Example #1
0
        async Task ParseAsync(GIFDecoderStreamReader stream, bool skipTypeIdentifier)
        {
            if (!skipTypeIdentifier)
            {
                TypeIdentifier = stream.ReadString(3);
            }
            else
            {
                TypeIdentifier = "GIF";
            }

            if (IsGIFHeader)
            {
                Version = stream.ReadString(3);
                Width   = stream.ReadShort();
                Height  = stream.ReadShort();

                int flags = stream.Read();
                BackgroundColorIndex = stream.Read();
                PixelAspectRatio     = stream.Read();

                if (UseGlobalColorTable(flags))
                {
                    GlobalColorTable = await GIFColorTable.CreateColorTableAsync(stream, GlobalColorTableSize(flags)).ConfigureAwait(false);

                    BackgroundColor = GlobalColorTable.Data[BackgroundColorIndex];
                }
            }
            else
            {
                throw new GIFDecoderFormatException("Unknown GIF format type identifier: " + TypeIdentifier);
            }
        }
Example #2
0
        public static async Task <GIFColorTable> CreateColorTableAsync(GIFDecoderStreamReader stream, short size)
        {
            var colorTable = new GIFColorTable(size);
            await colorTable.ParseAsync(stream).ConfigureAwait(false);

            return(colorTable);
        }
Example #3
0
        async Task ParseGIFBitmapHeaderAsync(GIFDecoderStreamReader stream)
        {
            Bounds     = new GIFBitmap.Rect(stream.ReadShort(), stream.ReadShort(), stream.ReadShort(), stream.ReadShort());
            ColorTable = _header.GlobalColorTable;

            int flags = stream.Read();

            if (UseLocalColorTable(flags))
            {
                ColorTable = await GIFColorTable.CreateColorTableAsync(stream, LocalColorTableSize(flags)).ConfigureAwait(false);
            }

            BackgroundColor = _header.BackgroundColor;
            IsInterlaced    = UseInterlace(flags);
        }