diff --git a/mm-core/inc/QCMetaData.h b/mm-core/inc/QCMetaData.h
index fe0799b..28bdb65 100644
--- a/mm-core/inc/QCMetaData.h
+++ b/mm-core/inc/QCMetaData.h
@@ -67,6 +67,8 @@ enum {
     kKeyHFR                  = 'hfr ',  // int32_t
     kKeyHSR                  = 'hsr ',  // int32_t
 
+    kKeySampleBits        = 'sbit', // int32_t (audio sample bit-width)
+    kKeyPcmFormat         = 'pfmt', //int32_t (pcm format)
     kKeyMinBlkSize        = 'mibs', //int32_t
     kKeyMaxBlkSize        = 'mabs', //int32_t
     kKeyMinFrmSize        = 'mifs', //int32_t