1 files changed, 42 insertions, 0 deletions
diff --git a/externals/oboe/src/flowgraph/resampler/LinearResampler.cpp b/externals/oboe/src/flowgraph/resampler/LinearResampler.cpp
new file mode 100644
index 0000000000..cb4932a5f8
--- /dev/null
+++ b/externals/oboe/src/flowgraph/resampler/LinearResampler.cpp
@@ -0,0 +1,42 @@
+/*
+ * Copyright 2019 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.
+ */
+
+#include "LinearResampler.h"
+
+using namespace RESAMPLER_OUTER_NAMESPACE::resampler;
+
+LinearResampler::LinearResampler(const MultiChannelResampler::Builder &builder)
+        : MultiChannelResampler(builder) {
+    mPreviousFrame = std::make_unique<float[]>(getChannelCount());
+    mCurrentFrame = std::make_unique<float[]>(getChannelCount());
+}
+
+void LinearResampler::writeFrame(const float *frame) {
+    memcpy(mPreviousFrame.get(), mCurrentFrame.get(), sizeof(float) * getChannelCount());
+    memcpy(mCurrentFrame.get(), frame, sizeof(float) * getChannelCount());
+}
+
+void LinearResampler::readFrame(float *frame) {
+    float *previous = mPreviousFrame.get();
+    float *current = mCurrentFrame.get();
+    float phase = (float) getIntegerPhase() / mDenominator;
+    // iterate across samples in the frame
+    for (int channel = 0; channel < getChannelCount(); channel++) {
+        float f0 = *previous++;
+        float f1 = *current++;
+        *frame++ = f0 + (phase * (f1 - f0));
+    }
+}