implemented WEBP images.

2026-07-08 01:30:18 +08:00 · 2016-05-20 04:01:40 +04:00
parent d20fed194c
commit 5f4c5d127f
6 changed files with 5526 additions and 0 deletions
--- a/ArcFormats/WebP/ImageWEBP.cs
+++ b/ArcFormats/WebP/ImageWEBP.cs
@@ -0,0 +1,145 @@
+//! \file       ImageWEBP.cs
+//! \date       Wed Apr 06 07:16:39 2016
+//! \brief      Google WEBP image format.
+//
+// Copyright (C) 2016 by morkt
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to
+// deal in the Software without restriction, including without limitation the
+// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+// sell copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+// IN THE SOFTWARE.
+//
+
+using System;
+using System.ComponentModel.Composition;
+using System.IO;
+using System.Windows.Media;
+using GameRes.Utility;
+
+namespace GameRes.Formats.Google
+{
+    internal class WebPMetaData : ImageMetaData
+    {
+        public WebPFeature  Flags;
+        public bool         IsLossless;
+        public long         DataOffset;
+        public int          DataSize;
+        public long         AlphaOffset;
+        public int          AlphaSize;
+    }
+
+    [Flags]
+    internal enum WebPFeature : uint
+    {
+        Fragments  = 0x0001,
+        Animation  = 0x0002,
+        Xmp        = 0x0004,
+        Exif       = 0x0008,
+        Alpha      = 0x0010,
+        Iccp       = 0x0020,
+    }
+
+    [Export(typeof(ImageFormat))]
+    public class WebPFormat : ImageFormat
+    {
+        public override string         Tag { get { return "WEBP"; } }
+        public override string Description { get { return "Google WebP image format"; } }
+        public override uint     Signature { get { return 0; } }
+
+        public override ImageMetaData ReadMetaData (Stream stream)
+        {
+            if (0x46464952 != FormatCatalog.ReadSignature (stream)) // 'RIFF'
+                return null;
+            var header = new byte[0x10];
+            if (8 != stream.Read (header, 0, 8))
+                return null;
+            if (!Binary.AsciiEqual (header, 4, "WEBP"))
+                return null;
+            bool found_vp8x = false;
+            var info = new WebPMetaData();
+            int chunk_size;
+            for (;;)
+            {
+                if (8 != stream.Read (header, 0, 8))
+                    return null;
+                chunk_size = LittleEndian.ToInt32 (header, 4);
+                int aligned_size = (chunk_size + 1) & ~1;
+                if (!found_vp8x && Binary.AsciiEqual (header, 0, "VP8X"))
+                {
+                    found_vp8x = true;
+                    if (chunk_size < 10)
+                        return null;
+                    if (chunk_size > header.Length)
+                        header = new byte[chunk_size];
+                    if (chunk_size != stream.Read (header, 0, chunk_size))
+                        return null;
+                    info.Flags = (WebPFeature)LittleEndian.ToUInt32 (header, 0);
+                    info.Width  = 1 + GetUInt24 (header, 4);
+                    info.Height = 1 + GetUInt24 (header, 7);
+                    if ((long)info.Width * info.Height >= (1L << 32))
+                        return null;
+                    continue;
+                }
+                if (Binary.AsciiEqual (header, 0, "VP8 ") || Binary.AsciiEqual (header, 0, "VP8L"))
+                {
+                    info.IsLossless = header[3] == 'L';
+                    info.DataOffset = stream.Position;
+                    info.DataSize = chunk_size;
+                    if (!found_vp8x)
+                    {
+                        if (chunk_size < 10 || 10 != stream.Read (header, 0, 10))
+                            return null;
+                        if (header[3] != 0x9D || header[4] != 1 || header[5] != 0x2A)
+                            return null;
+                        if (0 != (header[0] & 1)) // not a keyframe
+                            return null;
+                        info.Width  = LittleEndian.ToUInt16 (header, 6) & 0x3FFFu;
+                        info.Height = LittleEndian.ToUInt16 (header, 8) & 0x3FFFu;
+                    }
+                    break;
+                }
+                if (Binary.AsciiEqual (header, 0, "ALPH"))
+                {
+                    info.AlphaOffset = stream.Position;
+                    info.AlphaSize   = chunk_size;
+                }
+                stream.Seek (aligned_size, SeekOrigin.Current);
+            }
+            if (0 == info.Width || 0 == info.Height)
+                return null;
+            return info;
+        }
+
+        static uint GetUInt24 (byte[] src, int offset)
+        {
+            return (uint)(src[offset] | src[offset+1] << 8 | src[offset+2] << 16);
+        }
+
+        public override ImageData Read (Stream stream, ImageMetaData info)
+        {
+            using (var reader = new WebPDecoder (stream, (WebPMetaData)info))
+            {
+                reader.Decode();
+                return ImageData.Create (info, reader.Format, null, reader.Output);
+            }
+        }
+
+        public override void Write (Stream file, ImageData image)
+        {
+            throw new NotImplementedException ("WebPFormat.Write not implemented");
+        }
+    }
+}