Using ring buffer for AudioVector in NetEq.

webrtc/modules/audio_coding/neteq/normal.cc

Index: webrtc/modules/audio_coding/neteq/normal.cc
diff --git a/webrtc/modules/audio_coding/neteq/normal.cc b/webrtc/modules/audio_coding/neteq/normal.cc
index 4400afb3b01517f8b43441e762fc48c1522d9d16..f99b3f200f4ff4fe0c81f28421ec26bc7db1d612 100644
--- a/webrtc/modules/audio_coding/neteq/normal.cc
+++ b/webrtc/modules/audio_coding/neteq/normal.cc
@@ -42,7 +42,6 @@ int Normal::Process(const int16_t* input,
     return 0;
   }
   output->PushBackInterleaved(input, length);
-  int16_t* signal = &(*output)[0][0];
 
   const int fs_mult = fs_hz_ / 8000;
   assert(fs_mult > 0);
@@ -63,24 +62,26 @@ int Normal::Process(const int16_t* input,
     expand_->Process(&expanded);
     expand_->Reset();
 
+    size_t length_per_channel = length / output->Channels();
+    std::unique_ptr<int16_t[]> signal(new int16_t[length_per_channel]);
     for (size_t channel_ix = 0; channel_ix < output->Channels(); ++channel_ix) {
       // Adjust muting factor (main muting factor times expand muting factor).
       external_mute_factor_array[channel_ix] = static_cast<int16_t>(
           (external_mute_factor_array[channel_ix] *
           expand_->MuteFactor(channel_ix)) >> 14);
 
-      int16_t* signal = &(*output)[channel_ix][0];
-      size_t length_per_channel = length / output->Channels();
+      (*output)[channel_ix].CopyTo(length_per_channel, 0, signal.get());
+
       // Find largest absolute value in new data.
       int16_t decoded_max =
-          WebRtcSpl_MaxAbsValueW16(signal, length_per_channel);
+          WebRtcSpl_MaxAbsValueW16(signal.get(), length_per_channel);
       // Adjust muting factor if needed (to BGN level).
       size_t energy_length =
           std::min(static_cast<size_t>(fs_mult * 64), length_per_channel);
       int scaling = 6 + fs_shift
           - WebRtcSpl_NormW32(decoded_max * decoded_max);
       scaling = std::max(scaling, 0);  // |scaling| should always be >= 0.
-      int32_t energy = WebRtcSpl_DotProductWithScale(signal, signal,
+      int32_t energy = WebRtcSpl_DotProductWithScale(signal.get(), signal.get(),
                                                      energy_length, scaling);
       int32_t scaled_energy_length =
           static_cast<int32_t>(energy_length >> scaling);
@@ -159,7 +160,7 @@ int Normal::Process(const int16_t* input,
     } else {
       // If no CNG instance is defined, just copy from the decoded data.
       // (This will result in interpolating the decoded with itself.)
-      memcpy(cng_output, signal, fs_mult * 8 * sizeof(int16_t));
+      (*output)[0].CopyTo(fs_mult * 8, 0, cng_output);
     }
     // Interpolate the CNG into the new vector.
     // (NB/WB/SWB32/SWB48 8/16/32/48 samples.)
@@ -169,8 +170,8 @@ int Normal::Process(const int16_t* input,
     for (size_t i = 0; i < static_cast<size_t>(8 * fs_mult); i++) {
       // TODO(hlundin): Add 16 instead of 8 for correct rounding. Keeping 8 now
       // for legacy bit-exactness.
-      signal[i] =
-          (fraction * signal[i] + (32 - fraction) * cng_output[i] + 8) >> 5;
+      (*output)[0][i] = (fraction * (*output)[0][i] +
+          (32 - fraction) * cng_output[i] + 8) >> 5;
       fraction += increment;
     }
   } else if (external_mute_factor_array[0] < 16384) {