original

[gb-231r1-is01/GB_2.3_IS01.git] / cts / apps / CtsVerifier / src / com / android / cts / verifier / audioquality / experiments / GainLinearityExperiment.java

diff --git a/cts/apps/CtsVerifier/src/com/android/cts/verifier/audioquality/experiments/GainLinearityExperiment.java b/cts/apps/CtsVerifier/src/com/android/cts/verifier/audioquality/experiments/GainLinearityExperiment.java
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+++ b/cts/apps/CtsVerifier/src/com/android/cts/verifier/audioquality/experiments/GainLinearityExperiment.java
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+/*
+ * Copyright (C) 2010 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.
+ */
+
+package com.android.cts.verifier.audioquality.experiments;
+
+import com.android.cts.verifier.R;
+import com.android.cts.verifier.audioquality.AudioQualityVerifierActivity;
+import com.android.cts.verifier.audioquality.Utils;
+
+import android.content.Context;
+
+/**
+ * Experiment to test the linearity of the microphone gain response.
+ *
+ * This plays a sequence of identical stimuli at increasing volumes and then
+ * analyzes the set of recordings.
+ */
+public class GainLinearityExperiment extends SequenceExperiment {
+    private static final int LEVELS = 4;
+    private static final float DB_STEP_SIZE = 10.0f;
+    private static final float TOLERANCE = 2.0f; // Maximum allowed deviation from linearity in dB
+    private static final int STIM_NUM = 31;
+
+    private short[] mReference = null;
+
+    public GainLinearityExperiment() {
+        super(true);
+    }
+
+    @Override
+    protected String lookupName(Context context) {
+        return context.getString(R.string.aq_linearity_exp);
+    }
+
+    @Override
+    protected int getTrials() {
+        return LEVELS;
+    }
+
+    @Override
+    protected byte[] getStim(Context context, int trial) {
+        float db = (trial - (LEVELS - 1)) * DB_STEP_SIZE;
+        if (mReference == null) {
+            mReference = Utils.byteToShortArray(Utils.getStim(context, STIM_NUM));
+        }
+        short[] samples = Utils.scale(mReference, db);
+        return Utils.shortToByteArray(samples);
+    }
+
+    @Override
+    protected void compare(byte[][] stim, byte[][] record) {
+        short[][] pcms = new short[LEVELS][];
+        for (int i = 0; i < LEVELS; i++) {
+            pcms[i] = Utils.byteToShortArray(record[i]);
+        }
+        // We specify the middle stimulus (LEVELS / 2) as the "reference":
+        float deviation = mNative.linearityTest(pcms, AudioQualityVerifierActivity.SAMPLE_RATE,
+                DB_STEP_SIZE, LEVELS / 2);
+        if (deviation < 0.0f) {
+            setScore(getString(R.string.aq_fail));
+            setReport(String.format(getString(R.string.aq_linearity_report_error), deviation));
+        } else if (deviation > TOLERANCE) {
+            setScore(getString(R.string.aq_fail));
+            setReport(String.format(getString(R.string.aq_linearity_report_normal),
+                    deviation, TOLERANCE));
+        } else {
+            setScore(getString(R.string.aq_pass));
+            setReport(String.format(getString(R.string.aq_linearity_report_normal),
+                    deviation, TOLERANCE));
+        }
+    }
+}