From cf8c35240b168b3037d01ee9ddd06cd4862ce18f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Martinez?= <jerome@mediaarea.net>
Date: Wed, 7 Jul 2021 20:58:26 +0200
Subject: [PATCH] + GIF: support of animated GIF

---
 Source/MediaInfo/Image/File_Gif.cpp | 135 +++++++++++++++++++++++-----
 1 file changed, 115 insertions(+), 20 deletions(-)

diff --git a/Source/MediaInfo/Image/File_Gif.cpp b/Source/MediaInfo/Image/File_Gif.cpp
index 91dc3a2a2..b6b4e37b1 100644
--- a/Source/MediaInfo/Image/File_Gif.cpp
+++ b/Source/MediaInfo/Image/File_Gif.cpp
@@ -63,38 +63,133 @@ bool File_Gif::FileHeader_Begin()
 //---------------------------------------------------------------------------
 void File_Gif::Read_Buffer_Continue()
 {
+    if (Buffer_Offset+Element_Size<File_Size)
+    {
+        Element_WaitForMoreData();
+        return;
+    }
+
     //Parsing
     Ztring Version;
     int16u Width, Height;
     int8u  BackgroundColorIndex, PixelAspectRatio, Resolution, GCT_Size;
     bool GCT_Flag, Sort;
-    Skip_UTF8 (3,                                               "Header");
-    Get_UTF8  (3, Version,                                      "Version");
-    Get_L2 (Width,                                              "Logical Screen Width");
-    Get_L2 (Height,                                             "Logical Screen Height");
-    BS_Begin();
-    Get_SB (   GCT_Flag,                                        "Global Color Table Flag");
-    Get_S1 (3, Resolution,                                      "Color Resolution");
-    Get_SB (   Sort,                                            "Sort Flag to Global Color Table");
-    Get_S1 (3, GCT_Size,                                        "Size of Global Color Table"); Param_Info1(Ztring::ToZtring((int16u)pow(2.0, 1+GCT_Size)));
-    BS_End();
-    Get_L1 (BackgroundColorIndex,                               "Background Color Index");
-    Get_L1 (PixelAspectRatio,                                   "Pixel Aspect Ratio");
+    Element_Begin1("Header");
+        Skip_UTF8 (3,                                           "Header");
+        Get_UTF8  (3, Version,                                  "Version");
+    Element_End0();
+    Element_Begin1("Logical Screen");
+        Get_L2 (Width,                                          "Logical Screen Width");
+        Get_L2 (Height,                                         "Logical Screen Height");
+        BS_Begin();
+        Get_SB (   GCT_Flag,                                    "Global Color Table Flag");
+        Get_S1 (3, Resolution,                                  "Color Resolution");
+        Get_SB (   Sort,                                        "Sort Flag to Global Color Table");
+        Get_S1 (3, GCT_Size,                                    "Size of Global Color Table"); Param_Info1(Ztring::ToZtring((int16u)pow(2.0, 1+GCT_Size)));
+        BS_End();
+        Get_L1 (BackgroundColorIndex,                           "Background Color Index");
+        Get_L1 (PixelAspectRatio,                               "Pixel Aspect Ratio");
+    Element_End0();
     if (GCT_Flag)
         Skip_XX((int16u)pow(2.0, 1+GCT_Size)*3,                 "Global Color Table");
-    Element_End0();
+    int64u DelayTime_Total=0;
+    Element_Begin1("Data");
+        while (Element_Offset<Element_Size-1)
+        {
+            Element_Begin0();
+                int8u Label;
+                Get_L1(Label,                                       "Label");
+                switch (Label)
+                {
+                    case 0x2C:
+                        Element_Name("Table-Based Image");
+                        Param_Info1("Image Separator");
+                        Element_Begin1("Image Descriptor");
+                        Skip_L2(                                    "Image Left Position");
+                        Skip_L2(                                    "Image Top Position");
+                        Skip_L2(                                    "Image Width");
+                        Skip_L2(                                    "Image Height");
+                        BS_Begin();
+                        Get_SB (   GCT_Flag,                        "Local Color Table Flag");
+                        Skip_SB(                                    "Interlace Flag");
+                        Skip_SB(                                    "Sort Flag");
+                        Skip_SB(                                    "Reserved");
+                        Skip_SB(                                    "Reserved");
+                        Get_S1 (3, GCT_Size,                        "Size of Local Color Table"); Param_Info1(Ztring::ToZtring((int16u)pow(2.0, 1+GCT_Size)));
+                        BS_End();
+                        Element_End0();
+                        if (GCT_Flag)
+                            Skip_XX((int16u)pow(2.0, 1+GCT_Size)*3, "Local Color Table");
+                        Element_Begin1("Image Data");
+                        Skip_L1(                                    "LZW Minimum Code Size");
+                        while (Element_Offset<Element_Size)
+                        {
+                            int8u Size;
+                            Get_L1(Size,                            "Block Size");
+                            if (!Size)
+                                break;
+                            Skip_XX(Size,                           "Data Values");
+                        }
+                        Element_End0();
+                        Element_End0();
+                        break;
+                    case 0x21:
+                        Element_Name("Extension");
+                        Param_Info1("Extension Introducer");
+                        Get_L1 (Label,                              "Extension Label");
+                        Element_Begin1("Extension");
+                        while (Element_Offset<Element_Size)
+                        {
+                            int8u Size;
+                            Get_L1(Size,                            "Block Size");
+                            if (!Size)
+                                break;
+                            switch (Label)
+                            {
+                                case 0xF9 :
+                                    if (Size==4)
+                                    {
+                                        Element_Info1("Graphic Control Extension");
+                                        Skip_L1("Flags");
+                                        int16u DelayTime;
+                                        Get_L2 (DelayTime,          "Delay Time");
+                                        Skip_L1("Transparent Color Index");
+                                        DelayTime_Total+=DelayTime;
+                                        Frame_Count++;
+                                        break;
+                                    }
+                                    // Fallthrough
+                                default:
+                                    Skip_XX(Size, "Data Values");
+                            }
+                        }
+                        Element_End0();
+                        break;
+                    default: ;
+                        if (Element_Offset<Element_Size)
+                            Skip_XX(Element_Size-Element_Offset-1,  "Unknown");
+                }
+            Element_End0();
+        Element_End0();
+    }
+    Skip_L1(                                                    "Trailer");
 
     FILLING_BEGIN();
         Accept("GIF");
 
-        Stream_Prepare(Stream_Image);
-        Fill(Stream_Image, 0, Image_Width, Width);
-        Fill(Stream_Image, 0, Image_Height, Height);
-        Fill(Stream_Image, 0, Image_Format, __T("GIF"));
-        Fill(Stream_Image, 0, Image_Format_Profile, Version);
-        Fill(Stream_Image, 0, Image_Codec, __T("GIF")+Version);
+        Stream_Prepare(DelayTime_Total?Stream_Video:Stream_Image);
+        if (DelayTime_Total)
+        {
+            Fill(Stream_Video, 0, Video_Duration, ((float)DelayTime_Total)*10);
+            Fill(Stream_Video, 0, Video_FrameCount, Frame_Count);
+        }
+        Fill(StreamKind_Last, 0, "Width", Width);
+        Fill(StreamKind_Last, 0, "Height", Height);
+        Fill(StreamKind_Last, 0, Fill_Parameter(StreamKind_Last, Generic_Format), __T("GIF"));
+        Fill(StreamKind_Last, 0, Fill_Parameter(StreamKind_Last, Generic_Format_Profile), Version);
+        Fill(StreamKind_Last, 0, Fill_Parameter(StreamKind_Last, Generic_Codec), __T("GIF")+Version);
         if (PixelAspectRatio)
-            Fill(Stream_Image, 0, Image_PixelAspectRatio, (((float)PixelAspectRatio)+15)/64);
+            Fill(StreamKind_Last, 0, "PixelAspectRatio", (((float)PixelAspectRatio)+15)/64);
 
         Finish("GIF");
     FILLING_END();