Audio : Add remote submix stream implementation

Bug: 286914845
Test: atest VtsHalAudioCoreTargetTest
Change-Id: Ia477458193ade9068eaf56e953ab670fee53cc7d
diff --git a/audio/aidl/default/r_submix/SubmixRoute.h b/audio/aidl/default/r_submix/SubmixRoute.h
new file mode 100644
index 0000000..5f7ea75
--- /dev/null
+++ b/audio/aidl/default/r_submix/SubmixRoute.h
@@ -0,0 +1,138 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+
+#include <mutex>
+
+#include <audio_utils/clock.h>
+
+#include <media/nbaio/MonoPipe.h>
+#include <media/nbaio/MonoPipeReader.h>
+
+#include <aidl/android/media/audio/common/AudioChannelLayout.h>
+
+#include "core-impl/Stream.h"
+
+using aidl::android::media::audio::common::AudioChannelLayout;
+using aidl::android::media::audio::common::AudioFormatDescription;
+using aidl::android::media::audio::common::AudioFormatType;
+using aidl::android::media::audio::common::PcmType;
+using ::android::MonoPipe;
+using ::android::MonoPipeReader;
+using ::android::sp;
+
+namespace aidl::android::hardware::audio::core::r_submix {
+
+static constexpr int kDefaultSampleRateHz = 48000;
+// Size at default sample rate
+// NOTE: This value will be rounded up to the nearest power of 2 by MonoPipe().
+static constexpr int kDefaultPipeSizeInFrames = (1024 * 4);
+
+// Configuration of the audio stream.
+struct AudioConfig {
+    int sampleRate = kDefaultSampleRateHz;
+    AudioFormatDescription format =
+            AudioFormatDescription{.type = AudioFormatType::PCM, .pcm = PcmType::INT_16_BIT};
+    AudioChannelLayout channelLayout =
+            AudioChannelLayout::make<AudioChannelLayout::Tag::layoutMask>(
+                    AudioChannelLayout::LAYOUT_STEREO);
+    size_t frameSize;
+    size_t frameCount;
+};
+
+class SubmixRoute {
+  public:
+    AudioConfig mPipeConfig;
+
+    bool isStreamInOpen() {
+        std::lock_guard guard(mLock);
+        return mStreamInOpen;
+    }
+    bool getStreamInStandby() {
+        std::lock_guard guard(mLock);
+        return mStreamInStandby;
+    }
+    bool isStreamOutOpen() {
+        std::lock_guard guard(mLock);
+        return mStreamOutOpen;
+    }
+    bool getStreamOutStandby() {
+        std::lock_guard guard(mLock);
+        return mStreamOutStandby;
+    }
+    long getReadCounterFrames() {
+        std::lock_guard guard(mLock);
+        return mReadCounterFrames;
+    }
+    int getReadErrorCount() {
+        std::lock_guard guard(mLock);
+        return mReadErrorCount;
+    }
+    std::chrono::time_point<std::chrono::steady_clock> getRecordStartTime() {
+        std::lock_guard guard(mLock);
+        return mRecordStartTime;
+    }
+    sp<MonoPipe> getSink() {
+        std::lock_guard guard(mLock);
+        return mSink;
+    }
+    sp<MonoPipeReader> getSource() {
+        std::lock_guard guard(mLock);
+        return mSource;
+    }
+
+    bool isStreamConfigValid(bool isInput, const AudioConfig streamConfig);
+    void closeStream(bool isInput);
+    ::android::status_t createPipe(const AudioConfig streamConfig);
+    void exitStandby(bool isInput);
+    bool hasAtleastOneStreamOpen();
+    int notifyReadError();
+    void openStream(bool isInput);
+    void releasePipe();
+    ::android::status_t resetPipe();
+    bool shouldBlockWrite();
+    void standby(bool isInput);
+    long updateReadCounterFrames(size_t frameCount);
+
+  private:
+    bool isStreamConfigCompatible(const AudioConfig streamConfig);
+
+    std::mutex mLock;
+
+    bool mStreamInOpen GUARDED_BY(mLock) = false;
+    int mInputRefCount GUARDED_BY(mLock) = 0;
+    bool mStreamInStandby GUARDED_BY(mLock) = true;
+    bool mStreamOutStandbyTransition GUARDED_BY(mLock) = false;
+    bool mStreamOutOpen GUARDED_BY(mLock) = false;
+    bool mStreamOutStandby GUARDED_BY(mLock) = true;
+    // how many frames have been requested to be read since standby
+    long mReadCounterFrames GUARDED_BY(mLock) = 0;
+    int mReadErrorCount GUARDED_BY(mLock) = 0;
+    // wall clock when recording starts
+    std::chrono::time_point<std::chrono::steady_clock> mRecordStartTime GUARDED_BY(mLock);
+
+    // Pipe variables: they handle the ring buffer that "pipes" audio:
+    //  - from the submix virtual audio output == what needs to be played
+    //    remotely, seen as an output for the client
+    //  - to the virtual audio source == what is captured by the component
+    //    which "records" the submix / virtual audio source, and handles it as needed.
+    // A usecase example is one where the component capturing the audio is then sending it over
+    // Wifi for presentation on a remote Wifi Display device (e.g. a dongle attached to a TV, or a
+    // TV with Wifi Display capabilities), or to a wireless audio player.
+    sp<MonoPipe> mSink GUARDED_BY(mLock);
+    sp<MonoPipeReader> mSource GUARDED_BY(mLock);
+};
+
+}  // namespace aidl::android::hardware::audio::core::r_submix