Add GLStreamTextureImage

content/common/gpu/media/avda_codec_image.cc

Index: content/common/gpu/media/avda_codec_image.cc
diff --git a/content/common/gpu/media/avda_codec_image.cc b/content/common/gpu/media/avda_codec_image.cc
index 6b0fa8a62658424e3b74e0e61262afb817112a5c..e0a0cb59c55a39ae0d3e8b5aae13098469fd3190 100644
--- a/content/common/gpu/media/avda_codec_image.cc
+++ b/content/common/gpu/media/avda_codec_image.cc
@@ -29,11 +29,12 @@ AVDACodecImage::AVDACodecImage(
       decoder_(decoder),
       surface_texture_(surface_texture),
       detach_surface_texture_on_destruction_(false),
-      texture_(0),
-      need_shader_info_(true),
-      texmatrix_uniform_location_(-1) {
+      texture_(0) {
+  // Default to a sane guess of "flip Y", just in case we can't get
+  // the matrix on the first call.
   memset(gl_matrix_, 0, sizeof(gl_matrix_));
-  gl_matrix_[0] = gl_matrix_[5] = gl_matrix_[10] = gl_matrix_[15] = 1.0f;
+  gl_matrix_[0] = gl_matrix_[10] = gl_matrix_[15] = 1.0f;
+  gl_matrix_[5] = -1.0f;
 }
 
 AVDACodecImage::~AVDACodecImage() {}
@@ -61,35 +62,29 @@ bool AVDACodecImage::CopyTexImage(unsigned target) {
   if (target != GL_TEXTURE_EXTERNAL_OES)
     return false;
 
-  // Verify that the currently bound texture is the right one.  If we're not
-  // copying to a Texture that shares our service_id, then we can't do much.
-  // This will force a copy.
-  // TODO(liberato): Fall back to a copy that uses the texture matrix.
   GLint bound_service_id = 0;
   glGetIntegerv(GL_TEXTURE_BINDING_EXTERNAL_OES, &bound_service_id);
+  // We insist that the currently bound texture is the right one.  We could
+  // make a new glimage from a 2D image.
   if (bound_service_id != shared_state_->surface_texture_service_id())
     return false;
 
-  // Attach the surface texture to our GL context if needed.
+  // If the surface texture isn't attached yet, then attach it.  Note that this
+  // will be to the texture in |shared_state_|, because of the checks above.
   if (!shared_state_->surface_texture_is_attached())
     AttachSurfaceTextureToContext();
 
-  // Make sure that we have the right image in the front buffer.
-  UpdateSurfaceTexture();
-
-  InstallTextureMatrix();
-
-  // TODO(liberato): Handle the texture matrix properly.
-  // Either we can update the shader with it or we can move all of the logic
-  // to updateTexImage() to the right place in the cc to send it to the shader.
-  // For now, we just skip it.  crbug.com/530681
+  // Make sure that we have the right image in the front buffer.  Note that the
+  // bound_service_id is guaranteed to be equal to the surface texture's client
+  // texture id, so we can skip preserving it if the right context is current.
+  UpdateSurfaceTexture(kDontRestoreBindings);
 
   // By setting image state to UNBOUND instead of COPIED we ensure that
   // CopyTexImage() is called each time the surface texture is used for drawing.
   // It would be nice if we could do this via asking for the currently bound
   // Texture, but the active unit never seems to change.
-  texture_->SetLevelImage(GL_TEXTURE_EXTERNAL_OES, 0, this,
-                          gpu::gles2::Texture::UNBOUND);
+  texture_->SetLevelStreamTextureImage(GL_TEXTURE_EXTERNAL_OES, 0, this,
+                                       gpu::gles2::Texture::UNBOUND);
 
   return true;
 }
@@ -123,11 +118,11 @@ void AVDACodecImage::OnMemoryDump(base::trace_event::ProcessMemoryDump* pmd,
                                   uint64_t process_tracing_id,
                                   const std::string& dump_name) {}
 
-void AVDACodecImage::UpdateSurfaceTexture() {
+void AVDACodecImage::UpdateSurfaceTexture(RestoreBindingsMode mode) {
   DCHECK(surface_texture_);
 
   // Render via the media codec if needed.
-  if (codec_buffer_index_ == kInvalidCodecBufferIndex || !media_codec_)
+  if (!IsCodecBufferOutstanding())
     return;
 
   // The decoder buffer is still pending.
@@ -142,12 +137,21 @@ void AVDACodecImage::UpdateSurfaceTexture() {
   codec_buffer_index_ = kInvalidCodecBufferIndex;
 
   // Swap the rendered image to the front.
-  scoped_ptr<ui::ScopedMakeCurrent> scoped_make_current;
-  if (!shared_state_->context()->IsCurrent(NULL)) {
-    scoped_make_current.reset(new ui::ScopedMakeCurrent(
-        shared_state_->context(), shared_state_->surface()));
-  }
+  scoped_ptr<ui::ScopedMakeCurrent> scoped_make_current = MakeCurrentIfNeeded();
+
+  // If we changed contexts, then we always want to restore it, since the caller
+  // doesn't know that we're switching contexts.
+  if (scoped_make_current)
+    mode = kDoRestoreBindings;
+
+  // Save the current binding if requested.
+  GLint bound_service_id = 0;
+  if (mode == kDoRestoreBindings)
+    glGetIntegerv(GL_TEXTURE_BINDING_EXTERNAL_OES, &bound_service_id);
+
   surface_texture_->UpdateTexImage();
+  if (mode == kDoRestoreBindings)
+    glBindTexture(GL_TEXTURE_EXTERNAL_OES, bound_service_id);
 
   // Helpfully, this is already column major.
   surface_texture_->GetTransformMatrix(gl_matrix_);
@@ -176,6 +180,8 @@ void AVDACodecImage::SetTexture(gpu::gles2::Texture* texture) {
 void AVDACodecImage::AttachSurfaceTextureToContext() {
   DCHECK(surface_texture_);
 
+  // We assume that the currently bound texture is the intended one.
+
   // Attach the surface texture to the first context we're bound on, so that
   // no context switch is needed later.
   glTexParameteri(GL_TEXTURE_EXTERNAL_OES, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
@@ -187,38 +193,48 @@ void AVDACodecImage::AttachSurfaceTextureToContext() {
   // We could do this earlier, but SurfaceTexture has context affinity, and we
   // don't want to require a context switch.
   surface_texture_->AttachToGLContext();
-  shared_state_->did_attach_surface_texture();
+  shared_state_->DidAttachSurfaceTexture();
 }
 
-void AVDACodecImage::InstallTextureMatrix() {
-  DCHECK(surface_texture_);
+scoped_ptr<ui::ScopedMakeCurrent> AVDACodecImage::MakeCurrentIfNeeded() {
+  DCHECK(shared_state_->context());
+  scoped_ptr<ui::ScopedMakeCurrent> scoped_make_current;
+  if (!shared_state_->context()->IsCurrent(NULL)) {
+    scoped_make_current.reset(new ui::ScopedMakeCurrent(
+        shared_state_->context(), shared_state_->surface()));
+  }
 
-  // glUseProgram() has been run already -- just modify the uniform.
-  // Updating this via VideoFrameProvider::Client::DidUpdateMatrix() would
-  // be a better solution, except that we'd definitely miss a frame at this
-  // point in drawing.
-  // Our current method assumes that we'll end up being a stream resource,
-  // and that the program has a texMatrix uniform that does what we want.
-  if (need_shader_info_) {
-    GLint program_id = -1;
-    glGetIntegerv(GL_CURRENT_PROGRAM, &program_id);
-
-    if (program_id >= 0) {
-      // This is memorized from cc/output/shader.cc .
-      const char* uniformName = "texMatrix";
-
-      // Within unittests this value may be -1.
-      texmatrix_uniform_location_ =
-          glGetUniformLocation(program_id, uniformName);
-    }
+  return scoped_make_current;
+}
 
-    // Only try once.
-    need_shader_info_ = false;
+void AVDACodecImage::GetTextureMatrix(float matrix[16]) {
+  if (IsCodecBufferOutstanding() && shared_state_ && surface_texture_) {
+    // Our current matrix may be stale.  Update it if possible.
+    if (!shared_state_->surface_texture_is_attached()) {
+      // Don't attach the surface texture permanently.  Perhaps we should
+      // just attach the surface texture in avda and be done with it.
+      GLuint service_id = 0;
+      glGenTextures(1, &service_id);
+      GLint bound_service_id = 0;
+      glGetIntegerv(GL_TEXTURE_BINDING_EXTERNAL_OES, &bound_service_id);
+      glBindTexture(GL_TEXTURE_EXTERNAL_OES, service_id);
+      AttachSurfaceTextureToContext();
+      UpdateSurfaceTexture(kDontRestoreBindings);
+      // Detach the surface texture, which deletes the generated texture.
+      surface_texture_->DetachFromGLContext();
+      shared_state_->DidDetachSurfaceTexture();
+      glBindTexture(GL_TEXTURE_EXTERNAL_OES, bound_service_id);
+    } else {
+      // Surface texture is already attached, so just update it.
+      UpdateSurfaceTexture(kDoRestoreBindings);
+    }
   }
 
-  if (texmatrix_uniform_location_ >= 0) {
-    glUniformMatrix4fv(texmatrix_uniform_location_, 1, false, gl_matrix_);
-  }
+  memcpy(matrix, gl_matrix_, sizeof(gl_matrix_));
+}
+
+bool AVDACodecImage::IsCodecBufferOutstanding() const {
+  return codec_buffer_index_ != kInvalidCodecBufferIndex && media_codec_;
 }
 
 }  // namespace content