private void writeFrame(BufferFrame src)
{
using var quant = new OctreeQuantizer();
using var buffI = new FrameBufferSource(ctx.Source.Width, ctx.Source.Height, PixelFormat.Indexed8Bpp);
var buffC = EncodeFrame.Source;
quant.CreateHistorgram(buffC.Span, buffC.Width, buffC.Height, buffC.Stride);
quant.Quantize(buffC.Span, buffI.Span, buffC.Width, buffC.Height, buffC.Stride, buffI.Stride);
var palette = quant.Palette;
using var pal = default(ComPtr <IWICPalette>);
HRESULT.Check(Wic.Factory->CreatePalette(pal.GetAddressOf()));
fixed(uint *ppal = palette)
HRESULT.Check(pal.Get()->InitializeCustom(ppal, (uint)palette.Length));
ctx.WicContext.DestPalette = pal;
ctx.Source = buffI;
using var frm = new WicImageEncoderFrame(ctx, encoder, src.Area);
using var frmmeta = default(ComPtr <IWICMetadataQueryWriter>);
HRESULT.Check(frm.WicEncoderFrame->GetMetadataQueryWriter(frmmeta.GetAddressOf()));
frmmeta.SetValue(Wic.Metadata.Gif.FrameDisposal, (byte)src.Disposal);
frmmeta.SetValue(Wic.Metadata.Gif.FrameDelay, (ushort)src.Delay);
if (src.Area.X != 0)
{
frmmeta.SetValue(Wic.Metadata.Gif.FrameLeft, (ushort)src.Area.X);
}
if (src.Area.Y != 0)
{
frmmeta.SetValue(Wic.Metadata.Gif.FrameTop, (ushort)src.Area.Y);
}
frmmeta.SetValue(Wic.Metadata.Gif.TransparencyFlag, true);
frmmeta.SetValue(Wic.Metadata.Gif.TransparentColorIndex, (byte)(palette.Length - 1));
frm.WriteSource(ctx, src.Area);
ctx.WicContext.DestPalette = null;
}
unsafe public void WriteAnimatedGif(PipelineContext ctx)
{
var cnt = ctx.ImageContainer as WicGifContainer ?? throw new NotSupportedException("Source must be a GIF");
using (var decmeta = ComHandle.Wrap(cnt.WicDecoder.GetMetadataQueryReader()))
using (var encmeta = ComHandle.Wrap(WicEncoder.GetMetadataQueryWriter()))
{
if (decmeta.ComObject.TryGetMetadataByName(Wic.Metadata.Gif.AppExtension, out var appext))
{
encmeta.ComObject.SetMetadataByName(Wic.Metadata.Gif.AppExtension, appext);
}
if (decmeta.ComObject.TryGetMetadataByName(Wic.Metadata.Gif.AppExtensionData, out var appdata))
{
encmeta.ComObject.SetMetadataByName(Wic.Metadata.Gif.AppExtensionData, appdata);
}
if (decmeta.ComObject.TryGetMetadataByName(Wic.Metadata.Gif.PixelAspectRatio, out var aspect))
{
encmeta.ComObject.SetMetadataByName(Wic.Metadata.Gif.PixelAspectRatio, aspect);
}
}
using var buffer = new FrameBufferSource(ctx.Source.Width, ctx.Source.Height, ctx.Source.Format);
var bspan = buffer.Span;
var lastSource = ctx.Source;
var wicBuffer = buffer.AsIWICBitmapSource();
var anictx = cnt.AnimationContext ??= new GifAnimationContext();
for (int i = 0; i < ctx.ImageContainer.FrameCount; i++)
{
if (i > 0)
{
ctx.Settings.FrameIndex = i;
ctx.ImageFrame.Dispose();
ctx.ImageFrame = ctx.ImageContainer.GetFrame(ctx.Settings.FrameIndex);
if (ctx.ImageFrame is WicImageFrame wicFrame)
{
ctx.Source = wicFrame.WicSource.AsPixelSource(nameof(IWICBitmapFrameDecode), true);
}
else
{
ctx.Source = ctx.ImageFrame.PixelSource.AsPixelSource();
}
MagicTransforms.AddGifFrameBuffer(ctx, false);
if (lastSource is ChainedPixelSource chain)
{
chain.ReInit(ctx.Source);
ctx.Source = chain;
}
}
fixed(byte *pbuff = bspan)
{
ctx.Source.CopyPixels(ctx.Source.Area, buffer.Stride, bspan.Length, (IntPtr)pbuff);
var curFormat = ctx.Source.Format;
var newFormat = PixelFormat.Indexed8Bpp;
bool alpha = curFormat.AlphaRepresentation != PixelAlphaRepresentation.None;
using var pal = ComHandle.Wrap(Wic.Factory.CreatePalette());
pal.ComObject.InitializeFromBitmap(wicBuffer, 256u, alpha);
ctx.WicContext.DestPalette = pal.ComObject;
using var conv = ComHandle.Wrap(Wic.Factory.CreateFormatConverter());
conv.ComObject.Initialize(wicBuffer, newFormat.FormatGuid, WICBitmapDitherType.WICBitmapDitherTypeErrorDiffusion, pal.ComObject, 10.0, WICBitmapPaletteType.WICBitmapPaletteTypeCustom);
ctx.Source = conv.ComObject.AsPixelSource($"{nameof(IWICFormatConverter)}: {curFormat.Name}->{newFormat.Name}", false);
using var frm = new WicImageEncoderFrame(ctx, this);
var srcmeta = ((WicImageFrame)ctx.ImageFrame).WicMetadataReader !;
using (var frmmeta = ComHandle.Wrap(frm.WicEncoderFrame.GetMetadataQueryWriter()))
{
var disp = srcmeta.TryGetMetadataByName(Wic.Metadata.Gif.FrameDisposal, out var fdisp) && (byte)fdisp.Value ! == (byte)GifDisposalMethod.RestoreBackground ? GifDisposalMethod.RestoreBackground : GifDisposalMethod.Undefined;
frmmeta.ComObject.SetMetadataByName(Wic.Metadata.Gif.FrameDisposal, new PropVariant((byte)disp));
if (srcmeta.TryGetMetadataByName(Wic.Metadata.Gif.FrameDelay, out var delay))
{
frmmeta.ComObject.SetMetadataByName(Wic.Metadata.Gif.FrameDelay, delay);
}
if (alpha)
{
frmmeta.ComObject.SetMetadataByName(Wic.Metadata.Gif.TransparencyFlag, new PropVariant(true));
frmmeta.ComObject.SetMetadataByName(Wic.Metadata.Gif.TransparentColorIndex, new PropVariant((byte)(pal.ComObject.GetColorCount() - 1)));
}
}
frm.WriteSource(ctx);
}
}
}
