Support videos with JPEG color range in GPU YUV convert path.

cc/output/gl_renderer.cc

Index: cc/output/gl_renderer.cc
diff --git a/cc/output/gl_renderer.cc b/cc/output/gl_renderer.cc
index cc9a752ecf5cda3c8406bb6a92f9503a3cf4dbe3..a757eea01af774ff3c87c9f196b27925fd3765d9 100644
--- a/cc/output/gl_renderer.cc
+++ b/cc/output/gl_renderer.cc
@@ -1723,8 +1723,18 @@ void GLRenderer::DrawYUVVideoQuad(const DrawingFrame* frame,
       0.0f, -.391f, 2.018f,
       1.596f, -.813f, 0.0f,
   };
+  float yuv_to_rgb_jpeg[9] = {
+      1.f, 1.f, 1.f,
+      0.0f, -.34414f, 1.772f,

[fbarchard, 2014/01/17 20:58:53]

prefer you use the jpeg coefficients from jdcolor.c
 *	R = Y                + 1.40200 * Cr
 *	G = Y - 0.34414 * Cb - 0.71414 * Cr
 *	B = Y + 1.77200 * Cb

[fbarchard, 2014/01/17 23:33:08]

matrix is transposed compared to the C code, so I think we're good here,
assuming jpeg is correct.

+      1.402f, -.71414, 0.0f,
+  };
+
   GLC(Context(),
-      Context()->uniformMatrix3fv(yuv_matrix_location, 1, 0, yuv_to_rgb));
+      Context()->uniformMatrix3fv(
+          yuv_matrix_location,
+          1,
+          0,
+          quad->has_jpeg_color_range ? yuv_to_rgb_jpeg : yuv_to_rgb));
 
   // These values map to 16, 128, and 128 respectively, and are computed
   // as a fraction over 256 (e.g. 16 / 256 = 0.0625).
@@ -1733,8 +1743,15 @@ void GLRenderer::DrawYUVVideoQuad(const DrawingFrame* frame,
   //   U - 128  : Turns unsigned U into signed U [-128,127]
   //   V - 128  : Turns unsigned V into signed V [-128,127]
   float yuv_adjust[3] = { -0.0625f, -0.5f, -0.5f, };
-  GLC(Context(), Context()->uniform3fv(yuv_adj_location, 1, yuv_adjust));
 
+  // Same as above, but without the head and footroom in Y.
+  float yuv_adjust_jpeg[3] = { 0.f, -0.5f, -0.5f, };
+
+  GLC(Context(),
+      Context()->uniform3fv(
+          yuv_adj_location,
+          1,
+          quad->has_jpeg_color_range ? yuv_adjust_jpeg : yuv_adjust));
 
   SetShaderOpacity(quad->opacity(), alpha_location);
   DrawQuadGeometry(frame, quad->quadTransform(), quad->rect, matrix_location);