From 46ba3676b854acbc69a4c7845f578d4c2886377b Mon Sep 17 00:00:00 2001 From: Jean-Michel Trivi Date: Fri, 8 Apr 2016 10:52:42 -0700 Subject: AAC/SBR encoder improvements * AAC-Encoder - AAC-ELD core encoder audio quality tuning. Update tuning tables, configure bitreservoir size and adapt afterburner iteration value. Modified file(s): libAACenc/src/aacenc.h libAACenc/src/aacenc_lib.cpp libAACenc/src/adj_thr.cpp libAACenc/src/adj_thr.h libAACenc/src/adj_thr_data.h libAACenc/src/bandwidth.cpp libAACenc/src/pnsparam.cpp libAACenc/src/qc_main.cpp - Introduze dead zone quantizer for ELD to improve audio quality at certain configurations. Modified file(s): libAACenc/src/aacenc_lib.cpp libAACenc/src/adj_thr.cpp libAACenc/src/adj_thr.h libAACenc/src/qc_data.h libAACenc/src/qc_main.cpp libAACenc/src/quantize.cpp libAACenc/src/quantize.h libAACenc/src/sf_estim.cpp libAACenc/src/sf_estim.h - Revise TNS module to improve ELD audio quality. - Use new window function and separate prediction gain according TNS filters. - Add missing memory initilization to TNS configuration. Modified file(s): libAACenc/src/aacenc_lib.cpp libAACenc/src/aacenc_tns.cpp libAACenc/src/aacenc_tns.h libAACenc/src/psy_main.cpp libAACenc/src/tns_func.h * SBR-Encoder - Revise frequency resolution calculation and handle differently depending on number of envelopes and split frames decision. - Add and adjust ELD SBR tuning tables. Modified file(s): libSBRenc/include/sbr_encoder.h libSBRenc/src/bit_sbr.h libSBRenc/src/env_est.cpp libSBRenc/src/fram_gen.cpp libSBRenc/src/fram_gen.h libSBRenc/src/mh_det.cpp libSBRenc/src/sbr_def.h libSBRenc/src/sbr_encoder.cpp libSBRenc/src/sbr_rom.cpp libSBRenc/src/tran_det.cpp - Replace ELD transient detector with fast implementation. Modified file(s): libSBRenc/src/env_est.cpp libSBRenc/src/env_est.h libSBRenc/src/fram_gen.cpp libSBRenc/src/sbr_def.h libSBRenc/src/sbr_encoder.cpp libSBRenc/src/tran_det.cpp libSBRenc/src/tran_det.h * FDK-Library - Introduce generic compare function in tools library. Modified file(s): libFDK/include/fixpoint_math.h libFDK/src/FDK_core.cpp * SBR-Encoder - Revise ELD frame splitter to improve bit distribution. Modified file(s): libSBRenc/include/sbr_encoder.h libSBRenc/src/bit_sbr.h libSBRenc/src/env_est.cpp libSBRenc/src/fram_gen.cpp libSBRenc/src/fram_gen.h libSBRenc/src/sbr_encoder.cpp libSBRenc/src/tran_det.cpp libSBRenc/src/tran_det.h - Configure amplitude resolution according the tonality of the audio signal. Modified file(s): libSBRenc/include/sbr_encoder.h libSBRenc/src/bit_sbr.h libSBRenc/src/env_est.cpp libSBRenc/src/nf_est.cpp libSBRenc/src/nf_est.h libSBRenc/src/sbr_def.h libSBRenc/src/sbr_encoder.cpp libSBRenc/src/ton_corr.cpp libSBRenc/src/ton_corr.h libSBRenc/src/tran_det.cpp libSBRenc/src/tran_det.h Change-Id: Ie0672b989a06ee63b50240616b8d1d4b790b6cb2 --- libSBRenc/src/mh_det.cpp | 32 ++++++++++++++++++++++++++------ 1 file changed, 26 insertions(+), 6 deletions(-) (limited to 'libSBRenc/src/mh_det.cpp') diff --git a/libSBRenc/src/mh_det.cpp b/libSBRenc/src/mh_det.cpp index 73d1b8b..bc80a15 100644 --- a/libSBRenc/src/mh_det.cpp +++ b/libSBRenc/src/mh_det.cpp @@ -2,7 +2,7 @@ /* ----------------------------------------------------------------------------------------------------------- Software License for The Fraunhofer FDK AAC Codec Library for Android -© Copyright 1995 - 2013 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. +© Copyright 1995 - 2015 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. All rights reserved. 1. INTRODUCTION @@ -663,10 +663,27 @@ static void transientCleanUp(FIXP_DBL **quotaBuffer, } -/**************************************************************************/ +/*****************************************************************************/ /*! - \brief Do detection for one tonality estimate. + \brief Detection for one tonality estimate. + + This is the actual missing harmonics detection, using information from the + previous detection. + + If a missing harmonic was detected (in a previous frame) due to too high + tonality differences, but there was not enough tonality difference in the + current frame, the detection algorithm still continues to trace the strongest + tone in the scalefactor band (assuming that this is the tone that is going to + be replaced in the decoder). This is done to avoid abrupt endings of sines + fading out (e.g. in the glockenspiel). + + The function also tries to estimate where one sine is going to be replaced + with multiple sines (due to the patching). This is done by comparing the + tonality flatness measure of the original and the SBR signal. + The function also tries to estimate (for the scalefactor bands only + containing one qmf subband) when a strong tone in the original will be + replaced by a strong tone in the adjacent QMF subband. \return none. @@ -694,10 +711,10 @@ static void detection(FIXP_DBL *quotaBuffer, for(i=0;i thresTemp){ pHarmVec[i] = 1; @@ -813,8 +830,11 @@ static void detectionWithPrediction(FIXP_DBL **quotaBuffer, if(newDetectionAllowed){ + /* Since we don't want to use the transient region for detection (since the tonality values + tend to be a bit unreliable for this region) the guide-values are copied to the current + starting point. */ if(totNoEst > 1){ - start = detectionStart; + start = detectionStart+1; if (start != 0) { FDKmemcpy(guideVectors[start].guideVectorDiff,guideVectors[0].guideVectorDiff,nSfb*sizeof(FIXP_DBL)); -- cgit v1.2.3