enable scalability experiment

Change-Id: Iba30805ba15c6c7cf16bd30e0eebfc4e9aeb2f17

av1/decoder/obu.c

diff --git a/av1/decoder/obu.c b/av1/decoder/obu.c
index aad4f22..b639412 100644
--- a/av1/decoder/obu.c
+++ b/av1/decoder/obu.c
@@ -61,7 +61,8 @@
     aom_rb_read_literal(rb, 2);
     aom_rb_read_literal(rb, 1);  // reserved
 #else
-    *obu_extension_header = (uint8_t)aom_rb_read_literal(rb, 8);
+    if (obu_extension_header)
+      *obu_extension_header = (uint8_t)aom_rb_read_literal(rb, 8);
 #endif
   }
 

build/cmake/aom_config_defaults.cmake

diff --git a/build/cmake/aom_config_defaults.cmake b/build/cmake/aom_config_defaults.cmake
index 58ce4ff..6a424a0 100644
--- a/build/cmake/aom_config_defaults.cmake
+++ b/build/cmake/aom_config_defaults.cmake
@@ -144,7 +144,7 @@
 set(CONFIG_RECT_TX_EXT 1 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_RECT_TX_EXT_INTRA 1 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_REFERENCE_BUFFER 1 CACHE NUMBER "AV1 experiment flag.")
-set(CONFIG_SCALABILITY 0 CACHE NUMBER "AV1 experiment flag.")
+set(CONFIG_SCALABILITY 1 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_SEGMENT_GLOBALMV 1 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_SEGMENT_PRED_LAST 1 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_SHORT_FILTER 1 CACHE NUMBER "AV1 experiment flag.")