16 bpp video stream capture, render and WebGL usage - Realsense R200 & SR300 support.

media/renderers/skcanvas_video_renderer.h

Index: media/renderers/skcanvas_video_renderer.h
diff --git a/media/renderers/skcanvas_video_renderer.h b/media/renderers/skcanvas_video_renderer.h
index 9323a82fed4d55c8160707d809c5fb6030186d33..2b25edbc0a3e24a6301c7cd641f75c1dafeb49db 100644
--- a/media/renderers/skcanvas_video_renderer.h
+++ b/media/renderers/skcanvas_video_renderer.h
@@ -23,7 +23,6 @@
 #include "third_party/skia/include/core/SkXfermode.h"
 
 class SkCanvas;
-class SkImage;
 
 namespace gfx {
 class RectF;
@@ -93,6 +92,29 @@ class MEDIA_EXPORT SkCanvasVideoRenderer {
       bool premultiply_alpha,
       bool flip_y);
 
+  // Method handles reinterpreting two components RG8 as 16 bit value for Y16
+  // format and optimizing upload-to-texture for some video frame and texture
+  // formats. If needed, there is a conversion followed by a tex(Sub)Image2D or
+  // tex(Sub)Image3D call.
+  // |format|, |internal_format|, |type| specify target texture |texture|.
+  // |xoffset|, |yoffset|, |zoffset| are used when functionID defines sub image
+  // calls.
+  // Returns false if there is no implementation for given parameters or if the
+  // call fails.
+  static bool TexImageImpl(const char* functionID,
+                           unsigned target,
+                           gpu::gles2::GLES2Interface* gl,
+                           VideoFrame* video_frame,
+                           int level,
+                           int internalformat,
+                           unsigned format,
+                           unsigned type,
+                           int xoffset,
+                           int yoffset,
+                           int zoffset,
+                           bool flipY,
+                           bool premultiplyAlpha);
+
   // In general, We hold the most recently painted frame to increase the
   // performance for the case that the same frame needs to be painted
   // repeatedly. Call this function if you are sure the most recent frame will
@@ -110,6 +132,32 @@ class MEDIA_EXPORT SkCanvasVideoRenderer {
   bool UpdateLastImage(const scoped_refptr<VideoFrame>& video_frame,
                        const Context3D& context_3d);
 
+  // Reinterpret the content of RG8 texture as R16 (normalized value) to float
+  // intermediate texture and then copy to texture. All the available RGB color
+  // components in the texture get the same value.
+  // Reinterpretting texture happens on canvas gl (context_3d) to enable caching
+  // resources for following calls. Target |texture| should live on |target_gl|
+  // after the call.
+  void CopyRG8ToTexture(const Context3D& context_3d,
+                        gpu::gles2::GLES2Interface* target_gl,
+                        VideoFrame* video_frame,
+                        unsigned texture,
+                        unsigned internal_format,
+                        unsigned type,
+                        bool flip_y);
+
+  // Helper method used by CopyRG8ToTexture. Target used for both
+  // |source_texture| and |target_texture| is GL_TEXTURE_2D.
+  void DoCopyRG8ToTexture(const Context3D& context_3d,
+                          unsigned source_texture,
+                          unsigned target_texture,
+                          unsigned format,
+                          unsigned internal_format,
+                          unsigned type,
+                          unsigned width,
+                          unsigned height,
+                          bool flip_y);
+
   // Last image used to draw to the canvas.
   sk_sp<SkImage> last_image_;
   // Timestamp of the videoframe used to generate |last_image_|.
@@ -119,6 +167,13 @@ class MEDIA_EXPORT SkCanvasVideoRenderer {
 
   // Used for DCHECKs to ensure method calls executed in the correct thread.
   base::ThreadChecker thread_checker_;
+  // Resources rg8_to_texture_* are used for RG8 to float texture GPU
+  // conversion.
+  unsigned rg8_to_texture_program_ = 0;
+  unsigned rg8_to_texture_vertices_buffer_ = 0;
+  // Used for cached GL resources (e.g. rg8_to_texture_program) lifecycle
+  // management.
+  unsigned cached_gl_resources_gr_context_id_ = 0;
 
   // Used for unit test.
   SkISize last_image_dimensions_for_testing_;