Adding YUVA support for enabling Alpha Playback

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 13e6d8a5efa8936e78d519cf52f1a2e893341f26..844050e2f15a8c6ff9975f09fbd680d8d3aeab00 100644
--- a/cc/output/gl_renderer.cc
+++ b/cc/output/gl_renderer.cc
@@ -79,6 +79,22 @@ bool NeedsIOSurfaceReadbackWorkaround() {
 #endif
 }
 
+// These values are magic numbers that are used in the transformation from YUV to RGB color values.

[danakj, 2013/04/04 15:01:55]

nit: 80 columns

upload should complain about this if you're synced to ToT.

[vignesh, 2013/04/04 22:06:14]

Done.

+// They are taken from the following webpage: http://www.fourcc.org/fccyvrgb.php
+float yuv_to_rgb[9] = {
+    1.164f, 1.164f, 1.164f,
+    0.f, -.391f, 2.018f,
+    1.596f, -.813f, 0.f,
+};
+
+// These values map to 16, 128, and 128 respectively, and are computed
+// as a fraction over 256 (e.g. 16 / 256 = 0.0625).
+// They are used in the YUV to RGBA conversion formula:
+//   Y - 16   : Gives 16 values of head and footroom for overshooting
+//   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, };
+
 }  // anonymous namespace
 
 scoped_ptr<GLRenderer> GLRenderer::Create(RendererClient* client,
@@ -1199,12 +1215,10 @@ void GLRenderer::DrawYUVVideoQuad(const DrawingFrame* frame,
                                   const YUVVideoDrawQuad* quad) {
   SetBlendEnabled(quad->ShouldDrawWithBlending());
 
-  const VideoYUVProgram* program = GetVideoYUVProgram();
-  DCHECK(program && (program->initialized() || IsContextLost()));
-
   const VideoLayerImpl::FramePlane& y_plane = quad->y_plane;
   const VideoLayerImpl::FramePlane& u_plane = quad->u_plane;
   const VideoLayerImpl::FramePlane& v_plane = quad->v_plane;
+  const VideoLayerImpl::FramePlane& a_plane = quad->a_plane;
 
   GLC(Context(), Context()->activeTexture(GL_TEXTURE1));
   ResourceProvider::ScopedSamplerGL y_plane_lock(
@@ -1215,49 +1229,64 @@ void GLRenderer::DrawYUVVideoQuad(const DrawingFrame* frame,
   GLC(Context(), Context()->activeTexture(GL_TEXTURE3));
   ResourceProvider::ScopedSamplerGL v_plane_lock(
       resource_provider_, v_plane.resource_id, GL_TEXTURE_2D, GL_LINEAR);
+  if (a_plane.resource_id) {

[danakj, 2013/04/04 15:01:55]

how about "bool use_alpha_plane = a_plane.resource_id != 0;" up near the top of
this method, then use that everywhere instead of always comparing to the
resource_id. I think that would help reading this method.

[vignesh, 2013/04/04 22:06:14]

Done.

+    ResourceProvider::ScopedSamplerGL a_plane_lock(

[danakj, 2013/04/04 15:01:55]

this seems like it works at the moment, but its name implies that it is valid
while it is in scope, which doesn't last the whole function.

You could solve this by storing it in a scoped_ptr and allocating it on the heap
with "new" instead.

[vignesh, 2013/04/04 22:06:14]

Done.

+        resource_provider_, a_plane.resource_id, GL_TEXTURE_2D, GL_LINEAR);
+  }
 
-  SetUseProgram(program->program());
+  int tex_scale_location;
+  int matrix_location;
+  int y_texture_location;
+  int u_texture_location;
+  int v_texture_location;
+  int a_texture_location;
+  int yuv_matrix_location;

[danakj, 2013/04/04 15:01:55]

nothing seems to set this.

can you initialize all of these variables to -1 here. then, set the ones you
intend to use to other values below.

[vignesh, 2013/04/04 22:06:14]

Done.

+  int yuv_adj_location;
+  int alpha_location;
+  if (!a_plane.resource_id) {
+    const VideoYUVProgram* program = GetVideoYUVProgram();
+    DCHECK(program && (program->initialized() || IsContextLost()));
+    SetUseProgram(program->program());
+    tex_scale_location = program->vertex_shader().tex_scale_location();
+    matrix_location = program->vertex_shader().matrix_location();
+    y_texture_location = program->fragment_shader().y_texture_location();
+    u_texture_location = program->fragment_shader().u_texture_location();
+    v_texture_location = program->fragment_shader().v_texture_location();
+    a_texture_location = program->fragment_shader().yuv_matrix_location();

[danakj, 2013/04/04 15:01:55]

why is this yuv_matrix_location and not just -1?

[vignesh, 2013/04/04 22:06:14]

Done.

+    yuv_adj_location = program->fragment_shader().yuv_adj_location();
+    alpha_location = program->fragment_shader().alpha_location();
+  } else {
+    const VideoYUVAProgram* program = GetVideoYUVAProgram();
+    DCHECK(program && (program->initialized() || IsContextLost()));
+    SetUseProgram(program->program());
+    tex_scale_location = program->vertex_shader().tex_scale_location();
+    matrix_location = program->vertex_shader().matrix_location();
+    y_texture_location = program->fragment_shader().y_texture_location();
+    u_texture_location = program->fragment_shader().u_texture_location();
+    v_texture_location = program->fragment_shader().v_texture_location();
+    a_texture_location = program->fragment_shader().yuv_matrix_location();

[danakj, 2013/04/04 15:01:55]

why is this yuv_matrix_location and not a_texture_location?

[vignesh, 2013/04/04 22:06:14]

Done.

+    yuv_adj_location = program->fragment_shader().yuv_adj_location();
+    alpha_location = program->fragment_shader().alpha_location();
+  }
 
   GLC(Context(),
-      Context()->uniform2f(program->vertex_shader().tex_scale_location(),
+      Context()->uniform2f(tex_scale_location,
                            quad->tex_scale.width(),
                            quad->tex_scale.height()));
+  GLC(Context(), Context()->uniform1i(y_texture_location, 1));
+  GLC(Context(), Context()->uniform1i(u_texture_location, 2));
+  GLC(Context(), Context()->uniform1i(v_texture_location, 3));
+  if (a_plane.resource_id) {
+    GLC(Context(), Context()->uniform1i(a_texture_location, 4));
+  }
+
   GLC(Context(),
-      Context()->uniform1i(program->fragment_shader().y_texture_location(), 1));
-  GLC(Context(),
-      Context()->uniform1i(program->fragment_shader().u_texture_location(), 2));
-  GLC(Context(),
-      Context()->uniform1i(program->fragment_shader().v_texture_location(), 3));
-
-  // These values are magic numbers that are used in the transformation from YUV
-  // to RGB color values.  They are taken from the following webpage:
-  // http://www.fourcc.org/fccyvrgb.php
-  float yuv_to_rgb[9] = {
-      1.164f, 1.164f, 1.164f,
-      0.0f, -.391f, 2.018f,
-      1.596f, -.813f, 0.0f,
-  };
-  GLC(Context(),
-      Context()->uniformMatrix3fv(
-          program->fragment_shader().yuv_matrix_location(), 1, 0, 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).
-  // They are used in the YUV to RGBA conversion formula:
-  //   Y - 16   : Gives 16 values of head and footroom for overshooting
-  //   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(
-          program->fragment_shader().yuv_adj_location(), 1, yuv_adjust));
+      Context()->uniformMatrix3fv(yuv_matrix_location, 1, 0, yuv_to_rgb));
+  GLC(Context(), Context()->uniform3fv(yuv_adj_location, 1, yuv_adjust));
 
-  SetShaderOpacity(quad->opacity(),
-                   program->fragment_shader().alpha_location());
-  DrawQuadGeometry(frame,
-                   quad->quadTransform(),
-                   quad->rect,
-                   program->vertex_shader().matrix_location());
+
+  SetShaderOpacity(quad->opacity(), alpha_location);
+  DrawQuadGeometry(frame, quad->quadTransform(), quad->rect, matrix_location);
 
   // Reset active texture back to texture 0.
   GLC(Context(), Context()->activeTexture(GL_TEXTURE0));
@@ -2209,6 +2238,16 @@ const GLRenderer::VideoYUVProgram* GLRenderer::GetVideoYUVProgram() {
   return video_yuv_program_.get();
 }
 
+const GLRenderer::VideoYUVAProgram* GLRenderer::GetVideoYUVAProgram() {
+  if (!video_yuva_program_)
+    video_yuva_program_ = make_scoped_ptr(new VideoYUVAProgram(context_));
+  if (!video_yuva_program_->initialized()) {
+    TRACE_EVENT0("cc", "GLRenderer::videoYUVAProgram::initialize");
+    video_yuva_program_->Initialize(context_, is_using_bind_uniform_);
+  }
+  return video_yuva_program_.get();
+}
+
 const GLRenderer::VideoStreamTextureProgram*
 GLRenderer::GetVideoStreamTextureProgram() {
   if (!Capabilities().using_egl_image)
@@ -2261,6 +2300,8 @@ void GLRenderer::CleanupSharedObjects() {
 
   if (video_yuv_program_)
     video_yuv_program_->Cleanup(context_);
+  if (video_yuva_program_)
+    video_yuva_program_->Cleanup(context_);
   if (video_stream_texture_program_)
     video_stream_texture_program_->Cleanup(context_);