diff options
Diffstat (limited to 'pica-client/echocanceller.cpp')
| -rw-r--r-- | pica-client/echocanceller.cpp | 92 |
1 files changed, 86 insertions, 6 deletions
diff --git a/pica-client/echocanceller.cpp b/pica-client/echocanceller.cpp index 60b427d..df151d6 100644 --- a/pica-client/echocanceller.cpp +++ b/pica-client/echocanceller.cpp @@ -35,7 +35,10 @@ EchoCanceller::EchoCanceller(int sampleRate, int frameMs, int tailMs) m_farHead(0), m_farCapacity(0), m_nearEnergy(0.0), - m_outEnergy(0.0) + m_outEnergy(0.0), + m_farEnergy(0.0), + m_processedSamples(0), + m_nextReportSamples(0) { if (frameMs <= 0) frameMs = 10; @@ -101,6 +104,10 @@ EchoCanceller::EchoCanceller(int sampleRate, int frameMs, int tailMs) m_farBlock.resize(m_frameSize); m_farFifo.reserve(m_farCapacity); + // Hold off the first report until there is a window's worth of audio + // behind the averages, otherwise it only says the call just started. + m_nextReportSamples = qint64(m_sampleRate) * kReportIntervalSec; + qDebug() << "Echo canceller:" << m_sampleRate << "Hz, frame" << m_frameSize << "samples, tail" << m_filterLength << "samples (" << (m_filterLength * 1000 / m_sampleRate) << "ms )"; @@ -133,6 +140,9 @@ void EchoCanceller::reset() QMutexLocker locker(&m_statMutex); m_nearEnergy = 0.0; m_outEnergy = 0.0; + m_farEnergy = 0.0; + m_processedSamples = 0; + m_nextReportSamples = qint64(m_sampleRate) * kReportIntervalSec; } } @@ -198,6 +208,7 @@ void EchoCanceller::processNearEnd(qint16 *pcm, int nsamples) double nearEnergy = 0.0; double outEnergy = 0.0; + double farEnergy = 0.0; int blocks = nsamples / m_frameSize; for (int b = 0; b < blocks; b++) @@ -217,6 +228,12 @@ void EchoCanceller::processNearEnd(qint16 *pcm, int nsamples) memset(m_farBlock.data(), 0, m_frameSize * sizeof(qint16)); } + // Measured before cancellation - this is the reference the filter is + // about to be given, so it says whether there was anything coming out + // of the speaker for it to work on. + for (int i = 0; i < m_frameSize; i++) + farEnergy += double(m_farBlock[i]) * double(m_farBlock[i]); + // speex_echo_cancellation() is happy to work in place on the near end // buffer, which is what lets this sit directly in the capture path // without another copy. @@ -229,11 +246,41 @@ void EchoCanceller::processNearEnd(qint16 *pcm, int nsamples) outEnergy += double(nearBlock[i]) * double(nearBlock[i]); } - QMutexLocker statLocker(&m_statMutex); - // Exponential forgetting, so erle() reflects the last few seconds rather - // than the whole call. - m_nearEnergy = m_nearEnergy * 0.95 + nearEnergy * 0.05; - m_outEnergy = m_outEnergy * 0.95 + outEnergy * 0.05; + // At least one whole block, guaranteed by the nsamples check on entry. + const int used = blocks * m_frameSize; + bool report = false; + + { + QMutexLocker statLocker(&m_statMutex); + + // Exponential forgetting, so erle() reflects the last few seconds + // rather than the whole call. Per sample, so a change in the capture + // path's block size does not move the levels. + m_nearEnergy = m_nearEnergy * 0.95 + (nearEnergy / used) * 0.05; + m_outEnergy = m_outEnergy * 0.95 + (outEnergy / used) * 0.05; + m_farEnergy = m_farEnergy * 0.95 + (farEnergy / used) * 0.05; + + m_processedSamples += used; + if (m_processedSamples >= m_nextReportSamples) + { + m_nextReportSamples = m_processedSamples + qint64(m_sampleRate) * kReportIntervalSec; + report = true; + } + } + + // Outside the lock: the accessors below take it themselves, and qDebug() + // does I/O that has no business happening with a mutex held on the + // capture thread. The values can shift by one block in between, which + // does not matter for a log line. + if (report) + { + int depth = farEndDepth(); + + qDebug("AEC: erle %+.1f dB mic %.1f dBFS far %.1f dBFS ref backlog %d ms%s", + erle(), nearEndLevelDb(), farEndLevelDb(), + (depth * 1000) / m_sampleRate, + depth >= m_farCapacity ? " [FIFO FULL - reference drifting]" : ""); + } } double EchoCanceller::erle() @@ -245,3 +292,36 @@ double EchoCanceller::erle() return 10.0 * log10(m_nearEnergy / m_outEnergy); } + +// Mean square of 16 bit samples to dBFS, with a floor so digital silence +// prints as a number rather than -inf. +static double level_db(double meanSquare) +{ + static const double kFullScale = 32768.0 * 32768.0; + + if (meanSquare <= 0.0) + return -120.0; + + double db = 10.0 * log10(meanSquare / kFullScale); + return db < -120.0 ? -120.0 : db; +} + +double EchoCanceller::nearEndLevelDb() +{ + QMutexLocker locker(&m_statMutex); + return level_db(m_nearEnergy); +} + +double EchoCanceller::farEndLevelDb() +{ + QMutexLocker locker(&m_statMutex); + return level_db(m_farEnergy); +} + +int EchoCanceller::farEndDepth() +{ + QMutexLocker locker(&m_farMutex); + + int pending = m_farFifo.size() - m_farHead; + return pending > 0 ? pending : 0; +} |