/// <summary>
/// Creates a new instance of the <see cref="GifFrame"/> class from the byte representation
/// starting from the current position in the <see cref="Stream"/>.
/// </summary>
/// <param name="stream">The <see cref="Stream"/> containing the byte representation of a <see cref="GifFrame"/>.</param>
/// <param name="globalColorTable">The global color table of the Gif.</param>
internal GifFrame(Stream stream, GifColorTable globalColorTable)
{
if (GifExtension.IsUpcoming(stream))
{
Extension = GifExtension.FromStream(stream);
}
Descriptor = new GifFrameDescriptor(stream);
ColorTable = Descriptor.HasLocalColorTable ? new GifColorTable(stream, Descriptor.SizeOfColorTable) : globalColorTable;
ColorData = GifLZW.Decode(stream);
}
/// <summary>
/// Writes the byte representation of this <see cref="GifFrame"/> to the given <see cref="Stream"/>.
/// </summary>
/// <param name="stream">The <see cref="Stream"/> to write to.</param>
internal void WriteToStream(Stream stream)
{
if (Extension != null)
{
Extension.WriteToStream(stream);
}
Descriptor.WriteToStream(stream);
if (Descriptor.HasLocalColorTable)
{
ColorTable.WriteToStream(stream);
}
GifLZW.Encode(stream, ColorData, GifColorTable.GetNumberOfEntries(ColorTable.ScreenDescriptorSize));
}
/// <summary>
/// Creates a new instance of the <see cref="Gif"/> class from the byte representation
/// starting from the current position in the <see cref="Stream"/>.
/// </summary>
/// <param name="stream">The <see cref="Stream"/> containing the byte representation of a <see cref="Gif"/>.</param>
public Gif(Stream stream)
{
Header = GifHeader.GetFromStream(stream);
LogicalScreenDescriptor = new GifLogicalScreenDescriptor(stream);
if (LogicalScreenDescriptor.HasGlobalColorTable)
{
GlobalColorTable = new GifColorTable(stream, LogicalScreenDescriptor.SizeOfColorTable);
}
Frames = new List <GifFrame>();
while (stream.PeakByte() != trailer)
{
Frames.Add(new GifFrame(stream, GlobalColorTable));
}
}