Bundled libwebp updated to version 0.5.1

This commit imports libwebp 0.5.1, including AUTHORS, COPYING, ChangeLog,
NEWS, PATENTS, README and src directories. In src, only includes header
and source files.

Upstream changes since 0.5.0 have been merged in.
Also updated version in qt_attribution.json.

Conflicts:
	src/3rdparty/libwebp.pri
	src/3rdparty/libwebp/qt_attribution.json
	src/3rdparty/libwebp/src/webp/config.h

Change-Id: I7d0c15400154c3b4ee8ff37665303307c4b84f9f
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@qt.io>
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@qt.io>

1 files changed, 66 insertions, 0 deletions

diff --git a/src/3rdparty/libwebp/src/utils/utils.c b/src/3rdparty/libwebp/src/utils/utils.c
index d8e3093..2602ca3 100644
--- a/src/3rdparty/libwebp/src/utils/utils.c
+++ b/src/3rdparty/libwebp/src/utils/utils.c
@@ -15,6 +15,7 @@
 #include <string.h>  // for memcpy()
 #include "../webp/decode.h"
 #include "../webp/encode.h"
+#include "../webp/format_constants.h"  // for MAX_PALETTE_SIZE
 #include "./utils.h"
 
 // If PRINT_MEM_INFO is defined, extra info (like total memory used, number of
@@ -237,3 +238,68 @@ void WebPCopyPixels(const WebPPicture* const src, WebPPicture* const dst) {
 }
 
 //------------------------------------------------------------------------------
+
+#define MAX_COLOR_COUNT         MAX_PALETTE_SIZE
+#define COLOR_HASH_SIZE         (MAX_COLOR_COUNT * 4)
+#define COLOR_HASH_RIGHT_SHIFT  22  // 32 - log2(COLOR_HASH_SIZE).
+
+int WebPGetColorPalette(const WebPPicture* const pic, uint32_t* const palette) {
+  int i;
+  int x, y;
+  int num_colors = 0;
+  uint8_t in_use[COLOR_HASH_SIZE] = { 0 };
+  uint32_t colors[COLOR_HASH_SIZE];
+  static const uint32_t kHashMul = 0x1e35a7bdU;
+  const uint32_t* argb = pic->argb;
+  const int width = pic->width;
+  const int height = pic->height;
+  uint32_t last_pix = ~argb[0];   // so we're sure that last_pix != argb[0]
+  assert(pic != NULL);
+  assert(pic->use_argb);
+
+  for (y = 0; y < height; ++y) {
+    for (x = 0; x < width; ++x) {
+      int key;
+      if (argb[x] == last_pix) {
+        continue;
+      }
+      last_pix = argb[x];
+      key = (kHashMul * last_pix) >> COLOR_HASH_RIGHT_SHIFT;
+      while (1) {
+        if (!in_use[key]) {
+          colors[key] = last_pix;
+          in_use[key] = 1;
+          ++num_colors;
+          if (num_colors > MAX_COLOR_COUNT) {
+            return MAX_COLOR_COUNT + 1;  // Exact count not needed.
+          }
+          break;
+        } else if (colors[key] == last_pix) {
+          break;  // The color is already there.
+        } else {
+          // Some other color sits here, so do linear conflict resolution.
+          ++key;
+          key &= (COLOR_HASH_SIZE - 1);  // Key mask.
+        }
+      }
+    }
+    argb += pic->argb_stride;
+  }
+
+  if (palette != NULL) {  // Fill the colors into palette.
+    num_colors = 0;
+    for (i = 0; i < COLOR_HASH_SIZE; ++i) {
+      if (in_use[i]) {
+        palette[num_colors] = colors[i];
+        ++num_colors;
+      }
+    }
+  }
+  return num_colors;
+}
+
+#undef MAX_COLOR_COUNT
+#undef COLOR_HASH_SIZE
+#undef COLOR_HASH_RIGHT_SHIFT
+
+//------------------------------------------------------------------------------