gpu: Add YCbCr 420v extension.

ui/gl/gl_image_io_surface.mm

Index: ui/gl/gl_image_io_surface.mm
diff --git a/ui/gl/gl_image_io_surface.mm b/ui/gl/gl_image_io_surface.mm
index d6ac250b84bc8849e403ea455980b75842ef5ca5..bf979dcca555dcfeca1a825de454e44c20362720 100644
--- a/ui/gl/gl_image_io_surface.mm
+++ b/ui/gl/gl_image_io_surface.mm
@@ -6,13 +6,17 @@
 
 #include <map>
 
+#include "base/callback_helpers.h"

[reveman, 2015/11/01 14:19:04]

is this used?

[Daniele Castagna, 2015/11/01 21:55:31]

Not anymore. Removed.

 #include "base/lazy_instance.h"
 #include "base/mac/foundation_util.h"
+#include "base/strings/stringize_macros.h"
 #include "base/trace_event/memory_allocator_dump.h"
 #include "base/trace_event/memory_dump_manager.h"
 #include "base/trace_event/process_memory_dump.h"
 #include "ui/gl/gl_bindings.h"
 #include "ui/gl/gl_context.h"
+#include "ui/gl/gl_helper.h"
+#include "ui/gl/scoped_binders.h"
 
 // Note that this must be included after gl_bindings.h to avoid conflicts.
 #include <OpenGL/CGLIOSurface.h>
@@ -26,11 +30,41 @@ namespace {
 using WidgetToLayerMap = std::map<gfx::AcceleratedWidget, CALayer*>;
 base::LazyInstance<WidgetToLayerMap> g_widget_to_layer_map;
 
+// clang-format off
+const char kVertexShader[] =
+STRINGIZE(
+  attribute vec2 a_position;
+  uniform vec2 a_size;
+  varying vec2 v_texCoord;
+  void main() {
+    gl_Position = vec4(a_position.x, a_position.y, 0.0, 1.0);
+    v_texCoord = (a_position + vec2(1,1)) * 0.5 * a_size;

[reveman, 2015/11/01 14:19:05]

s/vec2(1,1)/vec2(1, 1)/ maybe vec2(1.0, 1.0)?

also maybe rename a_size to a_texScale to make it more clear what that is used
for and that also makes this shader not explicitly aware of the use of
texture_rectangle.

[Daniele Castagna, 2015/11/01 21:55:31]

Done.

+  }
+);
+
+const char kFragmentShader[] =
+STRINGIZE(
+  uniform sampler2DRect a_y_texture;
+  uniform sampler2DRect a_uv_texture;
+  varying vec2 v_texCoord;
+  void main() {
+    vec3 yuv_adj = vec3(-0.0625, -0.5, -0.5);
+    mat3 yuv_matrix = mat3(vec3(1.164, 1.164, 1.164),
+                           vec3(0.0, -.391, 2.018),
+                           vec3(1.596, -.813, 0.0));
+    vec3 yuv = vec3(texture2DRect(a_y_texture, v_texCoord).r,
+        texture2DRect(a_uv_texture, v_texCoord * 0.5).rg);

[reveman, 2015/11/01 14:19:04]

nit: Horizontally align texture2DRect to have consistent formatting within this
shader (match alignment of arguments passed to mat3 above)

[Daniele Castagna, 2015/11/01 21:55:31]

Done.

+    gl_FragColor = vec4( yuv_matrix * (yuv + yuv_adj), 1.0);

[reveman, 2015/11/01 14:19:04]

nit: s/vec4( yuv_mat.../vec4(yuv_mat.../

[Daniele Castagna, 2015/11/01 21:55:31]

Done.

+  }
+);
+// clang-format on
+
 bool ValidInternalFormat(unsigned internalformat) {
   switch (internalformat) {
     case GL_R8:
     case GL_BGRA_EXT:
     case GL_RGB:
+    case GL_RGB_YCBCR_420V_CHROMIUM:
     case GL_RGB_YCBCR_422_CHROMIUM:
     case GL_RGBA:
       return true;
@@ -66,7 +100,6 @@ bool ValidFormat(BufferFormat format) {
 GLenum TextureFormat(BufferFormat format) {
   switch (format) {
     case BufferFormat::R_8:
-    case BufferFormat::YUV_420_BIPLANAR:
       return GL_RED;
     case BufferFormat::BGRA_8888:
     case BufferFormat::RGBA_8888:
@@ -82,6 +115,7 @@ GLenum TextureFormat(BufferFormat format) {
     case BufferFormat::RGBX_8888:
     case BufferFormat::BGRX_8888:
     case BufferFormat::YUV_420:
+    case BufferFormat::YUV_420_BIPLANAR:
       NOTREACHED();
       return 0;
   }
@@ -93,14 +127,12 @@ GLenum TextureFormat(BufferFormat format) {
 GLenum DataFormat(BufferFormat format) {
   switch (format) {
     case BufferFormat::R_8:
-    case BufferFormat::YUV_420_BIPLANAR:
       return GL_RED;
     case BufferFormat::BGRA_8888:
     case BufferFormat::RGBA_8888:
       return GL_BGRA;
     case BufferFormat::UYVY_422:
       return GL_YCBCR_422_APPLE;
-      break;
     case BufferFormat::ATC:
     case BufferFormat::ATCIA:
     case BufferFormat::DXT1:
@@ -110,6 +142,7 @@ GLenum DataFormat(BufferFormat format) {
     case BufferFormat::RGBX_8888:
     case BufferFormat::BGRX_8888:
     case BufferFormat::YUV_420:
+    case BufferFormat::YUV_420_BIPLANAR:
       NOTREACHED();
       return 0;
   }
@@ -121,7 +154,6 @@ GLenum DataFormat(BufferFormat format) {
 GLenum DataType(BufferFormat format) {
   switch (format) {
     case BufferFormat::R_8:
-    case BufferFormat::YUV_420_BIPLANAR:
       return GL_UNSIGNED_BYTE;
     case BufferFormat::BGRA_8888:
     case BufferFormat::RGBA_8888:
@@ -138,6 +170,7 @@ GLenum DataType(BufferFormat format) {
     case BufferFormat::RGBX_8888:
     case BufferFormat::BGRX_8888:
     case BufferFormat::YUV_420:
+    case BufferFormat::YUV_420_BIPLANAR:
       NOTREACHED();
       return 0;
   }
@@ -146,6 +179,18 @@ GLenum DataType(BufferFormat format) {
   return 0;
 }
 
+GLuint SetupVertexBuffer() {
+  GLuint vertex_buffer = 0;
+  glGenBuffersARB(1, &vertex_buffer);
+  gfx::ScopedBufferBinder buffer_binder(GL_ARRAY_BUFFER, vertex_buffer);
+
+  GLfloat data[] = {-1.f, -1.f, 1.f, -1.f, -1.f, 1.f, 1.f, 1.f};
+  glBufferData(GL_ARRAY_BUFFER, sizeof(data), data, GL_STATIC_DRAW);
+  glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, sizeof(GLfloat) * 2, 0);
+
+  return vertex_buffer;
+}
+
 }  // namespace
 
 GLImageIOSurface::GLImageIOSurface(const gfx::Size& size,
@@ -183,6 +228,13 @@ bool GLImageIOSurface::Initialize(IOSurfaceRef io_surface,
 
 void GLImageIOSurface::Destroy(bool have_context) {
   DCHECK(thread_checker_.CalledOnValidThread());
+  if (have_context) {

[reveman, 2015/11/01 14:19:04]

Can you add framebuffer_ to this 'if' clause? I know the GL will ignore these
calls when passed 0 but "if (have_context && framebuffer_)" match the condition
for when we create this state and I think that makes it a bit easier to
understand.

[Daniele Castagna, 2015/11/01 21:55:30]

Done.

+    glDeleteProgram(program_);
+    glDeleteShader(vertex_shader_);
+    glDeleteShader(fragment_shader_);
+    glDeleteBuffersARB(1, &vertex_buffer_);
+    glDeleteFramebuffersEXT(1, &framebuffer_);
+  }
   io_surface_.reset();
 }
 
@@ -194,6 +246,11 @@ unsigned GLImageIOSurface::GetInternalFormat() { return internalformat_; }
 
 bool GLImageIOSurface::BindTexImage(unsigned target) {
   DCHECK(thread_checker_.CalledOnValidThread());
+  // YUV_420_BIPLANAR is not supported by BindTexImage.

[reveman, 2015/11/01 14:19:04]

nit: can you add a blinkline after the DCHECK as otherwise is looks like it's
grouped and related to this format check

[Daniele Castagna, 2015/11/01 21:55:31]

Done.

+  // Returning false here will result in conversion to RGB in CopyTexImage.

[reveman, 2015/11/01 14:19:04]

nit: maybe something like "CopyTexImage is supported by this format as that
performs conversion to RGB as part of the copy operation." as what returning
false here results in is really up to the user of this API. They can call
CopyTexImage if they like but they don't have to.

[Daniele Castagna, 2015/11/01 21:55:30]

Done.

+  if (format_ == BufferFormat::YUV_420_BIPLANAR)
+    return false;
+
   if (target != GL_TEXTURE_RECTANGLE_ARB) {
     // This might be supported in the future. For now, perform strict
     // validation so we know what's going on.
@@ -218,7 +275,99 @@ bool GLImageIOSurface::BindTexImage(unsigned target) {
 }
 
 bool GLImageIOSurface::CopyTexImage(unsigned target) {
-  return false;
+  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK(io_surface_);
+  if (format_ != BufferFormat::YUV_420_BIPLANAR)

[reveman, 2015/11/01 14:19:05]

nit: blankline after DCHECKs and maybe move the io_surface_ DCHECK down to where
it's first used..

[Daniele Castagna, 2015/11/01 21:55:31]

Done.

+    return false;
+
+  if (target != GL_TEXTURE_2D) {
+    LOG(ERROR) << "YUV_420_BIPLANAR requires TEXTURE_2D target";
+    return false;
+  }
+
+  if (!framebuffer_) {
+    glGenFramebuffersEXT(1, &framebuffer_);
+    vertex_buffer_ = SetupVertexBuffer();
+    vertex_shader_ = gfx::GLHelper::LoadShader(GL_VERTEX_SHADER, kVertexShader);
+    fragment_shader_ =
+        gfx::GLHelper::LoadShader(GL_FRAGMENT_SHADER, kFragmentShader);
+    program_ = gfx::GLHelper::SetupProgram(vertex_shader_, fragment_shader_);
+    gfx::ScopedUseProgram use_program(program_);
+
+    size_location_ = glGetUniformLocation(program_, "a_size");
+    DCHECK_NE(-1, size_location_);
+    int y_sampler_location = glGetUniformLocation(program_, "a_y_texture");
+    DCHECK_NE(-1, y_sampler_location);
+    int uv_sampler_location = glGetUniformLocation(program_, "a_uv_texture");
+    DCHECK_NE(-1, uv_sampler_location);
+
+    glUniform1i(y_sampler_location, 0);
+    glUniform1i(uv_sampler_location, 1);
+  }
+
+  CGLContextObj cgl_context =
+      static_cast<CGLContextObj>(gfx::GLContext::GetCurrent()->GetHandle());
+
+  GLuint yuv_textures[2];

[reveman, 2015/11/01 14:19:04]

nit: ..textures[2] = {};

[Daniele Castagna, 2015/11/01 21:55:30]

Done.

+  glGenTextures(2, yuv_textures);
+  DCHECK(yuv_textures[0] && yuv_textures[1]);

[reveman, 2015/11/01 14:19:04]

nit: one DCHECK for each texture is preferred

[Daniele Castagna, 2015/11/01 21:55:30]

Done.

+
+  GLint target_texture = 0;
+  glGetIntegerv(GL_TEXTURE_BINDING_2D, &target_texture);
+  DCHECK(target_texture);
+
+  GLint previous_active_texture = 0;
+  glGetIntegerv(GL_ACTIVE_TEXTURE, &previous_active_texture);

[reveman, 2015/11/01 14:19:04]

is this still used?

[Daniele Castagna, 2015/11/01 21:55:30]

Nop. Gone.

+
+  CGLError cgl_error = kCGLNoError;
+  {
+    gfx::ScopedActiveTexture active_texture0(GL_TEXTURE0);
+    gfx::ScopedTextureBinder texture_y_binder(GL_TEXTURE_RECTANGLE_ARB,
+                                              yuv_textures[0]);
+    cgl_error = CGLTexImageIOSurface2D(
+        cgl_context, GL_TEXTURE_RECTANGLE_ARB, GL_RED, size_.width(),
+        size_.height(), GL_RED, GL_UNSIGNED_BYTE, io_surface_.get(), 0);
+    if (cgl_error != kCGLNoError) {
+      LOG(ERROR) << "Error in CGLTexImageIOSurface2D for the Y plane. "
+                 << cgl_error;
+      glDeleteTextures(2, yuv_textures);
+      return false;
+    }
+    {
+      gfx::ScopedActiveTexture active_texture1(GL_TEXTURE1);
+      gfx::ScopedTextureBinder texture_uv_binder(GL_TEXTURE_RECTANGLE_ARB,
+                                                 yuv_textures[1]);
+      cgl_error = CGLTexImageIOSurface2D(
+          cgl_context, GL_TEXTURE_RECTANGLE_ARB, GL_RG, size_.width() / 2,
+          size_.height() / 2, GL_RG, GL_UNSIGNED_BYTE, io_surface_.get(), 1);
+      if (cgl_error != kCGLNoError) {
+        LOG(ERROR) << "Error in CGLTexImageIOSurface2D for the UV plane. "
+                   << cgl_error;
+        glDeleteTextures(2, yuv_textures);
+        return false;
+      }
+
+      gfx::ScopedFrameBufferBinder framebuffer_binder(framebuffer_);
+      gfx::ScopedViewport viewport(0, 0, size_.width(), size_.height());
+      glViewport(0, 0, size_.width(), size_.height());
+      glFramebufferTexture2DEXT(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
+                                GL_TEXTURE_2D, target_texture, 0);

[reveman, 2015/11/01 14:19:04]

Do we need a glTexImage2D call for the target texture before this? there's no
guarantee that the target texture has been defined when CopyTexImage is called.
This function should define it. It's only in CopyTexSubImage that we can assume
that the texture has already been defined.

[Daniele Castagna, 2015/11/01 21:55:31]

We do need it. Added it.

+      DCHECK_EQ(static_cast<GLenum>(GL_FRAMEBUFFER_COMPLETE),
+                glCheckFramebufferStatusEXT(GL_FRAMEBUFFER));
+
+      gfx::ScopedUseProgram use_program(program_);
+      glUniform2f(size_location_, size_.width(), size_.height());
+
+      gfx::ScopedEnableVertexAttribArray enable_vertex_attrib_array(0);
+      gfx::ScopedBufferBinder buffer_binder(GL_ARRAY_BUFFER, vertex_buffer_);
+      glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+
+      // Detach the output texture from the fbo.
+      glFramebufferTexture2DEXT(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
+                                GL_TEXTURE_2D, 0, 0);
+    }
+  }
+  return true;
 }
 
 bool GLImageIOSurface::CopyTexSubImage(unsigned target,