private void EncodeGlobal <TPixel>(Image <TPixel> image, QuantizedFrame <TPixel> quantized, int transparencyIndex, Stream stream)
where TPixel : struct, IPixel <TPixel>
{
var palleteQuantizer = new PaletteQuantizer(this.quantizer.Diffuser);
for (int i = 0; i < image.Frames.Count; i++)
{
ImageFrame <TPixel> frame = image.Frames[i];
ImageFrameMetaData metaData = frame.MetaData;
GifFrameMetaData frameMetaData = metaData.GetFormatMetaData(GifFormat.Instance);
this.WriteGraphicalControlExtension(frameMetaData, transparencyIndex, stream);
this.WriteImageDescriptor(frame, false, stream);
if (i == 0)
{
this.WriteImageData(quantized, stream);
}
else
{
using (QuantizedFrame <TPixel> paletteQuantized
= palleteQuantizer.CreateFrameQuantizer(image.GetConfiguration(), () => quantized.Palette).QuantizeFrame(frame))
{
this.WriteImageData(paletteQuantized, stream);
}
}
}
}
public void CloneIsDeep()
{
var metaData = new ImageFrameMetaData();
ImageFrameMetaData clone = metaData.DeepClone();
Assert.False(metaData.GetFormatMetaData(GifFormat.Instance).Equals(clone.GetFormatMetaData(GifFormat.Instance)));
}
public void ConstructorImageFrameMetaData()
{
const int frameDelay = 42;
const int colorTableLength = 128;
const GifDisposalMethod disposalMethod = GifDisposalMethod.RestoreToBackground;
var metaData = new ImageFrameMetaData();
GifFrameMetaData gifFrameMetaData = metaData.GetFormatMetaData(GifFormat.Instance);
gifFrameMetaData.FrameDelay = frameDelay;
gifFrameMetaData.ColorTableLength = colorTableLength;
gifFrameMetaData.DisposalMethod = disposalMethod;
var clone = new ImageFrameMetaData(metaData);
GifFrameMetaData cloneGifFrameMetaData = clone.GetFormatMetaData(GifFormat.Instance);
Assert.Equal(frameDelay, cloneGifFrameMetaData.FrameDelay);
Assert.Equal(colorTableLength, cloneGifFrameMetaData.ColorTableLength);
Assert.Equal(disposalMethod, cloneGifFrameMetaData.DisposalMethod);
}
private void EncodeLocal <TPixel>(Image <TPixel> image, QuantizedFrame <TPixel> quantized, Stream stream)
where TPixel : struct, IPixel <TPixel>
{
ImageFrame <TPixel> previousFrame = null;
GifFrameMetaData previousMeta = null;
foreach (ImageFrame <TPixel> frame in image.Frames)
{
ImageFrameMetaData metaData = frame.MetaData;
GifFrameMetaData frameMetaData = metaData.GetFormatMetaData(GifFormat.Instance);
if (quantized is null)
{
// Allow each frame to be encoded at whatever color depth the frame designates if set.
if (previousFrame != null && previousMeta.ColorTableLength != frameMetaData.ColorTableLength &&
frameMetaData.ColorTableLength > 0)
{
quantized = this.quantizer.CreateFrameQuantizer <TPixel>(
image.GetConfiguration(),
frameMetaData.ColorTableLength).QuantizeFrame(frame);
}
else
{
quantized = this.quantizer.CreateFrameQuantizer <TPixel>(image.GetConfiguration())
.QuantizeFrame(frame);
}
}
this.bitDepth = ImageMaths.GetBitsNeededForColorDepth(quantized.Palette.Length).Clamp(1, 8);
this.WriteGraphicalControlExtension(frameMetaData, this.GetTransparentIndex(quantized), stream);
this.WriteImageDescriptor(frame, true, stream);
this.WriteColorTable(quantized, stream);
this.WriteImageData(quantized, stream);
quantized?.Dispose();
quantized = null; // So next frame can regenerate it
previousFrame = frame;
previousMeta = frameMetaData;
}
}
