1 files changed, 66 insertions, 0 deletions
diff --git a/third_party/libwebp/yuv.h b/third_party/libwebp/yuv.h
new file mode 100644
index 0000000..5a9fce2
--- /dev/null
+++ b/third_party/libwebp/yuv.h
@@ -0,0 +1,66 @@
+// 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/
+// -----------------------------------------------------------------------------
+//
+// inline YUV->RGB conversion function
+//
+// Author: Skal (pascal.massimino@gmail.com)
+
+#ifndef WEBP_DECODE_YUV_H_
+#define WEBP_DECODE_YUV_H_
+
+#include "webp/decode_vp8.h"
+
+#if defined(__cplusplus) || defined(c_plusplus)
+extern "C" {
+#endif
+
+enum { YUV_FIX = 16,                // fixed-point precision
+       YUV_RANGE_MIN = -227,        // min value of r/g/b output
+       YUV_RANGE_MAX = 256 + 226    // max value of r/g/b output
+};
+extern int16_t VP8kVToR[256], VP8kUToB[256];
+extern int32_t VP8kVToG[256], VP8kUToG[256];
+extern uint8_t VP8kClip[YUV_RANGE_MAX - YUV_RANGE_MIN];
+
+inline static void VP8YuvToRgb(uint8_t y, uint8_t u, uint8_t v,
+                               uint8_t* const rgb) {
+  const int r_off = VP8kVToR[v];
+  const int g_off = (VP8kVToG[v] + VP8kUToG[u]) >> YUV_FIX;
+  const int b_off = VP8kUToB[u];
+  rgb[0] = VP8kClip[y + r_off - YUV_RANGE_MIN];
+  rgb[1] = VP8kClip[y + g_off - YUV_RANGE_MIN];
+  rgb[2] = VP8kClip[y + b_off - YUV_RANGE_MIN];
+}
+
+inline static void VP8YuvToRgba(int y, int u, int v, uint8_t* const rgba) {
+  VP8YuvToRgb(y, u, v, rgba);
+  rgba[3] = 0xff;
+}
+
+inline static void VP8YuvToBgr(uint8_t y, uint8_t u, uint8_t v,
+                               uint8_t* const bgr) {
+  const int r_off = VP8kVToR[v];
+  const int g_off = (VP8kVToG[v] + VP8kUToG[u]) >> YUV_FIX;
+  const int b_off = VP8kUToB[u];
+  bgr[0] = VP8kClip[y + b_off - YUV_RANGE_MIN];
+  bgr[1] = VP8kClip[y + g_off - YUV_RANGE_MIN];
+  bgr[2] = VP8kClip[y + r_off - YUV_RANGE_MIN];
+}
+
+inline static void VP8YuvToBgra(int y, int u, int v, uint8_t* const bgra) {
+  VP8YuvToBgr(y, u, v, bgra);
+  bgra[3] = 0xff;
+}
+
+// Must be called before everything, to initialize the tables.
+void VP8YUVInit();
+
+#if defined(__cplusplus) || defined(c_plusplus)
+}    // extern "C"
+#endif
+
+#endif  // WEBP_DECODE_YUV_H_