diff --git a/media/libstagefright/binding/include/mp4_demuxer/H264.h b/media/libstagefright/binding/include/mp4_demuxer/H264.h
index 8ac64aeb66a9..a9c32faf7f69 100644
--- a/media/libstagefright/binding/include/mp4_demuxer/H264.h
+++ b/media/libstagefright/binding/include/mp4_demuxer/H264.h
@@ -413,6 +413,7 @@ public:
   static already_AddRefed<mozilla::MediaByteBuffer> DecodeNALUnit(
     const mozilla::MediaByteBuffer* aNAL);
 
+  /* Check if out of band extradata contains a SPS NAL */
   static bool HasSPS(const mozilla::MediaRawData* aSample);
   static bool HasSPS(const mozilla::MediaByteBuffer* aExtraData);
   // Extract SPS and PPS NALs from aSample by looking into each NALs.