diff --git a/drm/libmediadrm/DescramblerImpl.cpp b/drm/libmediadrm/DescramblerImpl.cpp
new file mode 100644
index 0000000..94e09e2
--- /dev/null
+++ b/drm/libmediadrm/DescramblerImpl.cpp
@@ -0,0 +1,107 @@
+
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+//#define LOG_NDEBUG 0
+#define LOG_TAG "DescramblerImpl"
+
+#include <media/cas/DescramblerAPI.h>
+#include <media/DescramblerImpl.h>
+#include <media/SharedLibrary.h>
+#include <utils/Log.h>
+#include <binder/IMemory.h>
+
+namespace android {
+
+static Status getBinderStatus(status_t err) {
+    if (err == OK) {
+        return Status::ok();
+    }
+    if (err == BAD_VALUE) {
+        return Status::fromExceptionCode(Status::EX_ILLEGAL_ARGUMENT);
+    }
+    if (err == INVALID_OPERATION) {
+        return Status::fromExceptionCode(Status::EX_ILLEGAL_STATE);
+    }
+    return Status::fromServiceSpecificError(err);
+}
+
+static String8 sessionIdToString(const CasSessionId &sessionId) {
+    String8 result;
+    for (size_t i = 0; i < sessionId.size(); i++) {
+        result.appendFormat("%02x ", sessionId[i]);
+    }
+    if (result.isEmpty()) {
+        result.append("(null)");
+    }
+    return result;
+}
+
+DescramblerImpl::DescramblerImpl(
+        const sp<SharedLibrary>& library, DescramblerPlugin *plugin) :
+        mLibrary(library), mPlugin(plugin) {
+    ALOGV("CTOR: mPlugin=%p", mPlugin);
+}
+
+DescramblerImpl::~DescramblerImpl() {
+    ALOGV("DTOR: mPlugin=%p", mPlugin);
+    release();
+}
+
+Status DescramblerImpl::setMediaCasSession(const CasSessionId& sessionId) {
+    ALOGV("setMediaCasSession: sessionId=%s",
+            sessionIdToString(sessionId).string());
+
+    return getBinderStatus(mPlugin->setMediaCasSession(sessionId));
+}
+
+Status DescramblerImpl::requiresSecureDecoderComponent(
+        const String16& mime, bool *result) {
+    *result = mPlugin->requiresSecureDecoderComponent(String8(mime));
+
+    return getBinderStatus(OK);
+}
+
+Status DescramblerImpl::descramble(
+        const DescrambleInfo& info, int32_t *result) {
+    ALOGV("descramble");
+
+    *result = mPlugin->descramble(
+            info.dstType != DescrambleInfo::kDestinationTypeVmPointer,
+            info.scramblingControl,
+            info.numSubSamples,
+            info.subSamples,
+            info.srcMem->pointer(),
+            info.srcOffset,
+            info.dstType == DescrambleInfo::kDestinationTypeVmPointer ?
+                    info.srcMem->pointer() : info.dstPtr,
+            info.dstOffset,
+            NULL);
+
+    return getBinderStatus(*result >= 0 ? OK : *result);
+}
+
+Status DescramblerImpl::release() {
+    ALOGV("release: mPlugin=%p", mPlugin);
+
+    if (mPlugin != NULL) {
+        delete mPlugin;
+        mPlugin = NULL;
+    }
+    return Status::ok();
+}
+
+} // namespace android
+