0x3B); //End file
}
finally
{
if (memoryStream != null)
{
memoryStream.Dispose();
}
//if (writer != null) writer.Close
}
}