summaryrefslogtreecommitdiffstats
path: root/media/libavextensions/common/ExtensionsLoader.hpp
diff options
context:
space:
mode:
Diffstat (limited to 'media/libavextensions/common/ExtensionsLoader.hpp')
-rw-r--r--media/libavextensions/common/ExtensionsLoader.hpp97
1 files changed, 97 insertions, 0 deletions
diff --git a/media/libavextensions/common/ExtensionsLoader.hpp b/media/libavextensions/common/ExtensionsLoader.hpp
new file mode 100644
index 0000000..15728ed
--- /dev/null
+++ b/media/libavextensions/common/ExtensionsLoader.hpp
@@ -0,0 +1,97 @@
+/*
+ * Copyright (c) 2013 - 2015, The Linux Foundation. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer in the documentation and/or other materials provided
+ * with the distribution.
+ * * Neither the name of The Linux Foundation nor the names of its
+ * contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
+ * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
+ * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include <dlfcn.h>
+#include <common/AVExtensionsCommon.h>
+#include <cutils/properties.h>
+
+namespace android {
+
+static const char * CUSTOMIZATION_LIB_NAME = "libavenhancements.so";
+
+/*
+ * Create strongly-typed objects of type T
+ * If the customization library exists and does contain a "named" constructor,
+ * invoke and create an instance
+ * Else create the object of type T itself
+ *
+ * Contains a static instance to dlopen'd library, But may end up
+ * opening the library mutiple times. Following snip from dlopen man page is
+ * reassuring "...Only a single copy of an object file is brought into the
+ * address space, even if dlopen() is invoked multiple times in reference to
+ * the file, and even if different pathnames are used to reference the file.."
+ */
+
+template <typename T>
+T *ExtensionsLoader<T>::createInstance(const char *createFunctionName) {
+ (void)createFunctionName;
+ // create extended object if extensions-lib is available and
+ // AV_ENHANCEMENTS is enabled
+#if ENABLE_AV_ENHANCEMENTS
+ bool enabled = property_get_bool("media.avenhancements.enabled", false);
+ if (enabled) {
+ createFunction_t createFunc = loadCreateFunction(createFunctionName);
+ if (createFunc) {
+ return reinterpret_cast<T *>((*createFunc)());
+ }
+ }
+#endif
+ // Else, create the default object
+ return new T;
+}
+
+template <typename T>
+void ExtensionsLoader<T>::loadLib() {
+ if (!mLibHandle) {
+ mLibHandle = ::dlopen(CUSTOMIZATION_LIB_NAME, RTLD_LAZY);
+ if (!mLibHandle) {
+ ALOGV("%s", dlerror());
+ return;
+ }
+ ALOGV("Opened %s", CUSTOMIZATION_LIB_NAME);
+ }
+}
+
+template <typename T>
+createFunction_t ExtensionsLoader<T>::loadCreateFunction(const char *createFunctionName) {
+ loadLib();
+ if (!mLibHandle) {
+ return NULL;
+ }
+ createFunction_t func = (createFunction_t)dlsym(mLibHandle, createFunctionName);
+ if (!func) {
+ ALOGW("symbol %s not found: %s",createFunctionName, dlerror());
+ }
+ return func;
+}
+
+//static
+template <typename T>
+void *ExtensionsLoader<T>::mLibHandle = NULL;
+
+} //namespace android