diff --git a/services/audioflinger/AudioStreamInSource.h b/services/audioflinger/AudioStreamInSource.h
new file mode 100644
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+++ b/services/audioflinger/AudioStreamInSource.h
@@ -0,0 +1,65 @@
+/*
+ * Copyright (C) 2012 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.
+ */
+
+#ifndef ANDROID_AUDIO_STREAM_IN_SOURCE_H
+#define ANDROID_AUDIO_STREAM_IN_SOURCE_H
+
+#include <hardware/audio.h>
+#include "NBAIO.h"
+
+namespace android {
+
+// not multi-thread safe
+class AudioStreamInSource : public NBAIO_Source {
+
+public:
+    AudioStreamInSource(audio_stream_in *stream);
+    virtual ~AudioStreamInSource();
+
+    // NBAIO_Port interface
+
+    virtual ssize_t negotiate(const NBAIO_Format offers[], size_t numOffers,
+                              NBAIO_Format counterOffers[], size_t& numCounterOffers);
+    //virtual NBAIO_Format format() const;
+
+    // NBAIO_Sink interface
+
+    //virtual size_t framesRead() const;
+    virtual size_t framesOverrun();
+    virtual size_t overruns() { (void) framesOverrun(); return mOverruns; }
+
+    // This is an over-estimate, and could dupe the caller into making a blocking read()
+    // FIXME Use an audio HAL API to query the buffer filling status when it's available.
+    virtual ssize_t availableToRead() { return mStreamBufferSizeBytes >> mBitShift; }
+
+    virtual ssize_t read(void *buffer, size_t count);
+
+    // NBAIO_Sink end
+
+#if 0   // until necessary
+    audio_stream_in *stream() const { return mStream; }
+#endif
+
+private:
+    audio_stream_in * const mStream;
+    size_t              mStreamBufferSizeBytes; // as reported by get_buffer_size()
+    size_t              mFramesOverrun;
+    size_t              mOverruns;
+};
+
+}   // namespace android
+
+#endif  // ANDROID_AUDIO_STREAM_IN_SOURCE_H