diff options
Diffstat (limited to 'apps/OboeTester/app/src/main/cpp/analyzer/BaseSineAnalyzer.h')
| -rw-r--r-- | apps/OboeTester/app/src/main/cpp/analyzer/BaseSineAnalyzer.h | 36 |
1 files changed, 32 insertions, 4 deletions
diff --git a/apps/OboeTester/app/src/main/cpp/analyzer/BaseSineAnalyzer.h b/apps/OboeTester/app/src/main/cpp/analyzer/BaseSineAnalyzer.h index 7c7fc80f..b9ae220f 100644 --- a/apps/OboeTester/app/src/main/cpp/analyzer/BaseSineAnalyzer.h +++ b/apps/OboeTester/app/src/main/cpp/analyzer/BaseSineAnalyzer.h @@ -45,6 +45,10 @@ public: mScaledTolerance = mMagnitude * getTolerance(); } + /** + * + * @return valid phase or kPhaseInvalid=-999 + */ double getPhaseOffset() { ALOGD("%s(), mPhaseOffset = %f\n", __func__, mPhaseOffset); return mPhaseOffset; @@ -129,7 +133,18 @@ public: double cosMean = mCosAccumulator / mFramesAccumulated; double magnitude = 2.0 * sqrt((sinMean * sinMean) + (cosMean * cosMean)); if (phasePtr != nullptr) { - double phase = atan2(cosMean, sinMean); + double phase; + if (magnitude < kMinValidMagnitude) { + phase = kPhaseInvalid; + ALOGD("%s() mag very low! sinMean = %7.5f, cosMean = %7.5f", + __func__, sinMean, cosMean); + } else { + phase = atan2(cosMean, sinMean); + if (phase == 0.0) { + ALOGD("%s() phase zero! sinMean = %7.5f, cosMean = %7.5f", + __func__, sinMean, cosMean); + } + } *phasePtr = phase; } return magnitude; @@ -153,9 +168,12 @@ public: if (mFramesAccumulated == mSinePeriod) { const double coefficient = 0.1; double magnitude = calculateMagnitudePhase(&mPhaseOffset); - ALOGD("%s(), mPhaseOffset = %f\n", __func__, mPhaseOffset); - // One pole averaging filter. - setMagnitude((mMagnitude * (1.0 - coefficient)) + (magnitude * coefficient)); + + ALOGD("%s(), phaseOffset = %f\n", __func__, mPhaseOffset); + if (mPhaseOffset != kPhaseInvalid) { + // One pole averaging filter. + setMagnitude((mMagnitude * (1.0 - coefficient)) + (magnitude * coefficient)); + } resetAccumulator(); return true; } else { @@ -193,9 +211,19 @@ protected: double mPhaseIncrement = 0.0; double mOutputPhase = 0.0; double mOutputAmplitude = 0.75; + // This is the phase offset between the output sine wave and the recorded + // signal at the tuned frequency. // If this jumps around then we are probably just hearing noise. + // Noise can cause the magnitude to be high but mPhaseOffset will be pretty random. + // If we are tracking a sine wave then mPhaseOffset should be consistent. double mPhaseOffset = 0.0; + // kPhaseInvalid indicates that the phase measurement cannot be used. + // We were seeing times when a magnitude of zero was causing atan2(s,c) to + // return a phase of zero, which looked valid to Java. This is a way of passing + // an error code back to Java as a single value to avoid race conditions. + static constexpr double kPhaseInvalid = -999.0; double mMagnitude = 0.0; + static constexpr double kMinValidMagnitude = 2.0 / (1 << 16); int32_t mFramesAccumulated = 0; double mSinAccumulator = 0.0; double mCosAccumulator = 0.0; |