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

webrtc/modules/audio_coding/neteq/expand.h

@@ -0,0 +1,187 @@
+/*
+ *  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_EXPAND_H_
+#define WEBRTC_MODULES_AUDIO_CODING_NETEQ_EXPAND_H_
+
+#include <assert.h>
+
+#include "webrtc/base/constructormagic.h"
+#include "webrtc/modules/audio_coding/neteq/audio_multi_vector.h"
+#include "webrtc/system_wrappers/interface/scoped_ptr.h"
+#include "webrtc/typedefs.h"
+
+namespace webrtc {
+
+// Forward declarations.
+class BackgroundNoise;
+class RandomVector;
+class SyncBuffer;
+
+// This class handles extrapolation of audio data from the sync_buffer to
+// produce packet-loss concealment.
+// TODO(hlundin): Refactor this class to divide the long methods into shorter
+// ones.
+class Expand {
+ public:
+  Expand(BackgroundNoise* background_noise,
+         SyncBuffer* sync_buffer,
+         RandomVector* random_vector,
+         int fs,
+         size_t num_channels)
+      : random_vector_(random_vector),
+        sync_buffer_(sync_buffer),
+        first_expand_(true),
+        fs_hz_(fs),
+        num_channels_(num_channels),
+        consecutive_expands_(0),
+        background_noise_(background_noise),
+        overlap_length_(5 * fs / 8000),
+        lag_index_direction_(0),
+        current_lag_index_(0),
+        stop_muting_(false),
+        channel_parameters_(new ChannelParameters[num_channels_]) {
+    assert(fs == 8000 || fs == 16000 || fs == 32000 || fs == 48000);
+    assert(fs <= kMaxSampleRate);  // Should not be possible.
+    assert(num_channels_ > 0);
+    memset(expand_lags_, 0, sizeof(expand_lags_));
+    Reset();
+  }
+
+  virtual ~Expand() {}
+
+  // Resets the object.
+  virtual void Reset();
+
+  // The main method to produce concealment data. The data is appended to the
+  // end of |output|.
+  virtual int Process(AudioMultiVector* output);
+
+  // Prepare the object to do extra expansion during normal operation following
+  // a period of expands.
+  virtual void SetParametersForNormalAfterExpand();
+
+  // Prepare the object to do extra expansion during merge operation following
+  // a period of expands.
+  virtual void SetParametersForMergeAfterExpand();
+
+  // Sets the mute factor for |channel| to |value|.
+  void SetMuteFactor(int16_t value, size_t channel) {
+    assert(channel < num_channels_);
+    channel_parameters_[channel].mute_factor = value;
+  }
+
+  // Returns the mute factor for |channel|.
+  int16_t MuteFactor(size_t channel) {
+    assert(channel < num_channels_);
+    return channel_parameters_[channel].mute_factor;
+  }
+
+  // Accessors and mutators.
+  virtual size_t overlap_length() const { return overlap_length_; }
+  int16_t max_lag() const { return max_lag_; }
+
+ protected:
+  static const int kMaxConsecutiveExpands = 200;
+  void GenerateRandomVector(int seed_increment,
+                            size_t length,
+                            int16_t* random_vector);
+
+  void GenerateBackgroundNoise(int16_t* random_vector,
+                               size_t channel,
+                               int16_t mute_slope,
+                               bool too_many_expands,
+                               size_t num_noise_samples,
+                               int16_t* buffer);
+
+  // Initializes member variables at the beginning of an expand period.
+  void InitializeForAnExpandPeriod();
+
+  bool TooManyExpands();
+
+  // Analyzes the signal history in |sync_buffer_|, and set up all parameters
+  // necessary to produce concealment data.
+  void AnalyzeSignal(int16_t* random_vector);
+
+  RandomVector* random_vector_;
+  SyncBuffer* sync_buffer_;
+  bool first_expand_;
+  const int fs_hz_;
+  const size_t num_channels_;
+  int consecutive_expands_;
+
+ private:
+  static const int kUnvoicedLpcOrder = 6;
+  static const int kNumCorrelationCandidates = 3;
+  static const int kDistortionLength = 20;
+  static const int kLpcAnalysisLength = 160;
+  static const int kMaxSampleRate = 48000;
+  static const int kNumLags = 3;
+
+  struct ChannelParameters {
+    // Constructor.
+    ChannelParameters()
+        : mute_factor(16384),
+          ar_gain(0),
+          ar_gain_scale(0),
+          voice_mix_factor(0),
+          current_voice_mix_factor(0),
+          onset(false),
+          mute_slope(0) {
+      memset(ar_filter, 0, sizeof(ar_filter));
+      memset(ar_filter_state, 0, sizeof(ar_filter_state));
+    }
+    int16_t mute_factor;
+    int16_t ar_filter[kUnvoicedLpcOrder + 1];
+    int16_t ar_filter_state[kUnvoicedLpcOrder];
+    int16_t ar_gain;
+    int16_t ar_gain_scale;
+    int16_t voice_mix_factor; /* Q14 */
+    int16_t current_voice_mix_factor; /* Q14 */
+    AudioVector expand_vector0;
+    AudioVector expand_vector1;
+    bool onset;
+    int16_t mute_slope; /* Q20 */
+  };
+
+  // Calculate the auto-correlation of |input|, with length |input_length|
+  // samples. The correlation is calculated from a downsampled version of
+  // |input|, and is written to |output|. The scale factor is written to
+  // |output_scale|. Returns the length of the correlation vector.
+  int16_t Correlation(const int16_t* input, size_t input_length,
+                      int16_t* output, int16_t* output_scale) const;
+
+  void UpdateLagIndex();
+
+  BackgroundNoise* background_noise_;
+  const size_t overlap_length_;
+  int16_t max_lag_;
+  size_t expand_lags_[kNumLags];
+  int lag_index_direction_;
+  int current_lag_index_;
+  bool stop_muting_;
+  scoped_ptr<ChannelParameters[]> channel_parameters_;
+
+  DISALLOW_COPY_AND_ASSIGN(Expand);
+};
+
+struct ExpandFactory {
+  ExpandFactory() {}
+  virtual ~ExpandFactory() {}
+
+  virtual Expand* Create(BackgroundNoise* background_noise,
+                         SyncBuffer* sync_buffer,
+                         RandomVector* random_vector,
+                         int fs,
+                         size_t num_channels) const;
+};
+
+}  // namespace webrtc
+#endif  // WEBRTC_MODULES_AUDIO_CODING_NETEQ_EXPAND_H_