From cd0c4683947231a7d3dc7811bedb75c5a965103c Mon Sep 17 00:00:00 2001 From: Jean-Michel Trivi Date: Wed, 25 Sep 2013 18:43:55 -0700 Subject: LoudnessEnhancer compatible with stereo imaging Use a single compressor for both channels. Envelope of signal is determined by looking at both channels. Bug 8413913 Change-Id: Ia9b6f34923d2977c60a3352500b858dfa1fab33c --- .../libeffects/loudness/EffectLoudnessEnhancer.cpp | 42 +++++++++------------- .../dsp/core/dynamic_range_compression-inl.h | 2 +- .../dsp/core/dynamic_range_compression.cpp | 35 ++++++++++++++++++ .../loudness/dsp/core/dynamic_range_compression.h | 3 ++ 4 files changed, 56 insertions(+), 26 deletions(-) (limited to 'media/libeffects') diff --git a/media/libeffects/loudness/EffectLoudnessEnhancer.cpp b/media/libeffects/loudness/EffectLoudnessEnhancer.cpp index dfc25db..91ed677 100644 --- a/media/libeffects/loudness/EffectLoudnessEnhancer.cpp +++ b/media/libeffects/loudness/EffectLoudnessEnhancer.cpp @@ -56,8 +56,7 @@ struct LoudnessEnhancerContext { int32_t mTargetGainmB;// target gain in mB // in this implementation, there is no coupling between the compression on the left and right // channels - le_fx::AdaptiveDynamicRangeCompression* mCompressorL; - le_fx::AdaptiveDynamicRangeCompression* mCompressorR; + le_fx::AdaptiveDynamicRangeCompression* mCompressor; }; // @@ -68,11 +67,10 @@ void LE_reset(LoudnessEnhancerContext *pContext) { ALOGV(" > LE_reset(%p)", pContext); - if ((pContext->mCompressorL != NULL) && (pContext->mCompressorR != NULL)) { + if (pContext->mCompressor != NULL) { float targetAmp = pow(10, pContext->mTargetGainmB/2000.0f); // mB to linear amplification ALOGV("LE_reset(): Target gain=%dmB <=> factor=%.2fX", pContext->mTargetGainmB, targetAmp); - pContext->mCompressorL->Initialize(targetAmp, pContext->mConfig.inputCfg.samplingRate); - pContext->mCompressorR->Initialize(targetAmp, pContext->mConfig.inputCfg.samplingRate); + pContext->mCompressor->Initialize(targetAmp, pContext->mConfig.inputCfg.samplingRate); } else { ALOGE("LE_reset(%p): null compressors, can't apply target gain", pContext); } @@ -176,13 +174,9 @@ int LE_init(LoudnessEnhancerContext *pContext) float targetAmp = pow(10, pContext->mTargetGainmB/2000.0f); // mB to linear amplification ALOGV("LE_init(): Target gain=%dmB <=> factor=%.2fX", pContext->mTargetGainmB, targetAmp); - if (pContext->mCompressorL == NULL) { - pContext->mCompressorL = new le_fx::AdaptiveDynamicRangeCompression(); - pContext->mCompressorL->Initialize(targetAmp, pContext->mConfig.inputCfg.samplingRate); - } - if (pContext->mCompressorR == NULL) { - pContext->mCompressorR = new le_fx::AdaptiveDynamicRangeCompression(); - pContext->mCompressorR->Initialize(targetAmp, pContext->mConfig.inputCfg.samplingRate); + if (pContext->mCompressor == NULL) { + pContext->mCompressor = new le_fx::AdaptiveDynamicRangeCompression(); + pContext->mCompressor->Initialize(targetAmp, pContext->mConfig.inputCfg.samplingRate); } LE_setConfig(pContext, &pContext->mConfig); @@ -215,8 +209,7 @@ int LELib_Create(const effect_uuid_t *uuid, pContext->mItfe = &gLEInterface; pContext->mState = LOUDNESS_ENHANCER_STATE_UNINITIALIZED; - pContext->mCompressorL = NULL; - pContext->mCompressorR = NULL; + pContext->mCompressor = NULL; ret = LE_init(pContext); if (ret < 0) { ALOGW("LELib_Create() init failed"); @@ -242,13 +235,9 @@ int LELib_Release(effect_handle_t handle) { return -EINVAL; } pContext->mState = LOUDNESS_ENHANCER_STATE_UNINITIALIZED; - if (pContext->mCompressorL != NULL) { - delete pContext->mCompressorL; - pContext->mCompressorL = NULL; - } - if (pContext->mCompressorR != NULL) { - delete pContext->mCompressorR; - pContext->mCompressorR = NULL; + if (pContext->mCompressor != NULL) { + delete pContext->mCompressor; + pContext->mCompressor = NULL; } delete pContext; @@ -293,11 +282,14 @@ int LE_process( //ALOGV("LE about to process %d samples", inBuffer->frameCount); uint16_t inIdx; float inputAmp = pow(10, pContext->mTargetGainmB/2000.0f); + float leftSample, rightSample; for (inIdx = 0 ; inIdx < inBuffer->frameCount ; inIdx++) { - inBuffer->s16[2*inIdx] = pContext->mCompressorL->Compress( - inputAmp * (float)inBuffer->s16[2*inIdx]); - inBuffer->s16[2*inIdx +1] = pContext->mCompressorR->Compress( - inputAmp * (float)inBuffer->s16[2*inIdx +1]); + // makeup gain is applied on the input of the compressor + leftSample = inputAmp * (float)inBuffer->s16[2*inIdx]; + rightSample = inputAmp * (float)inBuffer->s16[2*inIdx +1]; + pContext->mCompressor->Compress(&leftSample, &rightSample); + inBuffer->s16[2*inIdx] = (int16_t) leftSample; + inBuffer->s16[2*inIdx +1] = (int16_t) rightSample; } if (inBuffer->raw != outBuffer->raw) { diff --git a/media/libeffects/loudness/dsp/core/dynamic_range_compression-inl.h b/media/libeffects/loudness/dsp/core/dynamic_range_compression-inl.h index fed8c2a..da75ceb 100644 --- a/media/libeffects/loudness/dsp/core/dynamic_range_compression-inl.h +++ b/media/libeffects/loudness/dsp/core/dynamic_range_compression-inl.h @@ -35,7 +35,7 @@ inline void AdaptiveDynamicRangeCompression::set_knee_threshold_via_target_gain( float target_gain) { const float decibel = target_gain_to_knee_threshold_.Interpolate( target_gain); - ALOGE("set_knee_threshold_via_target_gain: decibel =%.3f", decibel); + ALOGV("set_knee_threshold_via_target_gain: decibel =%.3fdB", decibel); set_knee_threshold(decibel); } diff --git a/media/libeffects/loudness/dsp/core/dynamic_range_compression.cpp b/media/libeffects/loudness/dsp/core/dynamic_range_compression.cpp index 2bbd043..7bd068e 100644 --- a/media/libeffects/loudness/dsp/core/dynamic_range_compression.cpp +++ b/media/libeffects/loudness/dsp/core/dynamic_range_compression.cpp @@ -102,5 +102,40 @@ float AdaptiveDynamicRangeCompression::Compress(float x) { return x; } +void AdaptiveDynamicRangeCompression::Compress(float *x1, float *x2) { + // Taking the maximum amplitude of both channels + const float max_abs_x = std::max(std::fabs(*x1), + std::max(std::fabs(*x2), kMinLogAbsValue)); + const float max_abs_x_dB = math::fast_log(max_abs_x); + // Subtract Threshold from log-encoded input to get the amount of overshoot + const float overshoot = max_abs_x_dB - knee_threshold_; + // Hard half-wave rectifier + const float rect = std::max(overshoot, 0.0f); + // Multiply rectified overshoot with slope + const float cv = rect * slope_; + const float prev_state = state_; + if (cv <= state_) { + state_ = alpha_attack_ * state_ + (1.0f - alpha_attack_) * cv; + } else { + state_ = alpha_release_ * state_ + (1.0f - alpha_release_) * cv; + } + compressor_gain_ *= + math::ExpApproximationViaTaylorExpansionOrder5(state_ - prev_state); + *x1 *= compressor_gain_; + if (*x1 > kFixedPointLimit) { + *x1 = kFixedPointLimit; + } + if (*x1 < -kFixedPointLimit) { + *x1 = -kFixedPointLimit; + } + *x2 *= compressor_gain_; + if (*x2 > kFixedPointLimit) { + *x2 = kFixedPointLimit; + } + if (*x2 < -kFixedPointLimit) { + *x2 = -kFixedPointLimit; + } +} + } // namespace le_fx diff --git a/media/libeffects/loudness/dsp/core/dynamic_range_compression.h b/media/libeffects/loudness/dsp/core/dynamic_range_compression.h index 4c015df..2821a78 100644 --- a/media/libeffects/loudness/dsp/core/dynamic_range_compression.h +++ b/media/libeffects/loudness/dsp/core/dynamic_range_compression.h @@ -55,6 +55,9 @@ class AdaptiveDynamicRangeCompression { // log(.) and exp(.). float Compress(float x); + // Stereo channel version of the compressor + void Compress(float *x1, float *x2); + // This version is slower than Compress(.) but faster than CompressSlow(.) float CompressNormalSpeed(float x); -- cgit v1.1