From 6792cf6361ff339e336287affb0bfe54bf6957a9 Mon Sep 17 00:00:00 2001
From: Jean-Michel Trivi <jmtrivi@google.com>
Date: Tue, 20 May 2014 17:39:03 -0700
Subject: AAC-Decoder: SBR delay for gapless

Revise decoder output delay determination. The output delay consisted of
  concealment and limiter delay. SBR delay was not covered but must be
  considered for gapless playback delay compensation.

Bug 9428126

Change-Id: I67483712c284de9b5378694f9db7acbed2547dd7
---
 libAACdec/src/aacdecoder_lib.cpp | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

(limited to 'libAACdec/src/aacdecoder_lib.cpp')

diff --git a/libAACdec/src/aacdecoder_lib.cpp b/libAACdec/src/aacdecoder_lib.cpp
index 8e3027a..82f85ab 100644
--- a/libAACdec/src/aacdecoder_lib.cpp
+++ b/libAACdec/src/aacdecoder_lib.cpp
@@ -110,7 +110,7 @@ amm-info@iis.fraunhofer.de
 /* Decoder library info */
 #define AACDECODER_LIB_VL0 2
 #define AACDECODER_LIB_VL1 5
-#define AACDECODER_LIB_VL2 9
+#define AACDECODER_LIB_VL2 10
 #define AACDECODER_LIB_TITLE "AAC Decoder Lib"
 #define AACDECODER_LIB_BUILD_DATE __DATE__
 #define AACDECODER_LIB_BUILD_TIME __TIME__
@@ -954,19 +954,22 @@ LINKSPEC_CPP AAC_DECODER_ERROR aacDecoder_DecodeFrame(
 
 
      if (sbrError == SBRDEC_OK) {
+       #define UPS_SCALE  2  /* Maximum upsampling factor is 4 (CELP+SBR) */
+       FIXP_DBL  upsampleFactor = FL2FXCONST_DBL(1.0f/(1<<UPS_SCALE));
 
        /* Update data in streaminfo structure. Assume that the SBR upsampling factor is either 1 or 2 */
        self->flags |= AC_SBR_PRESENT;
        if (self->streamInfo.aacSampleRate != self->streamInfo.sampleRate) {
          if (self->streamInfo.frameSize == 768) {
-           self->streamInfo.frameSize =  (self->streamInfo.aacSamplesPerFrame * 8) / 3;
+           upsampleFactor = FL2FXCONST_DBL(8.0f/(3<<UPS_SCALE));
          } else {
-           self->streamInfo.frameSize =  self->streamInfo.aacSamplesPerFrame << 1;
+           upsampleFactor = FL2FXCONST_DBL(2.0f/(1<<UPS_SCALE));
          }
        }
-       /* Correct the additional concealment delay figures */
-       self->streamInfo.outputDelay -= self->sbrParams.bsDelay * self->streamInfo.aacSamplesPerFrame;
-       self->streamInfo.outputDelay += self->sbrParams.bsDelay * self->streamInfo.frameSize;
+       /* Apply upsampling factor to both the core frame length and the core delay */
+       self->streamInfo.frameSize    =       (INT)fMult((FIXP_DBL)self->streamInfo.aacSamplesPerFrame<<UPS_SCALE, upsampleFactor);
+       self->streamInfo.outputDelay  = (UINT)(INT)fMult((FIXP_DBL)self->streamInfo.outputDelay<<UPS_SCALE, upsampleFactor);
+       self->streamInfo.outputDelay += sbrDecoder_GetDelay( self->hSbrDecoder );
 
        if (self->psPossible) {
          self->flags |= AC_PS_PRESENT;
-- 
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