stagefright: disable automatic experiments

allow manually-enabled experiments only in eng and userdebug builds

Bug: 20894667
Change-Id: Ie6c93e9482a84ed3aaf6aa0abd909f14cfea4e9b

3 files changed, 33 insertions, 4 deletions

diff --git a/media/libmediaplayerservice/nuplayer/Android.mk b/media/libmediaplayerservice/nuplayer/Android.mk
index cc6f743..cd20837 100644
--- a/media/libmediaplayerservice/nuplayer/Android.mk
+++ b/media/libmediaplayerservice/nuplayer/Android.mk
@@ -25,7 +25,12 @@ LOCAL_C_INCLUDES := \
 	$(TOP)/frameworks/av/media/libmediaplayerservice              \
 	$(TOP)/frameworks/native/include/media/openmax
 
-LOCAL_CFLAGS += -Werror -Wall -DENABLE_STAGEFRIGHT_EXPERIMENTS
+LOCAL_CFLAGS += -Werror -Wall
+
+# enable experiments only in userdebug and eng builds
+ifneq (,$(filter userdebug eng,$(TARGET_BUILD_VARIANT)))
+LOCAL_CFLAGS += -DENABLE_STAGEFRIGHT_EXPERIMENTS
+endif
 
 LOCAL_CLANG := true
 
diff --git a/media/libstagefright/Android.mk b/media/libstagefright/Android.mk
index b86c749..2529aa7 100644
--- a/media/libstagefright/Android.mk
+++ b/media/libstagefright/Android.mk
@@ -127,8 +127,12 @@ LOCAL_SHARED_LIBRARIES += \
         libdl \
         libRScpp \
 
-LOCAL_CFLAGS += -Wno-multichar -Werror -Wno-error=deprecated-declarations -Wall \
-        -DENABLE_STAGEFRIGHT_EXPERIMENTS
+LOCAL_CFLAGS += -Wno-multichar -Werror -Wno-error=deprecated-declarations -Wall
+
+# enable experiments only in userdebug and eng builds
+ifneq (,$(filter userdebug eng,$(TARGET_BUILD_VARIANT)))
+LOCAL_CFLAGS += -DENABLE_STAGEFRIGHT_EXPERIMENTS
+endif
 
 LOCAL_CLANG := true
 
diff --git a/media/libstagefright/foundation/ADebug.cpp b/media/libstagefright/foundation/ADebug.cpp
index 24fa561..2c5f544 100644
--- a/media/libstagefright/foundation/ADebug.cpp
+++ b/media/libstagefright/foundation/ADebug.cpp
@@ -29,6 +29,8 @@
 #include <AStringUtils.h>
 #include <AUtils.h>
 
+#define UNUSED(x) ((void)(x))
+
 namespace android {
 
 //static
@@ -130,7 +132,24 @@ bool ADebug::getExperimentFlag(
     long level = GetLevelFromProperty(name, "debug.stagefright.experiments", undefined);
     if (level != undefined) {
         ALOGI("experiment '%s': %s from property", name, level ? "ENABLED" : "disabled");
-        return level != 0;
+        return allow && (level != 0);
+    }
+
+#ifndef ENABLE_STAGEFRIGHT_AUTO_EXPERIMENTS
+    UNUSED(modulo);
+    UNUSED(limit);
+    UNUSED(plus);
+    UNUSED(timeDivisor);
+    return false;
+#else
+    // Disable automatic experiments in "non-experimental" builds (that is, _all_ builds
+    // as there is no "experimental" build).
+    // TODO: change build type to enable automatic experiments in the future for some builds
+    char value[PROPERTY_VALUE_MAX];
+    if (property_get("ro.build.type", value, NULL)) {
+        if (strcmp(value, "experimental")) {
+            return false;
+        }
     }
 
     static volatile int32_t haveSerial = 0;
@@ -164,6 +183,7 @@ bool ADebug::getExperimentFlag(
     bool enable = allow && (counter % modulo < limit);
     ALOGI("experiment '%s': %s", name, enable ? "ENABLED" : "disabled");
     return enable;
+#endif
 }
 
 }  // namespace android