diff --git a/tv/tuner/aidl/default/Demux.cpp b/tv/tuner/aidl/default/Demux.cpp
index 60fd899..11e7131 100644
--- a/tv/tuner/aidl/default/Demux.cpp
+++ b/tv/tuner/aidl/default/Demux.cpp
@@ -31,8 +31,12 @@
 
 #define WAIT_TIMEOUT 3000000000
 
-Demux::Demux(int32_t demuxId, std::shared_ptr<Tuner> tuner) {
+Demux::Demux(int32_t demuxId, uint32_t filterTypes) {
     mDemuxId = demuxId;
+    mFilterTypes = filterTypes;
+}
+
+void Demux::setTunerService(std::shared_ptr<Tuner> tuner) {
     mTuner = tuner;
 }
 
@@ -346,6 +350,22 @@
     return mFilters[filterId]->getTpid();
 }
 
+int32_t Demux::getDemuxId() {
+    return mDemuxId;
+}
+
+bool Demux::isInUse() {
+    return mInUse;
+}
+
+void Demux::setInUse(bool inUse) {
+    mInUse = inUse;
+}
+
+void Demux::getDemuxInfo(DemuxInfo* demuxInfo) {
+    *demuxInfo = {.filterTypes = mFilterTypes};
+}
+
 void Demux::startFrontendInputLoop() {
     ALOGD("[Demux] start frontend on demux");
     // Stop current Frontend thread loop first, in case the user starts a new
diff --git a/tv/tuner/aidl/default/Demux.h b/tv/tuner/aidl/default/Demux.h
index 7f0b0a7..7d7aee4 100644
--- a/tv/tuner/aidl/default/Demux.h
+++ b/tv/tuner/aidl/default/Demux.h
@@ -53,7 +53,7 @@
 
 class Demux : public BnDemux {
   public:
-    Demux(int32_t demuxId, std::shared_ptr<Tuner> tuner);
+    Demux(int32_t demuxId, uint32_t filterTypes);
     ~Demux();
 
     ::ndk::ScopedAStatus setFrontendDataSource(int32_t in_frontendId) override;
@@ -98,6 +98,12 @@
     void sendFrontendInputToRecord(vector<int8_t> data, uint16_t pid, uint64_t pts);
     bool startRecordFilterDispatcher();
 
+    void getDemuxInfo(DemuxInfo* demuxInfo);
+    int32_t getDemuxId();
+    bool isInUse();
+    void setInUse(bool inUse);
+    void setTunerService(std::shared_ptr<Tuner> tuner);
+
   private:
     // Tuner service
     std::shared_ptr<Tuner> mTuner;
@@ -183,6 +189,9 @@
     vector<uint8_t> mPesOutput;
 
     const bool DEBUG_DEMUX = false;
+
+    int32_t mFilterTypes;
+    bool mInUse = false;
 };
 
 }  // namespace tuner
diff --git a/tv/tuner/aidl/default/Tuner.cpp b/tv/tuner/aidl/default/Tuner.cpp
index 8c715a0..0c1ae2d 100644
--- a/tv/tuner/aidl/default/Tuner.cpp
+++ b/tv/tuner/aidl/default/Tuner.cpp
@@ -17,6 +17,7 @@
 //#define LOG_NDEBUG 0
 #define LOG_TAG "android.hardware.tv.tuner-service.example-Tuner"
 
+#include <aidl/android/hardware/tv/tuner/DemuxFilterMainType.h>
 #include <aidl/android/hardware/tv/tuner/Result.h>
 #include <utils/Log.h>
 
@@ -60,6 +61,16 @@
     mMaxUsableFrontends[FrontendType::ISDBS3] = 1;
     mMaxUsableFrontends[FrontendType::DTMB] = 1;
 
+    mDemuxes[0] =
+            ndk::SharedRefBase::make<Demux>(0, (static_cast<int32_t>(DemuxFilterMainType::TS) |
+                                                static_cast<int32_t>(DemuxFilterMainType::MMTP) |
+                                                static_cast<int32_t>(DemuxFilterMainType::TLV)));
+    mDemuxes[1] =
+            ndk::SharedRefBase::make<Demux>(1, (static_cast<int32_t>(DemuxFilterMainType::MMTP) |
+                                                static_cast<int32_t>(DemuxFilterMainType::TLV)));
+    mDemuxes[2] = ndk::SharedRefBase::make<Demux>(2, static_cast<int32_t>(DemuxFilterMainType::IP));
+    mDemuxes[3] = ndk::SharedRefBase::make<Demux>(3, static_cast<int32_t>(DemuxFilterMainType::TS));
+
     mLnbs.resize(2);
     mLnbs[0] = ndk::SharedRefBase::make<Lnb>(0);
     mLnbs[1] = ndk::SharedRefBase::make<Lnb>(1);
@@ -78,6 +89,28 @@
     return ::ndk::ScopedAStatus::ok();
 }
 
+::ndk::ScopedAStatus Tuner::getDemuxInfo(int32_t in_demuxId, DemuxInfo* _aidl_return) {
+    if (mDemuxes.find(in_demuxId) == mDemuxes.end()) {
+        return ::ndk::ScopedAStatus::fromServiceSpecificError(
+                static_cast<int32_t>(Result::INVALID_ARGUMENT));
+    } else {
+        mDemuxes[in_demuxId]->getDemuxInfo(_aidl_return);
+        return ::ndk::ScopedAStatus::ok();
+    }
+}
+
+::ndk::ScopedAStatus Tuner::getDemuxIds(std::vector<int32_t>* _aidl_return) {
+    ALOGV("%s", __FUNCTION__);
+
+    int numOfDemuxes = mDemuxes.size();
+    _aidl_return->resize(numOfDemuxes);
+    int i = 0;
+    for (auto e = mDemuxes.begin(); e != mDemuxes.end(); e++) {
+        (*_aidl_return)[i++] = e->first;
+    }
+    return ::ndk::ScopedAStatus::ok();
+}
+
 ::ndk::ScopedAStatus Tuner::openFrontendById(int32_t in_frontendId,
                                              std::shared_ptr<IFrontend>* _aidl_return) {
     ALOGV("%s", __FUNCTION__);
@@ -94,17 +127,49 @@
     return ::ndk::ScopedAStatus::ok();
 }
 
+::ndk::ScopedAStatus Tuner::openDemuxById(int32_t in_demuxId,
+                                          std::shared_ptr<IDemux>* _aidl_return) {
+    ALOGV("%s", __FUNCTION__);
+
+    if (mDemuxes.find(in_demuxId) == mDemuxes.end()) {
+        ALOGW("[   WARN   ] Demux with id %d isn't available", in_demuxId);
+        *_aidl_return = nullptr;
+        return ::ndk::ScopedAStatus::fromServiceSpecificError(
+                static_cast<int32_t>(Result::INVALID_ARGUMENT));
+    }
+
+    if (mDemuxes[in_demuxId]->isInUse()) {
+        return ::ndk::ScopedAStatus::fromServiceSpecificError(
+                static_cast<int32_t>(Result::UNAVAILABLE));
+    } else {
+        mDemuxes[in_demuxId]->setTunerService(this->ref<Tuner>());
+        mDemuxes[in_demuxId]->setInUse(true);
+
+        *_aidl_return = mDemuxes[in_demuxId];
+        return ::ndk::ScopedAStatus::ok();
+    }
+}
+
 ::ndk::ScopedAStatus Tuner::openDemux(std::vector<int32_t>* out_demuxId,
                                       std::shared_ptr<IDemux>* _aidl_return) {
     ALOGV("%s", __FUNCTION__);
 
-    mLastUsedId += 1;
-    mDemuxes[mLastUsedId] = ndk::SharedRefBase::make<Demux>(mLastUsedId, this->ref<Tuner>());
+    bool found = false;
+    int32_t demuxId = 0;
+    for (auto e = mDemuxes.begin(); e != mDemuxes.end(); e++) {
+        if (!e->second->isInUse()) {
+            found = true;
+            demuxId = e->second->getDemuxId();
+        }
+    }
 
-    out_demuxId->push_back(mLastUsedId);
-    *_aidl_return = mDemuxes[mLastUsedId];
-
-    return ::ndk::ScopedAStatus::ok();
+    if (found) {
+        out_demuxId->push_back(demuxId);
+        return openDemuxById(demuxId, _aidl_return);
+    } else {
+        return ::ndk::ScopedAStatus::fromServiceSpecificError(
+                static_cast<int32_t>(Result::UNAVAILABLE));
+    }
 }
 
 ::ndk::ScopedAStatus Tuner::getDemuxCaps(DemuxCapabilities* _aidl_return) {
@@ -115,6 +180,18 @@
     // Support time filter testing
     _aidl_return->bTimeFilter = true;
 
+    // set filterCaps as the bitwize OR of all the demux' caps
+    std::vector<int32_t> demuxIds;
+    getDemuxIds(&demuxIds);
+    int32_t filterCaps = 0;
+
+    for (int i = 0; i < demuxIds.size(); i++) {
+        DemuxInfo demuxInfo;
+        getDemuxInfo(demuxIds[i], &demuxInfo);
+        filterCaps |= demuxInfo.filterTypes;
+    }
+    _aidl_return->filterCaps = filterCaps;
+
     return ::ndk::ScopedAStatus::ok();
 }
 
@@ -250,13 +327,13 @@
             break;
         }
     }
-    mDemuxes.erase(demuxId);
+    mDemuxes[demuxId]->setInUse(false);
 }
 
 void Tuner::removeFrontend(int32_t frontendId) {
     map<int32_t, int32_t>::iterator it = mFrontendToDemux.find(frontendId);
     if (it != mFrontendToDemux.end()) {
-        mDemuxes.erase(it->second);
+        mDemuxes[it->second]->setInUse(false);
     }
     mFrontendToDemux.erase(frontendId);
 }
diff --git a/tv/tuner/aidl/default/Tuner.h b/tv/tuner/aidl/default/Tuner.h
index a77c930..2656933 100644
--- a/tv/tuner/aidl/default/Tuner.h
+++ b/tv/tuner/aidl/default/Tuner.h
@@ -46,7 +46,11 @@
                                           std::shared_ptr<IFrontend>* _aidl_return) override;
     ::ndk::ScopedAStatus openDemux(std::vector<int32_t>* out_demuxId,
                                    std::shared_ptr<IDemux>* _aidl_return) override;
+    ::ndk::ScopedAStatus openDemuxById(int32_t in_demuxId,
+                                       std::shared_ptr<IDemux>* _aidl_return) override;
     ::ndk::ScopedAStatus getDemuxCaps(DemuxCapabilities* _aidl_return) override;
+    ::ndk::ScopedAStatus getDemuxInfo(int32_t in_demuxId, DemuxInfo* _aidl_return) override;
+    ::ndk::ScopedAStatus getDemuxIds(std::vector<int32_t>* _aidl_return) override;
     ::ndk::ScopedAStatus openDescrambler(std::shared_ptr<IDescrambler>* _aidl_return) override;
     ::ndk::ScopedAStatus getFrontendInfo(int32_t in_frontendId,
                                          FrontendInfo* _aidl_return) override;
@@ -77,12 +81,10 @@
     // Static mFrontends array to maintain local frontends information
     map<int32_t, std::shared_ptr<Frontend>> mFrontends;
     map<int32_t, int32_t> mFrontendToDemux;
-    map<int32_t, std::shared_ptr<Demux>> mDemuxes;
+    map<int32_t, std::shared_ptr<Demux>> mDemuxes;  // use demuxId as the key in
+                                                    // this sample implementation
     // To maintain how many Frontends we have
     int mFrontendSize;
-    // The last used demux id. Initial value is -1.
-    // First used id will be 0.
-    int32_t mLastUsedId = -1;
     vector<std::shared_ptr<Lnb>> mLnbs;
     map<FrontendType, int32_t> mMaxUsableFrontends;
 };