diff --git a/dom/media/AudioSampleFormat.h b/dom/media/AudioSampleFormat.h
index ebfa68c4c5b9..997180c65bc4 100644
--- a/dom/media/AudioSampleFormat.h
+++ b/dom/media/AudioSampleFormat.h
@@ -80,6 +80,11 @@ AudioSampleToFloat(int16_t aValue)
 {
   return aValue/32768.0f;
 }
+inline float
+AudioSampleToFloat(int32_t aValue)
+{
+  return aValue/(float)(1U<<31);
+}
 
 template <typename T> T FloatToAudioSample(float aValue);
 
diff --git a/dom/media/platforms/ffmpeg/FFmpegAudioDecoder.cpp b/dom/media/platforms/ffmpeg/FFmpegAudioDecoder.cpp
index a15bb13ef596..55cd4c000d2b 100644
--- a/dom/media/platforms/ffmpeg/FFmpegAudioDecoder.cpp
+++ b/dom/media/platforms/ffmpeg/FFmpegAudioDecoder.cpp
@@ -91,6 +91,25 @@ CopyAndPackAudio(AVFrame* aFrame, uint32_t aNumChannels, uint32_t aNumAFrames)
         *tmp++ = AudioSampleToFloat(data[channel][frame]);
       }
     }
+  } else if (aFrame->format == AV_SAMPLE_FMT_S32) {
+    // Audio data already packed. Need to convert from S16 to 32 bits Float
+    AudioDataValue* tmp = audio.get();
+    int32_t* data = reinterpret_cast<int32_t**>(aFrame->data)[0];
+    for (uint32_t frame = 0; frame < aNumAFrames; frame++) {
+      for (uint32_t channel = 0; channel < aNumChannels; channel++) {
+        *tmp++ = AudioSampleToFloat(*data++);
+      }
+    }
+  } else if (aFrame->format == AV_SAMPLE_FMT_S32P) {
+    // Planar audio data. Convert it from S32 to 32 bits float
+    // and pack it into something we can understand.
+    AudioDataValue* tmp = audio.get();
+    int32_t** data = reinterpret_cast<int32_t**>(aFrame->data);
+    for (uint32_t frame = 0; frame < aNumAFrames; frame++) {
+      for (uint32_t channel = 0; channel < aNumChannels; channel++) {
+        *tmp++ = AudioSampleToFloat(data[channel][frame]);
+      }
+    }
   }
 
   return audio;
@@ -176,9 +195,9 @@ FFmpegAudioDecoder<LIBAV_VER>::GetCodecId(const nsACString& aMimeType)
 {
   if (aMimeType.EqualsLiteral("audio/mpeg")) {
     return AV_CODEC_ID_MP3;
-  }
-
-  if (aMimeType.EqualsLiteral("audio/mp4a-latm")) {
+  } else if (aMimeType.EqualsLiteral("audio/flac")) {
+    return AV_CODEC_ID_FLAC;
+  } else if (aMimeType.EqualsLiteral("audio/mp4a-latm")) {
     return AV_CODEC_ID_AAC;
   }
 
diff --git a/dom/media/platforms/ffmpeg/FFmpegDataDecoder.cpp b/dom/media/platforms/ffmpeg/FFmpegDataDecoder.cpp
index 55b071d5a3ae..390e92a053da 100644
--- a/dom/media/platforms/ffmpeg/FFmpegDataDecoder.cpp
+++ b/dom/media/platforms/ffmpeg/FFmpegDataDecoder.cpp
@@ -90,7 +90,9 @@ FFmpegDataDecoder<LIBAV_VER>::InitDecoder()
       mCodecContext->sample_fmt != AV_SAMPLE_FMT_FLT &&
       mCodecContext->sample_fmt != AV_SAMPLE_FMT_FLTP &&
       mCodecContext->sample_fmt != AV_SAMPLE_FMT_S16 &&
-      mCodecContext->sample_fmt != AV_SAMPLE_FMT_S16P) {
+      mCodecContext->sample_fmt != AV_SAMPLE_FMT_S16P &&
+      mCodecContext->sample_fmt != AV_SAMPLE_FMT_S32 &&
+      mCodecContext->sample_fmt != AV_SAMPLE_FMT_S32P) {
     NS_WARNING("FFmpeg audio decoder outputs unsupported audio format.");
     return NS_ERROR_FAILURE;
   }
diff --git a/dom/media/platforms/ffmpeg/FFmpegDecoderModule.h b/dom/media/platforms/ffmpeg/FFmpegDecoderModule.h
index 8e2da51679f8..969ac7e0be23 100644
--- a/dom/media/platforms/ffmpeg/FFmpegDecoderModule.h
+++ b/dom/media/platforms/ffmpeg/FFmpegDecoderModule.h
@@ -45,35 +45,24 @@ public:
   already_AddRefed<MediaDataDecoder>
   CreateAudioDecoder(const CreateDecoderParams& aParams) override
   {
-#ifdef USING_MOZFFVPX
-    return nullptr;
-#else
     RefPtr<MediaDataDecoder> decoder =
       new FFmpegAudioDecoder<V>(mLib,
                                 aParams.mTaskQueue,
                                 aParams.mCallback,
                                 aParams.AudioConfig());
     return decoder.forget();
-#endif
   }
 
   bool SupportsMimeType(const nsACString& aMimeType,
                         DecoderDoctorDiagnostics* aDiagnostics) const override
   {
     AVCodecID videoCodec = FFmpegVideoDecoder<V>::GetCodecId(aMimeType);
-#ifdef USING_MOZFFVPX
-    if (videoCodec == AV_CODEC_ID_NONE) {
-        return false;
-    }
-    return !!FFmpegDataDecoder<V>::FindAVCodec(mLib, videoCodec);
-#else
     AVCodecID audioCodec = FFmpegAudioDecoder<V>::GetCodecId(aMimeType);
     if (audioCodec == AV_CODEC_ID_NONE && videoCodec == AV_CODEC_ID_NONE) {
       return false;
     }
     AVCodecID codec = audioCodec != AV_CODEC_ID_NONE ? audioCodec : videoCodec;
     return !!FFmpegDataDecoder<V>::FindAVCodec(mLib, codec);
-#endif
   }
 
   ConversionRequired
diff --git a/dom/media/platforms/ffmpeg/FFmpegLibs.h b/dom/media/platforms/ffmpeg/FFmpegLibs.h
index ec1fa57035c9..291ed77898ae 100644
--- a/dom/media/platforms/ffmpeg/FFmpegLibs.h
+++ b/dom/media/platforms/ffmpeg/FFmpegLibs.h
@@ -26,6 +26,7 @@ extern "C" {
 #define AV_CODEC_ID_MP3 CODEC_ID_MP3
 #define AV_CODEC_ID_VP8 CODEC_ID_VP8
 #define AV_CODEC_ID_NONE CODEC_ID_NONE
+#define AV_CODEC_ID_FLAC CODEC_ID_FLAC
 typedef CodecID AVCodecID;
 #endif
 
diff --git a/dom/media/platforms/ffmpeg/ffvpx/moz.build b/dom/media/platforms/ffmpeg/ffvpx/moz.build
index f3de587ef556..aee58b5b0d29 100644
--- a/dom/media/platforms/ffmpeg/ffvpx/moz.build
+++ b/dom/media/platforms/ffmpeg/ffvpx/moz.build
@@ -10,6 +10,7 @@ EXPORTS += [
 ]
 
 UNIFIED_SOURCES += [
+    '../FFmpegAudioDecoder.cpp',
     '../FFmpegDataDecoder.cpp',
     '../FFmpegDecoderModule.cpp',
     '../FFmpegVideoDecoder.cpp',