Decode dynamic range control improvements

* AAC-Decoder

   - Only set the program reference level if it has changed compared to the
     previous value. This allows setting it on a frame-by-frame basis without
     limitations.
     Modified file(s):
        libAACdec/src/aacdec_drc.cpp
        libAACdec/src/aacdec_drc.h

   - Add expiry counter for the program reference level.
     Modified file(s):
        libAACdec/src/aacdec_drc.cpp
        libAACdec/src/aacdec_drc_types.h

   - Disable scaling of light compression gain values when heavy compression
     mode is enabled to have the full light compression as fallback if no heavy
     values are available.
     Modified file(s):
        libAACdec/src/aacdec_drc.cpp
        libAACdec/src/aacdecoder_lib.cpp
        libAACdec/src/aacdec_drc_types.h

   - Change initialization and channel disabling to improve start-up behavior in
     SBR decoder.
     Modified file(s):
        libSBRdec/src/sbrdecoder.cpp
        libSBRdec/src/sbrdec_drc.cpp

Bug 9428126

Change-Id: Ie1d3949c53910506da2547d32fe3bf6ee7606eb4

1 files changed, 3 insertions, 5 deletions

diff --git a/libSBRdec/src/sbrdec_drc.cpp b/libSBRdec/src/sbrdec_drc.cpp
index af71c41..a834c0b 100644
--- a/libSBRdec/src/sbrdec_drc.cpp
+++ b/libSBRdec/src/sbrdec_drc.cpp
@@ -127,8 +127,8 @@ void sbrDecoder_drcInitChannel (
   hDrcData->currFact_exp = 1;
   hDrcData->nextFact_exp = 1;
 
-  hDrcData->numBandsCurr = 0;
-  hDrcData->numBandsNext = 0;
+  hDrcData->numBandsCurr = 1;
+  hDrcData->numBandsNext = 1;
 
   hDrcData->winSequenceCurr = 0;
   hDrcData->winSequenceNext = 0;
@@ -490,9 +490,7 @@ void sbrDecoder_drcApply (
   if (hDrcData == NULL) {
     return;
   }
-  if ( (hDrcData->enable == 0)
-    || ((hDrcData->numBandsCurr == 0) && (hDrcData->numBandsNext == 0))
-     ) {
+  if (hDrcData->enable == 0) {
     return;  /* Avoid changing the scaleFactor even though the processing is disabled. */
   }