RTP: Add a baseline echo suppressor.

Change-Id: I832f1f572f141fd928afe671b12d0b59f2a8e0b1

1 files changed, 51 insertions, 0 deletions

diff --git a/voip/jni/rtp/EchoSuppressor.h b/voip/jni/rtp/EchoSuppressor.h
new file mode 100644
index 0000000..85decf5
--- /dev/null
+++ b/voip/jni/rtp/EchoSuppressor.h
@@ -0,0 +1,51 @@
+/*
+ * Copyrightm (C) 2010 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 __ECHO_SUPPRESSOR_H__
+#define __ECHO_SUPPRESSOR_H__
+
+#include <stdint.h>
+
+class EchoSuppressor
+{
+public:
+    // The sampleCount must be power of 2.
+    EchoSuppressor(int sampleRate, int sampleCount, int tailLength);
+    ~EchoSuppressor();
+    void run(int16_t *playbacked, int16_t *recorded);
+
+private:
+    int mScale;
+    int mSampleCount;
+    int mWindowSize;
+    int mTailLength;
+    int mRecordLength;
+    int mRecordOffset;
+
+    float *mXs;
+    float *mXYs;
+    float *mXXs;
+    float mYY;
+
+    float *mXYRecords;
+    float *mXXRecords;
+    float *mYYRecords;
+
+    float mLastX;
+    float mLastY;
+};
+
+#endif