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/preemptive_expand.cc b/webrtc/modules/audio_coding/neteq/preemptive_expand.cc
new file mode 100644
index 0000000..b2dc3e6
--- /dev/null
+++ b/webrtc/modules/audio_coding/neteq/preemptive_expand.cc
@@ -0,0 +1,110 @@
+/*
+ * 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.
+ */
+
+#include "webrtc/modules/audio_coding/neteq/preemptive_expand.h"
+
+#include <algorithm> // min, max
+
+#include "webrtc/common_audio/signal_processing/include/signal_processing_library.h"
+
+namespace webrtc {
+
+PreemptiveExpand::ReturnCodes PreemptiveExpand::Process(
+ const int16_t* input,
+ int input_length,
+ int old_data_length,
+ AudioMultiVector* output,
+ int16_t* length_change_samples) {
+ old_data_length_per_channel_ = old_data_length;
+ // Input length must be (almost) 30 ms.
+ // Also, the new part must be at least |overlap_samples_| elements.
+ static const int k15ms = 120; // 15 ms = 120 samples at 8 kHz sample rate.
+ if (num_channels_ == 0 ||
+ input_length / num_channels_ < (2 * k15ms - 1) * fs_mult_ ||
+ old_data_length >= input_length / num_channels_ - overlap_samples_) {
+ // Length of input data too short to do preemptive expand. Simply move all
+ // data from input to output.
+ output->PushBackInterleaved(input, input_length);
+ return kError;
+ }
+ return TimeStretch::Process(input, input_length, output,
+ length_change_samples);
+}
+
+void PreemptiveExpand::SetParametersForPassiveSpeech(size_t len,
+ int16_t* best_correlation,
+ int* peak_index) const {
+ // When the signal does not contain any active speech, the correlation does
+ // not matter. Simply set it to zero.
+ *best_correlation = 0;
+
+ // For low energy expansion, the new data can be less than 15 ms,
+ // but we must ensure that best_correlation is not larger than the length of
+ // the new data.
+ // but we must ensure that best_correlation is not larger than the new data.
+ *peak_index = std::min(*peak_index,
+ static_cast<int>(len - old_data_length_per_channel_));
+}
+
+PreemptiveExpand::ReturnCodes PreemptiveExpand::CheckCriteriaAndStretch(
+ const int16_t *input, size_t input_length, size_t peak_index,
+ int16_t best_correlation, bool active_speech,
+ AudioMultiVector* output) const {
+ // Pre-calculate common multiplication with |fs_mult_|.
+ // 120 corresponds to 15 ms.
+ int fs_mult_120 = fs_mult_ * 120;
+ assert(old_data_length_per_channel_ >= 0); // Make sure it's been set.
+ // Check for strong correlation (>0.9 in Q14) and at least 15 ms new data,
+ // or passive speech.
+ if (((best_correlation > kCorrelationThreshold) &&
+ (old_data_length_per_channel_ <= fs_mult_120)) ||
+ !active_speech) {
+ // Do accelerate operation by overlap add.
+
+ // Set length of the first part, not to be modified.
+ size_t unmodified_length = std::max(old_data_length_per_channel_,
+ fs_mult_120);
+ // Copy first part, including cross-fade region.
+ output->PushBackInterleaved(
+ input, (unmodified_length + peak_index) * num_channels_);
+ // Copy the last |peak_index| samples up to 15 ms to |temp_vector|.
+ AudioMultiVector temp_vector(num_channels_);
+ temp_vector.PushBackInterleaved(
+ &input[(unmodified_length - peak_index) * num_channels_],
+ peak_index * num_channels_);
+ // Cross-fade |temp_vector| onto the end of |output|.
+ output->CrossFade(temp_vector, peak_index);
+ // Copy the last unmodified part, 15 ms + pitch period until the end.
+ output->PushBackInterleaved(
+ &input[unmodified_length * num_channels_],
+ input_length - unmodified_length * num_channels_);
+
+ if (active_speech) {
+ return kSuccess;
+ } else {
+ return kSuccessLowEnergy;
+ }
+ } else {
+ // Accelerate not allowed. Simply move all data from decoded to outData.
+ output->PushBackInterleaved(input, input_length);
+ return kNoStretch;
+ }
+}
+
+PreemptiveExpand* PreemptiveExpandFactory::Create(
+ int sample_rate_hz,
+ size_t num_channels,
+ const BackgroundNoise& background_noise,
+ int overlap_samples) const {
+ return new PreemptiveExpand(
+ sample_rate_hz, num_channels, background_noise, overlap_samples);
+}
+
+} // namespace webrtc