/// <summary>
/// Write an image frame to the file
/// </summary>
/// <param name="image"><c>BitmapSource</c> to encode</param>
public void AddFrame(BitmapSource image)
{
if (!Ready)
{
return;
}
if (!Animated && FrameCount == 1)
{
return;
}
if (image.PixelHeight != Height || image.PixelWidth != Width)
{
return;
}
if (image.Palette != ColorPalette)
{
return;
}
int nStride = (image.PixelWidth * image.Format.BitsPerPixel + 7) / 8;
byte[] pixels = new byte[image.PixelHeight * nStride];
image.CopyPixels(pixels, nStride, 0);
//Graphics Control Extension
byte[] gct = new byte[8];
gct[0] = 0x21;
gct[1] = 0xF9;
gct[2] = 0x04;
gct[3] = 0x00; //Packed Field
gct.Replace(4, BitConverter.GetBytes((UInt16)FrameTime));
gct[6] = 0x00; //Transparency Color Index
gct[7] = 0x00;
//Image Descriptor
byte[] id = new byte[10];
id[0] = 0x2C;
id.Replace(1, BitConverter.GetBytes((UInt16)0)); //Left
id.Replace(3, BitConverter.GetBytes((UInt16)0)); //Top
id.Replace(5, BitConverter.GetBytes((UInt16)image.PixelWidth)); //Width
id.Replace(7, BitConverter.GetBytes((UInt16)image.PixelHeight)); //Height
id[9] = 0x00; //Packed Field
DataStream.Write(gct, 0, gct.Length);
DataStream.Write(id, 0, id.Length);
//Image Data
var lzw = new Gif.Components.LZWEncoder(image.PixelWidth, image.PixelHeight, pixels, image.Format.BitsPerPixel);
lzw.Encode(DataStream);
FrameCount++;
}
private void ProcessQueue()
{
while (true)
{
if (ImageQueue.Count > 0)
{
Processing = true;
var image = ImageQueue.Dequeue();
//Graphics Control Extension
byte[] gct = new byte[8];
gct[0] = 0x21;
gct[1] = 0xF9;
gct[2] = 0x04;
gct[3] = 0x00; //Packed Field
gct.Replace(4, BitConverter.GetBytes((UInt16)FrameTime));
gct[6] = 0x00; //Transparency Color Index
gct[7] = 0x00;
//Image Descriptor
byte[] id = new byte[10];
id[0] = 0x2C;
id.Replace(1, BitConverter.GetBytes((UInt16)0)); //Left
id.Replace(3, BitConverter.GetBytes((UInt16)0)); //Top
id.Replace(5, BitConverter.GetBytes((UInt16)image.Width)); //Width
id.Replace(7, BitConverter.GetBytes((UInt16)image.Height)); //Height
id[9] = 0x00; //Packed Field
DataStream.Write(gct, 0, gct.Length);
DataStream.Write(id, 0, id.Length);
//Image Data
var lzw = new Gif.Components.LZWEncoder(image.Width, image.Height, image.PixelData, image.BitsPerPixel);
lzw.Encode(DataStream);
FrameCount++;
Processing = false;
}
}
}
