Move dead submodules in-tree

Signed-off-by: swurl <swurl@swurl.xyz>

externals/oboe/tests/testResampler.cpp

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+/*
+ * Copyright 2022 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.
+ */
+
+/*
+ * Test FlowGraph
+ */
+
+#include "math.h"
+#include "stdio.h"
+
+#include <gtest/gtest.h>
+#include <oboe/Oboe.h>
+
+#include "flowgraph/resampler/MultiChannelResampler.h"
+
+using namespace oboe::resampler;
+
+// Measure zero crossings.
+static int32_t countZeroCrossingsWithHysteresis(float *input, int32_t numSamples) {
+    const float kHysteresisLevel = 0.25f;
+    int zeroCrossingCount = 0;
+    int state = 0; // can be -1, 0, +1
+    for (int i = 0; i < numSamples; i++) {
+        if (input[i] >= kHysteresisLevel) {
+            if (state < 0) {
+                zeroCrossingCount++;
+            }
+            state = 1;
+        } else if (input[i] <= -kHysteresisLevel) {
+            if (state > 0) {
+                zeroCrossingCount++;
+            }
+            state = -1;
+        }
+    }
+    return zeroCrossingCount;
+}
+
+static constexpr int kChannelCount = 1;
+
+/**
+ * Convert a sine wave and then look for glitches.
+ * Glitches have a high value in the second derivative.
+ */
+static void checkResampler(int32_t sourceRate, int32_t sinkRate,
+        MultiChannelResampler::Quality quality) {
+    const int kNumOutputSamples = 10000;
+    const double framesPerCycle = 81.379; // target output period
+
+    int numInputSamples = kNumOutputSamples * sourceRate / sinkRate;
+
+    std::unique_ptr<float[]>  inputBuffer = std::make_unique<float[]>(numInputSamples);
+    std::unique_ptr<float[]>  outputBuffer = std::make_unique<float[]>(kNumOutputSamples);
+
+    // Generate a sine wave for input.
+    const double kPhaseIncrement = 2.0 * sinkRate / (framesPerCycle * sourceRate);
+    double phase = 0.0;
+    for (int i = 0; i < numInputSamples; i++) {
+        inputBuffer[i] = sin(phase * M_PI);
+        phase += kPhaseIncrement;
+        while (phase > 1.0) {
+            phase -= 2.0;
+        }
+    }
+    int sourceZeroCrossingCount = countZeroCrossingsWithHysteresis(inputBuffer.get(), numInputSamples);
+
+    // Use a MultiChannelResampler to convert from the sourceRate to the sinkRate.
+    std::unique_ptr<MultiChannelResampler>  mcResampler;
+    mcResampler.reset(MultiChannelResampler::make(kChannelCount,
+                                                 sourceRate,
+                                                 sinkRate,
+                                                 quality));
+    int inputFramesLeft = numInputSamples;
+    int numRead = 0;
+    float *input = inputBuffer.get(); // for iteration
+    float *output = outputBuffer.get();
+    while (inputFramesLeft > 0) {
+        if (mcResampler->isWriteNeeded()) {
+            mcResampler->writeNextFrame(input);
+            input++;
+            inputFramesLeft--;
+        } else {
+            mcResampler->readNextFrame(output);
+            output++;
+            numRead++;
+        }
+    }
+
+    // Flush out remaining frames from the flowgraph
+    while (!mcResampler->isWriteNeeded()) {
+        mcResampler->readNextFrame(output);
+        output++;
+        numRead++;
+    }
+
+    ASSERT_LE(numRead, kNumOutputSamples);
+    // Some frames are lost priming the FIR filter.
+    const int kMaxAlgorithmicFrameLoss = 5;
+    EXPECT_GT(numRead, kNumOutputSamples - kMaxAlgorithmicFrameLoss);
+
+    int sinkZeroCrossingCount = countZeroCrossingsWithHysteresis(outputBuffer.get(), numRead);
+    // The sine wave may be cut off partially. This may cause multiple crossing
+    // differences when upsampling.
+    const int kMaxZeroCrossingDelta = std::max(sinkRate / sourceRate / 2, 1);
+    EXPECT_LE(abs(sourceZeroCrossingCount - sinkZeroCrossingCount), kMaxZeroCrossingDelta);
+
+    // Detect glitches by looking for spikes in the second derivative.
+    output = outputBuffer.get();
+    float previousValue = output[0];
+    float previousSlope = output[1] - output[0];
+    for (int i = 0; i < numRead; i++) {
+        float slope = output[i] - previousValue;
+        float slopeDelta = fabs(slope - previousSlope);
+        // Skip a few samples because there are often some steep slope changes at the beginning.
+        if (i > 10) {
+            EXPECT_LT(slopeDelta, 0.1);
+        }
+        previousValue = output[i];
+        previousSlope = slope;
+    }
+
+#if 0
+    // Save to disk for inspection.
+    FILE *fp = fopen( "/sdcard/Download/src_float_out.raw" , "wb" );
+    fwrite(outputBuffer.get(), sizeof(float), numRead, fp );
+    fclose(fp);
+#endif
+}
+
+
+TEST(test_resampler, resampler_scan_all) {
+    const int rates[] = {8000, 11025, 22050, 32000, 44100, 48000, 64000, 88200, 96000};
+    const MultiChannelResampler::Quality qualities[] =
+    {
+        MultiChannelResampler::Quality::Fastest,
+        MultiChannelResampler::Quality::Low,
+        MultiChannelResampler::Quality::Medium,
+        MultiChannelResampler::Quality::High,
+        MultiChannelResampler::Quality::Best
+    };
+    for (int srcRate : rates) {
+        for (int destRate : rates) {
+            for (auto quality : qualities) {
+                if (srcRate != destRate) {
+                    checkResampler(srcRate, destRate, quality);
+                }
+            }
+        }
+    }
+}
+
+TEST(test_resampler, resampler_8000_11025_best) {
+    checkResampler(8000, 11025, MultiChannelResampler::Quality::Best);
+}
+TEST(test_resampler, resampler_8000_48000_best) {
+    checkResampler(8000, 48000, MultiChannelResampler::Quality::Best);
+}
+
+TEST(test_resampler, resampler_8000_44100_best) {
+    checkResampler(8000, 44100, MultiChannelResampler::Quality::Best);
+}
+
+TEST(test_resampler, resampler_11025_24000_best) {
+    checkResampler(11025, 24000, MultiChannelResampler::Quality::Best);
+}
+
+TEST(test_resampler, resampler_11025_48000_fastest) {
+    checkResampler(11025, 48000, MultiChannelResampler::Quality::Fastest);
+}
+TEST(test_resampler, resampler_11025_48000_low) {
+    checkResampler(11025, 48000, MultiChannelResampler::Quality::Low);
+}
+TEST(test_resampler, resampler_11025_48000_medium) {
+    checkResampler(11025, 48000, MultiChannelResampler::Quality::Medium);
+}
+TEST(test_resampler, resampler_11025_48000_high) {
+    checkResampler(11025, 48000, MultiChannelResampler::Quality::High);
+}
+
+TEST(test_resampler, resampler_11025_48000_best) {
+    checkResampler(11025, 48000, MultiChannelResampler::Quality::Best);
+}
+
+TEST(test_resampler, resampler_11025_44100_best) {
+    checkResampler(11025, 44100, MultiChannelResampler::Quality::Best);
+}
+
+TEST(test_resampler, resampler_11025_88200_best) {
+   checkResampler(11025, 88200, MultiChannelResampler::Quality::Best);
+}
+
+TEST(test_resampler, resampler_16000_48000_best) {
+    checkResampler(16000, 48000, MultiChannelResampler::Quality::Best);
+}
+
+TEST(test_resampler, resampler_44100_48000_low) {
+    checkResampler(44100, 48000, MultiChannelResampler::Quality::Low);
+}
+TEST(test_resampler, resampler_44100_48000_best) {
+    checkResampler(44100, 48000, MultiChannelResampler::Quality::Best);
+}
+
+// Look for glitches when downsampling.
+TEST(test_resampler, resampler_48000_11025_best) {
+    checkResampler(48000, 11025, MultiChannelResampler::Quality::Best);
+}
+TEST(test_resampler, resampler_48000_44100_best) {
+    checkResampler(48000, 44100, MultiChannelResampler::Quality::Best);
+}
+TEST(test_resampler, resampler_44100_11025_best) {
+    checkResampler(44100, 11025, MultiChannelResampler::Quality::Best);
+}