EGL: update EGL_ANDROID_recordable extension.

This change adds an enum value and a description of the expected
implementations to the EGL_ANDROID_recordable extension specification.
It also adds the new enum value to the 'eglext.h' header.

Change-Id: Ia0de2d5613708445ff83b85a7e550f9417531ee4

2 files changed, 37 insertions, 5 deletions

diff --git a/opengl/include/EGL/eglext.h b/opengl/include/EGL/eglext.h
index 1123e16..6a199db 100644
--- a/opengl/include/EGL/eglext.h
+++ b/opengl/include/EGL/eglext.h
@@ -226,7 +226,7 @@ typedef EGLBoolean (EGLAPIENTRYP PFNEGLGETSYNCATTRIBNVPROC) (EGLSyncNV sync, EGL
 #ifndef EGL_ANDROID_image_native_buffer
 #define EGL_ANDROID_image_native_buffer 1
 struct ANativeWindowBuffer;
-#define EGL_NATIVE_BUFFER_ANDROID       0x3140  /* eglCreateImageKHR target */
+#define EGL_NATIVE_BUFFER_ANDROID               0x3140  /* eglCreateImageKHR target */
 #endif
 
 #ifndef EGL_ANDROID_swap_rectangle
@@ -237,6 +237,11 @@ EGLAPI EGLBoolean EGLAPIENTRY eglSetSwapRectangleANDROID (EGLDisplay dpy, EGLSur
 typedef EGLBoolean (EGLAPIENTRYP PFNEGLSETSWAPRECTANGLEANDROIDPROC) (EGLDisplay dpy, EGLSurface draw, EGLint left, EGLint top, EGLint width, EGLint height);
 #endif
 
+#ifndef EGL_ANDROID_recordable
+#define EGL_ANDROID_recordable 1
+#define EGL_RECORDABLE_ANDROID                  0x3142  /* EGLConfig attribute */
+#endif
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/opengl/specs/EGL_ANDROID_recordable.txt b/opengl/specs/EGL_ANDROID_recordable.txt
index cf44465..8dbd26f 100644
--- a/opengl/specs/EGL_ANDROID_recordable.txt
+++ b/opengl/specs/EGL_ANDROID_recordable.txt
@@ -55,7 +55,7 @@ New Tokens
     Accepted by the <attribute> parameter of eglGetConfigAttrib and
     the <attrib_list> parameter of eglChooseConfig:
 
-        EGL_RECORDABLE_ANDROID                      0xXXXX
+        EGL_RECORDABLE_ANDROID                      0x3142
 
 Changes to Chapter 3 of the EGL 1.4 Specification (EGL Functions and Errors)
 
@@ -103,11 +103,38 @@ Issues
 
     RESOLVED: It should not affect sorting.  Some implementations may not have
     any drawback associated with using a recordable EGLConfig.  Such
-    implementations should not have to double-up some of their configs to  one sort earlier than .
-    Implementations that do have drawbacks can use the existing caveat
-    mechanism to report this drawback to the client.
+    implementations should not have to double-up some of their configs to  one
+    sort earlier than .  Implementations that do have drawbacks can use the
+    existing caveat mechanism to report this drawback to the client.
+
+    3. How is this extension expected to be implemented?
+
+    RESPONSE: There are two basic approaches to implementing this extension
+    that were considered during its design.  In both cases it is assumed that a
+    color space conversion must be performed at some point because most video
+    encoding formats use a YUV color space.  The two approaches are
+    distinguished by the point at which this color space conversion is
+    performed.
+
+    One approach involves performing the color space conversion as part of the
+    eglSwapBuffers call before queuing the rendered image to the ANativeWindow.
+    In this case, the VisualID of the EGLConfig would correspond to a YUV
+    Android HAL pixel format from which the video encoder can read.  The
+    EGLConfig would likely have the EGL_SLOW_CONFIG caveat because using that
+    config to render normal window contents would result in an RGB -> YUV color
+    space conversion when rendering the frame as well as a YUV -> RGB
+    conversion when compositing the window.
+
+    The other approach involves performing the color space conversion in the
+    video encoder.  In this case, the VisualID of the EGLConfig would
+    correspond to an RGB HAL pixel format from which the video encoder can
+    read.  The EGLConfig would likely not need to have any caveat set, as using
+    this config for normal window rendering would not have any added cost.
 
 Revision History
 
+#2 (Jamie Gennis, July 15, 2011)
+    - Added issue 3.
+
 #1 (Jamie Gennis, July 8, 2011)
     - Initial draft.