--- a/media/libstagefright/binding/AnnexB.cpp
+++ b/media/libstagefright/binding/AnnexB.cpp
@@ -272,21 +272,16 @@ AnnexB::ConvertSampleToAVCC(mozilla::Med
 }
 
 already_AddRefed<mozilla::MediaByteBuffer>
 AnnexB::ExtractExtraData(const mozilla::MediaRawData* aSample)
 {
   MOZ_ASSERT(IsAVCC(aSample));
 
   RefPtr<mozilla::MediaByteBuffer> extradata = new mozilla::MediaByteBuffer;
-  if (HasSPS(aSample->mExtraData)) {
-    // We already have an explicit extradata, re-use it.
-    extradata = aSample->mExtraData;
-    return extradata.forget();
-  }
 
   // SPS content
   mozilla::Vector<uint8_t> sps;
   ByteWriter spsw(sps);
   int numSps = 0;
   // PPS content
   mozilla::Vector<uint8_t> pps;
   ByteWriter ppsw(pps);

--- a/media/libstagefright/binding/include/mp4_demuxer/AnnexB.h
+++ b/media/libstagefright/binding/include/mp4_demuxer/AnnexB.h
@@ -24,19 +24,18 @@ public:
   // Convert a sample from Annex B to AVCC.
   // an AVCC extradata must not be set.
   static bool ConvertSampleToAVCC(mozilla::MediaRawData* aSample);
   static bool ConvertSampleTo4BytesAVCC(mozilla::MediaRawData* aSample);
 
   // Parse an AVCC extradata and construct the Annex B sample header.
   static already_AddRefed<mozilla::MediaByteBuffer> ConvertExtraDataToAnnexB(
     const mozilla::MediaByteBuffer* aExtraData);
-  // Extract SPS and PPS NALs from aSample, aSample must be in AVCC format.
-  // If aSample already contains an extradata with an SPS, it will be returned
-  // otherwise the SPS/PPS NALs are searched in-band.
+  // Extract SPS and PPS NALs from aSample by looking into each NALs.
+  // aSample must be in AVCC format.
   static already_AddRefed<mozilla::MediaByteBuffer> ExtractExtraData(
     const mozilla::MediaRawData* aSample);
   static bool HasSPS(const mozilla::MediaRawData* aSample);
   static bool HasSPS(const mozilla::MediaByteBuffer* aExtraData);
   // Returns true if format is AVCC and sample has valid extradata.
   static bool IsAVCC(const mozilla::MediaRawData* aSample);
   // Returns true if format is AnnexB.
   static bool IsAnnexB(const mozilla::MediaRawData* aSample);