Add WebP library to Chromium...

third_party/libwebp/yuv.c

+// Copyright 2010 Google Inc.
+//
+// This code is licensed under the same terms as WebM:
+//  Software License Agreement:  http://www.webmproject.org/license/software/
+//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
+// -----------------------------------------------------------------------------
+//
+// YUV->RGB conversion function
+//
+// Author: Skal (pascal.massimino@gmail.com)
+
+#include "yuv.h"
+
+#if defined(__cplusplus) || defined(c_plusplus)
+extern "C" {
+#endif
+
+enum { YUV_HALF = 1 << (YUV_FIX - 1) };
+
+int16_t VP8kVToR[256], VP8kUToB[256];
+int32_t VP8kVToG[256], VP8kUToG[256];
+uint8_t VP8kClip[YUV_RANGE_MAX - YUV_RANGE_MIN];
+
+static int done = 0;
+
+void VP8YUVInit() {
+  if (done) {
+    return;
+  }
+  for (int i = 0; i < 256; ++i) {
+    VP8kVToR[i] = (89858 * (i - 128) + YUV_HALF) >> YUV_FIX;
+    VP8kUToG[i] = -22014 * (i - 128) + YUV_HALF;
+    VP8kVToG[i] = -45773 * (i - 128);
+    VP8kUToB[i] = (113618 * (i - 128) + YUV_HALF) >> YUV_FIX;
+  }
+  for (int i = YUV_RANGE_MIN; i < YUV_RANGE_MAX; ++i) {
+    const int j = ((i - 16) * 76283 + YUV_HALF) >> YUV_FIX;
+    VP8kClip[i - YUV_RANGE_MIN] = (j < 0) ? 0 : (j > 255) ? 255 : j;
+  }
+  done = 1;
+}
+
+#if defined(__cplusplus) || defined(c_plusplus)
+}    // extern "C"
+#endif