Rename neteq4 folder to neteq

Keep the old neteq4/audio_decoder_unittests.isolate while waiting for
a hard-coded reference to change.

This CL effectively reverts r6257 "Rename neteq4 folder to neteq".

BUG=2996
TBR=tina.legrand@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/21629004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@6367 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/modules/audio_coding/neteq/accelerate.h b/webrtc/modules/audio_coding/neteq/accelerate.h
new file mode 100644
index 0000000..2da9993
--- /dev/null
+++ b/webrtc/modules/audio_coding/neteq/accelerate.h
@@ -0,0 +1,77 @@
+/*
+ *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_MODULES_AUDIO_CODING_NETEQ_ACCELERATE_H_
+#define WEBRTC_MODULES_AUDIO_CODING_NETEQ_ACCELERATE_H_
+
+#include <assert.h>
+
+#include "webrtc/base/constructormagic.h"
+#include "webrtc/modules/audio_coding/neteq/audio_multi_vector.h"
+#include "webrtc/modules/audio_coding/neteq/time_stretch.h"
+#include "webrtc/typedefs.h"
+
+namespace webrtc {
+
+// Forward declarations.
+class BackgroundNoise;
+
+// This class implements the Accelerate operation. Most of the work is done
+// in the base class TimeStretch, which is shared with the PreemptiveExpand
+// operation. In the Accelerate class, the operations that are specific to
+// Accelerate are implemented.
+class Accelerate : public TimeStretch {
+ public:
+  Accelerate(int sample_rate_hz, size_t num_channels,
+             const BackgroundNoise& background_noise)
+      : TimeStretch(sample_rate_hz, num_channels, background_noise) {
+  }
+
+  virtual ~Accelerate() {}
+
+  // This method performs the actual Accelerate operation. The samples are
+  // read from |input|, of length |input_length| elements, and are written to
+  // |output|. The number of samples removed through time-stretching is
+  // is provided in the output |length_change_samples|. The method returns
+  // the outcome of the operation as an enumerator value.
+  ReturnCodes Process(const int16_t* input,
+                      size_t input_length,
+                      AudioMultiVector* output,
+                      int16_t* length_change_samples);
+
+ protected:
+  // Sets the parameters |best_correlation| and |peak_index| to suitable
+  // values when the signal contains no active speech.
+  virtual void SetParametersForPassiveSpeech(size_t len,
+                                             int16_t* best_correlation,
+                                             int* peak_index) const OVERRIDE;
+
+  // Checks the criteria for performing the time-stretching operation and,
+  // if possible, performs the time-stretching.
+  virtual ReturnCodes CheckCriteriaAndStretch(
+      const int16_t* input, size_t input_length, size_t peak_index,
+      int16_t best_correlation, bool active_speech,
+      AudioMultiVector* output) const OVERRIDE;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(Accelerate);
+};
+
+struct AccelerateFactory {
+  AccelerateFactory() {}
+  virtual ~AccelerateFactory() {}
+
+  virtual Accelerate* Create(int sample_rate_hz,
+                             size_t num_channels,
+                             const BackgroundNoise& background_noise) const;
+};
+
+}  // namespace webrtc
+#endif  // WEBRTC_MODULES_AUDIO_CODING_NETEQ_ACCELERATE_H_