Verified Commit ea595122 authored by John Lin's avatar John Lin Committed by ma1
Browse files

Bug 2021955 - drop extra channels when out of downmixer's capability. a=RyanVM 

Original Revision: https://phabricator.services.mozilla.com/D300812

Differential Revision: https://phabricator.services.mozilla.com/D302855
parent 65f632f6

dom/media/AudioConverter.cpp

+9 −1
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 
#include <cmath>



#include "mozilla/CheckedInt.h"

#include "nsFmtString.h"



/*

 *  Parts derived from MythTV AudioConvert Class
@@ -189,7 +190,12 @@ size_t AudioConverter::DownmixAudio(void* aOut, const void* aIn, 
    return aFrames;

  }



  if (!mIn.Layout().IsValid() || !mOut.Layout().IsValid()) {

  // The downmix matrix below only handles 3 to 8 input channels. For more

  // than 8 channels (or invalid layouts) fall back to dropping extra channels.

  if (!mIn.Layout().IsValid() || !mOut.Layout().IsValid() || inChannels > 8) {

    NS_WARNING(nsFmtCString("Dumb remixing: {} channels in, {} channels out",

                            inChannels, outChannels)

                   .get());

    // Dumb copy dropping extra channels.

    if (mIn.Format() == AudioConfig::FORMAT_FLT) {

      dumbUpDownMix(static_cast<float*>(aOut), outChannels,
@@ -245,6 +251,7 @@ size_t AudioConverter::DownmixAudio(void* aOut, const void* aIn, 
           {0.3366f, 0.1943f},

           {0.1943f, 0.3366f}},

      };

      MOZ_DIAGNOSTIC_ASSERT(inChannels < std::size(dmatrix) + 3);

      // Re-write the buffer with downmixed data

      const float* in = static_cast<const float*>(aIn);

      float* out = static_cast<float*>(aOut);
@@ -294,6 +301,7 @@ size_t AudioConverter::DownmixAudio(void* aOut, const void* aIn, 
           {3184, 5514},

           {5514, 3184},

           {3184, 5514}}};

      MOZ_DIAGNOSTIC_ASSERT(inChannels < std::size(dmatrix) + 3);

      // Re-write the buffer with downmixed data

      const int16_t* in = static_cast<const int16_t*>(aIn);

      int16_t* out = static_cast<int16_t*>(aOut);