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, 10 insertions, 0 deletions

diff --git a/libAACdec/src/aacdec_drc.h b/libAACdec/src/aacdec_drc.h
index 124b6f5..2ebae2c 100644
--- a/libAACdec/src/aacdec_drc.h
+++ b/libAACdec/src/aacdec_drc.h
@@ -143,6 +143,16 @@ int aacDecoder_drcProlog (
         UCHAR  channelMapping[],
         int    numChannels );
 
+/**
+ * \brief Apply DRC. If SBR is present, DRC data is handed over to the SBR decoder.
+ * \param self AAC decoder instance
+ * \param pSbrDec pointer to SBR decoder instance
+ * \param pAacDecoderChannelInfo AAC decoder channel instance to be processed
+ * \param pDrcDat DRC channel data
+ * \param ch channel index
+ * \param aacFrameSize AAC frame size
+ * \param bSbrPresent flag indicating that SBR is present, in which case DRC is handed over to the SBR instance pSbrDec
+ */
 void aacDecoder_drcApply (
         HANDLE_AAC_DRC          self,
         void                   *pSbrDec,