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Improve encoder audio quality for low bitreservoir configuration. 

Bug: 149489652
Test: atest android.media.cts.EncoderTest#testAACEncoders
Change-Id: I87d5695a93b1f130b95b45d48157e6aaf947709d
This commit is contained in:
Fraunhofer IIS FDK 2019-12-19 17:24:21 +01:00 committed by Jean-Michel Trivi
parent 6b0aab087d
commit 79305e068e
1 changed files with 7 additions and 4 deletions
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11
libAACenc/src/aacenc.cpp
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@ -1,7 +1,7 @@
/* ----------------------------------------------------------------------------- /* -----------------------------------------------------------------------------
Software License for The Fraunhofer FDK AAC Codec Library for Android Software License for The Fraunhofer FDK AAC Codec Library for Android
© Copyright 1995 - 2018 Fraunhofer-Gesellschaft zur Förderung der angewandten © Copyright 1995 - 2019 Fraunhofer-Gesellschaft zur Förderung der angewandten
Forschung e.V. All rights reserved. Forschung e.V. All rights reserved.
1. INTRODUCTION 1. INTRODUCTION
@ -114,6 +114,8 @@ amm-info@iis.fraunhofer.de
#include "genericStds.h" #include "genericStds.h"
#define BITRES_MIN \
300 /* default threshold for using reduced/disabled bitres mode */
#define BITRES_MAX_LD 4000 #define BITRES_MAX_LD 4000
#define BITRES_MIN_LD 500 #define BITRES_MIN_LD 500
#define BITRATE_MAX_LD 70000 /* Max assumed bitrate for bitres calculation */ #define BITRATE_MAX_LD 70000 /* Max assumed bitrate for bitres calculation */
@ -550,7 +552,8 @@ AAC_ENCODER_ERROR FDKaacEnc_Initialize(
(config->minBitsPerFrame != -1) ? config->minBitsPerFrame : 0; (config->minBitsPerFrame != -1) ? config->minBitsPerFrame : 0;
qcInit.minBits = fixMin(qcInit.minBits, averageBitsPerFrame & ~7); qcInit.minBits = fixMin(qcInit.minBits, averageBitsPerFrame & ~7);
} else { } else {
INT bitreservoir = -1; /* default bitrservoir size*/ INT bitreservoir = -1; /* default bitreservoir size*/
bitresMin = BITRES_MIN;
if (isLowDelay(config->audioObjectType)) { if (isLowDelay(config->audioObjectType)) {
INT brPerChannel = config->bitRate / config->nChannels; INT brPerChannel = config->bitRate / config->nChannels;
brPerChannel = fMin(BITRATE_MAX_LD, fMax(BITRATE_MIN_LD, brPerChannel)); brPerChannel = fMin(BITRATE_MAX_LD, fMax(BITRATE_MIN_LD, brPerChannel));
@ -601,9 +604,9 @@ AAC_ENCODER_ERROR FDKaacEnc_Initialize(
qcInit.nSubFrames = config->nSubFrames; qcInit.nSubFrames = config->nSubFrames;
qcInit.padding.paddingRest = config->sampleRate; qcInit.padding.paddingRest = config->sampleRate;
if (qcInit.bitRes >= bitresMin * config->nChannels) { if (qcInit.maxBits - qcInit.averageBits >= bitresMin * config->nChannels) {
qcInit.bitResMode = AACENC_BR_MODE_FULL; /* full bitreservoir */ qcInit.bitResMode = AACENC_BR_MODE_FULL; /* full bitreservoir */
} else if (qcInit.bitRes > 0) { } else if (qcInit.maxBits > qcInit.averageBits) {
qcInit.bitResMode = AACENC_BR_MODE_REDUCED; /* reduced bitreservoir */ qcInit.bitResMode = AACENC_BR_MODE_REDUCED; /* reduced bitreservoir */
} else { } else {
qcInit.bitResMode = AACENC_BR_MODE_DISABLED; /* disabled bitreservoir */ qcInit.bitResMode = AACENC_BR_MODE_DISABLED; /* disabled bitreservoir */