/// <summary>
/// Reads an individual gif frame.
/// </summary>
/// <typeparam name="TPixel">The pixel format.</typeparam>
/// <param name="image">The image to decode the information to.</param>
/// <param name="previousFrame">The previous frame.</param>
private void ReadFrame <TPixel>(ref Image <TPixel> image, ref ImageFrame <TPixel> previousFrame)
where TPixel : unmanaged, IPixel <TPixel>
{
this.ReadImageDescriptor();
IManagedByteBuffer localColorTable = null;
Buffer2D <byte> indices = null;
try
{
// Determine the color table for this frame. If there is a local one, use it otherwise use the global color table.
if (this.imageDescriptor.LocalColorTableFlag)
{
int length = this.imageDescriptor.LocalColorTableSize * 3;
localColorTable = this.configuration.MemoryAllocator.AllocateManagedByteBuffer(length, AllocationOptions.Clean);
this.stream.Read(localColorTable.Array, 0, length);
}
indices = this.configuration.MemoryAllocator.Allocate2D <byte>(this.imageDescriptor.Width, this.imageDescriptor.Height, AllocationOptions.Clean);
this.ReadFrameIndices(indices);
ReadOnlySpan <Rgb24> colorTable = MemoryMarshal.Cast <byte, Rgb24>((localColorTable ?? this.globalColorTable).GetSpan());
this.ReadFrameColors(ref image, ref previousFrame, indices, colorTable, this.imageDescriptor);
// Skip any remaining blocks
this.SkipBlock();
}
finally
{
localColorTable?.Dispose();
indices?.Dispose();
}
}
public void Dispose()
{
Unlock();
if (buffer2D != null)
{
buffer2D.Dispose();
}
buffer.Dispose();
}